Objetivou-se avaliar o desempenho, a digestibilidade das dietas, a retenção corporal de nutrientes e o desenvolvimento da mucosa intestinal de pintos de corte de 1 a 8 dias de idade, alimentados com dietas contendo níveis crescentes de levedura de cana-de-açúcar. Utilizou-se 300 pintos de corte, com um dia de idade, distribuídos em delineamento inteiramente casualizado, composto de cinco tratamentos e seis repetições de 10 aves. Os tratamentos consistiram de níveis crescentes de 0; 1,25; 2,5; 3,75 e 5,0% de inclusão de levedura. Não houve efeito da levedura sobre o desempenho zootécnico. Houve redução no coeficiente de metabolizabilidade da energia bruta, na energia metabolizável aparente e a aparente corrigida com os níveis crescentes. O nível de 2,09% promoveu menor retenção corporal de proteína bruta, enquanto a retenção de gordura foi linear crescente. A altura de vilos e relação vilo:cripta do jejuno aumentou linearmente, a profundidade das criptas do íleo apresentaram menor profundidade no nível de 2,40% de levedura. A inclusão da levedura de cana-de-açúcar até 5% em dietas de pintos na fase pré-inicial não afeta o desempenho zootécnico, proporciona melhor desenvolvimento da mucosa intestinal; entretanto, reduz a energia metabolizável das dietas e aumenta a retenção de gordura corporal. Palavras-chave: avaliação nutricional, frango de corte, vilosidades intestinais, retenção de nutrientes, Saccharomyces cerevisiae. ABSTRACT. Performance, digestibility, body composition and gut morphology of broiler chicks fed diets containing yeast cane sugar. The objective was to evaluate the performance, digestibility of diets, body retention of nutrients and the development of intestinal mucosa of post hatching broilers, of one up to eight day old, fed diets containing different levels of sugar cane yeast (Saccharomyces cerevisiae). It was used 300 one day old chicks in a completely randomized design with five treatments and six replicates of 10 birds. The treatments consisted of increasing levels of 0, 1.25, 2.5, 3.75 and 5.0% inclusion of yeast. No effect of yeast on performance. There was a reduction in the coefficients of apparent metabolizable of gross energy, apparent metabolizable energy, apparent metabolizable energy corrected by nitrogen balance with increasing levels. The level of 2.09% results in lower retention of body protein, while the retention of fat was increased linearly. The height of villus and villous height:crypt depth ratio of the jejunum was increased linearly, and the depths of crypts of the ileum had lower depth level of 2.40% yeast. The inclusion of yeast cane sugar levels up to 5% in diets for broiler in the post hatching doesn't affect the performance and provides better development of the intestinal mucosa in the jejunum, however reduces metabolizable energy of diets and increases greater retention of body fat.

-A total of 450 one-day-old male broiler chicks were used to evaluate the effect of the sugarcane yeast on performance, body composition, and development of the intestinal mucosa. The experiment was carried out in a completely randomized design with five treatments and six replicates of 15 birds. Sugarcane yeast was included in the experimental diets at the levels of 0, 12.5, 25.0, 37.5, and 50.0 g kg −1 . Body weight, weight gain, feed intake, and feed conversion were determined. At the end of the experiment, four broiler chicks were slaughtered per experimental unit: two were used for evaluation of moisture content, crude protein, fat, and body ash and the other two were used in the collection of small-intestine segments for evaluation of villus height and crypt depth. The increasing yeast levels resulted in a linear increase in feed intake and feed conversion. Inclusion of more than 14.4 g kg −1 yeast resulted in a reduction of body ash content. Villus height and crypt depth in the jejunum showed maximum values at the sugarcane yeast levels of 20.9 and 20.6 g kg −1 , respectively. In the ileum, the crypt depth reduction at the level of 25.6 g kg −1 also resulted in an increase in villus:crypt ratio. Yeast inclusion increases feed intake and feed conversion, improves body mineral absorption, and increases villus height in the jejunum and the villus:crypt ratio in the ileum of broiler chicks.

The objective of this study was to determine prediction equations to estimate the nitrogen-corrected apparent metabolizable energy (AMEn) values of animal meals used in broiler diets through meta-analysis. A bibliographic review was undertaken with studies conducted in Brazil from 2000 to 2016 to catalogue information on AMEn values and the following chemical elements in the composition of the feedstuffs: crude protein (CP), ether extract (EE), gross energy (GE), mineral matter (MM), calcium (Ca), and phosphorus (P). Groups were also catalogued and formed according to sex and age of birds. Chemical correlations were analyzed, and a multiple linear regression model with the stepwise procedure was used to examine the association between the variables, which were included in the equation as a function of their importance. High and significant correlation coefficients between the independent (GE, MM, CP, EE, Ca, and P) and dependent variable (AMEn) contribute to the understanding of variations in the energy values of these feedstuffs. According to the coefficients of determination, the best equations to estimate AMEn of poultry offal meal and meat and bone meal are AMEn = 6139 − 45.5 CP + 0.356 GE −123.5 MM (R 2 = 0.8302) and AMEn = 2267 + 19.9 CP + 67.9 EE − 44.4 MM (R 2 = 0.9021), respectively.

The objective of this study was to evaluate levels of inclusion of an enzyme complex (EC) in corn-and soybean meal-based diets for laying hens on the digestibility of nutrients and energy. A metabolism trial was conducted using 75 Dekalb Brown laying hens at 26 weeks of age, which were distributed into five treatments with five replicates in a completely randomized design. The ingredients used in the diets received an additional (enriched) 3% methionine, lysine, cysteine, threonine, tryptophan, and metabolizable energy and 33.3% phosphorus. Treatments consisted of diets including 0, 150, 200, 250, or 300 mg.kg-1 EC. We determined apparent metabolizable energy (AME); nitrogen-corrected AME (AMEn); apparent metabolizability coefficients of dry matter (DM AM), crude protein (CP AM), gross energy (GE AM), and phosphorus (P AM); digestible crude protein (CP D); and intake, retention, and excretion of phosphorus. No effects of EC levels were detected on the metabolizable energy values or digestibility coefficients, except for CP AM , which showed a quadratic response (maximum coefficient at 89.0 mg.kg-1 EC). A quadratic effect was also observed for CP D (minimum at 115 mg.kg-1 EC), P excretion (maximum at 173.2 mg.kg-1 EC), and P retention (maximum at 122.4 mg.kg-1 EC) when EC was used. The use of the EC in corn-and soybean meal-based diets for laying hens improves their ileal digestibility of protein and apparent digestibility of phosphorus. However, EC addition to the diets does not affect AME, AMEn, or their metabolizability coefficients.