Linoleic acid requirement of turkey poults

Effect of dietary fatty acids on humoral immune response of turkeys

1. This study examined the effect of increasing amounts of dietary polyunsaturated fatty acids on the fatty acid composition in serum and antibody production following a standard vaccination programme in growing turkeys. Turkey poults were fed on 5 diets containing 75g/kg added fat made up of different proportions of palm and soyabean oils, and were vaccinated against Newcastle disease, infectious bronchitis and necrotic enteritis according to a standard vaccination programme. Blood samples were taken before and one week after each vaccination. 2. Fatty acid composition in serum reflected the composition of the diets although arachidonic acid concentration was not changed by dietary fatty acid content. Growth, erythrocyte and leukocyte parameters were not affected by the respective diets. 3. Specific antibody production was related quadratically to serum linoleic and total n-6 polyunsaturated fatty acid concentrations. No correlation was found with linolenic or arachidonic acids. 4. It is concluded that dietary fatty acid composition can augment the specific anti-vaccine immune response in turkey poults.

Fatty acid requirements of breeding turkeys

1. Turkey hens were fed during the breeding period on 5 diets containing different amounts of linoleic acid and total fat provided by varying supplements of maize or olive oils. 2. Reproductive performance of the turkeys increased in response to dietary linoleic acid. Eleven g linoleic acid/kg diet gave optimum poult production. 3. Egg weight did not show a significant response to dietary fat content. 4. Adipose tissue fatty acid composition of the hens was influenced by dietary oleic and linoleic acid content.

Response of growing turkeys to dietary energy levels

Two consecutive trials were conducted with male Large White turkeys grown from day-old to 20 weeks of age on diets formulated to contain 0, 2, 4, 6, and 8% fat with constant amino acid energy ratios. The addition of 2 and 4% fat significantly improved body weight gain; higher levels gave no further improvement. Feed conversion efficiency was improved by the addition of fat to the diet, but caloric efficiency remained relatively constant over the range of energy levels, indicating that there was not "extra-caloric" effect of fat observed in this study. Possible contributions of methods of feed formulation toward the possibility of the occurrence of this phenomenon are discussed.

Sulfur amino acid requirement and foot pad dermatitis in turkey poults

Five experiments were conducted with Large White poults to determine the effect of methionine and other sulfur-containing compounds on the incidence and severity of dermatitis and on growth and feed efficiency to three or four weeks of age. The poults were housed in battery brooders with wire screen floors in four experiments" and in floor pens with litter in one experiment. Male turkeys were used in four experiments and female turkeys in one experiment. Either a corn-soy diet or a cornstarch-soy diet was used as the basal diet in the various studies. A high incidence of foot-pad dermatitis was observed in poults fed the basal diets unsupplemented with methionine. A high incidence of a dermatitis on the upper part of the beak was also observed in poults maintained in battery brooders but not in floor pens. Adding methionine to the diets significantly lowered the incidence and severity of dermatitis, but cystine and potassium sulfate failed to modify dermatitis. Some foot-pad dermatitis was still observed in poults fed levels of methionine more than adequate to meet the requirements for optimum growth and feed efficiency. The incidence and severity of foot-pad dermatitis generally increased with age during the experiment among poults fed methionine-supplemented diets. Although methionine deficiency is a major cause of foot-pad dermatitis in poults, other environmental or dietary factors also appeared to be involved in the development of the condition. The methionine requirement for optimum growth, feed efficiency, and prevention of dermatitis was approximately 0.6% or 2.1 g. per mcal. of metabolizable energy (M.E.). This is higher than the present recommendation of the National Research Council. With corn-soybean meal diets the requirement for total sulfur amino acids is approximately 1.05% or 3.7 g. per mcal. of M.E.