Augusto Vidal da Costa Gomes

Valores nutricionais de milhos de diferentes qualidades para frangos de corte

This work was carried out to determine the nutritional value of corn of different qualities, obtained by means of stratification in densimetric table, for broilers in different ages. The corns were designed as: MDA - high density corn; MDI - medium density corn; MDB - low density corn and MDT - total density corn, composed by 30% MDA, 60% MDI and 10% MDB. Two biological assays were carried out using the traditional total excreta collection method to determine the apparent metabolizable energy corrected by nitrogen balance (AMEN). The first assay was carried out using Cobb chicks with 11 to 19 days old and in the second assay, with chicks with 29 to 37 days old. Chemical analyses were made to estimate the nutritional profile, classification of the grains according to density and comparison by means of prediction equation estimatives the energy values and mycotoxins. The digestible amino acids profiles were obtained by NIR. The values of AMEN of corns of different qualities (MDA, MDI, MDB and MDT) for broilers in initial phase were respectively: 3308; 3121; 2937 and 3239 kcal/kg; and broilers in growing phase were respectively: 3413, 3362, 3174 and 3348 kcal/kg. These results indicated significant energy losses of low density corn and the efficiency of the densimetric table to stratify the grains by quality. The different AMEN values between birds ages suggest better energy utilization efficiency as age increases. The prediction equations could be used to estimate energy value of corn by its classification or density. However, the error associated to each prediction equation could compromise the accuracy of the nutritional value. The contaminations by aflatoxins and trichothecenes changed with quality of the stratified corn, important factor to be considered in the broilers feeding.

Digestion of carbohydrates of forages in horses

This work was carried out to evaluate the fractions of carbohydrates and estimate the apparent digestibility of these nutrients in two digestion assays with horses. In assay 1, five horses were allotted to a complete randomized blocks design and treatments were seven forages hays, alfalfa (Medicago sativa), peanut forage (Arachis pintoi), desmodio (Desmodium ovalifolium), pigeon pea (Cajanus cajan), lime-yellow pea (Macrotyloma axillare), stylo (Stylosanthes guianensis) e coastcross (Cynodon dactylon), evaluated with the mobile nylon bag technique. In assay 2, four horses were allotted to a 4 × 4 Latin Square design and fed with coastcross hay with four different processed forms with the objective of evaluating whether a reduction of the particle size affected the carbohydrate digestibility. Results showed that horses had high digestion of non-fibrous carbohydrate and hydrolysable carbohydrate and rapidly fermentable carbohydrate fractions of forages. Among the forages analyzed, peanut forage, stylo and lime-yellow pea, presented high nutrient digestibility, and the peanut forage nutrients presented digestibility above 70%, demonstrating potential to be used in diets for horses. The coastcross hay processing in different grinding degrees does not affect the fibrous and non-fibrous carbohydrate fractions digestibility. Analysis of fibrous and non-fibrous carbohydrate fractions is a good indicative of nutritional value of feeds, and could be included in the evaluation of the quality of diets for horses.Neste estudo, foram realizados dois ensaios com os objetivos de avaliar o fracionamento dos carboidratos de alimentos volumosos e estimar a digestibilidade desses nutrientes em dois ensaios de digestao com equinos. No ensaio 1, foram utilizados cinco equinos em delineamento de blocos casualizados, com sete tratamentos - fenos de alfafa (Medicago sativa); amendoim forrageiro (Arachis pintoi); desmodio (Desmodium ovalifolium); guandu (Cajanus cajan); macrotiloma (Macrotyloma axillare); estilosantes (Stylosanthes guianensis); ou coastcross (Cynodon dactylon) - avaliados pela tecnica de sacos de nailon moveis. No ensaio 2, foram utilizados quatro equinos em delineamento quadrado latino 4 × 4, alimentados com feno de coastcross em quatro tipos de moagem com o objetivo de avaliar se a reducao do tamanho de particula interfere na digestibilidade dos carboidratos. Os resultados comprovaram que os equinos possuem alta eficiencia na digestao dos carboidratos nao-fibrosos e de suas fracoes hidrolisaveis e rapidamente fermentaveis. Os fenos de amendoim forrageiro, estilosantess e macrotiloma apresentaram elevada digestibilidade dos carboidratos fibrosos e nao-fibrosos, enquanto a digestibilidade de todos os nutrientes do amendoim forrageiro foi superior a 70%, o que indica potencial para uso desta leguminosa em dietas para equinos. O processamento do feno de coastcross nao influenciou a digestibilidade das fracoes dos carboidratos fibrosos e nao-fibrosos. A analise dos carboidratos fibrosos e nao-fibrosos e um bom indicativo do valor nutricional dos alimentos e pode ser incluida na avaliacao da qualidade de alimentos para equinos.

Desenvolvimento de órgãos do trato gastrintestinal e desempenho de frangos de corte arraçoados na fase pré-alojamento

The objective of this study was to evaluate the use of pre-housing diet in chicks from different Cobb broiler breeders ages. A total of 840 broiler chickens were distributed in randomized experimental design, in a 2x2 factorial scheme (two broiler breeder ages x two kind of diets), and seven replicates with 30 chicks each. The treatments consisted of chicks from broiler breeders of 33 and 68 weeks of age given different kind of diets. The parameters feed intake, feed conversion, body weight, daily weight gain and productive efficiency index were assessed weekly until the 42 day old. At 1; 2 and 7 days of age, two birds per repetition, totaling 14 birds per treatment were sacrificed for study of gastrintestinal organs. The administration of pre-housing diet affected the weight of the chicks at 2; 7 and 14 days old, but do not affect the rate of production efficiency in broilers at the end of the trial period. Breeder age influenced the weight of the chicks at all ages analyzed. The weights of gastrintestinal organs were not affected by the diet. Considering the results for the parameters of the performance obtained in this study, the pre-housing diet supply in the post-hatching influenced positively in the development of the organs of the gastrointestinal tract and the growth performance of broilers in the initial phase of growth. It can be used as an alternative for feeding a new market that slaughter chickens at this age.

Digestibilidade da ração de frangos de corte suplementados com probióticos e antibiótico

The objective of this experiment was to evaluate the diets digestibility in broiler chickens with and without antibiotic and probiotics, in the initial phase (one to 20 days) and finish phase (21 to 40 days). Chickens distributed in a completely randomized design were used in four treatments: Treatment 1- Control diet; Treatment 2 - Control diet + 0.02% probiotic 1 (Calsporin 10®), Treatment 3 - Control diet + 2.0% initial phase and 0.63% finish phase probiotic 2 (Estibion aves®); Treatment 4 - Control diet + 0.013% of antibiotic (Bacitracina de Zinco®), and five repetitions, with ten and eight birds, respectively, were used in each experimental unit, which were kept in metabolism cages. The results demonstrate that the digestibility of dry matter, nitrogen and apparent metabolized energy were not affected by the supplementation of antibiotic and probiotics in the broiler chickens diet.

Substituição do farelo de soja por farelo de algodão na alimentação de coelhos em crescimento

Replacement of soybean meal by cottonseed meal as feed for growing rabbits. Two experiments were carried out aiming to evaluate the use of cottonseed meal as feed for growing rabbits. Eight White New Zealand rabbits, 50 days old, male and female, were used in the digestibility trial. The experimental period lasted for 12 days (8 days of adaptation and 4 days of whole faeces collection). Cottonseed meal was offered as the only food source, with the addition of 0.5% NaCl and 0.4% vitamin mineral mixture. The cottonseed meal was then moisted with 40% water, forming a paste. The apparent digestibility coefficients were: 66.81; 84.65; 41.14; 39.00 and 68.27% for dry matter, crude protein, neutral detergent fiber, acid detergent fiber and gross energy, respectively. In the performance trial, 32 White New Zealand rabbits (16 males and 16 females), 41 days old, were used and kept in individual cages. Data was analyzed under a randomized design with eight replications and four treatments (four levels of crude protein replacement of soybean meal by cottonseed meal crude protein: 0; 33; 66 and 100%). At the end of the experiment, the rabbits (76 days old) were finished for carcass evaluation. An increase was observed (p < 0.05) in daily feed intake and feed/gain ratio, but there was no significant effect on average live weight gain and carcass quality. The results show that cottonseed meal can totally replace soybean meal as feed for growing rabbits, depending only on economic factors, such as the ever-changing prices for each type of feed.

Desempenho e características da carcaça de frangos de corte alimentados com rações de diferentes formas físicas

Um experimento foi realizado para avaliar a influencia da forma fisica da racao sobre o desempenho e as caracteristicas da carcaca de frangos de corte. Foram utilizados 240 pintos de corte machos, distribuidos e alojados em baterias metalicas de tres andares em delineamento de blocos ao acaso com 4 formas fisicas de racao e 6 repeticoes com 10 aves por unidade experimental, considerando cada andar um bloco. Os tratamentos consistiram em racoes farelada, peletizada, expandida e expandida peletizada. Os indices de desempenho foram analisados no periodo de 1 a 22 e 1 a 39 dias de idade das aves. Duas aves com peso medio do grupo foram retiradas de cada repeticao e abatidas aos 40 dias de idade para avaliacao da carcaca. A forma fisica da racao afetou o desempenho e as caracteristicas da carcaca dos frangos. Nos periodos de 1 a 22 dias e de 1 a 39 dias, os frangos que consumiram o alimento farelado apresentaram menor consumo de racao, peso medio e ganho de peso, enquanto aqueles que receberam racao peletizada nao apresentaram diferenca no peso medio, ganho de peso e conversao alimentar em relacao aqueles que receberam racao expandida peletizada. Os maiores resultados para essas variaveis foram observados para aves alimentadas com racao peletizada ou expandida peletizada. As aves que receberam racao expandida peletizada apresentaram melhores resultados de peso de carcaca e dos cortes em relacao aquelas que receberam a racao farelada e este melhor resultado nao diferiu do encontrado para as aves alimentadas com racao peletizada. Recomenda-se o uso de racoes na forma fisica peletizada ou expandida peletizada, pois promoveram os melhores indices zootecnicos.

Efeito da granulometria do bagaço de cana sobre as características digestivas e a contribuição nutritiva dos cecotrofos

Two experiments using New Zealand White x Californian rabbits were carried out with the objective of evaluating the effect of fiber source particle size on digestive traits of growing rabbit and the production, chemical composition and cecotrophes nutritive contribuition on dry matter (DM) and crude protein (CP) base. Four diets were prepared with different particle size of sugar cane bagasse with average geometric diameters of .231, .506, .616 and .833 mm. The productive performance and weight of the full and empty digestive tract, digestive tract content, full and empty cecum and cecum content were not affected, however the ammonia nitrogen percentage in the caecum content was significantly increased by increasing particle size of sugar cane bagasse. In cecotrophy evaluation, effects of particle size on cecotrophes production, DM and CP content ingested were observed, but the cecotrophes chemical composition was not affected by diets.