Can early weaning in the previous lactation of beef cows affect the metabolism and postnatal development of female offspring?

Abstract

This study aimed to compare the effects of early weaning (EW; 150 days) and conventional weaning (CW; 240 days) during early pregnancy on the postnatal metabolism, development, and productive performance of female calves born from secondiparous (SEC) and multiparous (MULT) cows. Fifty-five Nelore female calves were evaluated: 25 from EW cows (10 SEC, 15 MULT) and 30 from CW cows (15 SEC, 15 MULT). From 90 to 150 days of age, all calves received creep feed (5 g/kg body weight [BW]). After weaning, calves were maintained on pasture and supplemented with 10 g/kg of BW of concentrate until 16 months (mo) of age. From 12 to 16 mo, heifers were assessed every 28 ± 3 days for BW, body condition score (BCS), and average daily gain (ADG), which was calculated from serial weight records. Carcass traits (ribeye area [REA], backfat thickness [BFT], and rump fat thickness [RFT]) were measured via ultrasound. Blood samples were collected to determine serum concentration of IGF-I, leptin, and plasma glucose. At 5 and 14 mo, a subgroup of 22 heifers (n = 10 for EW and 12 for CW) was selected for liver biopsy to assess the gene expression of IGF-I, IGFBP, and GHR. No significant interactions were found between dam parity, weaning strategy, or time for BW, BCS, ADG, REA, serum IGF-I, leptin, and plasma concentration for glucose (P > 0.1). A significant effect of time (P < 0.05) indicated increased in BW, BCS, LMA, BFT, and RTF throughout the experimental period. Heifers from MULT cows were 2.67 kg heavier between 13 to 15 mo than those from SEC cows (P = 0.04). Dam parity also influenced BCS (P = 0.01), with MULT-derived heifers presenting higher BCS than those from SEC cows. For carcass traits, a significant dam parity x weaning interaction was observed for RTF (P = 0.04), indicating that EW-SEC heifers had lower rump fat deposition compared to EW-MULT and CW heifers. IGF-I gene expression was 1.4-fold greater (P = 0.01) at 5 mo compared 14 mo. For IGFBP, a dam parity × time interaction (P = 0.05) revealed that heifers from MULT cows had a 1.8-fold higher expression at 14 mo than at 5 mo. In conclusion, early weaning in the preceding lactation did not negatively affect the subsequent offspring's performance or metabolic profile, except for a reduction in rump fat thickness in EW-SEC heifers.

Keywords: Beef cattle; Body development; Heifer; Nelore; Nutritional status.