Effect of vitamin E levels on the cell-mediated immunity of broilers vaccinated against coccidiosis

Studies on the relationships between animal nutrition and immunity have sought reliable methodologies to measure responses. Cell-mediated immune response is similarly studied in humans. The cutaneous basophil hypersensitivity test (CBH) is one of the methods to measure that response and consists in the infiltration of inflammatory cells, particularly of lymphocytes and basophils, as result of the application of substances capable of inducing cell proliferation in determined sites, such as wings, wattle, and interdigital space in birds. CBH is considered a simple and fast method and can be applied in birds of different ages. In immunocompetence studies with poultry, phytohemagglutinin-P (PHA-P) is a commonly used substance, despite the variability of the response related to the method of application (intradermal injection) and the antigens used. In the present experiment, PHA-P was used to observe the cell-mediated immune response of 216 chicks fed three dietary levels of vitamin E from 1 to 36 days of age. All birds were immunologically challenged by vaccination against coccidiosis at three days of age and against Newcastle Disease (NCD) at 14 and 30 days of age. At 36 days of age, birds were submitted to the CBH test according to the methodology of Corrier & DeLoach (1990). Birds fed 65mg/kg of vitamin E presented lasting cell reaction (p<0.08), which indicates that this vitamin E level improved cell immune response of birds due to its antioxidant and immunomodulating properties. The use of this vitamin E level can be considered by nutritionists under practical conditions, aiming to improve broiler immunity.(AU)

Effect of vitamin E levels on the cell-mediated immunity of broilers vaccinated against coccidiosis

Studies on the relationships between animal nutrition and immunity have sought reliable methodologies to measure responses. Cell-mediated immune response is similarly studied in humans. The cutaneous basophil hypersensitivity test (CBH) is one of the methods to measure that response and consists in the infiltration of inflammatory cells, particularly of lymphocytes and basophils, as result of the application of substances capable of inducing cell proliferation in determined sites, such as wings, wattle, and interdigital space in birds. CBH is considered a simple and fast method and can be applied in birds of different ages. In immunocompetence studies with poultry, phytohemagglutinin-P (PHA-P) is a commonly used substance, despite the variability of the response related to the method of application (intradermal injection) and the antigens used. In the present experiment, PHA-P was used to observe the cell-mediated immune response of 216 chicks fed three dietary levels of vitamin E from 1 to 36 days of age. All birds were immunologically challenged by vaccination against coccidiosis at three days of age and against Newcastle Disease (NCD) at 14 and 30 days of age. At 36 days of age, birds were submitted to the CBH test according to the methodology of Corrier & DeLoach (1990). Birds fed 65mg/kg of vitamin E presented lasting cell reaction (p<0.08), which indicates that this vitamin E level improved cell immune response of birds due to its antioxidant and immunomodulating properties. The use of this vitamin E level can be considered by nutritionists under practical conditions, aiming to improve broiler immunity.

Effect of vitamin E levels on the cell-mediated immunity of broilers vaccinated against coccidiosis

Studies on the relationships between animal nutrition and immunity have sought reliable methodologies to measure responses. Cell-mediated immune response is similarly studied in humans. The cutaneous basophil hypersensitivity test (CBH) is one of the methods to measure that response and consists in the infiltration of inflammatory cells, particularly of lymphocytes and basophils, as result of the application of substances capable of inducing cell proliferation in determined sites, such as wings, wattle, and interdigital space in birds. CBH is considered a simple and fast method and can be applied in birds of different ages. In immunocompetence studies with poultry, phytohemagglutinin-P (PHA-P) is a commonly used substance, despite the variability of the response related to the method of application (intradermal injection) and the antigens used. In the present experiment, PHA-P was used to observe the cell-mediated immune response of 216 chicks fed three dietary levels of vitamin E from 1 to 36 days of age. All birds were immunologically challenged by vaccination against coccidiosis at three days of age and against Newcastle Disease (NCD) at 14 and 30 days of age. At 36 days of age, birds were submitted to the CBH test according to the methodology of Corrier & DeLoach (1990). Birds fed 65mg/kg of vitamin E presented lasting cell reaction (p 0.08), which indicates that this vitamin E level improved cell immune response of birds due to its antioxidant and immunomodulating properties. The use of this vitamin E level can be considered by nutritionists under practical conditions, aiming to improve broiler immunity.

Comparison of the effects of semi-refined rice oil and soybean oil on meat oxidative stability, carcass yield, metabolism, and performance of broilers

Two experiments (EXP 1 and EXP 2) were conducted to compare soybean oil (SO) and semi-refined rice oil (RBO) added to broilers diets. In EXP 1, 400 male Ross x Ross 308 broilers were reared in battery cages, and their performance was evaluated. A metabolism assay was performed. In EXP 2, 1344 broilers from the same strain were reared in floor pens with rice husks litter. In addition to performance, carcass yield and meat oxidative stability were evaluated. In both EXP, birds were distributed in a 2x4 factorial arrangement, with two types of oils (SO or RBO) and four oil inclusion levels (1%, 2.5%, 4%, or 5.5%). Two periods were considered: starter (1 to 21 days of age) and grower (22 to 42 days). In both EXP, oil type had no influence on starter performance. Although treatments promoted similar in weight gain (WG) and feed intake (FI), grower birds fed RBO had better feed conversion (FCR) in EXP 2, but not in EXP1. In both trials, increasing dietary oil levels negatively influenced FI and positively FCR. Weight gain was similar among all treatments in EXP 1, whereas in EXP 2, WG was higher when 4 and 5.5% oil was included in the feed. RBO presented 94% fat metabolizability, and crude energy and metabolizable energy levels of 9.260 and 8.714 kcal/kg, respectively. Carcass yield was not influenced by oil type; however, oil inclusion level negatively affected breast yield. The experimental treatments had no effect on meat oxidative stability. RBO can be used as an alternative to soybean oil in broilers diets.

Comparison of the effects of semi-refined rice oil and soybean oil on meat oxidative stability, carcass yield, metabolism, and performance of broilers

Two experiments (EXP 1 and EXP 2) were conducted to compare soybean oil (SO) and semi-refined rice oil (RBO) added to broilers diets. In EXP 1, 400 male Ross x Ross 308 broilers were reared in battery cages, and their performance was evaluated. A metabolism assay was performed. In EXP 2, 1344 broilers from the same strain were reared in floor pens with rice husks litter. In addition to performance, carcass yield and meat oxidative stability were evaluated. In both EXP, birds were distributed in a 2x4 factorial arrangement, with two types of oils (SO or RBO) and four oil inclusion levels (1%, 2.5%, 4%, or 5.5%). Two periods were considered: starter (1 to 21 days of age) and grower (22 to 42 days). In both EXP, oil type had no influence on starter performance. Although treatments promoted similar in weight gain (WG) and feed intake (FI), grower birds fed RBO had better feed conversion (FCR) in EXP 2, but not in EXP1. In both trials, increasing dietary oil levels negatively influenced FI and positively FCR. Weight gain was similar among all treatments in EXP 1, whereas in EXP 2, WG was higher when 4 and 5.5% oil was included in the feed. RBO presented 94% fat metabolizability, and crude energy and metabolizable energy levels of 9.260 and 8.714 kcal/kg, respectively. Carcass yield was not influenced by oil type; however, oil inclusion level negatively affected breast yield. The experimental treatments had no effect on meat oxidative stability. RBO can be used as an alternative to soybean oil in broilers diets.