Economies in the use of animal by-products in poultry rations: II. Vitamin and amino-acid provision for laying hens

Abstract

1. Birds fed on rations devoid of animal byproducts from hatching until 18 months of age were equal in laying performance and health to those that had received animal supplements.2. The stimulation of early growth by feeding aureomycin did not affect the final weight of pullets, their egg production or the incidence of broodiness.3. The ‘animal protein factor(s)’ was of limited importance for egg production. There was a suggestive indication of an effect of a deficiency of the factor(s) when birds on an all-plant ration had been laying for 6 months without access to their droppings. Limited access to ‘unfermented’ droppings, which provided the only dietary source of the factor(s) during both rearing and laying periods, was sufficient to meet the need of the birds for sustained egg production.

The Continuous Feeding of an Antibiotic to Laying Hens

“…Sample birds of greater dry eviscerated weight gained pro-A NTIBIOTICS fed to hens at low levels, i. under 10 grams per ton, showed no effect on egg production or on any other factors studied in experiments conducted by several investigators (Berg et al, 1952;Petersen and Lampman, 1952;Brown et al, 1953;Carpenter et al, 1954;Sherwood and Milby, 1954). This difference was about 0.5% when measurements were made soon after chilling and about 0.3% after the birds were shipped about 300 miles.…”

Effect of Nutrient Density and Protein-Energy Interrelationships on Reproductive Performance of the Hen

“…^V TUMEROUS investigations have shown -^ ^ that reasonable rates of egg production could be achieved with rations which represent a range in protein content from 11 to 18% (Graham, 1934;Heiman et al, 1956;Reid et al, 1951;Carpenter et al, 1954;Heywang et al, 1955;Thornton et al, 1956;Milton and Ingram, 1957;and Hochreich et al, 1958).…”

Economies in Pig and Poultry Feeding

“…Combinations of cereals, wheat offals and groundnut meal, containing 14% protein meet the needs of indoor birds but combinations of plant products containing only I I yo are deficient in protein. However, I I yo protein in the ration is close to adequacy for indoor birds when 8 out of the 11% is derived from cereals and the remaining 3% from fish meal (Carpenter, Duckworth & Ellinger, 1954).…”