Composição química e digestibilidade de partes e subprodutos de aves nas formas crua e cozida para cães / Chemical composition and digestibility of raw and cooked chicken parts for dogs

Determinou-se a composição de partes da carcaça - pescoço, dorso e pés de aves -, e sua digestibilidade, usadas para cães nas formas crua e cozida. Os animais, pesados antes e depois do período experimental, foram alimentados uma vez ao dia, com livre acesso ao alimento por uma hora. Cada animal recebeu aproximadamente 50g alimento/kg de peso. As fezes, coletadas diariamente, foram pesadas e congeladas até a realização das análises bromatológicas. Os pés apresentaram os maiores valores de proteína bruta (PB) e matéria mineral (MM), o pescoço, o maior valor de energia bruta (EB), e o dorso, os de matéria seca (MS), matéria orgânica (MO) e extrato etéreo (EE). O cozimento não alterou a composição dos alimentos, entretanto os alimentos cozidos apresentaram teores menores em PB e maiores em EE. Os coeficientes de digestibilidade da MO e da PB do pescoço aumentaram significativamente quando este foi cozido, e os valores de energia metabolizável (EM) e energia digestível (ED) diminuíram. O cozimento do dorso resultou em redução de EM e ED. Os coeficientes de digestibilidade da MS, MO e PB e a ED e EM do pé foram significativamente maiores para os pés cozidos.

In order to use an ingredient to formulate dog foods, it is ideal to the industry to know its properties including the digestibility. So, this work studied the chemical composition and the digestibility of chicken parts used to feed dogs, since they are used frequently by the dog food industry. The ingredients were raw and cooked neck, back, and feet. The animals were weighted before and after the experimental period and food was served once a day. The food was weighted before and after being served. Each animal consumed approximately 50g food/kg body weight. The feces were collected daily and freezed as well as the food until the bromatological analyses procedures. The feet had the highest values for crude protein (CP) and mineral content (MC); while the back, the highest values for dry matter (DM), organic matter (OM), and fat. Cooking had no significant effect on chemical composition of the ingredients. Considering the digestibility coefficient, OM and CP of neck had a significant increase when it was used in the cooked form; but, the metabolizable energy (ME) and the digestible energy (DE) values considerably decreased. For the back, the heat treatment resulted in a significant reduction of ME and DE and the digestibility coefficients of DM, OM, and CP, and ME, and DE of the feet were higher using the same treatment.

Manipulation of the fatty acids composition of poultry meat and giblets by dietary inclusion of two oil sources and conjugated linoleic acid / Mudança na composição de ácidos graxos das vísceras e da carne de aves tratadas com uma dieta contendo ácido linoléico conjugado e duas fontes de óleo

The effect of dietary conjugated linoleic acid (CLA) in association with two vegetable oil sources on the fatty acids of meat and giblets of broiler chickens was evaluated. Two hundred 21-day-old broiler chickens were distributed in a completely randomized factorial design 2 x 5 (two oil sources, soybean or canola oil; and five levels of CLA, 0.0, 2.5, 5.0, 7.5, and 10.0g/kg). The addition of CLA to the diet resulted in an increase (P<0.05) in CLA deposition in the analyzed tissues. CLA supplementation also reduced (P<0.05) the rate of polyunsaturated to saturated fatty acids in thigh, breast, heart, and gizzard. There was interaction of CLA x oil source (P<0.05). The intake of soybean oil, associated with increasing CLA, resulted in an increase in lipid deposition in edible portions as observed by an increase in the overall content of fatty acids, including CLA, while the use of canola oil, associated with increasing CLA in the diet, resulted in a decrease in lipid content in edible portions, specifically regarding that of saturated fat (P<0.05) in breast meat and liver and in the content of monounsaturated fatty acids (P<0.05) in thigh, breast, liver, and gizzard.

Avaliou-se o efeito da suplementação de ácido linoléico conjugado (CLA) associado com duas fontes de óleo na dieta de frangos de corte sobre a composição de ácidos graxos das vísceras e da carne de aves. Duzentos frangos de corte, machos, com 21 dias de idade, foram distribuídos em delineamento inteiramente ao acaso, em arranjo fatorial 2 x 5 (duas fontes de óleo, soja e canola e cinco níveis de CLA, 0,0, 2,5, 5,0, 7,5 e 10,0g/kg). A adição de CLA na dieta resultou em aumento (P<0,05) de sua deposição na carne e nas vísceras de aves. Foi observado decréscimo (P<0,05) na taxa de poliinsaturados:saturados nas carnes da coxa e do peito, no coração e na moela com a suplementação de CLA. Houve interação (P<0,05) CLA x fonte de óleo. O uso de teores crescentes de CLA na dieta contendo óleo de soja na dieta resultou em aumento (P<0,05) no conteúdo lipídico. O contrário foi verificado com a utilização de óleo de canola, especificamente no conteúdo de ácidos graxos saturados (P<0,05) na carne do peito e no fígado e de monoinsaturados (P<0,05) nas carnes do peito e da coxa, fígado e moela.

Research note: putrescine effects on performance of male broiler chicks fed low-protein diets supplemented with essential amino acids.

The purpose of the present study was to determine whether a polyamine deficiency could account for the reduced performance of broiler chicks fed a low-protein diet supplemented with several synthetic amino acids in comparison with those fed a more conventional CP concentration. Male broiler chicks were fed equicaloric diets calculated to contain 23, 20, or 17% CP. Each diet was supplemented with 0, .05, or .10% putrescine in a 3 x 3 factorial arrangement of treatments. Body weight gain of chicks fed the 17% CP diet was significantly (P less than .05) less than that of those fed the higher protein diets and feed conversion ratio significantly increased as the CP concentration decreased. Adding putrescine failed to significantly affect any of the parameters within each CP concentration. A deficiency of polyamines does not appear to explain the lower performance of broiler chicks fed low CP diets with added synthetic amino acids.

Gut stasis in chickens infected with Eimeria.

The duration and locations of gut stasis were examined in chickens infected with either Eimeria acervulina or E. maxima. Gut passage time (GPT) was used to determine gut stasis. The location of feed retention was determined qualitatively and quantitatively. Infections with both species were associated with increased GPT from Days 5 to 13 postinoculation. Feed appeared to be retained in the crop and gizzard of infected birds when judged visually. However, measurements of total dry matter retained in various regions of the gastrointestinal tract did not differ significantly from each other.

Dietary selenium status and plasma thyroid hormones in chicks.

Experiments were conducted to study the effect of marginal levels of selenium and vitamin E on plasma thyroid hormones of meattype chicks. Plasma thyroxine (T4) was significantly increased when a semipurified diet was supplemented with either selenium or vitamin E. Triiodothyronine (T3) was also significantly increased by vitamin E and in one experiment with selenium supplementation. No significant increase in these hormones was observed in birds fed a corn-soybean-meal diet supplemented with these nutrients. Plasma corticosterone level was reduced and weight of the bursa of Fabricius increased by selenium or vitamin E supplementation. These nutrients may be necessary for providing the optimum thyroid conditions for activity of thyroid peroxidase.

Effect of natural feedstuffs added to a semi-purified diet on Eimeria tenella infection.

Experiments were conducted to study the effect of addition of natural feedstuffs to a semi-purified (SP) diet on Eimeria tenella infection of chickens. Chicks were fed the experimental diet throughout the experimental period and were orally inoculated with 200,000 sporulated oocysts of E. tenella at 14 days of age. Addition of corn, but not soybean meal, to a SP diet increased mortality and decreased body weight gain due to the coccidial infection in comparison with chickens fed the SP diet. Addition of corn gluten meal or replacement of poultry fat by corn oil or glucose by corn starch in the SP diet did not significantly change any of the parameters studied. Addition of 20% of corn fermentation solubles (CFS)-but not 20% of distillers dried grains with solubles, wheat bran, or rice bran-to the SP diet, resulted in significantly higher mortality from the coccidial infection. Addition of 5 or 10% of CFS to the SP diet significantly increased mortality in chicks compared to those fed the SP diet, but feeding the residue of CFS after extraction with chloroform-methanol followed by water did not increase mortality. These studies show that corn and CFS contain factors that enhance E. tenella infection in chicks fed a semi-purified diet, but other natural feedstuffs such as soybean meal do not.

Effect of selenium and vitamin E on the development of immunity to coccidiosis in chickens.

Six experiments were conducted using broiler chickens to study the effect of selenium (Se) or vitamin E supplementation of a corn-soybean meal diet on the immune response to coccidiosis. Immunized chickens fed diets supplemented with .25 ppm Se or 100 IU vitamin E/kg of diet had increased body weight gain and feed intake and a tendency for lower feed conversion ratio than chickens fed unsupplemented diet after a challenge with 150,000 oocysts of Eimeria tenella. In two experiments, chickens fed .25 and .50 ppm of Se and immunized against E. tenella had higher body weight gain and a tendency for higher feed intake and lower feed conversion ratio than unsupplemented chickens when challenged with 150,000 oocysts of E. tenella. Except for a reduction on cecal lesion scores and blood packed cell volume in Experiments 1 and 4, respectively, no dietary effect was observed on cecal lesion score or blood packed cell volume of immunized chickens. Dietary supplementation with selenium or vitamin E reduced mortality and increased body weight gain of nonimmunized chickens infected with E. tenella in three of four experiments. These studies suggest that immunization of chickens against coccidiosis is enhanced by Se or vitamin E supplementation.

Effect of selenium on peripheral blood leucocytes of chickens infected with Eimeria.

Experiments were conducted to study the effects of dietary selenium (Se) on peripheral blood leucocytes of chickens infected with coccidia. Primary coccidial infection significantly increased blood leucocyte number at 6 days postinfection (PI) in three of four experiments when chicks were fed a corn-soy diet, and in all four experiments at 11 days PI. When chickens were fed a semipurified (SP) diet, coccidial infection did not affect the blood leucocytes number at 6 days PI but significantly increased blood leucocyte number at 11 days PI. In the primary infection, Se significantly decreased blood leucocyte number in four of six experiments at 6 days PI and significantly increased the blood leucocyte number in three of five experiments at 11 days PI. In the secondary infection, chickens had significantly more blood leucocytes than chickens given a primary infection at 8 or 24 hr after challenge. Selenium significantly increased blood leucocyte number at 8 hr after challenge in one experiment and produced numerically higher leucocyte number in three other experiments. The results of these studies indicate that dietary Se supplementation modifies the number of peripheral blood leucocytes in chickens infected with coccidia.

The effect of feeding a semipurified diet to chickens infected with coccidia.

Four experiments were conducted using broiler chicks to study the effects of feeding a semipurified diet on coccidial infection. Chickens fed a semipurified diet and inoculated with E. tenella had a very mild infection with little or no mortality and no effect on body weight gain, feed intake, feed conversion ratio, and blood cell loss as judged by hematocrit. At necropsy the infected chickens had light cecal lesions. However, no difference in response was observed between chickens fed either the corn-soybean meal or the semipurified diet and inoculated with a mixture of E. acervulina, E. maxima, and E. brunetti. Chickens fed a diet composed of 25% of the corn-soybean meal diet plus 75% of the semipurified diet and inoculated with E. tenella had the same mortality as chickens fed the corn-soybean meal diet. Feeding chickens the semipurified diet as early as 6 days before inoculation did not affect the severity of E. tenella infection. No difference was observed in the intestinal or cecal pH or food passage time of noninfected chickens fed either the corn-soybean meal or the semipurified diet. No differences were found in the number of oocysts discharged between 2 and 9 hr after inoculation expressed as a percentage of the infective dose. The results of these studies show that a semipurified diet ameliorates infection of chickens with the cecal parasite E. tenella but not coccidial infections of the small intestine.

Amelioration of pale bird syndrome in chicks by vitamin E and selenium.

Vitamin E and/or selenium supplementation of a corn-soybean diet fed to broiler chicks in floor pens ameliorated the effect of an outbreak of pale bird syndrome diagnosed when the chicks were 3 weeks old. Supplementation significantly reduced both mortality and the effects of disease on body weight gain. The added nutrients only partly overcame the effect of the disease on body weight gain when infected chicks were compared with uninfected chicks.