<b>Requirement of energy and protein of beef cattle on tropical pasture</b> - doi: 10.4025/actascianimsci.v35i4.21143

Abstract

ABSTRACT. Protein and energy requirements of beef cattle, aged between 4 and 18 months old, on tropical pastures, were estimated. Forty-six Nellore calves (138.3 ± 3.4 kg BW and 90-150 days old), kept on pasture, were distributed in a maintenance group (restricted feeding) or in nutritional plans, receiving a supplements with different amounts of protein and carbohydrate or non-supplemented. The net energy requirement for weight gain (NE g ) was obtained by linear regression of logarithm of retained energy as a function of logarithm of empty body weight gain. The net energy requirement for maintenance (NE m ) was estimated by the exponential relation between heat production and metabolizable energy intake. Net protein requirement for weight gain (RP) was estimated by multiple linear regression of retained protein in the weight gain of empty body (EBWG) and retained energy. The efficiency of metabolizable energy (ME) used for maintenance and for weight gain was 0.55 and 0.26, respectively. The ME requirement for maintenance was 124 kcal EBW Exigências de proteína e energia de bovinos de corte em pastagem tropical RESUMO. Objetivou-se estimar as exigências de proteína e energia de bovinos de corte em pastagens tropicais dos 4 até 18 meses de idade. Foram utilizados 46 bezerros Nelore (138,3 ± 3,4 kg e 90-150 dias de idade) em pastagem, distribuídos em um grupo de mantença (alimentação restrita) ou em planos nutricionais, recebendo suplemento com diferentes quantidades de proteína e carboidrato, ou não suplementados. A exigência de energia líquida para ganho de peso (EL g ) foi obtida por regressão linear do logaritmo da energia retida em função do logaritmo do ganho de peso corporal vazio. A exigência de energia líquida para mantença (EL m ) foi estimada pela relação exponencial entre a produção de calor e consumo de energia metabolizável. A exigência líquida de proteína para ganho de peso (PR) foi estimada pela regressão linear múltipla da proteína retida no ganho de peso de corpo vazio (GPCVZ) e da energia retida. A eficiência de uso da energia metabolizável (EM) para mantença foi de 0,55 e para o ganho de peso foi de 0,26. A exigência de EM para mantença foi de 124 kcal PCVZ

Assessment of different seedling production techniques ofEuterpe edulis

“…Euterpe edulis Mart. also known as Palmiteiro, is one of the most representative and explored species from the Tropical Atlantic Rainforest [1]- [3], and is considered one of the most important [4]. Its slim, cylindrical, and straight stipe with a great green sheath is easily recognizable [1].…”

“…The economic relevance of this species is its use as the heart of palm (the youngest part of the stipe, apical meristem, and young leaves) source. The heart of palm from this species presents high economic value and is an important product in the Brazilian and international markets [3], [4], [8], [9]. Besides, this species does not present tillers from the stipe basis [4].…”

“…The heart of palm from this species presents high economic value and is an important product in the Brazilian and international markets [3], [4], [8], [9]. Besides, this species does not present tillers from the stipe basis [4]. Thus, harvesting the heart of palm from E. edulis implicates in the individual's death.…”

“…Furthermore, the illegal harvesting of this species heart of palm has been focusing on individuals at least 2 meters high. This criterion not only affects young individuals but also those in the reproductive phase (between six-and nine-year-old individuals), which is incompatible with this species slow life cycle, leading to a reduction in the natural populations and extinction [1], [4], [9]. E. edulis is also a key species in ecologic studies of the Atlantic rainforest [9].…”

Parametrization of the Davis Growth Model using data of crossbred Zebu cattle

“…Although there are several studies on nutritional requirements of cattle in Brazil (Marcondes et al, 2010a, b;Paulino et al, 2010;Sainz et al, 2006;Valente et al, 2013), the DGM parameterization for Zebu genetics explored under Brazilian conditions has never included the estimation of parameter distribution by nonparametric bootstrap and statistical inferences.…”