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

Abstract

Objective: 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. Materials and Methods: 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. Results and Discussion: 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. Implications and Applications: 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.