Dietary protein and energy requirements of juvenile freshwater angelfish

Avaliaram-se as exigências nutricionais de proteína e energia em juvenis de acará-bandeira (Pterophyllum scalare). Utilizou-se delineamento inteiramente casualizado, em esquema fatorial 3 × 2, com três níveis de proteína bruta (26, 30 e 34%), dois de energia digestível (3.100 e 3.300 kcal/kg de ração) e três repetições. Juvenis com peso médio de 2,33 ± 0,26 g foram distribuídos em aquários contendo 25 litros de água, temperatura controlada (26 ± 1ºC) e filtro biológico, na densidade de estocagem de seis animais por aquário. Os peixes foram alimentados à vontade às 9, 14 e 16h30. Na análise do desempenho produtivo, foram avaliados o peso final, o comprimento final, o ganho de peso, o consumo de ração, a conversão alimentar, a taxa de crescimento específico, a taxa de eficiência protéica e o fator de condição. As dietas contendo 26% PB proporcionaram maiores valores para taxa de eficiência protéica apenas em relação às dietas contendo 34% PB. As exigências nutricionais de proteína e energia em juvenis de acará-bandeira podem ser atendidas com dietas contendo 26% PB e 3.100 kcal ED/kg.

Body Composition and Net Energy Requirements for Maintenance of Non-Castrated Water Buffaloes (Bubalus bubalis)

The research aimed to estimate body contents of protein and energy and net requirements of energy for maintenance of buffaloes, slaughtered at different stages of maturity. There were used 14 Mediterranean intact males with initial average body weight of 352.2 +/- 24.3 kg and average age of 24 months. The animais were randomly divided into four experimental groups. One group was designed to slaughter at the beginning of the experimental period (IS). The animals of another group were restricting fed, receiving, individually, levels of protein and energy 15% above maintenance (RF). The animals of the two remaining groups were individually fed ad libitum (SW450 and SW500) to reach weights corresponding to 100 and 110 percent of the mature weight of the buffalo cows (respectively 450 and 550 kg). The ration contained ground-corn cobs, soybean meal, urea, minerals, and signal-grass (Brachiaria decumbens) hay, with a concentrate: roughage ratio of 50: 50 and 13% of crude protein on a dry matter basis. To estimate changes in body composition inside the range of weights included in the trial, linear regression equations of log protein (kg), fat (kg) and energy (Mcal) as a function of log empty-body-weight (EBW), in kg, were fitted. Energy requirements for maintenance were obtained as estimated heat production at zero level of energy intake. Buffaloes submitted to fattening in feedlot presented early body fat deposition, and had with the same live weight lower protein content and higher fat content and energy per unit weight than european-zebu crossbred cattle.

Energy requirements for maintenance and growth of Caninde goat kids

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Energy Requirements for Maintenance and Growth of Male Saanen Goat Kids

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Energy Requirements in Early Life Are Similar for Male and Female Goat Kids

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Protein and energy requirements of castrated male Saanen goats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Energy requirements for growth of pubertal female Saanen goats

Previous research on energy requirements of female Saanen goats, using the factorial approach, has not considered the specific requirements for maintenance and growth during the pubertal phase. Thus, the purpose of this study was to estimate energy requirements for maintenance (Trial 1) and growth (Trial 2) of non-pregnant and non-lactating female Saanen goats at the pubertal phase from 30 to 45 kg. In Trial 1, the net energy requirements for maintenance (NEm ) were estimated using 18 female Saanen goats randomly assigned to three levels of intake: ad libitum, and 70% and 40% of ad libitum intake. These animals were pair-fed in six slaughter groups, each consisting of one animal for each level of intake. In Trial 2, the net energy requirements for growth (NEg ) were estimated using 18 female Saanen goats, which were fed ad libitum and slaughtered at targeted BW of 30, 38 and 45 kg. The NEm was 52 kcal/kg(0.75) of BW. The NEg increased from 3.5 to 4.7 Mcal/kg of BW gain as BW increased from 30 to 45 kg. Our results suggest that the guidelines of the major feeding systems for the entire growth phase may not be adequate for females at pubertal phase.

Energy and protein requirements for maintenance and growth of Boer crossbred kids

Meat production by goats has become an important livestock enterprise in several parts of the world. Nonetheless, energy and protein requirements of meat goats have not been defined thoroughly. The objective of this study was to determine the energy and protein requirements for maintenance and growth of 34 3/4 Boer x 1/4 Saanen crossbred, intact male kids (20.5 +/- 0.24 kg of initial BW). The baseline group was 7 randomly selected kids, averaging 21.2 +/- 0.36 kg of BW. An intermediate group consisted of 6 randomly selected kids, fed for ad libitum intake, that were slaughtered when they reached an average BW of 28.2 +/- 0.39 kg. The remaining kids (n = 21) were allocated randomly on d 0 to 3 levels of DMI (treatments were ad libitum or restricted to 70 or 40% of the ad libitum intake) within 7 slaughter groups. A slaughter group contained 1 kid from each treatment, and kids were slaughtered when the ad libitum treatment kid reached 35 kg of BW. Individual body components (head plus feet, hide, internal organs plus blood, and carcass) were weighed, ground, mixed, and subsampled for chemical analyses. Initial body composition was determined using equations developed from the composition of the baseline kids. The calculated daily maintenance requirement for NE was 77.3 +/- 1.05 kcal/kg(0.75) of empty BW (EBW) or 67.4 +/- 1.04 kcal/kg(0.75) of shrunk BW. The daily ME requirement for maintenance (118.1 kcal/g(0.75) of EBW or 103.0 kcal/kg(0.75) of shrunk BW) was calculated by iteration, assuming that the heat produced was equal to the ME intake at maintenance. The partial efficiency of use of ME for NE below maintenance was 0.65. A value of 2.44 +/- 0.4 g of net protein/kg(0.75) of EBW for daily maintenance was determined. Net energy requirements for growth ranged from 2.55 to 3.0 Mcal/kg of EBW gain at 20 and 35 kg of BW, and net protein requirements for growth ranged from 178.8 to 185.2 g/kg of EBW gain. These results suggest that NE and net protein requirements for growing meat goats exceed the requirements previously published for dairy goats. Moreover, results from this study suggest that the N requirement for maintenance for growing goats is greater than the established recommendations.

Energy and protein requirements of male and female saanen goats

Pós-graduação em Zootecnia - FCAV

Modelling energy utilisation in broiler breeder hens

1. The objective of this study was to determine a metabolisable energy ( ME) requirement model for broiler breeder hens. The influence of temperature on ME requirements for maintenance was determined in experiments conducted in three environmental rooms with temperatures kept constant at 13, 21 and 30 degrees C using a comparative slaughter technique. The energy requirements for weight gain were determined based upon body energy content and efficiency of energy utilisation for weight gain. The energy requirements for egg production were determined on the basis of egg energy content and efficiency of energy deposition in the eggs.2. The following model was developed using these results: ME = kgW(0.75)(806.53 - 26.45T + 0.50T(2)) + 31.90G + 10.04EM, where kgW(0.75) is body weight (kg) raised to the power 0.75, T is temperature (degrees C), G is weight gain (g) and EM is egg mass (g).3. A feeding trial was conducted using 400 Hubbard Hi-Yield broiler breeder hens and 40 Peterson males from 31 to 46 weeks of age in order to compare use of the model with a recommended feeding programme for this strain of bird. The application of the model in breeder hens provided good productive and reproductive performance and better results in feed and energy conversion than in hens fed according to strain recommendation. In conclusion, the model evaluated predicted an ME intake which matched breeder hens' requirements.

Modeling energy utilization in broiler breeders, laying hens and broilers

The factorial approach has been used to partition the energy requirements into maintenance, growth, and production. The coefficients determined for these purposes can be used to elaborate energy requirement models. These models consider the body weight, weight gain, egg production, and environmental temperature to determine the energy requirements for poultry. Predicting daily energy requirement models can help to establish better and more profitable feeding programs for poultry. Studies were conducted at UNESP-Jaboticabal to determine metabolizable energy (ME) requirement models for broiler breeders, laying hens, and broilers. These models were evaluated in performance trials and provided good adjustments. Therefore, they could be used to establish nutritional programs. This review aims to outline the results found at UNESP studies and to show the application of models in nutritional programs for broiler breeders, laying hens, and broilers.

Modelling energy utilization for laying type Pullets

Three trials were carried out to determine energy metabolized (EM) requirement model for starting and growing pullets from different strains, at five ambient temperatures and different percentage feather coverage. In Trial I, metabolizable energy requirements for maintenance (MEm) and efficiency of energy utilization were estimated using 64 birds of two different strains, Hy-Line W36 (HLW36) and Hy-Line Semi-heavy (HLSH), from 9 to 13 weeks of age. The effects of ambient temperature (12, 18, 24, 30 and 36ºC) and percentage feather coverage (0, 50 and 100%) on MEm were assessed in the second trial, using 48 birds per temperature per strain (HLSH and HLW36) from 9 to 13 weeks of age. Trial III evaluated ME requirements for weight gain (MEg) using 1,200 birds from two light strains (HLW36 and Hisex Light, HL) and two semi-heavy strains (HLSH and Hisex Semi-heavy, HSH) reared until 18 weeks of age. According to the prediction models, MEm changed as a function of temperature and feather coverage, whereas MEg changed as a function of age and bird strain. Thus, two models were developed for birds aged 1 to 6 weeks, one model for the light strain and one for the semi-heavy strain. Energy requirements (ER) were different among strains from 7 to 12 weeks, and therefore 4 models were elaborated. From 13 to 18 weeks, one single model was produced for semi-heavy birds, since ER between semi-heavy strains were not different, whereas two different models were elaborated for the light layers. MEg of light birds was higher than MEg of semi-heavy birds, independent of age.

Modeling metabolizable energy utilization in broiler breeder pullets

The objective of this study was to determine models for ME requirements for broiler breeder pullets using the factorial method. The influence of the temperature on maintenance ME requirements was determined by experiments conducted in three environmental rooms with temperature kept constant at 15, 22, and 30°C, using the comparative slaughter technique. The energy requirements for weight gain were determined based on the body energy content and efficiency of energy utilization for weight gain. Two ME requirement models for each age were developed using the coefficients for maintenance and weight gain. The models for 3 to 8 wk were ME = W 0.75 (186.52 - 1.94T) + 2.47WG, and ME = W 0.75 (174 - 1.88T) + 2.83WG; for 9 to 14 wk, ME = W 0.75 (186.52 - 1.94T) + 2.69WG, and ME = W 0.75 (174 - 1.88T) + 2.50WG; and 15 to 20 wk, ME = W 0.75 (186.52 - 1.94T) + 2.76WG, and ME = W 0.75 (174 - 1.88T) + 3.24WG. In these equations, W is BW (kg), T is temperature (°C), and WG is daily weight gain (g). These models were compared to the breeder's recommendations in a feeding trial from 5 to 20 wk of age. Models 1 and 2 provided energy intakes that promoted BW smaller than the breeder's recommendation. However, all breeder pullets had weights above the standard recommendation. Model 2 gave the smallest ME intake and BW close to the standard recommendation and provided the best prediction of ME requirements.

Modeling energy utilization and growth parameter description for broiler chickens

Two experiments were conducted to develop and evaluate a model to estimate ME requirements and determine Gompertz growth parameters for broilers. The first experiment was conducted to determine maintenance energy requirements and the efficiencies of energy utilization for fat and protein deposition. Maintenance ME (ME m) requirements were estimated to be 157.8, 112.1, and 127.2 kcal of ME/kg 0.75 per day for broilers at 13, 23, and 32°C, respectively. Environmental temperature (T) had a quadratic effect on maintenance requirements (ME m = 307.87 - 15.63T + 0.3105T 2; r 2= 0.93). Energy requirements for fat and protein deposition were estimated to be 13.52 and 12.59 kcal of ME/g, respectively. Based on these coefficients, a model was developed to calculate daily ME requirements: ME = BW 0.75 (307.87 - 15.63T + 0.3105 T 2) + 13.52 G f + 12.59 G p. This model considers live BW, the effects of environmental temperature, and fractional fat (G f) and protein (G p) deposition. The second experiment was carried out to estimate the growth parameters of Ross broilers and to collect data to evaluate the ME requirement model proposed. Live BW, empty feather-free carcass, weight of the feathers, and carcass chemical compositions were analyzed until 16 wk of age. Parameters of Gompertz curves for each component were estimated. Males had higher growth potential and higher capacity to deposit nutrients than females, except for fat deposition. Data of BW and body composition collected in this experiment were fitted into the energy model proposed herein and the equations described by Emmans (1989) and Chwalibog (1991). The daily ME requirements estimated by the model determined in this study were closer to the ME intake observed in this trial compared with other models. ©2005 Poultry Science Association, Inc.