TY - JOUR ID - 121 TI - Effect of different levels of monensin in diets containing whole cottonseed on milk production and composition of lactating dairy cows JO - Iranian Journal of Veterinary Research JA - IJVR LA - en SN - 1728-1997 AU - Fatahnia, F. AU - Rowghani, E. AU - Hosseini, A. R. AU - Darmani Kohi, H. AU - Zamiri, M. J. AD - Department of Animal Sciences, College of Agriculture, Ilam University, Ilam, Iran AD - Department of Animal Sciences, College of Agriculture, Shiraz University, Shiraz, Iran AD - Graduated from College of Agriculture, Ilam University, Ilam, Iran AD - Department of Animal Sciences, College of Agriculture, Gilan University, Rasht, Iran Y1 - 2010 PY - 2010 VL - 11 IS - 3 SP - 206 EP - 213 KW - Monensin KW - Whole cottonseed KW - Milk fatty acid composition KW - Dairy cow DO - 10.22099/ijvr.2010.121 N2 - The objective of this study was to determine the effects of feeding different levels of monensin on feed intake, milk production and composition, and milk fattyacid profile in lactating Holstein cows. Four multiparous cows averaging 517 ± 47 (SD) kg in body weight and 101 ± 19.8 (SD) days in milk were housed individually in tie-stalls. The study was conducted as a 4 × 4 Latin square design for four periods (14-d for adaptation and 7-d for sampling). Cows were offered four dietary treatments (0, 10, 20, or 30 mg of monensin/kg of DM) as total mixed ration, twice daily. Dry matter (DM) intake was similar among treatments. Monensin supplementation significantly increased (P<0.05) milk yield and 4% fat corrected milk (FCM). Milk fat and protein percentages were not affected by monensin supplementation, but fat yield was increased. Monensin reduced the percentage of the short-chain and saturated fatty acids in milk fat, but had no effect on the percentages of medium- and long-chain fatty acids. Monensin supplementation increased (P<0.05) unsaturated fatty acids concentrations in milk fat. Based on the results of this study, feeding monensin was effective in inhibiting the biohydrogenation of unsaturated fatty acids in the rumen, and consequently increased the percentageof unsaturated fatty acids in milk fat, which improves the health characteristics of milk for human consumption. UR - https://ijvr.shirazu.ac.ir/article_121.html L1 - https://ijvr.shirazu.ac.ir/article_121_5759a0b6e67a5327d1ad2c64b8e84890.pdf ER -