Effects of maternal late-gestation nutrition on dam and subsequent progeny growth and performance of beef cattle

Abstract

Our objective was to evaluate the effects of forage type and supplementation level on dam and subsequent progeny growth and progeny reproductive performance in heifers. Multiparous, May-calving cows (n = 652) were managed over 6 production cycles and arranged in a 2 × 2 factorial. They were assigned to 1 of 2 forage types: subirrigated meadow (M) or upland range (R) for 116 ± 2 d, and then 1 of 2 supplementation groups: no supplement (NoSp) or 0.45 kg/d of 33% CP (DM) supplement (Sp) for 85 ± 2 d. Body weight gain was greatest for MSp cows and intermediate for MNoSp cows, followed by RSp and then RNoSp cows ( P = 0.02). Treatment-period BCS gain was increased ( P < 0.01) in Sp cows. Sex-specific differences in postnatal progeny BW through development were detected ( P ≤ 0.05). Heifer progeny increased ( P = 0.01) percent mature BW at breeding. Pregnancy rate as a primiparous cow was increased ( P = 0.02) by maternal meadow grazing. Heifer progeny’s first calf BW ( P = 0.04) and risk of dystocia was increased ( P = 0.04) by dam supplementation. These results suggest differences in maternal late-gestation diet composition due to differences in supplementation and forage specie type and growth result in altered postnatal phenotypes of both female and male progeny.