Preliminary investigation of milk production in Angus heifers exposed to different nutrition in utero

Milk yield (MY) and composition were measured on one day in Weeks 7, 9 and 11 in 17 offspring of Angus cows fed for high (1.2 kg/d; HB) or medium (0.5 kg/d; MB) liveweight gain (LWG) for 10 days before insemination and medium (0.5 kg/d; MA) or low (0.01 kg/d; LA) LWG during gestation. Mean MYs in the progeny were; Week 7: 5790 ± 420 g/d, Week 9: 7418 ± 447 g/d, Week 11: 6244 ± 392 g/d. Better feeding before mating had little effect on MY or milk crude protein (CP%) in the progeny but tended to reduce the milkfat% (Week 9; HB (n = 8) 3.50 ± 0.17% versus MB (n = 8) 3.74 ± 0.22%) (P <0.19), casein (Week 11; HB 2.59 ± 0.03% versus MB 2.68 ± 0.04%) (P = 0.11) and lactose (Week 11; HB 5.18 ± 0.13% versus MB 5.42 ± 0.05%) (P = 0.075). Better feeding of the dam after artificial insemination did not significantly increase MY of the progeny (Week 9; MA (n = 9) 7972 ± 378 g/d versus LA (n = 8) 6794 ± 826 g/d) (P = 0.23), or milkfat%, decreased CP (Week 9; MA 3.22 ± 0.07% versus LA 3.41 ± 0.08%) (P <0.09) and casein% (at Weeks 7 and 9 identical values of MA 2.52 ± 0.06% versus LA 2.69 ± 0.07%), but increased lactose% after the peak of lactation (Week 11 MA 5.42 ± 0.06% versus LA 5.15 ± 0.14%) (P <0.08). Feeding before and after conception may affect the nutrition of the grand generation