Biological and economic performance of genetic groups under different diets

Abstract

A grazing trial to evaluate biological and economic efficiencies for rearing young animals exclusively on pasture from weaning at 7 months of age, with average initial weight of 220 ± 12 kg, to slaughter was conducted from May 2006 to October 2007. Two levels of combined supplementation during the first dry period and four genetic groups (F1 Angus-Nellore; ½Braford-¼Angus-¼Nellore; ½Brahman-¼Angus-¼Nellore; and ⅝Charolais-⅜Nellore) were used following a 4 by 2 factorial arrangement and eight replications in a completely randomized design. During both dry periods, eight paddocks of deferred Brachiaria brizantha were utilized. During the first dry period, concentrated mix (CM) and protein-mineral mixture (PMM) were provided in quantities of 0.8% and 0.2% of body weight (BW), respectively, for 142 days. During the subsequent rainy period, the animals were transferred to eight guinea grass paddocks for 197 days. During the second dry period, the animals were allocated to the same eight palisade grass paddocks used during the previous dry season. Steers had received supplementary diet with the same CM used before at 0.8% of BW. Animals supplemented with CM gained more BW than those supplemented with PMM; however, during the rainy season, steers supplemented with PMM performed better than those receiving CM during the preceding dry period. Using concentrate since the first dry season is a risky option in economic terms, as only the Angus-Nellore group showed a positive but small gain.

Different Grass Availabilities of Tropical Pasture on Performances and Carcasses of Lambs

“…In those regions, productions of animals are mostly finished on pasture. However, this type of system is known to possibly result in the reduced or worsened carcass composition (Euclides et al, 2018).…”

Producción, calidad y utilización de ensilajes de gramíneas tropicales en la dieta de rumiantes

“…Estima-se que aproximadamente 47% da carne e leite mundial de ruminantes vêm de regiões tropicais e subtropicais (FAPRI, 2019). Nessas regiões, os pastos nativos foram substituídos por gramíneas forrageiras de origem africana de metabolismo C4 com grande potencial em acumular forragem, particularmente às dos gêneros Brachiaria, Panicum e Cynodon (Euclides et al, 2018a;Euclides et al, 2018b;Euclides et al, 2019;Pontes et al, 2016). Essas plantas forrageiras têm sido estudadas intensivamente nas últimas décadas, apresentando elevada produção por unidade de área e tem reduzido o custo de produção (Euclides et al, 2018b), esses fatores são responsáveis por tornar a produção de ruminantes brasileira competitiva em nível mundial.…”

“…Nessas regiões, os pastos nativos foram substituídos por gramíneas forrageiras de origem africana de metabolismo C4 com grande potencial em acumular forragem, particularmente às dos gêneros Brachiaria, Panicum e Cynodon (Euclides et al, 2018a;Euclides et al, 2018b;Euclides et al, 2019;Pontes et al, 2016). Essas plantas forrageiras têm sido estudadas intensivamente nas últimas décadas, apresentando elevada produção por unidade de área e tem reduzido o custo de produção (Euclides et al, 2018b), esses fatores são responsáveis por tornar a produção de ruminantes brasileira competitiva em nível mundial. Entretanto, a maior produção dessas gramíneas ocorre nos períodos de maior disponibilidade de fatores abióticos (luz, temperatura e precipitação), o que promove à estacionalidade na produção forrageira (Gurgel et al, 2017), sendo necessário o uso de tecnologias de conservação de forragens para manter alimentos de maior qualidade em tempos de escassez.…”

The effect of residual nitrogen fertilization on the yield components, forage quality, and performance of beef cattle fed on Mombaça grass

“…The body weight per area gain was highest in the pastures under the residual effect of 300 kg ha -1 of N and lowest in those at 100 kg ha -1 , with once again an intermediate value at 200 kg ha -1 (table 6). This result can be attributed to the variation in stocking rate values, since pasture productivity is a result of the combination of individual performance and stocking rate (13,19). Since there was no difference for individual performance between N doses, the observed behavior for stocking rate was repeated for the body weight gain per hectare.…”

“…The productivity of a pasture is evaluated based on the individual performance of the animals and the stocking rate used (13,18). The individual performance depends on the genetic potential of the animal (19) and the quantity, quality, and form of forage that it is fed (15). Also, the N fertilization promotes increases in forage accumulation (5), altering pasture dynamics (20,28) with direct reflexes in animal and per area production (16).…”