Flavio Alves Longo

Efeito do nível de energia metabolizável da dieta no desempenho e metabolismo energético de frangos de corte

Objetivou-se, nesta pesquisa, estudar o efeito dos niveis de energia metabolizavel (EM) da dieta sobre o desempenho e o metabolismo energetico de frangos de corte machos na fase de crescimento (22 a 43 dias de idade) em condicoes de temperatura ambiente. Foram utilizadas 288 aves distribuidas aleatoriamente por tres niveis de energia da dieta (3.050, 3.200 e 3.350 kcal/kg) e tres niveis de alimentacao (ad libitum, 75 e 50% do ad libitum), com quatro repeticoes de oito aves, para determinacao das exigencias de mantenca e das eficiencias energeticas. Foi utilizado o metodo do abate comparativo, sendo que 12 aves foram abatidas no inicio do ensaio experimental, para determinacao da composicao corporal inicial, e 144 aves foram usadas para determinacao da energia metabolizavel das dietas experimentais. Os niveis de energia influenciaram na ingestao de energia metabolizavel (IEM) e, consequentemente, a retencao de energia na carcaca (ER) e a producao de calor (PC). As exigencias de energia metabolizavel de mantenca (EMm) determinadas foram 131,12; 140,96 e 131,78 kcal/kg0,75/dia para os niveis de energia alto, medio e baixo, respectivamente. O nivel de energia mais alto (3.350 kcal/kg) na dieta dos frangos de corte proporcionou melhores resultados de desempenho, enquanto o medio (3.200 kcal/kg), melhor equilibrio na eficiencia de utilizacao de energia para deposicao de proteina e gordura, consequentemente, melhor qualidade da carcaca, em decorrencia da menor deposicao de gordura.

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°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 (°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.

Exigências energéticas para mantença e para o crescimento de frangos de corte

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 (T) on the maintenance requirement (MEm=300.14 - 14.61 T + 0.2876 T2, r2=0.90) was detected. Metabolizable energy requirements for weight gain for males and females were of 3.72 and 3.98; 4.21 and 3.93; 4.51 and 7.04 kcal/g, for the periods from 1 to 21, 22 to 42 and 43 to 56 days of age, respectively. Considering the requirements, prediction models were designed for ME requirements using adjustments for body weight, daily weight gain and temperature. The models predicted the ME requirements for broilers as redult of from breed manual recommendations and the studied models.

Adição de gesso agrícola em três tipos de cama de aviário na fixação de nitrogênio e no desempenho de frango de corte

Trabalho apresentado pelo primeiro autor a Faculdade de Ciencias Agrarias e Veterinarias da Universidade do Estado de Sao Paulo (FCAV/UNESP), Jaboticabal, para Graduacao em Zootecnia. Zootecnista formada pela FCAV/UNESP – Jaboticabal. Professores do Departamento de Zootecnia, FCAV/UNESP, 14884-900, Jaboticabal. E-mail: sakomura@fcav.unesp.br. Autor para correspondencia. Estudante de Pos-Graduacao em Producao Animal, FCAV/UNESP, Jaboticabal. RESUMOAn experiment was conducted to determine the effects of the addition or not of calcium sulfate and three differents types of litter (rice seed coat. wood shaver and peanut seed coat). on the pH, dry matter and nitrogen fixation in the litter and on the broiler performance. A randomized complete design with a factorial arrangement of 3 x 2 x 2 {three different type of litter, two levels of calcium sulfate and two sex) was used with three replicates (n = 1440; 40 chicks per replicate) per treatment. In each treatment was used 35kg of litter and O or 15kg of calcium sulfate. The broiler performance was evaluated at 21, 38 and 45 days of age. Samples of litter were coilected at the end of the experiment. The results show that the addition or not of calcium sulfate did not influence the performance of the birds and did not decrease the lose of nitrogen through ammonia volatilization, but decreased the pH in the litter. The litter the differents types of materiais used in the litter did not influence the broilers performance. However, when the wood shaver was used, the feed in take was higher. The dry matter and nitrogen were not affected by any of the parameters studied. The different types of material and levels of calcium sulfate used in the litter did not affect the dry matter and nitrogen content. The nitrogen content where the inale were raised was higher than the litter of the females. This may be affected by the higher manure production by the males.

Efeito da temperatura ambiente e do sistema de criação sobre as exigências de energia metabolizável para mantença de aves reprodutoras pesadas

This study was conducted to evaluate the effect of the temperature and rearing system on the apparent metabolizable energy requirements for maintenance (MEm) for broiler breeder hens. In the experiment 1, MEm was determined with birds in cages. One hundred-ninety-two birds were housed in climatic chambers at 13, 21 and 30oC. The birds were assigned to four treatments with four replications of four birds each. The treatments were: ad libitum intake, 70, 50 and 30% of ad libitum intake. Comparative slaughter technique was used to determine the retained energy (RE). Maintenance metabolizable energy requirements (MEm) and efficiency of energy utilization (k) were determined by the ME intake (MEI) and retained energy (RE) ratio. In the experiment 2, the MEm was determined with birds on the floor. Ninety-six birds were allotted to three temperatures (13, 21 e 30oC) with four replication of eight birds each. The comparative slaughter technique was used to determined the RE and MEm requirements was determined by: EMm=EMI-(RE/k). The MEm requirements for birds in cages were 111.2, 91.5 and 88.5kcal/kg0.75/day and for birds on floor 130.8, 112.9 and 111.0kcal/kg0.75/day at 13, 21 and 30oC, respectively. Birds raised on floor had MEm higher 21.8% than those in cages, probably due to the energy expenditure for physical activity.

Ovo em pó na alimentação de leitões recém-desmamados

Two experiments were carried out to determine the chemical composition, nutrients digestibility and digestible energy and protein of spray-dried egg (OP) and to study the performance and plasma and blood components of weanling pigs fed diets containing OP. In the Experiment I, eight pigs were used for digestibility assay. The animals were assigned to two treatments and four replications/treatment. The treatments consisted of a basal diet and test diet (70% of basal diet + 30% of OP). The method was the partial faeces collection (0.5% Cr2O3). The apparent digestibility coefficients of dry matter, gross energy, crude protein and crude fat were, respectively, 80.81, 87.14, 82.00, and 70.55%. From the results of apparent digestibility coeficients and the values of crude protein (56.53%) and gross energy (5,897 kcal/kg), values of 43.90% of digestible protein and 5,140 kcal/kg of digestible energy for OP were calculated. In the Experiment II, ninety pigs were weaned at 24 days of age with 5.6 kg live weight. The treatments consisted of five dietary levels of 0, 25, 50, 75 and 100%, as a replacement of plasma (PS) protein for OP protein. Pigs were alloted to a randomized block design with nine replications per treatment. No treatment effects were observed on performance for 1-14 day post-weaning phase. For the 15-28 d phase and for the total period, linear reductions of GDP and CDR were observed, as the dietary OP levels increased. No treatment effects were observed on plasma and blood components by the inclusion of spray-dried egg. It was not recommended to replace the PS by OP in nursery diets.

Equações de predição das exigências protéicas para frangos de corte

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 (7 to 21 days - PB = 1.323xW0.75 + 0.256xG, 22 to 42 days - PB = 1.323xW0.75 + 0.277xG, and 43 to 56 days - PB = 1.323xW0.75 + 0.283xG) and females (7 to 21 days - PB = 1.748xW0.75 + 0.258xG, 22 to 42 days - PB = 1.748xW0.75 + 0.274xG, and 43 a 56 days - PB = 1.748xW0.75 + 0.300xG) where W = body weight (kg) and G = daily weight gain (g/day). The prediction equations utilization is recommended to determine the minimal nitrogen or crude protein requirements considering the amino acid requirements.

Effect of dietary betaine supplementation on the performance, carcass yield, and intestinal morphometrics of broilers submitted to heat stress

The objective of this study was to evaluate the effect of betaine in methionine- and choline-reduced diets fed to broilers submitted to heat stress. In total, 1,408 male broilers were randomly distributed into eight treatments, according to 2 x 4 (environment x diet) factorial arrangement, with eight replicates of 2 birds each. Birds were reared environmental chambers under controlled temperature (25-26 °C) or cyclic heat-stressing temperature (25-31 °C). The following diets were tested: positive control (PC), formulated to meet broiler nutritional requirements; negative control (NC), with reduced DL-methionine and choline chloride levels; and with two supplementation levels of natural betaine to the negative control diet (NC+NB1 and NC+NB2). Live performance, carcass traits, and intestinal morphometrics were evaluated when broilers were 45 days of age. The results showed that all evaluated parameters were influenced by the interaction between environment and diet, except for breast meat drip loss. The breakdown of the interactions showed that birds fed the PC diet and reared in the controlled environment had greater breast drip loss than those submitted to the cyclic heat-stress environment. Birds submitted to cyclic heat stress and fed the PC diet presented the lowest feed intake. Feed conversion ratio was influenced only by diet. The FCR of broilers fed the NC+NB2 diet was intermediate relative to those fed the PC and NC diets. The addition of betaine in the diet, with 11.18% digestible methionine and 24.73% total choline reductions, did not affect broiler live performance, carcass yield, or intestinal morphometrics.

Equação de predição da exigência de proteína bruta para aves reprodutoras pesadas na fase de produção

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 nitrogen requirement and the other to determine nitrogen use efficiency for body deposition, from 26 to 33 weeks old. The crude protein requirement for egg production (CPe) was determined by content of crude protein of eggs measured in birds from 31 to 37 weeks old. The protein requirement for maintenance was 2,282 mg CP/kg0.75/day and the protein efficiency 60.79%. The nitrogen requirement for weight gain and egg production were: 356 mgCP/g and 262 mg of CP/g, respectively, and the protein efficiency utilization were: 40 and 46.80% for weight gain and egg production, respectively. The prediction equation for broiler breeder hens was : CP = 2,282W0.75 + 0.356G + 0.262 EM, where CP is crude protein requirement (g/bird/day), W is body weight (kg), G is weight gain (g/day) and EM is egg mass (g/day).

Modelling energy utilization in poultry

Models of daily energy requirement can help to establish better and more profitable feeding programs for poultry. Studies have been conducted at UNESP-Jaboticabal-Brazil with the aim of studying energy utilization in broiler breeders, laying hens, and broilers, and to establish metabolisable energy requirement models. The factorial approach was used to partition the energy requirements into maintenance, growth, and production components. The resulting models consider body weight, weight gain, egg production, and environmental temperature for the determination of the energy requirements of poultry. These models were evaluated in performance trials and provided good estimates. Therefore, they can be used to establish nutritional programs. The aim of this chapter is to describe the development of these models and to outline the results of our studies at UNESP.