title: The protein requirement of laying pullets with changing seasons in the tropics.
abstract: 1. The protein requirements of White Leghorn laying pullets were evaluated in summer and winter using isocaloric diets containing 12-8, 15-0, 16-6, 18-5 and 21-6% protein. 2. The age at 50% production of summer-raised pullets was about 2 weeks later than that of winter-raised pullets irrespective of the concentration of dietary protein. 3. Egg production in summer-increased with increasing concentrations of protein up to 18-5%; further increases had no significant effect: in winter, egg production was similar provided the diet contained at least 15-0%. 4. The data on egg production, food consumption and egg weight indicated that the protein requirement of White Leghorn pullets is met by diets containing about 19% protein in summer and 15% in winter.
mesh_terms: D000818:Animals; D002645:Chickens / Q000378:metabolism* / Q000502:physiology; D004044:Dietary Proteins / Q000378:metabolism*; D004531:Eggs; D005260:Female; D009751:Nutritional Requirements; D010058:Oviposition; D012621:Seasons; D012741:Sexual Maturation; D014329:Tropical Climate
chemical_list: D004044:Dietary Proteins