The importance of endogenous nutrition of chicks from divergent strains for growing tested by deutectomy

Effects of yolk sac removal (deutectomy) upon performance of chicks from three divergent strains were tested to evaluate the importance of endogenous nutrition on the post-hatch phase. Chicks from three different strains (Hy-Line W98, Cobb 500, and JA57) were submitted to a surgery procedure after hatching. Half of them had the residual yolk removed, and the other constituted a sham-deutectomized group. After operation, chicks were designated to a 3 x 2 factorial design (3 strains x 2 presence/absence of yolk sac), in a total of six experimental groups and ten replications of two to four birds. During 14 experimental days all birds were fed ad libitum a 21% CP and 3050 kcal/kg EM mash diet. Data were analyzed by ANOVA, and Tukey's test (p<0.05). Relative yolk sac weights were similar among chicks from different breeders, averaging 11.7% to 13.5%. Comparing to sham-operated, deuctetomized chicks had lower weight gain at 7 and 14d, indicating that endogenous nutrition, via yolk sac, is very important to galliform birds whatever their strain. Hy-line deutectomized chicks gained 40% less body weight at the 7th day as compared to their sham counterparts. Analysis of the same criterion to Cobb and JA57 groups revealed a decrease of 16.1% and 10.8%, respectively, on weight gain efficiency. At the 14th rearing day, Hy-Line chicks had the lowest weight gain, followed by JA57s' and Cobbs'. The results suggested that chicks selected for fast growth are less dependent on endogenous nutrition, responding better when exogenous nutrition is associated to yolk assimilation

Desenvolvimento de Órgãos da Digestão e Rendimento de Carcaça de Frangos de Corte de Diversas Origens Genéticas Criados com Bebedouros Pendular e Nipple Development of Digestive Organs and Carcass Yield of Broilers from Diverse Genetic Origin Raised with Regular or Nipple Drinkers

O uso de linhas genéticas de diferentes fontes comerciais em programas de reprodução de frangos de corte permite produzir gerações comerciais mais bem adaptadas a realidades diversas e otimizar os potenciais de desempenho do frango de corte com os da reprodutora. Entretanto, a prática predominante no Brasil é o uso de pais e mães de mesma origem. O uso de bebedouros tipo "nipple" vem sendo difundido com a perspectiva de gerar benefícios ainda não comprovados inteiramente na prática. Esse estudo avaliou a evolução dos órgãos da digestão, o desempenho vivo e o rendimento de carcaça e das partes de frangos de corte de diferentes cruzamentos entre reprodutores machos de diversos cruzamentos entre linhagens comerciais (R, I, S, e H) com fêmeas também de origem variável (R, I, e H) em sistemas de produção com bebedouros pendular ou nipple. As aves dos diferentes cruzamentos apresentaram curvas de crescimento com diferentes intensidades em momentos distintos, determinando desempenhos em peso vivo sempre superiores para o cruzamento RR. O rendimento de peito, entretanto, foi maior para o cruzamento IH. O cruzamento SH, de mais baixo peso corporal, evidenciou rendimentos de carcaça inferiores a todos os demais. O tipo de bebedouro não influenciou nenhum resultado de desempenho vivo ou de rendimento de carcaça, independentemente da linhagem. Os órgãos da digestão apresentaram proporções do peso vivo decrescentes com a idade, mas não evidenciaram efeito de cruzamento entre linhagens ou tipo de bebedouro.<br>Breeding programs using parents from different genetic companies allow the production of commercial generations of broilers directed to attend diverse market situations, but they also serve to optimize the performance of the breeder female. However, this is not a current practice in Brazil where most of the commercial broilers being raised are originated from crosses within the same genetic company. The use of nipple drinkers in broiler houses has increased in the last few years; however, practical benefits have not been proved yet. This study evaluated the development of the digestive organs, live performance and carcass and cut up yields from broilers originated of the crossing between breeder males from four commercial strains (R, I, S, and H) with females also from various origins (R, I, and H) raised in pens with bell or nipple drinkers. Birds’ growth curves varied with strain cross and led to better body weight at marketing for the RR strain cross. Breast yield, however, was better for the cross IH. The SH strain cross showed a consistently lower body weight and carcass yield at all ages. The type of drinker did not affect any measured response regardless of the strain cross. Strain crosses or type of drinkers did not affect development of the digestive organs

Desempenho de Frangos de Corte Alimentados com Ovo em Pó Perfomance of Broiler Fed Dried Whole Eggs

Um experimento foi conduzido para estudar a adição do ovo em pó na dieta de frangos de corte no período de 1 a 28 dias, sendo dividido em duas fases (1 a 7 e 8 a 28 dias). No período de 1 a 7 dias, as aves receberam dietas contendo 0%, 5%, 10%, 15% e 20% de ovo em pó e de 8 a 28 dias de idade as aves foram distribuídas em um arranjo fatorial 2x5 (2 níveis de ovo em pó - 0% e 5% - e os 5 níveis da fase anterior). No período de 1 a 7 dias as aves do tratamento controle apresentaram melhor ganho de peso e as aves alimentadas com dietas contendo 20% de ovo em pó apresentaram menor ganho de peso e pior conversão alimentar. As aves deste mesmo tratamento apresentaram também menor peso e comprimento do intestino. Na segunda fase (8 a 28 dias) não houve interação entre os tratamentos estudados. O desempenho, peso e comprimento do intestino não foram afetados pelos tratamentos, ocorrendo apenas maior peso do coração em aves que receberam ovo em pó nesta fase. Os resultados obtidos demonstram ser economicamente inviável a utilização de ovo em pó na dietas de frangos de corte no período de 1 a 28 dias e pela falta de resposta que este ingrediente promove no desempenho da ave.<br>A experiment was conducted to study the addition of dried whole eggs (DWE) in broilers diets from 1 to 28 days of age in two phases (1to 7 and 8 to 28 days). From 1 to 7 days the birds received the diets with 0, 5, 10, 15 and 20% DWE and from 8 to 28 days of age the birds were assigned in a factorial arrangement 2x5 (2 levels of DWE - 0% and 5% - and the five previous levels). From 1 to 7 days of age birds fed control diet without DWE showed better weight gain and those fed the highest level of DWE showed the worst feed conversion. In the second phase (8 to 28 days) no interaction was found between treatments and also performance, gut weight and gut length were not affected by treatments. The results obtained suggest that the addition of DWE does not results in beneficial effects in broiler diets

Behavior of broiler chickens in four different substrates: a choice test

The aim of this study was to determine the selection of bedding material by broiler chickens during the rearing period and whether the choice was determinant to their performing a specific behavior. To achieve this objective, a choice test was designed. A choice pen was constructed where birds could move freely around the four selected materials (straw, wood shavings, rice hulls and sand). Chickens were introduced in this pen in four groups of eight birds, three days a week for one hour per day and group, for four weeks. The location and the activity performed by each broiler were recorded every five minutes. Results showed a preference for sand compared with the other three substrates. However, differences between the behaviors performed in each bedding material were shown mainly for resting (preferably performed on wood shavings and straw), dust bathing (on sand), pecking and scratching (on rice hulls). Other factors, such as the time of day, were also found to have effects on fighting and drinking, and changes in behavioral patterns (resting, preening, eating, standing and pecking) were also detected as broilers grew older

Hematological values and body, heart and liver weights of male and female broiler embryos of young and old breeder eggs

This study analyzed broiler breeder age (29 or 60 wk-old) effects on physical characteristics of eggs (initial mass, mass loss, volume, diameter, surface area and density) and of eggshells(weight, volume, thickness, conductance, and porosity ), as well as the influence of embryo sex on hematological parameters and body, liver and heart weights during incubation (at days 13, 15, 18 and 21). Physical parameter values were lower in 29-wk-old broiler breeder eggs than those of 60-wk-old breeders, except for relative eggshell weight, which was higher. In both male and female embryos, erythrocytic parameters and the body, liver, and heart weights increased during the incubation. The embryos and their organs were heavier when derived from 60-wk-old breeder eggs as compared to 29-wk-old breeder eggs. At hatching, hematocrit values were higher in males than in females. Thrombocytes were the most frequent leukocytes in the blood. Thrombocyte percentage decreased and lymphocyte percentage increased during the last days of incubation. The results showed maternal age influence only on body, heart and liver weights, focal sex-related influence the hematocrit at hatching, and temporal effect of incubation on body and organ weights, as well as on red blood cell count, hematocrit, hemoglobin, plasma glucose, and lymphocytes, which increased during the incubation period, while mean corpuscular volume and thrombocyte values decreased