N.C. Baião

Effects of lipid sources in the diet of laying hens on the fatty acid profiles of egg yolks

The effects of different dietary lipids on the fatty acid profiles of eggs produced by 20- and 54-wk-old Dekalb laying hens were investigated. The 4 treatments were based on the lipid source added to the diet: soybean oil, sunflower oil, linseed oil, or control (no added oil). The experimental design was a simple random-sample design using a 4 × 2 factorial arrangement (4 treatments and 2 ages). The fatty acid composition of the yolks of eggs produced by the laying hens was analyzed. The fatty acid profiles found in the egg yolks were the same as those provided in each diet. Eggs laid by hens fed the diet containing soybean oil had a large amount of n-6 polyunsaturated fatty acids (PUFA), whereas eggs laid by hens fed the diet containing linseed oil had the highest percentage of n-3 PUFA. A decrease in PUFA deposition in egg yolks was observed as the laying hens got older. Eggs of hens fed the diet containing linseed oil presented an n-6:n-3 ratio of 2.01 in younger chickens and 2.17 in older ones. The trans fat percentages found in the egg yolks of all treatments were very low. It was concluded that the quantity of fatty acids present in the egg yolk may be altered according to the source of lipids in the diets; the addition of linseed oil to the ration of laying hens resulted in the production of n-3-enriched eggs and excellent n-6:n-3 ratios, and the egg yolks had insignificant amounts of trans fat, irrespective of the different lipid sources added to the diets or the age of the chickens.

Qualidade de ovos de consumo submetidos a diferentes condições de armazenamento

The internal quality of 768 commercial white eggs from 40-week-old Hy-Line laying hens was evaluated after storage under different conditions. The eggs were submitted to treatments in a factorial scheme of 2x4x8, being two types of package (using plastic film or not), four periods of storage (zero, five, 10, and 15 days), and eight refrigerated storage times (zero, five, 10, 15, 20, 25, 30 and 35 days). The values of Haugh Unities (HU) and albumen pH were measured. The HU values significantly decreased (P<0.05) during storage mainly at room temperature. Wrapping the eggs packages with plastic film showed efficient in preserving their internal quality since it kept HU higher for a longer storage time. The pH values of the eggs increased during the storage time (P<0.05), independently of both storage temperature and packaging. It was concluded that temperature and time of storage of eggs influenced on the values of HU and wrapping the eggs packages with plastic film improved their internal quality.

Efeito da classificação dos ovos sobre o rendimento de incubação e os pesos do pinto e do saco vitelino

Two experiments were carried out to study the effects of broiler breeder age on weight uniformity of 1,080 eggs and yolks, and the effects of 9,216 eggs classified prior to setting on hatchability, embryonic mortality, and the relationship between chick and yolk sac weights. In the first study, the three treatments were eggs from broiler breeders on 31st (M31), 38th (M38), and 43th (M43)-week of age. In the second study, eggs produced by three broiler breeders flocks (31st, 38th, and 43th wk of age) were divided in six treatments; A: eggs weighting from 66 to 72g, 33,3% of them produced by broiler breeders of different ages; B: eggs weighting from 58 to 65g, 33,3% of them produced by broiler breeders of different ages; C: eggs weighting from 52 to 57g, 33,3% of them produced by broiler breeders of different ages; D: eggs from 31-wk-old broiler breeders, weighting from 52 to 72g; E: eggs from 38-wk-old broiler breeders, weighting from 52 to 72g; F: eggs from 43-wk- old broiler breeders weighting from 52 to 72g. Eggs produced by M31 had egg and yolk weights more uniform than the eggs collected from M43. Treatment A had the worst hatchability, higher embryonic mortality after 15 days of incubation, and produced heavier hatched chicks with superior absolute and relative weights of yolk sac.

Efeito de fontes lipídicas sobre o desempenho de frangos de corte

A completely randomized design with six replicates of 30 birds per experimental unit was used to evaluate the effect of five fat sources of diets (soybean oil, poultry fat, acidulated soybean oil soapstock and a mix of soybean oil plus poultry fat and soybean oil plus acidulated soybean oil soapstock) on the performance of male Ross broilers, during the growing period (1-45 days of age). The diets for each phase were isonutritional. Broilers fed on soybean oil showed higher weight gain in comparison to the birds fed on diets containing acidulated soybean oil soapstock (P<0.05), but no differences were observed among the other treatments. The feed intake of birds fed on soybean oil was higher compared to the birds fed on acidulated soybean soapstock diet and mix of soybean oil plus acidulated soybean oil soapstock diet. No treatment effect was observed for feed:weight gain ratio and viability. Soybean oil diet resulted in better broiler performance in comparison to acidulated soybean oil soapstock diet.

Qualidade de ovos comerciais submetidos a diferentes condições de armazenamento

Physical-chemical egg qualities of 1440 egg from commercial layer hens of different ages (30 and 60-week-old) submitted to storage under room temperature or refrigeration conditions were evaluated according to the following traits: Haugh Unities (UH); pH of albumen (pH); total solids of albumen and yolk; and weight and percentage of albumen, yolk, and shell. Decrease of inner quality of the evaluated eggs was observed during the experiment, mainly eggs from old-layers, which presented the worst values of AA and HU when stored at room temperature. It was concluded that age, temperature and time of storage of eggs influenced egg quality.

Efeito do período de jejum pré-abate sobre o rendimento de carcaça de frango de corte

Avaliaram-se os efeitos de cinco periodos (quatro, oito, 12, 14 e 16 horas) de jejum pre-abate sobre a perda de peso e rendimento de carcaca e cortes de frangos de corte. Foram utilizados 240 frangos (120 machos e 120 femeas), linhagem Cobb, criados ate 44 dias de idade. No 44o dia, as aves foram separadas de acordo com o periodo de jejum (tratamentos) e o sexo, cada tratamento com 24 repeticoes. Nos tratamentos de quatro, oito, 12 e 16 horas, o jejum foi alimentar e no tratamento de 14 horas, o jejum foi alimentar e hidrico. O teste utilizado para as analises das medias foi o SNK (Student-Newman-Keuls). Foram analisadas as seguintes variaveis: perda de peso vivo apos o jejum, taxa de absorcao de agua pela carcaca, rendimentos da carcaca inteira e dos cortes comerciais coxa e sobrecoxa, peito, dorso, asa, pes e cabeca e pescoco, rendimentos da moela e figado e peso dos intestinos. Os periodos de jejum de oito, 12, 14, e 16 horas apresentaram maior rendimento de carcaca, sendo superiores ao periodo de quatro horas de jejum (P 0,05). As femeas absorveram mais agua do que os machos, e apresentaram rendimentos de carcaca e cortes comerciais superiores aos dos machos (P<0,05).

Rendimento, composição e teor de ácidos graxos da carcaça de frangos de corte alimentados com diferentes fontes lipídicas

A completely randomized design, with six replicates of one bird per experimental unit was used to evaluate the effect of different fat sources of diets (soybean oil, poultry fat, acidulated soybean oil soapstock and a mix of soybean oil plus poultry fat and soybean oil plus acidulated soybean oil soapstock) on carcass yield, composition of the breast, thigh and whole chicken and fatty acid profile of the whole carcass of broilers. No effects of fat source on carcass yield and cuts, composition of crude protein, humidity and ether extract of the whole chicken, whole leg and breast were observed (P>0,05). The birds fed on poultry fat diet showed a higher percentage of monounsaturated fatty acid on the carcass than birds fed on diets with the others fat sources. The deposition of polyunsaturated fatty acids was influenced by fat source added to the diet. The fatty acid profile of the whole carcass of broilers was influenced by the fat source added to the diets.

Pododermatite de contato em frangos de corte

Occurrence of contact pododermatitis in broilers in the State of Minas Gerais, Brazil, is reported. Lesions in the footpad were detected as early as 13 days of age and progressed to ulceration. Histologically, primarily inflammatory and degenerative changes mostly at the epidermal-dermal junction were observed. Retrospective evaluation indicated that pododermatitis in these cases were associated with exposure to high litter moisture during the first days of life.

Efeitos da forma física da ração sobre a digestibilidade dos nutrientes e desempenho de frangos de corte

Two experiments were carried out in order to compare the effects of physical form of ration on feed digestibility and performance of broiler chickens. In the first experiment 480 day-old male Ross broiler chicks were used during the 42 days of trial, following a completely randomized design of three treatments: three physical forms of ration (mash, pellet and expanded-pellet) with eight replicates of twenty birds each. In the second experiment 900 day-old male Ross broiler chicks were used during the 42 day of trial, following the same design, but with 10 replications of 30 birds each. No significant difference in the coefficient of dry matter metabolization was observed. The metabolizable protein was higher in pellet-expanded ration and lower in mash ration (P<0.05). The processing of diet significantly increased the metabolizable ether extract (P<0.05) and values of 68.87, 74.64 and 74.44% were observed for mash, pellet and expanded-pellet rations, respectively. Body weight of broilers increased as the intensity of processing of ration reaching 2.597, 2.828 and 2.874kg for mash, pellet and expanded-pellet rations, respectively (P<0.05). Birds fed processed rations showed higher feed consumption and lower feed conversion (P<0.05). The physical form of ration did not affect viability of birds.

Efeitos do tamanho da partícula e da forma física da ração sobre o desempenho, rendimento de carcaça e peso dos órgãos digestivos de frangos de corte

Compararam-se os efeitos do tamanho da particula e da forma fisica da racao sobre o desempenho, rendimento de carcaca e peso dos orgaos digestivos de frangos de corte. Foram utilizados 900 aves (machos) da linhagem Ross-308, de 1 a 47 dias de idade. O delineamento experimental foi inteiramente ao acaso com arranjo fatorial 3×2 (tres formas fisicas - farelada, granulada e expandida-granulada - e dois tamanhos de particula - media e grossa), com cinco repeticoes de 30 aves. Observou-se efeito de interacao entre granulometria e forma fisica da racao para peso vivo (P granulada > farelada). Nao foram observadas diferencas entre o peso dos frangos que receberam as racoes com granulometria grossa e processadas. Os frangos alimentados com as racoes fareladas e granulometria grossa foram significativamente mais leves em relacao aos frangos dos outros tratamentos. O consumo de racao nao foi influenciado pela granulometria. Observou-se efeito da interacao granulometria e forma fisica da racao para conversao alimentar e viabilidade (P<0,05). Nas racoes com granulometria media a melhor conversao alimentar e a mortalidade mais elevada foram observadas com a racao expandida-granulada. Esse comportamento nao foi observado nas racoes com granulometria grossa. A forma fisica e a granulometria das racoes nao influenciaram o rendimento de carcaca. As racoes processadas produziram frangos com menor peso da moela e maior peso do figado em relacao ao peso corporal.