Lf Araújo

Energy and lysine for broilers from 44 to 55 days of age

An experiment was conducted to evaluate the performance and carcass yield of broilers at 55 days of age fed diets with different levels of metabolizable energy and lysine. Evaluated data of performance were weight gain, feed intake, energy intake, lysine intake, caloric conversion and feed conversion. Carcass assessment was performed based on data from carcass yield, breast weight, whole wings, whole legs, back, head + neck, feet and abdominal fat. A 3 x 3 factorial arrangement was used, with 3 levels of metabolizable energy (3,200; 3,400 and 3,600 kcal ME/kg) and 3 lysine levels (0.95%; 1.05% and 1.15%). There was no interaction between the two factors. Nevertheless, increasing levels of metabolizable energy improved weight gain (745 g; 841 g and 910 g, respectively) and feed intake was higher in broilers receiving the diets with 3,200 and 3,600 kcal ME/kg. Overall performance was not affected by lysine levels. Feed conversion values were 2.69, 2.42 and 2.14 for birds fed diets with 3,200; 3,400 and 3,600†kcal ME/kg, respectively. Carcass yield and breast weight increased with higher levels of energy and lysine in the diets.

Effect of phytase in laying hen diets with different phosphorus sources

An experiment was conducted to evaluate the effects of the enzyme phytase in diets formulated with different phosphorus sources on performance, eggshell quality and excretion of commercial laying hens. Two hundred and eighty-eight commercial Hyssex Brown laying hens were evaluated during two production phases, which included eight twenty-eight-day cycles, using a completely randomized design in a 3x2 factorial with six replicates of eight birds per treatment. Three phosphorus sources (calcium and sodium phosphate, micro-granulated dicalcium phosphate and triple super phosphate) and two phytase levels (0 or 1000 FTU/kg diet) were tested in the composition of the diets. After the post-peak period, triple super phosphate decreased bird performance and eggshell quality. It was possible to reduce the levels of phosphorus supplementation when phytase was added to the diet. Besides, phytase supplementation reduced phosphorus, calcium and nitrogen excretions, but affected mean egg weight at production peak.

Utilização da levedura desidratada (Saccharomyces cerevisiae) para leitões na fase inicial

An experiment was conducted to evaluate the effect of different levels of dried yeast (Saccharomyces cerevisiae) in diets about performance and intestinal morphology of piglets at initial phase. They used 280 piglets (females and castrated males) from genetic lines, weaned with 21 days of age, allocated in 20 pens in randomized design blocks, with 5 replications and 4 treatments (0, 5, 10 and 15% dried yeast addition). Samples of duodenum and jejunum of 3 piglets slaughtered at 45 days of age were collected from each treatment to study intestinal morphology. The increasing levels of dried yeast in rations did not affect significantly the weight gain, feed intake and feed conversion. In relation of duodenum and jejunum there was no significative effect (P>0.05) of dried yeast increased levels on villous height, crypt depth and villous crypt ratio. The results allowed to conclude that dried yeast can be added up to 15% in initial phase piglets diets.

Redução do nível protéico da dieta, através da formulação baseada em aminoácidos digestíveis

One experiment was conducted to study the reduction of protein level, through formulation based in digestible amino acids, using broilers in the initial phase. Eight hundred one-day-old male chicks, Cobb, were weighted and distributed in a random design, envolving four treatments (22%, 20% and 18% crude protein with digestible aminoacids and one control treatment with 22% crude protein based on total amino acids), envolving 4 replications of 50 birds each. Data from weight gain, feed intake and feed conversion were collected. When broilers were fed control diet, the same weight gain and feed conversion were obtained when compared with birds fed 22% crude protein and total amino acids and 20% crude protein formulated on digestible amino acids. It is possible to work diets with less protein level (20% crude protein) without affecting the performance when diet is formulated based on digestible amino acids.

Diferentes critérios de formulação de rações para frangos de corte no período de 1 a 21 dias de idade

Two experiments were conducted with the objective of evaluate different criterion of feed formulation based on total and digestible amino acids for broilers from 1 to 21 days of age. The diets were formulated to attend methionine, methionine+cystine, lysine and threonine recommendations. In the first experiment, eight hundred males birds, Hubbard, were allocated in experimental design with four formulations criterions, for attempt recommendations in total amino acids - NRC (1994), Rostagno et al. (1992), Degussa (1997) e AEC (1993), with 4 replications of 50 broilers each, profiles of amino acids (methionine, methionine+cystine, lysine and threonine) for broilers. In experiment two, six hundred males birds, Cobb, were allocated in experimental design with three formulations criterions, for attempt recommendations in digestible amino acids - Rostagno et al. (2000), Baker & Han (1994) and Degussa (1997), with 4 replications of 50 broilers each, profiles of amino acids (methionine, methionine+cystine, lysine and threonine) for broilers. Weight gain, feed intake and feed conversion were evaluated. The obtained results demonstrated that there is no difference in performance of broilers fed with different criterion formulation based on total amino acids. Diets formulated with digestible amino acids, the standard established for Baker & Han (1994) resulting in best performance of broilers in the available period.

Efeito dos ácidos lático e butírico, isolados e associados, sobre o desempenho e morfometria intestinal em frangos de corte

During the last years, the national poultry keeping has suffered constant challenges, having as objective to diversify the consuming market of the broiler to around of the world. However, each market presents different requirements, as in the case of the European market that establishes the exclusion of antibiotics as promotional of growth in the feeding of the broilers. Aiming at this problematic one, this study was become fullfilled, with the objective to analyze the results of the association of the butyric and lactic acids as additives in the ration of broilers, in comparison to the results gotten for the usually used promoters of growth in the diets of broilers. They had been evaluated: the animal performance, humoral immunology and intestinal morfometric of the birds. 1400 male chickens of the commercial ancestry Ross had been used, dividing them in five groups with different treatments to that if it relates to the additive use. Being a group it has controlled absent of additive, a group with butyric acid, a group with lactic acid, the fourth group with the association of butyric and lactic acids, and the fifth group with avilamicina (antibiotic) as promotional of traditionally used growth in the production of broilers. The performance results had indicated that the interaction of acid ones was significant in the initial phase, mean while did not occur an additive effect of acid ones, being the use of the butyric acid separately more recommendable during this phase. Already in the growth phase, the interaction was significant with an additive effect, recommending its use in the rations of growth. In accordance with the average headings of antibodies gotten in the study, the interaction was significant in the third sampling and showed a synergic effect of acid ones, being the combination of acids in question a powerful modulator of the humoral immunity. Meanwhile, the results gotten in the analyses of intestinal morfometric had not been conclusive. In general terms, one requires more organic acid studies that confirm the use of as the promotional ones of growth.

Desempenho de poedeiras comerciais submetidas ou não a diferentes métodos de debicagem

One experiment was conducted using 288 Isa Babcock laying hens, to study the effects of beak trimming (not trimming, light and severe). The hens were distributed in an at random experimental design, in factorial arrangement 3x3 ( first x second beak trimming ). The first one was done at nine days of age and the second at twelve weeks of age. Feed intake, body weight, egg production and feed conversion in four periods of twenty eight days each was evaluated. According to the results, the birds at severe beak trimming showed less feed intake and worst egg production (P<0.05).

Regulação da ingestão protéica na tilápia do Nilo, Oreochromis niloticus

The free-choice feed and regulation of protein intake were investigated in juveniles reverted males of tilapia do Nilo, Oreochromis niloticus. During the experiment 1000 fish (reverted males) with similar weigth and length were maintained in eight aquariuns supplied with recirculated water (groups of 125 fish each aquarium). Fish were fed by demand-feeders, containing the two experimental diets, formulated to contain 15% and 40% protein each and distributed in four treatments (A: 15% protein diet on one hand and 40% protein diet on the other hand, B: alike in A, therefore with an inversion on both hands, C: the two feeders supplied with 15% protein diet, D the two feeders supplied with 40% protein diet) The Latin Square was the estatistical method used for the experiment, and the treatments were distributed into four stages (I, II, III and IV). A one week stop after each stage was stipulated and the fish received a 30% protein diet. The results showed that no differences about the intake was detected between fish fed by diets containing 15% and 40% protein in the same aquarium. However, with same diets in the tanks ( Treatment C and D), the animals that were fed with the 15% protein diet showed better feed intake. The percentage of regulated protein during the experiment was about 24% protein. The results confirm the hipoteses of free-choice ability by tilapia-do-Nilo to detect the level of protein in the diet.

Different criteria of feed formulation for broilers aged 43 to 49 days

An experiment was carried out to evaluate different formulated feeds for broilers from 43 to 49 days of age. Six hundred male Cobb broilers were distributed in a completely at random experimental design with 3 treatments (3 different criteria of feed formulation) and 4 repetitions per treatment, with 50 birds each. Diets were formulated with different criteria of digestible amino acid inclusion (methionine, methionine+cystine, lysine and threonine), according to the profiles recommended by Baker and Chung (1992), Degussa (1997) and Rostagno (2000) Live performance and carcass yield were evaluated in birds fed the different diets from 43 to 49 days of age). The profile established by Degussa (1997) resulted in best live performance. All profiles supplied the nutritional requirements of the birds for adequate carcass yield, but Degussa (1997) profile resulted in highest breast yield.

Evaluation of Different Digestible Lysine Levels for Male Broilers During the Period of 18 to 40 Days of Age

A total of 1.500 male Cobb 500 broilers were used to determine the optimal digestible lysine level for 18 to 40-day-old broilers. The experimental period started when broilers were 18 days old and had an initial average weight of 737 ± 20 g. A completely randomized experimental design was applied, with five lysine levels, totaling five treatments with 10 replicates of 30 birds each. The experimental diets contained equal energy and protein levels, and 0.86, 0.95, 1.04, 1.13, and 1.22% digestible lysine. The following parameters were evaluated: average body weight at 40 days of age, daily weight gain, daily feed intake, feed conversion ratio, carcass yield and parts yield, and abdominal fat percentage. There was a quadratic effect (p<0.05) of digestible lysine levels on average body weight at 40 days of age, daily weight gain, and breast yield, and a cubic effect on feed conversion ratio and abdominal fat. There was no influence of lysine levels of daily feed intake, carcass yield, leg, or wing yields. It was concluded that digestible lysine requirements for male broilers during the evaluated period was 1.22% for performance and 1.04% for carcass yield.