Effect of dietary fiber, genetic strain and age on the digestive metabolism of broiler chickens

In this study, 360 male broilers, out of which 240 of a fast-growing strain (Cobb500), and 120 of a slow-growing strain (Label Rouge), were used to evaluate the effect of dietary fiber on digesta transit time and digestive metabolism during the period of 1 to 42 days of age. A completely randomized experimental design with a 3x2 factorial arrangement was applied, consisting of three groups of birds (slow-growing – SG; fast-growing fed ad libitum – FGAL; and fast-growing pair-fed with SG broilers – FGPF) and two iso-protein diets (a 3100 kcal ME/kg low-fiber diet –LFD- and a 2800 kcal ME/ kg high-fiber diet –HFD- with 14% wheat bran and 4% oat hulls). HFD-fed birds presented lower ME retention (p < 0.001) and lower dry matter metabolizability (DMM) (p < 0.001), which is possibly related to the shorter digesta transit time observed in these birds (p < 0.001). DMM was reduced with age, whereas metabolizable energy remained almost constant (p < 0.001) independently of strain. This may be related to the increase in feed intake as birds age. The slowgrowing strain did not present better utilization of the high-fiber diet as compared to the fast-growing strain in none of the analyzed ages, even though showing a significant better use of fiber and dietary energy from 31 days of age

Can the Fine Wheat Bran be a Betaine Source in Poultry Diets?

ABSTRACT The effect of fine wheat bran (FWB) as a methyl donor source on performance, metabolism, body composition and blood traits of growing broilers was studied. Three hundred and twenty broilers from eight to 28 d of age, distributed in a randomized block design, with five treatments and eight replicates of eight animals each were used. The experimental diets were: NC, formulated with 72% of the Met+Cys requirement; Met, formulated with 85% of the Met+Cys equivalents by DL-methionine addition; Bet, formulated with 85% of the Met+Cys equivalents by anhydrous betaine addition; Fwb-, formulated with 72% of the Met+Cys requirement and 20% FWB; and Fwb+, formulated with 85% of the Met+Cys requirement and 20% FWB. Feed intake was reduced (p0.05) between the positive control diets. Supplementation of DL-methionine and anhydrous betaine showed the same (p>0.05) metabolizability of nutrients. Treatments with higher DL-methionine levels (Met and Fwb+) promoted more weight of feathers (p<0.05). Animals fed with FWB showed the lowest (p<0.05) body gains. In conclusion, FWB inclusion did not promote methyl radicals supply

Growth and deposition of body components of intermediate and high performance broilers

The objectives of the present study were to determine the parameters of Gompertz equations and to determine curves and growth rate, feed intake and body component deposition, as well as allometric coefficients of body water, protein, and fat relative to live weight of male and female broilers of intermediate performance (C44) and high performance (Cobb-500) genetic strains. In total, 384 one-d-old chicks were distributed into four treatments: male Cobb 500, male C44, female Cobb 500, and female C44, with six replicates of 16 birds, according to a completely randomized experimental design. Average body weight, weight gain, and feed intake were weekly determined, and six birds, representing the average weight of each treatment, were sacrificed to determine body composition. Growth curves were built applying Gompertz function, with excellent fit, and growth, feed intake, and tissue deposition rates were obtained by its derivatives. Superior growth rate was obtained for Cobb 500 male broilers. This genetic strain has higher feed intake capacity, which is achieved earlier than in the C44 strain. Protein and fat deposition maturity was reached earlier in males than in females in Cobb 500. The allometric coefficients showed earlier maturity for body water in C44 and females. In terms of body protein, male Cobb 500 broilers reached maturity earlier than females and C44. Body fat deposition maturity was reached earlier in Cobb 500 than in C44. The Gompertz equations obtained in the present study efficiently described body growth, feed intake, and deposition of body components, with a coefficient of determination higher than 0.99

COMPARAÇÃO DE MEDIDAS DA CAPACIDADE TAMPONANTE DE MATÉRIAS–PRIMAS E DIETAS UTILIZADAS PARA LEITÕES

Buffering capacity (BC) of severalfeeds and diets for pigs was evaluated by differentways: initial pH (pHi), titratable acidity or alkalinity(AT) and BC. For the experiment were used 32samples of different ingredients, mineral supplementmix and diets, classified as amino acids, mineralsupplements, cereals and its raw products, soybeanand its raw products, animal products, and completediets. PHi was measured in three solutions with 10g sample diluted in 90 ml distilled deionized water,in which one either chloridric acid, formic acid ora commercial acidifier based in formic acid, wereused to reduce the pH just to 5.0, or NaOH, whenthe pHi was lower than 5.0. AT was defined as theoverall acid or alkali amount required to change thepH between the pHi and 5.0, and was expressed asmEq/100 g sample dry matter. CT was calculatedby dividing the AT values by the whole pH range,with the values obtained with each acid sourceused as replicates of each sample. Results of eachmeasure were submitted to an ANOVA consideringthe classifications. Linear correlation between thepHi and BC was also evaluated. Minerals and aminoacids showed extreme higher and lower values inall measures and were divided in subgroups. Dietsand products of soybean and cereal showed similarpHi values, but were different by the other measures(P<0,05). CT showed higher sensibility than AT.PHi displayed inconsistent correlation with BC, andwas considered a not trustable estimate of thatphysicochemical property.Avaliou-se a capacidade tamponante(CT) de diferentes ingredientes e dietas para leitões,por meio de diferentes medidas: pH inicial (pHi),acidez ou alcalinidade tituláveis (AT) e CT. Foramutilizadas 32 amostras de diferentes ingredientes,pré-misturas e dietas, classificadas como aminoácidos,suplementos minerais, cereais e subprodutos,soja e subprodutos, ingredientes de origem animale dietas completas. O pHi foi mensurado em trêssoluções com 10 g de amostra diluídas em 90 ml deágua destilada e deionizada, nas quais foi adicionadoácido clorídrico, ou ácido fórmico ou um acidificantecomercial à base de ácido fórmico, para reduzir opH até 5,0, ou NaOH, quando o pHi foi menor que5,0. A AT foi definida como a quantidade de ácidoou base necessária para alterar o pH entre o pHie 5,0, expresso em mEq/100 g de matéria seca deamostra. A CT foi calculada dividindo-se os valoresde AT pelo intervalo de pH considerado, sendo osvalores obtidos com cada ácido considerados replicatasde cada amostra. Os resultados com cadamedida foram submetidos à ANOVA considerandoas classificações. A correlação entre o pHi e a CTfoi também avaliada. Os suplementos minerais e osaminoácidos apresentaram valores extremos emtodas as medidas, e foram separados em subgrupos.As classes soja, cereais e dietas mostraram valoressimilares de pHi, mas diferiram quanto às outras medidas(P<0,05). A CT demonstrou mais sensibilidadeque a AT. O pHi apresentou correlação inconsistentecom a CT, não sendo uma estimativa confiável destapropriedade físico-química