Improvement of the nutritive value of rye for broiler chickens by gamma irradiation-induced viscosity reduction

A study was undertaken with chickens to determine the effect of irradiation treatment on the viscosity-inducing properties of polysaccharide components of rye. Three-week body weight, food utilisation, fat retention, and bone ash of chicks were substantially improved by irradiating rye (0 to 10 Mrad) and were maximal at 6 Mrad. Irradiation of the entire diet resulted in no further improvement over irradiating the rye fraction alone. The improved performance coincided with radiation-induced damage to rye polysaccharides, as indicated by reduced viscosity and increased concentrations of reducing sugars.

Utilisation of rye by chickens: effect of microbial status, diet gamma irradiation and sodium taurocholate supplementation

Several experiments were conducted to determine the influence of intestinal microflora when rye diets are fed to young chicks. In a conventional environment dietary rye severely depressed growth, amino acid and fat retention, and metatarsal bone ash. These conditions could be effectively alleviated by gamma irradiation of the diet and maintenance in a germ-free environment. In gnotobiotic chicks associated with streptococci dietary rye caused effects similar to those seen in a conventional environment, however the responses were less severe. Since addition of sodium taurocholate improved fat retention from a rye diet to a greater extent than from a wheat diet, a deficiency of conjugated bile salts might contribute to the steatorrhea observed in rye-fed chicks.

Self-selection of calcium during the rearing and early laying periods of White Leghorn pullets

The ability of pullets to selectively consume calcium to meet the requirements of the rearing and early laying period was studied in White Leghorns. In the first of two experiments, 456 pullets were fed either an .89% calcium rearing diet (control) or a .35% calcium diet in combination with a separate source of 38% calcium chick-sized grit (calcium self-selection) from 35 to 126 days of age. Twenty-four pullets from each of these rearing treatments were selected for the second experiment at 112 days of age and were housed in individual laying cages. Rearing treatments were continued until 176 days of age with mash and grit consumption recorded daily for each pullet. From 177 to 225 days of age these pullets were fed a 3.50% calcium diet containing either ground limestone or oyster shell as a calcium source or a .35% calcium diet fed in combination with a separate source of oyster shell. Pullet calcium intake reflected the requirements for growth during the rearing period, calcium storage in the medullary bone 19 days prior to lay, and egg shell formation during the laying period; average calcium intake for these periods was 1.18, 2.08, and greater than 3.50%, respectively. Pullets also demonstrated the ability to compensate for rearing deficiencies by increased calcium consumption when fed oyster shell on an ad lib basis. Calcium consumption was found to be significantly higher on days when an oviposition occurred than when no eggs were laid. Mash consumption during the early laying period also reflected the reproductive status of the hen with the highest consumption on days when both oviposition and ovulation occurred, intermediate consumption when either oviposition or ovulation occurred, and lowest consumption when neither oviposition nor ovulation was detected.

Genetics of the buttercup plumage pattern

Genetic analysis of the Buttercup breed of chickens indicates that they carry the buttercup allele (ebc) at the E locus, modified by the columbian-like primary pattern mutation Db and a secondary pattern gene resulting in autosomal barring. The interactions between ebc and the Db alleles are clarified by both F2 and testcross data. Homozygous ebc in the absence of Db results in a modified stripe pattern, whereas the light parallel back stripes are irregular and wider than those of wild type chicks. The dorsal head stripe is also broken and irregular, while the ground color is of a lighter shade of tan. Adult ebc/ebc db+/db+ males are typical black-breasted wild types as suggested previously by Brumbaugh and Hollander (1965). Adult females closely resemble the brown (eb/eb) phenotype. Further proof that the buttercup gene is an allele at the E locus is provided by F2 segregation data for crosses between Buttercup (ebc/cbc db+/db+) and Light Brown Leghorns (e+/e+ db+/db+) and Black Langshans (E/Edb+/db+).