|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|5593361||1405078||2017||5 صفحه PDF||سفارش دهید||دانلود کنید|
- This study represents an attempt to use a composite additive to alleviate HS.
- RPC may alleviate HS and improve dairy cow performance.
This study was conducted to evaluate the effects of supplemental rumen-protected capsule (RPC) on animal performance, serological indicators, and serum heat shock protein 70 (HSP70) of lactating Holstein cows under heat stress (HS). During summer months, 30 healthy multiparous lactating Holstein cows with a parity number of 3.1 Â± 0.44, 70 Â± 15 d in milk, an average body weight of 622 Â± 62Â kg, and an average milk yield of 32.28 Â± 0.96Â kg/d, were used. The cows were randomly allocated to two groups: a control group and an RPC-supplemented group (0.13373Â kg K2SO4, 0.02488Â kg vitamin C, 0.021148Â kg niacin, and 0.044784Â kgÂ gamma-aminobutyric acid per cow). During the 42-d experiment, ambient air temperature and relative humidity inside and outside the barn were recorded hourly every day for the determination of temperature-humidity index (THI). Milk and blood samples were collected every week, and body weight and body condition scoring were measured on day 0. Based on the THI values, the animals had moderate HS. On day 42, the RPC group had lower HSP70, adrenocorticotropic hormone (P = 0.0001), lactate dehydrogenase (P = 0.0338), and IL-6 (P = 0.0724) levels than the control group, with no significant differences in creatine kinase, glucocorticoid, or IL-2 levels. Milk yield, energy-corrected milk, and dry matter intake were higher in RPC than in the control group (P = 0.0196). There were no significant differences in milk fat or daily protein levels between the two groups; however, daily protein and milk fat levels were higher in the RPC group than in the control group (P = 0.0114 and P = 0.0665, respectively). Somatic cell counts were no different between the two groups. In conclusion, RPC may alleviate HS and improve dairy cow performance.
Journal: Journal of Thermal Biology - Volume 69, October 2017, Pages 249-253