Effect of type of forage offered and breed on performance of crossbred suckler heifers and their calves

Authors

• Merja Manninen Agricultural Research Centre of Finland, Animal Production Research, FIN-31600 Jokioinen, Finland
• Ilmo Aaronen Agricultural Research Centre of Finland, Animal Production Research
• Marja-Leena Puntila Agricultural Research Centre of Finland, Animal Production Research, FIN-31600 Jokioinen, Finland
• Reijo Heikkilä Agricultural Research Centre of Finland, Karelia Research Station
• Seija Jaakkola Agricultural Research Centre of Finland, Animal Production Research, FIN-31600 Jokioinen, Finland

DOI: https://doi.org/10.23986/afsci.72868

Abstract

Thirty Hereford-Ayrshire (HfAy) and 29 Limousine-Ayrshire (LiAy) spring-calving heifers in calf to a Aberdeen Angus (Ab) bull were used to study the effects of cow breed and winter diet on performance. The diets were either primarily based on hay (H, 2/3 of dry matter (DM) intake, silage 1/3) or silage (S, 2/3 of DM intake, hay 1/3). In addition, animals were offered 1.0 kg milled barley per head daily for two months prior to calving and 1.5 kg/day from calving until grazing commenced. Animals also had free access to barley straw. During the indoor feeding period from 15 December to 1 June HfAy-heifers consumed slightly but not significantly more feed DM, metabolizable energy and AAT (amino acids absorbed from the small intestine) than LiAy-heifers on both diets. At the start of the experiment LiAy- and HfAy-heifers were 572 and 596 (P<0.05) days of age, respectively. Corresponding ages at calving were 732 and 729 days. The type of forage feeding did not affect the rate of pre partum live weight gain (LWG). The calving difficulties observed were minor. Average milk production of HfAy-cows was higher (P<0.01) than that of LiAy-cows. Calf LWG from birth to weaning was 1058 and 987 g/day for HfAy- and LiAy-progeny, respectively. Corresponding values for the progeny of cows fed S- and H-diets were 1009 and 1036 g/day. All HfAy-cows and 87.1% of LiAy-cows were successfully rebred to Charolais (Ch) sires. Both S- and H-based diets were suitable for crossbred heifers. Although the energy intake was below Finnish recommendations on both diets, particularly pre partum, live weight of 488 kg for HfAy- and 476 kg for LiAy-heifers pre partum proved to be adequate. The incidence of calving difficulties was low.