ABSTRACT A comparative slaughter trial was conducted to estimate the body composition and net requirements of Cu, Zn, Mn, Fe, and Co for growth of castrated Moxotó goat kids, with15.69±0.78 kg initial body weight (BW), grazing in the semiarid region of Brazil. The baseline group consisted of four randomly selected kids (15.37±0.30 kg BW). Thirty-two kids were randomly allocated into eight groups (considered as block), distributed among four levels of concentrate supplementation (0, 0.5, 1.0, and 1.5% BW). Animals in […]

This work was conducted to determine the energy requirements for broilers using the factorial method. The metabolizable energy (ME) requirements for maintenance (MEm) were determined at 13, 23 and 32ºC (±2 C) by the comparative slaughter technique. ME requirements for weight gain were estimated considering the net efficiency of energy utilization for growth and body energy content. The energy requirements for maintenance were of 159.36, 116.17, and 128.66 kcal/kg0.75/day at 13, 23, and 32ºC, respectively, and quadratic effect of temperature […]

The objective of this work was to establish a model to estimate the metabolizable energy (ME) requirements for laying hens from Lohmann LSL line, by the factorial method. To determine the influence of ambient temperature on ME requirements for the maintenance, experiments were accomplished in environmental controlled rooms at constant temperatures of 12, 22 and 31 ºC, by the comparative slaughtering technique. The net energy for weight gain was determined by regression of carcass energy content in function of body […]

The objective of this research was to evaluate the prediction equations of the protein requirements for broiler breeder pullets, that was previously determined at Faculdade de Ciências Agrárias e Veterinárias UNESP – Jaboticabal. The equations were compared with standard recommendation for the used strain. Two hundred and eighty eight broiler breeder pullets for Hubbard Hy-Yield strain at 5 weeks old were assigned to a randomized design with two treatments and six replication of 24 pullets until 14 weeks and 20 […]

The objective of this study was to determine a model for crude protein requirements (CP) for laying hen by the factorial method. The protein maintenance requirement was determine by the nitrogen balance technique . The crude protein requirement for weight gain was determined based on body nitrogen content and nitrogen efficiency for body deposition. The crude protein requirement for egg production was determined based on the nitrogen content of eggs and nitrogen efficiency for egg deposition. Considering the requirements for […]

The objective of this study was to determine the protein requirement for broiler breeder hens using factorial method. The requirement of crude protein for maintenance (CPm) was determined using nitrogen balance technique in metabolism assay. The birds were fed with four protein levels in order to get a positive, a close to zero and a negative nitrogen balance. To determine the crude protein weight gain requirement (CPg), two experiments were carried out. The first was calculate to determine the net […]

The objective of this study was to determine prediction equations for crude protein (CP) requirements for males and females broilers using the factorial method. In order to determine the crude protein for the maintenance was used the nitrogen balance technique. The crude protein requirements for weight gain were determined based on body nitrogen content and nitrogen utilization efficiency for the diet. Considering the requirements for maintenance and weight gain were elaborated prediction equations for CP requirements (g/bird/day) for males broilers […]