Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2008.1582.1587GhorbaniBehnam VahdaniNarges ZerehdaranSaeed 1220081112To investigate the effects of niacin supplementation
in the diet of high producing cows at early lactation, 21 holstein dairy
cows were used in this experiment. Animal were assigned in to three groups
based on their milk yield and calving date soon after parturition. They
were received a basal diet and 0 (group 1), 6 (group 2), 12 (group 3)
g of supplementation niacin per day over a 10 weeks experimental period.
Milk volume was recorded and milk samples were collected for each cow
at two weeks interval for analysis of fat, protein, lactose and SNF (Solid-None
Fat). Blood samples were also taken for the measurement of glucose, triglyceride,
Beta-hydroxy butyrate and total protein at two weeks intervals. No significant
difference were observed between milk yield, milk fat , protein, lactose
and SNF content in cows received niacin compared to the control group
(p>0.05). Plasma glucose in groups 2 and 3 compared to the control
were higher and this difference were statistically significant (p<0.05).
Blood triglycerides were not significantly affected by niacin supplementation.
BHBA were lower in cows received niacin and this difference were significant
(p<0.05). The trend of changes in the amount of blood total protein
were identical in all three groups whole the level of this factor was
always higher in control group compared to the others groups. Niacin has
showed an increase in the level of plasma glucose and a notable decrease
in the amount of blood triglyceride, β -hydroxy butyrate and total
protein, which may be due to the effect of this vitamin on the energy
metabolism in cows.]]>AOAC,199015th Edn.,pp: 200-210pp: 200-210Bergman, E.N., 197154936948DiPalma, J.R. and W.S.Thayer,199111169187Drackley, J.K., 19921992pp: 8Emery, R.S., N. Burg, L.D. Brown and G.N. Blank,19644710741079French, P.D.,200487345352Fronk, T.J. and L.H. Schultz,19796218041807Fronk, T.J., L.H. Schultz and A.R. Hardie,19806310801090Grummer, R.R., 19937638823896Kronfeld, D.S. and F. Raggi,196490219224Madison-Anderson, R.J., D.J. Schinggoethe, M.J. Brouk, R.J. Baer and M.R. Lentsch, 19978013291338Minor, D.J., S.L.Troewr, B.D. Strang, R.D. Shaver and R.R. Grummer,199881189200NRC,20017th Edn.,Pages: 405Pages: 405Nurmio, P., K. Roine, T. Juokslahti and A. Loman,197426370381Pires, J.A.A. and R.R. Grummer,20079037253732Riddell, D.O., E.E. Bartley and A.D. Dayton, 1981in vitro and on diary cattle growth and milk production. ]]>64782791Santschi, D.E., R. Barthiaume, J.J. Matte, A.F. Mustafa and C.L. Girard, 20058820432054SAS Institute,1999-20001999-2000Schwab, E.C., D.Z. Caraveillo and R.D. Shaver,200521239247Vazquez-Anon, M., S. Bertics, M. Luck and R.R. Grummer,19947715211528Veenhuizen, J.J., J.K. Drackley, M.J. Richard, T.P. Sanderson, L.D. Miller and J.W. Young,19917442384253Williamson, D.H., J. Mellanby and H.A. Krebs,1962829096Zinn, R.A., F.N. Owens, R.L. Stuart, J.R. Dunbar and B.B. Norman,198765267277