Avaliação do perfil hormonal de vacas leiteiras no pós-parto e desenvolvimento de uma plataforma farmacêutica de liberação prolongada para hormônios

Abstract

This thesis aimed to develop a pharmaceutical platform for extended release of Follicle Stimulating Hormone (FSH) for bovine superovulation (SOV). In vitro and tests were performed on the applicability and bioavailability of FSH in dairy cows. The gelation temperature was 34ºC, with hormone release for at least 36 hours (single dose) and 48 hours (double dose, with an interval of 24 hours). It is concluded that the pharmaceutical vehicle was able to prolong the FSH release time and could possibly simplify SOV protocols, by reducing the number of applications. In addition, the objective was to determine the influence of Progesterone (P4) and Vitamin D3 (VitD3) levels on the feeding behavior of dairy cows in the recent postpartum period. Forty-one Holstein cows, multiparous, from 2 to 4 lactations were used. During days 0 (day of calving), 1, 2, 3 and 7 postpartum, variables that analyze the feeding behavior of the animals were measured, through the feeders (Intergado®) and smart collars (Cowmed Assistant®), in addition to the analyzes blood, to assess the levels of VitD3, P4, glucose and free fatty acids. Colostrum production was recorded up to 7 days postpartum and milk production was recorded up to 60 days postpartum. The animals were categorized in relation to VitD3 and P4 levels on day 0. Cows with VitD3 levels >60ng/mL constituted the ALTAD3 group and below this value, the MODERADAD3.Cows with P4>0.70ng/mL were allocated to the ALTAP4 group and below this value to the BAIXAP4 group. The groups were analyzed separately between ALTAD3 and MODERADAD3 and between MENORP4 and MAIORP4. The MENORP4 group had higher production of colostrum (30.03±1.08; P=0.03) and milk (44.95± 0.40; P=0.02), more visits to troughs with consumption ( 38.17±1.55; P=0.001) and rumination time (619.87±18.49; P=0.001) compared to the MAIORP4 group. The ALTAD3 group had fewer visits to the troughs with (31.03±1.72; P=0.001) and without (18.01±1.73; P=0.001) consumption than the animals in the MODERADAD3 group. It is concluded that the levels of VitD3 and P4 on the day of calving can influence parameters of feeding behavior during the first postpartum week of dairy cows.