NUTRITIONAL AND METABOLIC EVALUATION IN NELLORE COWS SUPPLEMENTED DURING PERI AND/OR POSTPARTUM KEEPING IN TROPICAL PASTURE

The aim of this study was to evaluate the effects of supplementation at peri and/or postpartum period on nutritional and metabolic responses in Nellore cows keeping in tropical pasture (Brachiaria decumbens). Forty-five pregnant cows with an average body weight (BW) of 543 ± 130 kg and 200± 30 days of gestation were housed in 8 paddocks with full access to water and mineral mix. Treatments evaluated during peripartum were: control (mineral mix) and supplemented (0.2 % of BW in supplement with 43.5% of crude protein, CP). After parturition, 4 supplementation strategies were evaluated: control (mineral mix peri and postpartum), SN (supplemented only at peripartum), NS (supplemented only at portpartum), and SS (supplemented peri and portpartum). The study was analyzed using PROC MIXED in SAS 9.4 (SAS Inst., Cary, NC) assuming a completely randomized design with 2 treatments at peripartum and 4 treatments at postpartum. Treatment, animal and paddock were considered as a fixed effect whereas treatment within paddock was considered random in both periods of evaluation. In peripartum period, there was no effect (P > 0.10) of supplementation on the values of performance characteristics and on ADGconc (average daily gain of conceptus) and BWbirth. Similarly, at peripartum, no significant differences (P > 0.10) on the intake in percentage and g/kg of BW parameters was observed. Yet, compared with control, supplementation did not (P > 0,10) affect the digestibility of OM and NDFap, but, a significant difference (P < 0.10) was observed in CP/OM digestibly ratio and CP digestibility at peripartum. The supplementation at peripartim affected (P < 0.10) plasma ureic nitrogen (PUN), but not (P > 0.10) the concentrations of BHB, NEFA, glucose, albumin, total proteins, IGF-1, leptin and insulin. No significant effects was observed (P>0.10) for the performance parameters in postpartum period, just for calf ADG, were significant effect (P<0.10) of maternal postpartum supplementation. There was no significant difference (P>0.10) for intake and digestibility in the postpartum period. No significant differences (P> 0.10) in treatment and sampling time were observed on blood levels of BHB, total proteins and albumin. The effect of sampling time (P < 0.10) for glucose, leptin, cholesterol and progesterone was verified. Significant effects (P<0.10) of postpartum supplementation were observed for NEFA, PUN, and cholesterol. There was an interaction effect between pre and postpartum treatment (P<0.10) for blood levels of NEFA, IGF-1, insulin and PUN indicating that animals not supplemented in peripartum were influenced more by supplementation at postpartum. Overall, independent of the supplementation period, animals with BSC above 5 at gestation, and supplemented have better metabolic status after parturition, and probably ovarian activity early that not supplemented.