Effect of polyunsaturated fatty acid supplementation on calf weight and reproductive parameters of brahman cows

The use of reproductive biotechnologies in breeding and breeding programs is aimed at obtaining superior products in terms of product characteristics. The reproductive performance of 134 cows subjected to synchronization of estrus for artificial insemination at fixed time was compared; without supplementation (T1) or with supplementation (T2) with polyunsaturated fatty acids (PUFA) from 15 days priori to the start of the protocol until day 75. The following protocol of synchronization was used: day 0: estradiol benzoate with intravaginal progesterone device; day 8:removal of the device and cloprostenol; day 10:artificial insemination at fixed time and application of human chorionic gonadotropin. After insemination the cows remained with a bull. A completely randomized model was used, and the Tukey test (P < 0.05) was used to interpret the means. There was a significant difference in the size of the preovulatory follicle size (P < 0.0018), and the corpus luteum size (P < 0.007) for supplemented cows. The pregnancy rate to fixed-time insemination for T1: 34.84 %; T2: 46.26 %, being 11.42 % higher for T2 (P < 0.05). Bull pregnancy rate T1: 37.86%; T2: 25.44 % was 12.42 % higher for T1 (P < 0.05), with no difference between treatments (P > 0.05) for total pregnancy rate. Calf weight gain during the experimental period favoured the supplemented calves (T1: 19.6 kg; T2: 33.07 kg). Supplementation of breeding cows with PUFAs increased pregnancy rates to artificial fixed-time insemination and reduce the interval between births.