The tryptophan requirement of broiler chicks.

The "available" tryptophan requirements of male and female broiler chicks were determined at 7-d intervals from 0 to 56 d, using a diet-dilution technique. Availability of tryptophan in the diets was estimated by growth assay with chicks. 2. The tryptophan requirements were 2.4 (males) and 2.2 g/kg of diet (female) from 0-7 d, and 1.7 g/kg (males and females) from 7-35 and 35-56 d. The absolute requirement of the chick for tryptophan increased with age and was significantly different for male and female birds. 3. A highly significantly predictive equation relating tryptophan requirement to mean body weight and gain was established.     

Mucopolysaccharidosis in a domestic short-haired cat--a disease distinct from that seen in the Siamese cat.

A 10-month-old male domestic short-haired cat was examined because of progressive lameness, a broad face with depressed nasal bridge, small ears, corneal clouding, and multiple bone dysplasia. The cat excreted excessive amounts of glycosaminoglycan (a component of connective tissue) in its urine and had evidence of lysosomal storage of glycosaminoglycans in fibroblasts and neurons. Activity of alpha-L-iduronidase, a lysosomal enzyme involved in glycosaminoglycan degradation, was deficient in cultured fibroblasts and leukocytes. The mucopolysaccharidosis was distinct from that seen in Siamese cats in terms of the pathologic changes and the specific enzyme deficiency.     

Isolation of picornavirus from feces and semen from an infertile bull.

Virus was isolated from semen and fecal samples from a bull with orchitis, testicular degeneration, aspermatogenesis, and loss of libido. Both isolates were classified as picornavirus, bovine enterovirus serotype I, on the basis of physical, chemical, and serologic characteristics. Veterinary practitioners that may suspect viral infection as a cause of bovine infertility should submit both semen and fecal samples for virus isolation and identification.