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 (MEm) 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 degrees C, respectively. Environmental temperature (T) had a quadratic effect on maintenance requirements (MEm = 307.87 - 15.63T + 0.3105T(2); r2= 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 T2) + 13.52 Gf + 12.59 Gp. This model considers live BW, the effects of environmental temperature, and fractional fat (Gf) and protein (Gp) 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 modelxs.
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°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 = kgW0·75(806·53–26·45T + 0·50T2) + 31·90G + 10·04EM, where kgW0·75 is body weight (kg) raised to the power 0·75, T is temperature (°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.
Aiming to evaluate the effect of tomato waste inclusion on productive performance and characteristics of carcass and main broiler chicken cuts, an experiment was carried out using 300 male Cobb chicks, distributed in a complete randomized design, with five rations and five replicates. Diets consisted of control ration based on corn and soybean meal and four rations with 5, 10, 15 and 20% of tomato waste. Feed intake, weight gain and feed conversion and, at the end of experiment, slaughter weight, gutted carcass without feet and head, breast, drumstick, thigh, wing, back, edible guts and belly fat were evaluated every week, as well as it was the yield. Tomato waste increased feed intake in the periods from 1 to 7, 8 to 14 and 29 to 36 days of age and worsened gain weight and feed conversion of broiler chickens up to 29 days of age. Regarding carcass weight (g) and weight of the noble parts, breast, drumstick and thighs decreased linearly in function of the use of tomato waste in poultry on pre- initial and initial phase, that is, up to 28 days old, but yield (%) was not affected except for yield of heart and liver. Use of tomato waste in ration of broiler chickens during the period from 1 to 28 days may decrease weight gain and worsen food conversion. Tomato waste may be used as ration ingredient in ration of broiler chicken in the breeding period from 29 to 42 days of age up to the level of 20% without harming weight gain and feed conversion of poultry.
3 January 2013 in The Brazilian Journal of Infectious Diseases
The zoonotic potential to cause human and/or animal infections among multidrug-resistant extraintestinal pathogenic Escherichia coli from avian origin was investigated. Twenty-seven extraintestinal pathogenic E. coli isolates containing the increased survival gene (iss) were obtained from the livers of healthy and diseased poultry carcasses at two slaughterhouses in Salvador, northeastern Brazil. The antimicrobial resistance-susceptibility profiles were conducted with antibiotics of avian and/or human use by the standardized disc-diffusion method. Antimicrobial resistance was higher for levofloxacin (51.8%), amoxicillin/clavulanic acid (70.4%), ampicillin (81.5%), cefalotin (88.8%), tetracycline (100%) and streptomycin (100%). The minimum inhibitory concentrations above the resistance breakpoints of doxycycline, neomycin, oxytetracycline and enrofloxacin reached, respectively, 88.0%, 100%, 75% and 91.7% of the isolates. Strains with high and low antimicrobial resistance were i.p. administered to Swiss mice, and histopathological examination was carried out seven days after infection. Resistance to goat and human serum complement was also evaluated. The results show that Swiss mice challenged with strain 2B (resistant to 11 antimicrobials) provoked a severe degeneration of hepatocytes besides lymphocytic infiltration in the liver, whereas the spleen showed areas of degeneration of the white and red pulp. Conversely, the spleen and liver of mice challenged with strain 4A (resistant to two antimicrobials) were morphologically preserved. In addition, complement resistance to goat and human serum was high for strain 2B and low for strain 4A. Our data show that multidrug resistance and pathogenesis can be correlated in extraintestinal pathogenic E. coli strains obtained from apparently healthy poultry carcasses, increasing the risk for human public healthy.
16 September 2022 in Revista Brasileira de Zootecnia
This study evaluated the effects of including Moringa oleifera (moringa) leaf meal on performance, carcass yield and characteristics, and relative organ weights of broilers from 10 to 42 days of age. We distributed 420 male Cobb 500 chicks in a completely randomized design with five treatments and six replicates with 14 birds each. Treatments consisted of five experimental diets in which the moringa leaf meal was included at 0, 1.5, 3.0, 4.5, and 6.0% in the diets. The following [...] ABSTRACT This study evaluated the effects of including Moringa oleifera (moringa) leaf meal on performance, carcass yield and characteristics, and relative organ weights of broilers from 10 to 42 days of age. We distributed 420 male Cobb 500 chicks in a completely randomized design with five treatments and six replicates with 14 birds each. Treatments consisted of five experimental diets in which the moringa leaf meal was included at 0, 1.5, 3.0, 4.5, and 6.0% in the diets. The following
1 December 2010 in Revista Brasileira de Zootecnia
Objetivou-se com este estudo avaliar o desempenho e a qualidade dos ovos de codornas japonesas (Coturnix japonica) alimentadas com rações cotendo sorgo de baixo tanino em substituição ao milho. Foram utilizadas 210 codornas japonesas fêmeas com 65 dias de idade, distribuídas em delineamento inteiramente casualizado com cinco rações experimentais (0; 25; 50; 75 e 100% de sorgo em substituição ao milho) e seis repetições de sete aves. No experimento, cuja duração foi de 112 dias, não houve efeito significativo dos níveis de sorgo nas rações sobre nenhuma das características de produção. Com aumento dos níveis de sorgo na ração, houve redução linear da cor da gema e do custo da ração. O sorgo de baixo tanino pode substituir totalmente o milho em rações para codornas japonesas em postura.