Effects of dam prepartum supplement level on performance and reproduction of heifer progeny

Objectives were to determine the effect of dam prepartum supplement level on growth performance, feed efficiency and reproductive performance of female progeny (127 heifers in year 1, 138 heifers in year 2). Mature, multiparous, fall-calving, Angus × Simmental cows (initial age = 5.6 ± 1.9 years, BW = 623 ± 70 kg, BCS = 5.7 ± 0.7) were used in a completely randomised design that included three supplement levels: no supplement (NS), low supplement, 2.16 kg·cow−1·d−1 (LS), or high supplement, 8.61 kg·cow−1·d−1 (HS). Cows grazed endophyte-infected tall fescue/red clover pastures and were bunk-fed supplement (70% dried distiller’s grains plus solubles [DDGS] and 30% soybean hulls) 103 ± 11 d prepartum to 2 ± 11 d postpartum. Dam prepartum supplementation did not affect (p ≥ .60) heifer progeny BW at weaning, breeding, nor at pregnancy verification. Dam prepartum supplementation did not affect (p ≥ .18) heifer progeny AI conception rate, overall pregnancy rate, nor calving rate. Calving date, calf birth BW, percentage of unassisted births, milk production and calf BW at 73 ± 16 d of age were not different (p ≥ .24) among heifer progeny, regardless of dam supplement level. In conclusion, these data suggest within a fall-calving, fescue-based production system, supplementing dams with 2.16 or 8.61 kg·cow−1·d−1 of a DDGS-based supplement does not affect growth performance and reproductive performance of subsequent female progeny.