J. E. Jones

Growth and carcass composition of female turkeys implanted with anabolic agents and fed high-protein and low-protein diets.

This laboratory investigated the anabolic effect of the synthetic steroid trienbolone acetate (TA) and found it effective in male and female meat turkeys without any apparent gross abnormalities (Poultry Sci., 61: 1386, 1982). The present study was undertaken to characterize the response of female turkeys, fed equicaloric diets varying in dietary protein density to anabolic agents implanted at 13 wks. TA and zeranol (Z) were tested singly and in combination (TAZ). Body weight gain and feed conversion at 16 wks of age were improved (P less than 0.01) with TA and TAZ. The response to TA was enhanced as dietary protein density increased. Carcass fat, protein, ash, energy, potassium, and calcium were not altered by implant treatment. A trend existed toward increased carcass fat with zeranol implantation. Carcass moisture (P less than 0.01) and sodium (P less than 0.05) were increased in the TA treatment. Blood plasma electrolytes were not affected by implant treatments but plasma calcium was decreased (P less than 0.05) by TAZ. No synergism was noted between TA and Z with respect to growth, feed conversion, carcass composition, plasma electrolytes with the exception of plasma calcium. No interaction was observed between dietary protein density and implant treatment. Performance variables increased and carcass fat decreased with increasing dietary protein density. These results confirm our earlier finding with respect to TA and provide additional evidence that dietary protein density influences the response of meat turkeys to TA. The data show that zeranol lacks an anabolic effect in turkeys.

The amylase gene−enzyme system of chickens. I: Allozymic and activity variation

Amylase allozymic and activity variation was studied in three flocks of chickens (Gallus domesticus). Individuals from one flock were studied to assess the effects of sex, tissue, and genotype on amylase activity. Additionally, the allozymes were purified and their specific activities compared. Variation was observed within and among the flocks. Two alleles were found to be segregating in the flocks, one flock being polymorphic and the other two monomorphic. Mean amylase activities among the three flocks were significantly different. The relationship of this activity variation to regulatory variation is discussed. There were no significant effects of sex or genotype on amylase activity and, in most cases, no correlation between activities in the various tissues. However, in heterozygotes one of the alloamylases had much lower activity than the other.

High dietary niacinamide and performance of male poults at 16 weeks of age

1. Male poults were fed diets with 50 and 100 mg supplemental niacinamide/kg and grown at stocking densities of 3.2 and 4.3 birds/m2 from 56 to 112 d. 2. At 50 mg/kg niacinamide high stocking density (HSD) depressed 112 d body weight and gain from 56-112d. High dietary niacinamide (100 mg/kg alleviated the growth depression under HSD but decreased body weight gain under low stocking density (LSD). 3. Dressed yield and hock width were not affected by dietary niacinamide or stocking density. 4. Dressed carcase composition was altered by stocking density. The dressed carcase of HSD birds contained 3.7% more protein and 7% less fat. 5. High dietary niacinamide tended to increase carcase protein (+2.4%) and decrease carcase fat (-4.0%).