Search

The current study aimed to evaluate the effects of parturition and different stages of milk production on Cardiac Troponin I activity (CTnI) and other cardiac markers. A total of 42 healthy dairy cattle with an average body weight of 520±17 kg and an average parity of 2.4±0.7 were randomly selected from a commercial dairy farm. Through a clinical examination and ECG recording conducted by a veterinarian, blood samples were collected from all cattle’s coccygeal vein one month before parturition (dry period), one week after parturition (early lactation), and 10 weeks after parturition (peak of the lactation). Dairy cows in the experimental group were observed closely before and during parturition and in the postpartum period. Biochemical parameters, including Cardiac Troponin I activity (CTnI), Creatine kinase (CK), Aspartate aminotransferase (AST), and Lactate dehydrogenase (LDH) were analyzed at three-time intervals. Regarding time intervals, there were no significant differences among the cattle in terms of CTnI, CK, LDH, AST, parturition, and different stages of milk production. It was found that the effect of late-stage gestation and different lactation periods on cardiac biomarkers in dairy cows was not significant. [ABSTRACT FROM AUTHOR]

Reproductive success is crucial in dairy farming as it heavily relies on the consumption of a complete mixed ration for the diet. The current study investigated the effects of adding saturated (SFA) and polyunsaturated fatty acids (PUFAs) to dairy cows' diets on reproductive performance and reproductive hormones during the transition period. A total of 30 Holstein dairy cows were randomly divided into three groups (10 animals in each group), based on parity and body condition score. The cows had an initial body weight of 567.5 ± 40.3 kg (mean ± SD), a body condition score of 3.5 ± 0.26 out of 5 (mean ± SD), and a parity of 1.7 ± 0.02 (mean ± SD). The control group received a balanced ration meeting all the nutrient requirements according to the National Research Council (NRC) guidelines. The SFA group received 1.4% of dry matter (DM) as palm oil (RumiFat®), while the omega group had 5% of DM as safflower (a source of n-6 fatty acids) added from 21 days before parturition to 21 days after, and 4% of DM as flaxseed (a source of n-3 fatty acids) added from 21 to 42 days after parturition. In the Omega group, estradiol concentration significantly increased on artificial insemination (AI) day (12.54 pg/mL). Additionally, serum prostaglandin F2-alpha concentration was significantly higher in the omega group (0.732 pg/mL on day 7 and 1.68 pg/mL on day 14) compared to other groups. The control group exhibited the highest progesterone concentrations at 14 and 21 days post-calving compared to the other groups, other groups. whereas the omega group highest concentration five days after AI. The omega group also showed a significantly higher mean number of follicles >10mm and larger ovulatory follicle diameter. Moreover, a higher percentage of pregnant cows at 120 days in milk, fewer open days, and lower service per conception were observed in the omega group compared to the other groups. In conclusion, supplementing dairy cows' diets with PUFAs during the transition period positively influenced ovarian function, hormone levels, and reproductive performance. [ABSTRACT FROM AUTHOR]

BACKGROUND: Many additives have been recommended to calf feed but the effects of each supplement have been under investigation especially during weaning stress. OBJECTIVES: The effects of dietary supplementation of probiotic (Protexin) and chromium-methionine chelate (Cr-Met) on triiodothyronine (T3), thyroxine (T4), total protein, albumin, zinc, and growth body-weight gain in dairy calves during weaning period was investigated. METHODS: A total of 28 dairy Holstein calves were randomly allocated to one of the four experimental treatments (n=7). The study commenced 21 days before weaning (average 70 days).The recommended dosage for both chromium-methionine chelate (Cr-Met) and probiotic (Protexin) is 2 gr/calf daily. Blood samples were collected from the jugular vein, 21 days before weaning and 3, 7 and 21 days after weaning. Serum consentrations of T3, T4, total protein, albumin, and zinc were measured. Bodyweight (BW) was measured 7 days before, at weaning and 7 days after weaning. RESULTS: No effect of different diets nor interaction was found for body weight gain, total protein, and albumin. No effect of different diets was observed for T4 although the interaction was observed between groups and time. An effect of different diets and time was found for T3 and the mean T3 concentration was lowest in group Protexin + Cr-Met. The mean Zinc concentration was at its highest level 21 days after weaning, while different diets did not affect the Zinc concentrations. CONCLUSIONS: There is no benefit associated with the separate or combined feeding of Protexin and Cr- Met on calves' growth performance according to weight gain, total protein, and thyroid hormones. [ABSTRACT FROM AUTHOR]