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Articles by P.W. Waldroup
Total Records ( 31 ) for P.W. Waldroup
  Cesar Coto , F. Yan , S. Cerrate , Z. Wang , P. Sacakli , P.W. Waldroup , J. T. Halley , C.J. Wiernusz and A. Martinez
  A study was conducted to evaluate the effects of dietary levels of calcium, nonphytate P (NPP), phytase and 25-hydroxycholecalciferol (25-OH) on live performance and bone development in male chicks fed a wheat-based diet. Dietary treatments consisted of a 2 x 2 x 4 x 4 factorial arrangements with two levels of supplemental phytase (0 or 1200 FTU/kg), two levels of 25-OH (0 or 69 µg/kg), four levels of calcium (0.20% less than a 2:1 ratio of Ca to NPP; 2:1 ratio of Ca to NPP; 0.20% Ca greater than a 2:1 ratio of Ca to NPP; 0.40% Ca greater than a 2:1 ratio of Ca to NPP) and four levels of NPP (0.35, 0.40, 0.45 and 0.50%) for a total of 64 treatments. The primary basal diet used to mix all experimental diets was supplemented with a complete vitamin mix containing 5500 IU of cholecalciferol. Each diet was fed to two pens of six male chicks of a commercial broiler strain in electrically heated battery brooders for three consecutive trials using the same diet mix for a total of six replicates per treatment. At 18 d birds were weighed, feed consumption determined and all birds killed for bone measurements. Toes from all birds within a pen were removed and ashed. Tibiae from both legs were removed and scored for incidence and severity of tibial dyschondroplasia and for incidence of calcium or phosphorus rickets. Ca: NPP ratios and calcium levels similar or higher than NRC (1994) recommendations appear necessary for adequate bird performance. Phytase supplementation improved performance parameters such as FCR and body weight, whereas the addition of 25-OH to diets already containing 5500 IU/kg of cholecalciferol had a negative effect on FCR due to a possible hypercalcemia condition. Bone development was improved by increasing phosphorus and calcium levels. Moreover, supplementation with 25-OH and its combination with phytase were effective in enhancing bone development. Increasing Ca levels consistently reduced leg abnormalities. Addition of 25-OH helped to relieve leg problems when suboptimal calcium levels were supplied while phytase supplementation was effective for this purpose when high Ca levels were given. The addition of these additives could be seen as an strategy to alleviate problems with suboptimal Ca: NPP ratios.
  Y.N. Min , F.Z. Liu , Z. Wang , C. Coto , S. Cerrate , F.P. Costa , F. Yan and P.W. Waldroup
  An experiment was conducted to evaluate the use of distillers dried grains with solubles (DDGS) combined with glycerin in broiler diets. In a 3x2 factorial arrangement, 600 one-day-old commercial strain Cobb 500 broilers were randomly assigned to experimental diets with 0, 15 and 30% DDGS of known composition; within each level of DDGS the diets contained 0 or 5% glycerin, respectively, from 0-42 days of age. Diets were formulated to meet digestible amino acid requirements and were fed in pelleted form. Each dietary treatment was replicated 4 times. Body weight gain and feed consumption were measured and carcass characteristics were evaluated at 42 days of age. Inclusion of 30% DDGS had no adverse effect on body weight of chicks; however birds fed diets with 30% DDGS had greater feed intake and poorer feed conversion than birds fed the control diet at most age periods. This was highly correlated to the reduced pellet quality of diets containing the high levels of DDGS. Birds fed diets with 30% DDGS also had significantly reduced dressing percentage compared to birds fed the control diet with no DDGS. However, there was no adverse effect on breast meat yield related to the higher levels of DDGS inclusion. Addition of 5% glycerin from biodiesel production to the diets had no significant effect on body weight, feed intake, or feed conversion. There was no significant effect of the addition of glycerin on dressing percentage or yield of various carcass parts. With one minor exception, there was no significant interaction between addition of glycerin and level of DDGS in the diet, even though pellet quality declined when glycerin was added to the diets. Overall, the results of this study demonstrates that 15% DDGS of known nutritional quality can be utilized in diets for growing broilers with no adverse effects provided diets are formulated on a digestible amino acid basis and meet the nutritional requirements of the broiler. Higher levels may be tolerated but there may be a loss in feed conversion unless pellet quality can be improved. A loss in dressing percentage at higher levels of DDGS has been consistently noted in this and previous studies. Incorporation of 5% glycerin from biodiesel production as a source of energy appears satisfactory.
  Z. Wang , S. Cerrate , F. Yan , P. Sacakli and P.W. Waldroup
  Two consecutive experiments compared different concentrations of inorganic trace minerals in broiler production under different ambient temperature. Both experiments had six treatments, consisting of 100, 80, 60, 40, 20 and 0% of normal trace mineral premix (TMP) inclusion rate with eight and four replicates of sixty male broilers in the first and second experiments, respectively. Experiment 1 began on January 9th and finished on February 20th while Experiment 2 began on July 19th and finished on August 29th. Body weight and feed consumption were determined at 14, 35 and 42 days. At 42nd day two birds per pen were killed and the tibia removed for bone ash determination. In Experiment 2, cohort birds were fed in battery pens from 35 to 37 days. with excreta samples collected for trace mineral analysis. In Experiment 1, birds with no TMP had significantly decreased body weight over all growth periods. Birds fed diets with 20% of normal TMP did not differ in performance from those fed higher levels up to 100% of normal addition rates. There was no difference in any growth variables in Experiment 2 when higher environmental temperatures were in effect. Reduction of TMP in broiler diets could reduce mineral excretion to environment. Levels of Fe, Cu, Mn and Zn in broiler excreta decreased when mineral premix levels were reduced.
  Z. Wang , S. Cerrate , C. Coto , F. Yan , F.P. Costa , A. Abdel-Maksoud and P.W. Waldroup
  A feeding trial was conducted in various levels of corn distillers dried grains with solubles (DDGS) were fed in broiler diets formulated to be either isocaloric using metabolizable energy levels similar to current U.S. poultry industry levels or formulated to contain optimum density commensurate with 1% supplemental poultry oil. In each diet type, levels of 0, 15 and 30% DDGS were incorporated. This resulted in six dietary treatments with four pens of 25 males per treatment. Diets were developed for starter (0-14 d), grower (15-28 days) and finisher periods (29-42 days) and were formulated to meet digestible amino acid specifications of a major poultry breeder, adjusted to the energy content of the diet. Bulk density and pellet quality of mixed feeds were determined. At the end of the study, five representative birds per pen were processed for dressing percentage and parts yield determination. Pellet quality decreased with increasing level of DDGS used. There was little difference in pellet quality between diets with 0 or 15% DDGS but quality deteriorated severely in diets with 30% DDGS. Diets formulated to optimum energy had better pellet quality due to lower supplemental poultry oil. Over the 42 days study, birds fed diets with 30% DDGS had significantly lower body weight and significantly higher feed conversion than did birds fed the control diet with no DDGS. Birds fed diets with 15% DDGS did not differ significantly in 42 days BW or feed conversion from birds fed the control diet with no DDGS nor with the birds fed diets with 30% DDGS. It appeared that a portion of the reduced performance associated with the higher level of DDGS might have been associated with the reduced pellet quality and the bulk density of the diet, rather than any nutritional deficiency. Therefore, approaches to feed manufacturing that enhance pellet quality may enhance usage of higher levels of DDGS in broiler diets.
  Cesar Coto , F. Yan , S. Cerrate , Z. Wang , P. Sacakli , J.T. Halley , C.J. Wiernusz , A. Martinez and P.W. Waldroup
  A study was conducted to evaluate the effects of dietary levels of calcium (Ca), nonphytate P (NPP), phytase (Phy) and 25-hydroxycholecalciferol (25-OH) on live performance and bone development in male chicks fed a corn-based diet. Dietary treatments consisted of a 2×2×4×4 factorial arrangements with two levels of supplemental phytase (0 or 1200 FTU kg-1), two levels of 25-OH (0 or 69 µg kg-1), four levels of Ca (0.20% less than a 2:1 ratio of Ca to NPP; 2:1 ratio of Ca to NPP; 0.20% Ca greater than a 2:1 ratio of Ca to NPP; 0.40% Ca greater than a 2:1 ratio of Ca to NPP) and four levels of NPP (0.35, 0.40, 0.45 and 0.50%) for a total of 64 treatments. The primary basal diet was supplemented with a complete vitamin mix containing 5500 IU of cholecalciferol. Each diet was fed to six replicates per treatment; each pen having 6 birds. At 18 d birds were weighed, feed consumption determined and all birds killed for bone measurements. Toes from all birds within a pen were removed and ashed. Tibiae from both legs were removed and scored for incidence and severity of tibial dyschondroplasia and for incidence of Ca or P rickets. Ca: NPP ratios and Ca levels similar or higher than NRC (1994) recommendations appear necessary for adequate bird performance. Phy supplementation improved FCR, whereas the addition of 25-OH to diets already containing 5500 IU kg-1 of cholecalciferol had a negative effect on FCR due to a possible hypercalcemia condition. Bone development was improved by increasing NPP and Ca levels. Moreover, supplementation with 25-OH was effective in reducing leg abnormalities. Addition of 25-OH helped to relieve leg problems when suboptimal Ca levels were supplied while Phy supplementation was effective for this purpose when high Ca levels were given. These additives could be seen as a strategy to alleviate problems with suboptimal Ca: NPP ratios.
  Zurong Wang , Sandro Cerrate , Cesar Coto , Fenglan Yan and P.W. Waldroup
  This study was conducted to evaluate the bioavailability of an organic copper source, MINTREX® Cu, compared with reagent grade Cu sulfate as a source of Cu in broiler diets. Nutritionally complete basal diets were supplemented with either copper sulfate or MINTREX Cu to provide diets with 0, 10, 25, 50, 125, 250 and 500 mg kg-1 of supplemental Cu. Fifty commercial broiler strain (Cobb 500) male chicks were placed in each of 48 pens. Each diet (except for 500 mg kg-1) was fed to four replicate pens. The 500 mg kg-1 level was fed to two replicate pens for each source. There were two feeding phases including starter (0-21 d) and grower (21-35 d). At the end of each phase, birds were weighed by pens and two birds per pen (four birds per pen for the 500 mg kg-1 levels) were killed to take liver and tibia samples for analysis of Cu concentration. Overall, there was no effect of Cu source or dietary Cu concentration on feed conversion or mortality. At 14 d the birds in the MINTREX treatment weighed significantly more than the birds in the Cu sulfate treatment. High Cu concentrations markedly decreased (p<0.0001) body weight regardless of Cu sources in both phases. Elevated dietary Cu concentration significantly increased (p<0.01) tibia ash Cu concentration for both Cu sources in both phases; however there was no good linear relationship between tibia Cu accumulation and non-zero Cu consumption. There were marked effects (p<0.05) of Cu source, concentration and their interaction on 14 d dry liver Cu concentration. Based on dry liver Cu concentration regressed on non-zero copper consumption, the relative bioavailability of MINTREX Cu was 111.63% for 14 d and 110.71% for 35 d when bioavailability of reagent grade Cu sulfate was set as 100%. This indicated that MINTREX Cu source has greater biological availability than reagent grade Cu sulfate for broilers.
  P.W. Waldroup , Z. Wang , C. Coto , S. Cerrate and F. Yan
  The rapid increase in production of ethanol from corn and other grains has resulted in growing quantities of byproducts, primarily distillers dried grains with solubles (DDGS). The use of DDGS in poultry diets is not new, but the supply of product encourages the use of higher percentages than has typically been used in the past. As greater quantities are used in the diet, it becomes increasingly essential that accurate nutrient values be assigned to the product. This review attempts to summarize results from various laboratories to provide a nutrient matrix that can be used to evaluate the potential use of DDGS in poultry feeds.
  Z. Wang , S. Cerrate , C. Coto , F. Yan and P.W. Waldroup
  An experiment was conducted to evaluate different levels of “new generation” distillers dried grains with solubles (DDGS) in broiler diets throughout a 49 d growing period, based a standardized nutrient matrix derived from a composite of literature values. Diets were formulated based on digestible amino acid content to typical U.S. poultry industry standards to contain 0, 5, 10, 15, 20, or 25% DDGS. Each dietary treatment was assigned to four replicate pens of 25 male chicks of a commercial broiler strain. Starter diets (0 to 14 d) were fed as crumbles; grower (14 to 35 d) and finisher (35 to 49 d) diets were fed as pellets. Bulk density (mass/volume) was determined on the crumbled or pelleted feeds. Body weights and feed consumption were determined at 14, 35 and 49 d of age. At the end of the study five representative birds per pen were processed to determine dressing percentage and parts yield. Increasing the DDGS in the diet generally reduced the weight per volume of feed. There were no significant effects of DDGS level on body weight; however chicks fed diets with 25% DDGS consumed significantly more feed and had poorer feed conversion compared to chicks fed the control diet with no DDGS. Birds fed 15 and 25% DDGS had significantly lower dressing percentage than did birds fed the control diet with no DDGS. Birds fed diets with 25% DDGS had significantly lower breast weight when expressed as percentage of live weight but not when expressed as a percentage of the carcass weight, compared to birds fed the control diet with no DDGS. Wing weight as percent of live weight and carcass weight was significantly greater for birds fed diets with 15% DDGS as compared to the control, while wing weight as percent of the carcass was significantly increased for birds fed the diet with 25% DDGS as compared to those fed the control diet with no DDGS. These results indicate that good quality DDGS could be used in broiler diets at levels of 15 to 20% with little adverse effect on live performance but might result in some loss of dressing percentage or breast meat yield.
  S. Cerrate , Z. Wang , C. Coto , F. Yan and P.W. Waldroup
  Male broilers from 11 to 49 days of age were assigned to one of four feeding treatments: Single diets (control), a choice of starter and finisher diets, a choice of high energy and high protein diets in relation to amino acid: lysine ratio and a choice of high energy and high protein diets in relation to amino acid: protein ratio. Birds fed both energy-protein treatments had worse body weight, feed conversion and carcass characteristics than did birds fed single diets or starter and finisher diets. The high energy-protein diets formulated in relation to lysine had the poorest carcass characteristics for all parameters except for wing and leg quarter yields. Birds given the choice feeding systems selected more high energy diet than high protein diet especially during the period of 11 to 22 days of age. Choice-fed broilers of both energy-protein treatments consumed less protein (total intake or percentage of consumed feed) for all periods, whereas these birds consumed similar energy intake at all age periods except for 42 to 49 days of age and higher energy density than did birds fed the other two feeding systems. As the choice-fed birds grew older, the selected energy content tended to wane while the selected protein contents tended to increase. These data indicate that the high protein diet formulated with amino acids in relation to lysine did not overcome the failure of choice feeding with high energy and high protein diets to sustain productivity since energy may be the driving force for feed selection.
  C.A. Coto , F. Yan , S. Cerrate , Z. Wang , P. Sacakli and P.W. Waldroup
  A study was conducted utilizing a 2 x 2 x 4 x 4 factorial arrangements in which a nutritionally adequate diet was fed with and without 1200 FTU/kg of phytase and with or without 69 μg/kg of 25-hydroxycholecalciferol, four levels of nonphytate phosphorus (NPP) (0.35, 0.40, 0.45, and 0.50%) and four levels of calcium (2:1 Ca:NPP ratio, 0.2% Ca less than the 2:1 ratio, 0.2% Ca more than the 2:1 ratio, and 0.4% Ca more than the 2:1 ratio) for a total of 64 treatments, each fed to two replicate pens of five male broilers in wire-floored battery brooders. At 14 d of age excreta samples were collected, frozen, freeze dried, and analyzed for total P (TP), Ca, and water-soluble P (WSP). The ratio of WSP/TP was calculated from these data. The TP, Ca and WSP in excreta increased as the NPP content of the diet increased. Phytase supplementation reduced TP and Ca but increased WSP concentration and the WSP/TP ratio; this effect might be reversed if levels of NPP lower than those evaluated in the present study are utilized to account for the improvement on phytate phosphorus digestion. The addition of Hy-D reduced TP and Ca concentration in broiler excreta. The most remarkable effect was seen by increasing dietary calcium levels above the 2:1 Ca:NPP ratio typically used in the poultry industry. As the dietary Ca increased, there were significantly reduced excreta levels of TP, WSP and the WSP/TP ratio was significantly reduced. Compared to chicks fed diets with the 2:1 Ca:NPP ratio, the WSP in excreta was reduced 40% by adding 0.20% more Ca and 54% by adding 0.40% more Ca. As the WSP fraction of broiler litter is the primary concern in eutrophication, increasing the dietary Ca level in conjunction with feeding closer to the P requirement should be a cost-effective means of combating the adverse effects of broiler litter on pastures.
  S. Cerrate , Z. Wang , C. Coto , F. Yan and P.W. Waldroup
  Male broilers of a commercial strain were grown to 10 d of age on a common starter diet and then from 11 to 49 days were offered single diets (control), a choice of starter and finisher diets, isoenergetic choices between 12 and 24 or 32% Crude Protein (CP) diets and isoenergetic choices between 15 and 24 or 32% CP diets. Birds fed the isoenergetic diets varying in protein content had almost similar body weight, feed intake, energy intake and carcass characteristics as did birds fed the control diets or the choice of starter and finisher diets. In general the feed and energy conversions by birds given the choice between 12 and 24 or 32% CP diets were worse than those of birds given the other feed systems; however, the protein consumption and conversion by birds fed the former diets were lower than those of birds fed the latter diets. There was a marked preference for the low protein diets (12 and 15% CP) over the high protein diets (24 and 32% CP), but this preference was reduced when the low protein diets were offered with the 24% CP diet. The levels of protein selected of the isoenergetic diets varying in protein content were lower than those of control diets or choice between finisher and starter diets and declined with age except for the last week of the experiment, possibly due to feed form variation. Birds given the choice between 15 and 24 or 32% CP diets had similar performance, except for slightly better protein conversion but slightly worse energy conversion, as those fed control diets or given a choice of starter and finisher diets; even though these choice-fed broilers chose lower protein contents than did birds fed the other two systems. These data indicate that choice of isoenergetic diets varying in protein content can be used to determine protein requirements of broilers, being more effective and efficient with a narrow range of two protein contents.
  S. Cerrate , C. Coto , Z. Wang , F. Yan , F.G. Costa and P.W. Waldroup
  Chicken from two broiler strains known to differ in growth rate and feed conversion (Growth) and in high breast meat yield (Yield) were grown to 10 days of age on a common starter diet and from 11-49 days were provided single diets (control) or isoenergetic choices between 15% and 24% or 15% and 32% crude protein (CP) diets. The Growth strain had greater body weight and intake of feed, protein and energy at all intervals except for 42-49 d of age as well as carcass characteristic in weight basis than did Yield strain. However, the latter strain had better feed, protein and energy conversion at 42-49 d of age and breast meat yield than did the former strain. Birds fed the isoenergetic diets varying in protein content had similar body weight, feed intake, feed conversion, energy intake, energy conversion and carcass characteristic expressed in relative term as did birds fed the control diets. Only for the last period of feeding (42-49 d of age), the protein consumption and conversion by birds fed choice of 15 and 24% CP were higher than those of birds fed the control diets. The Growth strain had a slightly greater preference for the high protein diet and consequently a higher protein intake compared to Yield strain. It seems that the selection of protein density was determined by the growth rate rather than the breast yield. There was a marked preference for the low protein diet (15% CP) over the high protein diets (24 and 32% CP), but this preference was reduced when the low protein diet was offered with the 24% CP diet. The levels of selected protein of birds given the choice diets were higher than those of control diets except for the period of 10-22 d of age and increased with age. These data indicate that these choice feeding systems can detect differences in protein requirement of two strains influenced by the growth rate.
  Z. Wang , S. Cerrate , C. Coto , F. Yan and P.W. Waldroup
  A trial was conducted to evaluate high levels of distillers dried grains with solubles (DDGS) in broiler diets throughout a 49 d growing period. Diets were formulated based on digestible amino acid content to contain 0, 10, 20, 30, 40, or 50% DDGS. Diets were formulated to be optimum nutrient density commensurate with approximately 1% supplemental poultry oil. Each dietary treatment was assigned to four replicate pens with 25 commercial male broiler chicks. Starter (0-14 d) and grower (14-35 d) diets were fed as pellets with finisher (35-49 d) diets fed as mash. Bulk density (mass/volume) was determined on all the diets. Body weights and feed consumption were determined at 14, 35, 42 and 49 d of age. At the conclusion of the study, five representative birds per pen were processed to determine dressing percentage and parts yield. Generally, the bulk density of pellet or mash diets in all different growth periods decreased as DDGS inclusion rates increased, especially in mash diets. Level of DDGS had little effect on body weight at any age until up to 20% inclusion, after which body weight declined significantly. Feed intake was not significantly affected by level of DDGS during all the periods except of 0-14 d. For the whole period (0-49 d), the estimated metabolizable energy intake by chickens was less as DDGS inclusion increased. Increasing DDGS levels significantly increased calorie conversion ratio (CCR, calorie/gain ratio), especially during the period of 0-42 and 0-49 d. Dressing percentage decreased linearly with increasing DDGS levels from 0-50%. There was a significant reduction in breast meat or leg quarter yield as a percentage of live weight with increasing DDGS inclusion, while birds fed higher levels of DDGS had higher wings as percentage of live weight. These results indicate that up to 30% DDGS could be used in broiler diets if price was justified. Inclusion of high levels of DDGS reduces the bulk density and pellet quality and may be a major reason for reduced performance. Low energy density of DDGS diets is probably the limiting factor in meeting the energy needs of the chick.
  S. Cerrate , Z. Wang , C. Coto , F. Yan and P.W. Waldroup
  Different size pellet dies and two levels of dietary energy density were used in prestarter broiler diets formulated to meet typical commercial standards. In the first experiment, birds reared in battery brooders were offered diets containing either 0.5 or 2.5% poultry oil from 0 to 14 days. Each group of diets was assigned different feed forms such as mash continuously through the study or mash, pellet diameters of 1.59, 2.38 and 3.17 mm dies or crumbled diets from 0-7 days followed by crumbled diets to 14 days and pelleted diets to 35 days. In the second experiment, birds reared in floor litter were assigned the same treatments as the previous study except the 2 levels of poultry oil were supplied from 0-42 days of age. During the first seven days birds fed the 1.59 and 2.38 mm diameter die or crumble diets had higher body weight than did birds fed the other feed forms; however, this positive effect was dissipated as the birds grew older. The feed intake kept almost the same tendency as the body weight. The feed conversion at 7 days was improved as pellet size was reduced. It is thought that this was due in large part to better nutritive value since, birds fed crumbled and pelleted diets have almost the same feed intake but different feed conversion. Birds given the mash feed during the whole period had lower body intake and feed intake than those birds fed other feed forms. The body weights and feed conversions at 35 and 42 days were improved as the level of poultry oil increased. Improvement in feed conversion by birds fed diets with 2.38 and 3.17 mm diameter die or crumble diets at 7 days and mash or 3.17 mm diameter die diets at 42 days was observed as the dietary energy level increased. These data indicate that pellet diameters of 1.59 or 2.38 mm can be beneficial during the prestarter period and can be more useful with 2.5% poultry oil.
  Z. Wang , S. Cerrate , C. Coto , P. Sacakli , F. Yan , F.G.P. Costa and P.W. Waldroup
  Two trials with identical experimental design were conducted approximately 20 months apart to evaluate the response of broiler chickens to the addition of NuPro®, a yeast product rich in nucleotides. In both trials, four dietary treatments were compared. The first treatment contained no NuPro®. For the second treatment, the diet with 2% NuPro® was fed only the first 7 days of life while for the third treatment, 2% NuPro® was fed for the first 14 d. For the fourth treatment, 2% NuPro® was fed for the first 7 days and also during the finisher period of 35-42 d of age. In both studies, each treatment was fed to six replicate groups of 60 male broilers of a commercial strain. Response to the addition of NuPro® varied between the two experiments. In the first study, addition of 2% NuPro® to the diet resulted in improvement in feed conversion. Response varied by age of bird and time during which the NuPro® was fed. At 7 d of age, there were no significant differences between birds that had been fed NuPro® and those fed the negative control diet. At 14 d of age, there were no significant differences in feed conversion among birds fed the various treatments, but feed conversion was numerically better for those birds that had been fed NuPro® for the first 7 or 14 d. At 35 d, birds that had been fed NuPro® for the first 7 d had significantly better feed conversion than those fed the control diet with birds fed NuPro® for the first 14 d being intermediate between these two groups. At 42 d, birds fed diets with 2% NuPro® for the first 7 d or for the first 7 d followed by feeding from 35-42 d had significantly lower feed conversion than those fed the control, with those fed NuPro® for the first 14 d being intermediate between these groups. However, in the second trial there was no significant effect of inclusion of NuPro on any of the parameters evaluated. There may be nutritional differences between batches of the product that influence the response of chicks.
  Y.N. Min , F. Yan , F.Z. Liu , C. Coto and P.W. Waldroup
  Glycerin, known as glycerol or glycerine, is the principal co-product of biodiesel production, produced through a NaOH- or KOH-catalyzed transesterification of the triacylglycerols in oils or fats with an alcohol. Glycerin is known to be a valuable ingredient for producing food, soaps, cosmetics and pharmaceuticals. Currently, with plenty of glycerin available to the world market, more uses are expected to develop, especially as a potential energy source for poultry diets, with approximately 4,100 kcal/kg of gross energy. Moreover, glycerin also plays a critical role in body cellular metabolism. Results from different laboratories on the use of glycerin as feed energy source for poultry are discussed in this article. Positive responses are obtained with glycerol content up to 10% in poultry diets. The AMEn also has been measured in several experiments. However, more indices such as carcass performance and blood parameters need to be determined in further studies.
  A. Abdel-Maksoud , F. Yan , S. Cerrate , C. Coto , Z. Wang and P.W. Waldroup
  There is still a debate about the possible difference in the relative bioefficacy between DL-Met and DL-HMB as a source of methionine activity for broilers. This experiment was conducted to determine if the interaction between Arg and Met is influenced by methionine sources (MetS) and methionine level (MetL) in diets for male broilers. A 3 x 2 x 5 factorial arrangement experimental design included three total Arg levels (1.25, 1.35 and 1.45), two Met sources (DL-Met and DL-HMB) and five equimolar levels of supplemental Met (0, 0.05, 0.10, 0.15 and 0.20%) for a total of 30 treatments. Each treatment was fed to 6 replicate pens of 6 male broilers in electrically heated battery brooders from 1-18 days of age. Chickens fed the 1.25% Arg level showed a significantly higher body weight compared to other treatment groups. The FCR and FE were significantly affected by the different levels of Arg in diets. However, FI was not significantly affected by dietary Arg levels. There was no interaction between Arg-MetS and Arg-MetL or any three-way interactions. There was no significant difference between the two Met sources on the performance of broilers. Body weight and FI were not significantly affected by MetL, but an increase of MetL in basal diet significantly improved FCR and FE. The interaction between MetS and MetL had no significant effect on the performance of broilers. These results indicate that the 1.25% total Arg level was sufficient to provide optimum body weight in broiler starter diets. Both MetS had the same relative effectiveness on the performance of broilers when supplemented with equimolar amounts in diets.
  A. Abdel-Maksoud , F. Yan , S. Cerrate , C. Coto , Z. Wang and P.W. Waldroup
  The present study was conducted to investigate the effects of dietary Crude Protein (CP), lysine and amino acid balance in male broiler diets on performance (weight gain and feed conversion, feed efficiency, protein efficiency ratio). Five test diet series were used: 1) the 23% CP diet; 2) the 21% CP diet; 3) the 21% CP diet plus additional amino acids (21.68% total CP) to provide at least as much of the essential amino acids as present in the 23% CP diet; 4) the 19% CP diet and 5) the 19% CP diet plus additional amino acids (20.31% total CP) to provide at least as much of the essential amino acids as present in the 23% CP diet. For each of the five test diets series, additional Lys was added to provide total Lys levels of 1.10, 1.15, 1.20, 1.25, 1.30, 1.35 and 1.40%. This resulted in a total of 35 final experimental treatments in a 5 x 7 factorial arrangement. Each treatment was fed to 6 replicate pens of 6 male broilers in electrically heated battery brooders from 1-18 days of age. Birds fed the low-protein diets (21%) supplemented with EAAs (21.68% total CP) showed significantly the highest BW and best FCR and FE. There were no significant differences in BW between birds fed control diet (23%) and 19% CP or 19% plus EAAs (20.31% total CP) and 21% CP. FC and PER were significantly affected by dietary protein levels. FCR and FE were significantly improved and BW increased significantly by increasing dietary lysine levels up to 1.25%. An interactions of CP with or without EAAs with dietary lysine level were significant for BW. FCR, FE, FC and PER not significantly influenced by interaction. Thus, our results suggest that maximum body weight could be obtained with a 21% low-CP plus EAA supplementation which was the same as that of the chicks fed high protein diet (23% CP). Optimum dietary lysine level for performance was affected by dietary protein level and amino acid balance.
  Cesar Coto , S. Cerate , Z. Wang , F. Yan and P.W. Waldroup
  A study was conducted to evaluate the carryover effect of maternal vitamin D level and source on performance and bone development of the progeny. Breeder hens were fed a vitamin D deficient diet for two months to deplete stores. After this period, experimental diets in a factorial arrangement were fed to the hens with five levels of cholecalciferol (0, 300, 600, 1200 and 2400 IU/kg) and two levels of 25OHD3 (HyD) (0 and 68 μg/kg) for a total of 10 treatments. At the end of two months on the experimental diets two sets of eggs were hatched. The progeny obtained were placed in battery brooders to 21 days by maternal diet and received a common diet. The first hatch received a diet with no vitamin D supplement whereas the second hatch received a diet with the same nutrient composition but containing 5500 IU/kg of cholecalciferol. The first set of birds responded to the maternal diet supplementation of vitamin D mostly during the first week post hatch with no clear pattern in later stages. The progeny receiving 5500 IU/kg of vitamin D in the diet responded to the maternal vitamin D supplementation even at 21 days and in a clearer trend. Feed conversion and body weight improved as the cholecalciferol level increased and with the inclusion of HyD in the maternal diet. The response when HyD was added was more noticeable at low levels of cholecalciferol supplementation with no difference at higher levels in the hen’s diet. Bone development of the progeny was improved with the addition of HyD in the maternal diet; this response was not influenced by increasing levels of cholecalciferol in the breeder diet. This study confirms the importance of the maternal vitamin D carryover for an adequate development of the progeny. Certainly, the vitamin D carryover effect did not overcome the effect of supplementing vitamin D directly in the progeny’s diet but it was capable of improving the performance of the progeny even three weeks post-hatch when a high level of cholecalciferol (5500 IU/kg) was present in the diet of the progeny. A carryover effect of HyD when added to the maternal diet was observed in this study, thus the feasibility of using the metabolite to supply vitamin D to the developing embryo was confirmed.
  Cesar Coto , S. Cerate , Z. Wang , F. Yan , Y. Min , F.P. Costa and P.W. Waldroup
  A study was conducted to evaluate the effect of the vitamin D level and source on the performance of broiler breeders and the deposition of this vitamin in egg yolk. Pullets reaching sexual maturity were depleted of vitamin D stores by feeding a vitamin D deficient diet during an eight week period. Following depletion, an experimental design was utilized consisting of a 5 x 2 factorial arrangement with four levels of dietary cholecalciferol (0, 300, 600, 1200 and 2400 IU/kg) and two levels of 25-hydroxycholecalciferol (25-OH, supplied as HyD) (0 and 68 μg/kg) for a total of 10 treatments. Each experimental diet was fed to two pens with 10 hens and 2 roosters that each received the experimental diets. Levels of 25-OH in plasma and in egg yolk were measured right after the depletion period and during the experimental phase. Performance parameters such as body weight, hen-day production, egg-shell thickness and egg mass were measured weekly. After the depletion period the level of 25-OH in plasma and egg yolk was below the detection limit confirming the depletion status. During the experimental phase the amount of 25-OH in plasma and egg yolk was higher as the cholecalciferol increased. When HyD was fed the level of 25-OH in plasma and egg yolk was higher than obtained when cholecalciferol was fed. Increasing levels of cholecalciferol improved egg shell thickness, hen-day production and egg mass. The addition of HyD improved egg-shell thickness, hen-day production and egg mass. The effect of HyD on performance was more noticeable at low levels of cholecalciferol with no difference at higher levels of cholecalciferol in the diet.
  F. Yan , C. Coto , Z. Wang , S. Cerrate , S.E. Watkins and P.W. Waldroup
  Various recommendations exist for formulating broiler diets. In this study, diet specifications were compared for four different scenarios which included U.S. Poultry Industry average, recommendations by two major breeders and Brazilian recommendations. For each of these, amino acid specifications were adjusted to a percent per Mcal basis as the various recommendations utilize different energy levels. Performance of birds formulated to different nutrient recommendations varied depending primarily upon the relative levels of crude protein, amino acids and metabolizable energy. Feeding diets higher in crude protein and amino acids tended to result in faster growth, especially in early stages, but were less efficient in conversion of crude protein and amino acids into body weight gain. Feeding diets higher in metabolizable energy tended to result in better feed conversion, however effects of dietary energy on calorie conversion were somewhat variable. Over the entire 49 d feeding period there were no significant differences among the various treatments for caloric efficiency. No economic analysis was made of the present study, as relative costs of energy and amino acids vary over time. However it is obvious that when protein costs are high relative to energy, feeding systems which recommend lower protein and amino acid levels should be more economical, while perhaps resulting in a small sacrifice in body weight gain, while feeding systems that recommend higher protein and amino acid levels might be more economical when protein is relatively lower in comparison to dietary energy costs. Because overall calorie utilization was similar among nutrient programs at the conclusion of the study, this could be used as an overall indication of economic efficiency when comparing the different nutrient programs.
  S.D. Goodgame , F.J. Mussini , C. Lu , C.D. Bradley and P.W. Waldroup
  Recent work has indicated that phytase enzymes may influence Sodium (Na) metabolism in the chick but to date no work has conclusively demonstrated that the Na requirement of the chick for live performance is influenced by phytase supplementation. In this study male broilers were fed diets with Na levels ranging from 0.10-0.28% using sodium bicarbonate as the primary source of supplemental Na. Diets were supplemented with no phytase, 500 FTU/kg (1x) or 2,000 FTU/kg (4x) of phytase. When phytase was added the dietary Ca and Nonphytate P (NPP) were adjusted in accordance with anticipated release of these minerals. For 1x phytase the Ca and NPP were reduced 0.10% each and for 4x phytase were reduced by 0.20% each. The combination of seven Na levels and three phytase treatments resulted in 21 dietary treatments, each of which was fed to six replicate pens of five male chicks housed in electrically heated battery brooders with wire floors. Experimental diets and tap water were provided for ad libitum consumption from day of hatch to 18 d. At 16 d of age excreta from each pen was collected and freeze dried to determine moisture content and the excreta analyzed to determine amounts of Ca, P and Na. There were no significant differences in Body Weight (BW), Feed Conversion (FCR), Feed Intake (FI), fecal moisture (FH2O), or mortality of broilers fed diets with different levels of phytase indicating that the dietary adjustment in NPP and Ca levels for the addition of the phytase did not adversely affect performance of the birds. The dietary Na level significantly affected BW, FCR, FI or FH2O. There were no significant interactions of dietary Na and level of phytase supplementation. Regression analysis showed an overall estimate of 0.18±0.01% Na for BW and 0.19±0.01% Na for FCR. There was little indication that the Na requirement was affected by phytase. The level of phytase and Na in the diet had significant effects on excreta levels of P, Ca and Na. The use of lower dietary levels of NPP and Ca in association with the addition of the phytase resulted in significant reduction in excreta levels of these minerals, but had no significant effect on levels of excreted Na. Increasing the dietary Na level significantly affected the levels of all three minerals in the excreta. Although the dietary Na level had significant effects on both excreta P and Ca, these followed no consistent trends with no significant difference in Ca or P excretion between chicks fed diets with the lowest and highest Na levels. There were significant interactions between dietary Na levels and levels of phytase supplementation for all three minerals in the excreta. However, these did not appear to follow any consistent pattern. While it is apparent that phytase influences the metabolism of Na within the body, the data from the present study suggests that this has little impact on the dietary need for Na.
  S.D. Goodgame , F.J. Mussini , C. Lu , C.D. Bradley , S.E. Watkins and P.W. Waldroup
  After a seven day depletion period of vitamin D supplementation beginning on day of hatch, male chicks of a commercial broiler strain were placed on diets supplemented with either a commercial source of 25-hydroxycholecalciferol (25-OH-D3) or a new source derived from fermentation. Levels of 0, 2.5, 5, 10, 20, 40, 60 and 80 μg/kg of each source were added to a common basal diet that was considered as marginal in calcium and phosphorus content. Each diet was fed to six pens of five birds each. Birds were then grown to 21 d of age at which time body weight and feed consumption were determined. All birds were euthanized by CO2 inhalation and all toes were removed and ashed. The right tibia was subjected to bone ash determination while the left tibia was subjected to break force analysis. Analysis of the data indicated no significant differences in performance between chicks fed the two sources of 25-OH-D3 (p<0.05) although numerical differences in weight gain and feed conversion were observed that neared statistical significance (p = 0.06 and 0.08, respectively). Estimates of the amount of 25-OH-D3 needed by the bird were approximately 10 μg/kg for tibia ash and 20 μg/kg for body weight and bone breaking force.
  S.D. Goodgame , F.J. Mussini , C. Lu , C.D. Bradley , N. Comert and P.W. Waldroup
  Recent studies have suggested that phytase enzymes may influence sodium (Na) metabolism in the chick. However, no studies have demonstrated that the dietary Na requirement itself is influenced by phytase supplementation. In the present study male broilers were fed diets with Na levels ranging from 0.10 to 0.28% using NaCl as the source of supplemental sodium. Diets were fed either without phytase or with 500 (1X), 1000 (2X), or 2000 (4X) FTU/kg of phytase. For 1X phytase the Ca and Nonphytate P (NPP) were reduced 0.10% each and 0.20% each for the 2X and 3X levels of phytase supplementation. The diets with 0.10% and 0.28% Na were blended to provide Na levels of 0.10, 0.13, 0.16, 0.19, 0.22, 0.25 and 0.28% Na. Aliquots of these diets were then supplemented with the 0, 1X, 2X and 4X levels of phytase in a 4 x 7 factorial arrangement of treatments, each of which was fed to six replicate pens of five male broilers in electrically heated battery brooders. Experimental diets and tap water were provided for ad libitum consumption from day of hatch to 18 d of age. At 16 d excreta samples from each pen were freeze dried to determine moisture, Ca and P content. At 18 d body weight and feed consumption were determined. Two birds per pen were killed by CO2 inhalation and tibias removed and subjected to bone breaking determination. Chicks fed diets with the different levels of phytase with diets adjusted for anticipated release of Ca and P did not differ significantly in BW, Feed Conversion (FCR), mortality, or fecal moisture content, indicating that the adjustments made for anticipated release of Ca and P was adequate in relation to these measurements. Sodium levels of the diet had significant effects on BW, FCR and fecal moisture. Fecal moisture increased with each level of sodium, so lower dietary levels would be beneficial in this regard. No significant effects on mortality were noted for sodium levels. No significant interactions were noted between sodium level and phytase supplementation for BW, FCR, fecal moisture, or mortality. Regression analyses suggested a sodium requirement of 0.21±0.02% for BW and 0.15±0.01% for FCR. Estimates of sodium requirement at different levels of phytase supplementation did not show any consistent effect of phytase supplementation on the sodium requirement for BW or FCR. Therefore there is no evidence that phytase supplementation will modifiy the dietary sodium requirement of the broiler chick.
  F.J. Mussini , C.A. Coto , S.D. Goodgame , C. Lu , A.J. Karimi , J.H. Lee and P.W. Waldroup
  The possibility of improving digestibility of nonstarch polysaccharides present in broiler diets by the use of different carbohydrase enzymes appears as an opportunity to enhance feed utilization by the birds. In this study, the effect of a beta-mannanase product on nutrient digestibility in corn-soybean meal diets was investigated. One-day-old chicks received a nutritionally complete corn-soybean meal for 19 days. At that time birds were randomly allocated to four treatments, each of which had six replicates of five birds housed in battery brooders with wire floors. Aliquots of the basal diet were supplemented with four levels of CTCZYME (CTC Bio Inc., Seoul Korea): 0%, 0.025%, 0.05% (recommended level) and 0.10%. Chromic oxide was used as an indigestible marker. Feed was analyzed for gross energy, chromium and amino acid content. After eight days of acclimation to the test diets, birds were sacrificed and ileal contents collected. Analysis of the ileal contents indicated that digestibility of Lys, Met, Thr, Trp, Arg, Leu, Ile, Cys and Val were significantly (p<0.0001) improved in a linear manner for each increment of enzyme. Ileal apparent metabolizable energy increased with each increment of CTCZYME level. These results show that the enzyme improves feed digestibility by making amino acids more available for the bird and increases energy utilization from the feed. These results suggest that lower levels of protein and energy could be used with the same results but further studies are required to estimate potential levels.
  F.J. Mussini , C.A. Coto , S.D. Goodgame , C. Lu , A.J. Karimi , J.H. Lee and P.W. Waldroup
  The effect of a commercial beta-Mannanase enzyme (CTCZYME; CTC Bio Inc., Seoul, Korea) on broiler performance and dry matter output in corn-soybean meal diets was investigated. One hundred and twenty one-day-old male chicks of a commercial broiler strain were fed for 19 d on a nutritionally adequate diet based on corn and soybean meal. At that time birds were randomly allocated to four treatments, each of which had six replicates of five birds each. Aliquots of the basal diet were supplemented with four levels of the CTCZYME: 0%, 0.025%, 0.05% (recommended level) and 0.1%. Chromic oxide was used as an indigestible marker. After eight days of acclimation excreta was collected daily, weighed and dried at 130°C for 24 h to obtain the dry matter output. After seven days of excreta collection the birds were weighed and the experiment was terminated. There were no significant differences for body weight gain, feed conversion or feed intake. The addition of CTCZYME at the inclusion level of 0.05% and 0.1% significantly reduced (p<0.002) the daily dry matter excreta output per bird. Analysis of the excreta showed a reduction of the nitrogen level as the level of CTCZYME increased, indicating an improvement in nitrogen utilization by the bird. Gross energy of the excreta decreased as the inclusion level of the enzyme increased. When the inclusion levels of the enzyme increased, calcium and phosphorus levels increased, possibly due to a concentration effect. Higher levels of chromium in the excreta were observed with the increment of the enzyme, suggesting an improvement on the digestibility of the feed product of the effect of the beta-mannanase. These data indicate that nutrient digestibility is enhanced by the effect of CTCZYME. The reason for the increasing digestibility not affecting the broiler performance may be due to the short time the enzyme was included in the diet. Another possibility is that a change in carcass composition may have occurred; more protein could have been deposited on the carcass instead of fat when the enzyme was included but further studies are required to confirm this assumption. Also, it has to be taken into account that the dietary protein levels provided the needs for the bird and they probably did not need to assimilate the now more available amino acids due to the effect of CTZyme.
  Y.N. Min , Z. Wang , C. Coto , F. Yan , S. Cerrate , F.Z. Liu and P.W. Waldroup
  This study was conducted to evaluate canola meal from biodiesel production as a feed ingredient for broilers. One-d-old commercial strain male broilers were randomly assigned to experimental diets with 0, 5, 10, 15, 20 and 25% canola meal. Diets were formulated to meet digestible amino acid requirements for periods of 0-14 d and 15-28 d. Each dietary treatment was replicated 6 times. Body weight and feed consumption were measured at 14 and 28 days of age. The results indicated that no significant (p>0.05) effect of canola levels was observed on feed intake, BW gain, feed conversion ratio, or mortality during the experimental period compared with control diets of soybean meal. Therefore, canola meal can be a valuable protein supplement for broilers when considered on a digestible amino acid basis. In this study, 25% canola was incorporated into broiler diets on a digestible amino acid basis without any negative effects on bird performance.
  Y.N. Min , F.Z. Liu , A. Hancock , C. Coto , C. Lu , A. Karimi , F. Yan and P.W. Waldroup
  A study was conducted to evaluate the effects of adding Rovabio Max, an exogenous enzyme containing xylanase, β-glucanase, pectinase, mannanase, phytase and α-galactosidase activity to broiler diets with normal or reduced nutrient levels. Positive control diets for 0-3 wk and 3-6 wk were prepared based on NRC (1994) recommendations with Lys adjusted to 1.2% for 0-3 wk and 1.1% for 3-6 wk. These diets were formulated with or without the addition of 20% Distillers Dried Grains with Solubles (DDGS) of known composition. Reduced nutrient diets were prepared by reducing dietary metabolizable energy by 40 kcal/lb (88 kcal/kg), Ca by 0.10% and available P by 0.12% (EPC) and by an additional reduction of 5% in essential amino acids (EPC+AA). All diets were then fed with or without the addition of Rovabio Max at 200 g/ton as suggested by the manufacturer. Each diet was fed to four pens of 60 male birds of a commercial strain (Cobb 500) maintained in litter floor pens. Birds were weighed and feed consumption determined at 21 and 42 d of age. Two birds per pen were killed and tibia ash determined at 21 and 42 d; five birds per pen were killed at 42 d to determine carcass dressing percentage and parts yield. Birds fed the EPC diets did not differ significantly from those fed the positive control diet for body weight, mortality, tibia ash, dressing percentage, or breast meat yield at any point in the study. Additional reduction in amino acid content of the diets (EPC+AA) resulted in a significant decrease in 42 d body weight and a reduction in 21 d tibia ash compared to birds fed the positive control diet. Numerical differences in feed conversion were observed for both levels of nutrient reduction but not commensurate to the reduction in dietary energy content. Therefore, response to any exogenous enzyme might be expected to be minimal. The only positive response to the addition of Rovabio Max was a significant improvement in 21 d tibia ash, due to the phytase activity of the enzyme combination. Inclusion of 20% DDGS in diets in the present study had no adverse effects on broiler performance. The response to the DDGS was significantly higher in diets with reduced amino acid levels; the DDGS sample in the present study contained similar levels of crude protein as in the assigned nutrient matrix but the quality of the product appeared to be superior as judged by the light color indicating minimal overheating. It would appear that the level of nutrient reduction in the present study was not sufficient to result in significant reduction in performance, other than tibia ash at 21 d. In order to demonstrate positive effects from this or other enzymes, it is necessary to have diets with a greater degree of nutrient reduction than imposed in the present study.
  Y.N. Min , F.Z. Liu , A. Karimi , C. Coto , C. Lu , F. Yan and P.W. Waldroup
  This experiment was conducted to evaluate the effect of a commercial carbohydrase preparation (Rovabio® Max AP) on protein and energy utilization of diets with 0 or 30% DDGS. One hundred and ninety two, 18-day old male broiler chicks of a commercial strain (Cobb 500) were randomly distributed among six treatments in a 2 x 3 factorial arrangement. Each treatment was replicated four times, with six chicks per replicate. Treatments included two basal diets containing 0 or 30% of DDGS; each supplemented with or without an enzyme preparation fed at the level recommended by the manufacturer (1X), two (2X) and four times (4X) the recommended level. After a five-day adaptation period, excreta samples were collected for determination of AME and N retention (NR). Body weight, feed intake, feed conversion, fecal gross energy (GE) and N, AME, AMEn, GE digestibility and NR were determined. The results showed that weight gain, feed intake, feed conversion ratio and mortality rate were not significantly affected by level of DDGS or enzyme inclusion in the diet, or their interactions. Excreta N and GE were significantly increased by inclusion of 30% of DDGS in the basal diet. While AME and AMEn values were not affected by the addition of high level of DDGS in the diet, GE digestibility and NR were significantly affected. Supplementation of either basal diet with different levels of enzyme had no significant effects on excreta N content or AME, GE digestibility, or NR values. Moreover, the interaction between different levels of DDGS and enzyme levels on performance or nutrient utilization parameters were not significant. These data indicate that the addition of the enzyme preparation used in this trial was not effective in improving nutrient utilization of corn-soybean meal diets with or without DDGS.
  F.J. Mussini , S.D. Goodgame , C. Lu , C.D. Bradley , S.M. Fiscus and P.W. Waldroup
  The utilization of vaccines has proven to be a good strategy to prevent coccidiosis but the process of immunity acquisition needs to be approached from a nutritional point of view as well if complete success in broiler performance is to be achieved. It has been reported that Glutamine (GLU) plays a key role both in the gastrointestinal tract and the immune system and its utilization could be beneficial to cocci-vaccinated broilers. In this study, twelve hundred one-day-old male chicks were vaccinated at a commercial hatchery with a coccidiosis vaccine and randomly allocated to four treatments, each of which had six replications with 50 birds per pen. Birds were maintained in pens with built up wood shavings litter. Each treatment consisted of the same basal diet that met average nutrient levels in the U.S. poultry industry with four different inclusion rates of GLU (0, 0.5, 0.75 and 1%). Birds were fed the experimental diets from 1 to 28 days of age and a common unsupplemented diet to 42 d. Body weights were significantly improved at 21 and 28 days for all the treatments where the GLU was included. Feed conversion was not significantly affected by the inclusion of GLU. There were no significant differences in body weight and feed conversion at 42 days but the numerical difference in weight between the control and the treatments with GLU observed earlier were maintained. At 43 days, eight birds per pen were processed in a pilot processing plant. Breast meat yield was not significantly different among treatments. Glutamine proved to be beneficial during the process of immunity acquisition improving broiler performance significantly until 28 days and maintaining the body weight difference until the end of the experiment.
  J. Yuan , A.J. Karimi , S.D. Goodgame , C. Lu , F.J. Mussini and P.W. Waldroup
  A study was conducted to evaluate an herbal methionine replacement product in diets for young broiler chicks. A corn-soybean meal diet that was complete in all respects but methionine was prepared and divided into three aliquots. One was supplemented with 0.30% DL methionine and another was supplemented with the herbal methionine replacement product. Each of these was then blended with the unsupplemented basal diet to provide diets with 0, 0.05, 0.10, 0.15, 0.20, 0.25 and 0.30% of either DL methionine or the herbal methionine replacement product. Each diet was fed to twelve pens of five male broiler type chicks each in electrically heated battery brooders. The diets and tap water were provided for ad libitum feeding from day of hatch to 18 d of age. Analysis of the diets indicated that the methionine activity of the diets with DL methionine was close to expected values but no apparent increase in analyzed methionine activity in diets supplemented with the herbal methionine replacement product. Body weight gain and feed conversion of birds fed the diets with DL methionine were significantly superior to that of birds fed the diets with the herbal methionine replacement product. No significant differences were observed between birds fed the two products for weight of digestive or immune organs when expressed as a percentage of body weight. These data suggest that the herbal methionine replacement product is not suitable for use as a methionine source in diets for young broiler chicks.
 
 
 
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