Quality Suckler Beef From Low and High Input Grassland Management Systems

Abstract

Spring calving cows were used in the years 1997 to 2003 in the development of planned low and high input systems of suckler beef production.The main objective of the study was to compare a semiintensive Grange (standard): system of suckler beef production with a more extensive REPS (Rural Environment Protection Scheme) compatible system. In the standard system the stocking rate was 0.80 ha per cow unit (cow plus heifer and steer progeny to slaughter at 20 and 23/24 months of age, respectively, plus replacements or its equivalent), a nitrogenous fertiliser application rate of 210 kg per ha and two silage harvests each year amounting to the equivalent of 87% of the total area harvested. The REPS system involved a 25% lower stocking rate, an annual nitrogen fertiliser application rate of 90 to 100 kg per ha and one silage harvest (portion in late May to provide good silage for the progeny and the remainder in June to provide lower quality silage for cows) amounting to 58% of the total area harvested. Between 1997 and 2000 the cow herd were Limousin x Friesians (LF) and Simmental x (Limousin x Friesians) (SLF). A herd of first calvers were introduced in 2001 and 2002 which in addition to LF and SLF included Limousin x (Limousin x Friesians), purebred Limousin and purebred Charolais. Charolais (or Simmental) sires were used on mature cows. Replacement heifers were bred to calve at 2 years of age using an easy calving Limousin bull. Concentrate inputs per animal were the same in the two systems. The main findings of the study were: • The mean nitrogenous application rates were 210 and 98 kg per ha in the standard and REPS systems, respectively. • Mean dry matter digestibility of the first-cut silages harvested early (May 19 to May 29), late (June 5 to June 13) and the second cut silage in the standard system (harvested in July/early August) were 716, 690 and 674 g/kg, respectively. • When averaged throughout two grazing seasons there was no difference between the standard and REPS systems in pregrazing or post-grazing sward heights. When examined over one grazing season the only major difference between the grazing areas was that the pasture crude protein content was higher in the standard system in both the pre-grazed (205 and 159 g/kg) and post-grazed (172 v 141 g/kg) swards. Cow liveweight and body condition score gains at pasture and calf gains from birth to weaning were the same for both systems. Carcass weights of the progeny were the same for the standard and REPS systems.