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Biomedical subjects

T S Nelson

Publications and source records attributed to T S Nelson.

40 records · Page 3Linked to original sources

Effect of age of maternal flock and strain on the incidence of tibial dyschondroplasia in growing chicks.

Two experiments were conducted to study the effects of age of the maternal flock (27 vs. 57 weeks of age at time the eggs were set) and strain of broiler chicks (Cobb 500, Ross, Arbor Acres, and Avian) on the incidence of tibial dyschondroplasia (TD) in broiler cockerels grown to 3 weeks of age. The chicks were fed a corn/soybean meal-based diet containing 3145 kcal metabolizable energy corrected for nitrogen retention (MEn)/kg, 24% protein, and 0.50% available phosphorus. Each treatment was replicated four times with eight chicks per pen. In Expt. 1, chicks from the old parent flock had significantly higher body weights (P < or = 0.05) than those from the young parent flock. There were no significant differences in feed efficiency or incidence of TD. In Expt. 2, body weights, feed efficiency, and TD were unaffected by strain.

Animal Feed↗

Digestion of feed by chicks with pale bird syndrome.

Unaffected chicks (normal) and chicks with pale bird syndrome (pale) were fed a control diet or a test diet obtained from the broiler house containing the pale chicks. Pale birds digested less (P less than 0.05) dry matter and ether extract than normal chicks, and the nitrogen content in their feces was greater. The chicks from both sources digested more (P less than 0.05) dry matter from the test feed but also excreted more (P less than 0.05) nitrogen than those fed the control diet. Neither diet resulted in differences in the digestion of ether extract. The cause of pale bird syndrome was related more to source of chicks rather than source of feed. Depigmentation may have resulted from decreased pigment absorption because of reduced absorption of dietary components, including ether extract.

Animals↗

Effect of dietary citrinin on urine excretion in broiler chickens.

Eight 4-week-old broiler chickens were used to study the effects of dietary citrinin on water consumption, urine excretion, and fecal moisture. The birds were colostomized by exteriorizing the colon directly below the vent. Plastic bags were attached to collect feces. Corn containing the various levels of citrinin was fed for 4 hr. Water consumption and urine excretion were measured, and fecal samples were retained for moisture determination. Analysis of variance indicated citrinin increased (p less than 0.05) both water consumption and urine excretion. Regression analysis isolated the linear component as being significant (p less than 0.05) for both water consumption and urine excretion, identifying the responses as linear through the bounds of the treatment levels. Fecal moisture showed no changes (p less than 0.05). The correlation coefficients yielded significant relationships between treatment vs. water consumption, treatment vs urine excretion and water consumption vs urine excretion.

Animals↗

An intermittent problem with tibial dyschondroplasia.

Broilers observed in the summer of 1978 had an excessively high incidence of tibial dyschondroplasia, causing both downgrading and loss of parts from broken legs. No etiological agent was determined. Birds held to 16 weeks of age retained the cartilaginous lesions. Bone ash was not diagnostic. Serology indicated no correlation with infectious bursal disease. No bacteria were isolated. The condition was not observed in the next placement of chicks.

Animals↗