The Effects of Dietary Protein Level on Productive Performance and Egg Quality of Four Strains of White Leghorn Hens

Abstract

The effects of a mid-laying period reduction in dietary protein level on productive performance was studied with 576 individually caged Single Comb White Leghorn hens from four strains. The hens on treatments 1 and 2 received diets that contained by calculation 17 and 15% protein, respectively, between 143 and 507 days of age, while those on treatment 3 received 17 and 13% protein diets from 143 to 325 and 326 and 507 days, respectively. For treatment 4, diets containing 15 and 13% protein were given during the same periods as for treatment 3. Egg quality measurements were taken on eggs laid over 5-day intervals when the birds were 182, 252, 316, 380, 436, and 485 days of age. Dietary protein level had no significant effects on feed intake, mortality, body weight, egg production, egg grade, specific gravity, egg weight, Haugh units, or blood spots. Protein intake had no effect on the 507-day body weights and on hen-day egg production, except for a small decrease for treatment 4, although the intakes of protein, leucine, and lysine were lower for treatments 3 and 4 between 326 and 507 days of age than the NRC requirements. Level of dietary protein had no effect on kg feed/dozen eggs but had a significant (P<.01) effect on kg feed/kg eggs. Strain of bird had a significant effect on body weight, egg production, specific gravity, egg weight, Haugh units, and blood spots at 485 days. There were no significant protein level X strain interactions.

Effects of Sodium Plus Potassium to Chloride Ratio in Practical-Type Diets on Blood Gas Levels in Three Strains of White Leghorn Hens and the Relationship Between Acid-Base Balance and Egg Shell Strength ,

“…These results agree with those reported by Hamilton et al (1979), but earlier Gowe (1977) and Hamilton (1978b) reported significant differences in albumen quality expressed as Haugh units. Generally, there was little evidence of effects on the egg from changes in the (Na+K)/Cl ratio.…”

Inbreeding Effects on Layer Performance at Two Levels of Protein Intake

“…The absence of any major genotype-protein level interaction in this study is in agreement with recent results of Hamilton (1978) but in contrast to results published by Deaton and Quisenberry (1965) for 14% to 17% protein rations and four egg production stocks; by Moreng et al (1964) for 13 to 17% protein and four commercial egg stocks; and by Harms et al (1966) for 11% to 17% protein and six stocks. In the last study, the interaction involved either the one meat line or ration protein levels outside the range of the present study.…”

“…The results of Deaton and Quisenberry (1965) are difficult to compare with those of the present study because the two rations they used each involved changes in protein level during the laying period. The lack of strain x protein level interaction in Hamilton's (1978) report may be explained by the small direct effects of either strain or protein levels on performance. Moreng et al (1964) concluded that their interaction was probably due to the failure of one strain to assimilate sufficient quantities of at least one amino acid.…”

Investigation on the Effects of Various Protein Levels with Constant Ratio of Digestible Sulfur Amino Acids and Threonine to Lysine on Performance, Egg Quality and Protein Retention in Two Strains of Laying Hens

“…Researchers found no changes in Haugh units in the early phase (20-43 weeks of age) of the production cycle when feeding low protein diets (Novak et al, 2006;Deaton and Quisenberry, 1965;Aitken et al, 1973;and Leeson and Caston, 1997). On the other hand, Hamilton (1978) observed no clear change in Haugh units when feeding low protein diets to 4 different strains of laying hens.…”