Including the combination of ß-carotene, vitamins ADE and biotin into mineral supplement for grazing beef cows can be a tool to optimise the reproductive performance.
This was shown by researchers from The University of São Paulo in Brazil. Vitamins are necessary for growth, reproduction and health and its deficiencies lead to negative symptoms in the organism. The positive role of carotenoids, especially β-carotene, in cow fertility was reported by several researches. Vitamin E treatment accelerates uterine involution in cows with foetal membranes retention. Furthermore, vitamin E protects the early embryo from the effects of environment heat stress. Vitamin D contributes to bone formation, calcium balance, and other physiological processes critical for lactating cattle and also contributes to reproductive performance and mammary development. Also, supplemental biotin 70 days post-partum for dairy cows increased plasma glucose and lowered non esterified fatty acids (NEFA), resulting in a better metabolic status.
The aim of this current experiment, published in the Livestock Science, was to evaluate the effects of feeding the combination of β-carotene and vitamins (ADE and biotin) on reproductive performance of grazing beef cows. To do so, a total of 430 suckled multiparous Nellore cows (Bos indicus, initial body weigh = 417 ± 58 kg) were used in a randomised block design. The control group received a mineral supplement: no β-carotene and vitamins. The treatment groups received a combination of 500 mg β-carotene, 70,000 IU Vit. A, 10,000 IU Vit. D3, 500 mg Vit. E and 10 mg biotin/cow/day into the mineral supplement. Animals were synchronised using estradiol/progesterone (E2/P4) based protocol. Pregnancy rate was evaluated 30 days after FTAI and 30 days after the end of breeding season. No difference in the cyclicity rate [presence of corpus luteum (CL); P = 0.31] before FTAI synchronisation protocol on day 11 was observed.
It was shown that including the combination of β-carotene, vitamins ADE and biotin into the mineral supplement increases the pregnancy rate at first FTAI in beef grazing tropical pasture. The blood β-carotene status at the beginning of the FTAI protocol is positively correlated with the pregnancy rate in grazing beef cows. Further studies could better evaluate the specific role of each vitamin and β-carotene in the metabolic processes related to the reproduction.
Source: Livestock Science