Performance and carcass quality of Limousine x Holstein bull and heifer calves in comparison with purebred Holstein bull calves when slaughtered at 17 months of age after two seasons of grazing

Summary

The objective of the present study was to compare growth performance, carcass quality characteristics, and production economy of 15 Danish Holstein bull (HB) calves, 15 Limousine x Danish Holstein crossbred bull (CB) calves and 15 Limousine x Danish Holstein crossbred heifer (CH) calves reared under organic conditions. Spring-born calves were purchased at private farms and at approximately 20 days of age with an average initial body weight of 52.9, 58.2 and 56.1 kg, (SEM 2.6) for HB, CB and CH, respectively. Calves were housed indoor until weaning at 3 months of age. Calves were gradually introduced to a grass-silage based ration from 3 to 4 months of age. From 4 to 7 months calves were kept on mix grass pasture of ryegrass and white clover. From 7 to 13.5 months calves were housed indoor in groups of 5 and fed a mixed ration with low-moderate energy content. From 13.5 to 17 months, the established groups of 5 animals were grazing in a rotational paddock system until slaughter. There was no difference in average daily gain from birth to turn-out 1st summer (ADGI1) (0.83 (SEM 0.02) kg/d). ADG during the first summer pasture period (ADGP1), ADG during the indoor winter period (ADGI2), and ADG during the second summer pasture period (ADGP2) were significant different between treatment groups. Thus, CB had greater ADG than CH for all three periods with DHB being in between (P<0.05). ADGP1 was 0.85, 0.89, and 0.76 (SEM 0.03) kg/d, ADGI2 was 1.06, 1.10 and 0.97 (SEM 0.02) kg/d, and ADGP2 was 0.88, 1.11, and 0.64 (SEM 0.04) kg/d for HB, CB, and CH, respectively. Final live weight were not different between HB and CB but was significantly lower for CH than HB and CB (480 vs. 534 and 575 (SEM 8) kg. Overall growth performance across all periods was 21% higher for CB than CH (P<0.05), and the average ADG of the crossbreds ((CB+CH)/2) was 2% lower than for HB. Crossbreeding improved EUROP conformation markedly in both CH (5.3) and CB (7.0) compared with HB (3.0) (P<0.001) and carcass weight was 4% higher in crossbreds. There was no difference in EUROP fatness between HB and CB (1.0-1.2) which were both too low and caused a high penalty in the payment (-0.25 euro/kg carcass), whereas CH had an acceptable fat cover (2.9). Carcass colour was too high for the bulls 3.9) but acceptable for CH (3.3, P<0.001). We conclude that it will be difficult to produce intact bulls on pasture that fulfil beef meat market requirements due to low fatness. With the improvements in carcass conformation and carcass weight and similar overall growth performance of the combined heifer and bull crossbreds, this will be beneficial compared with purebred Holstein bulls.