Dietary self-selection of laying hens inadequate to overcome the effects of high environmental temperature.
Two environmental temperatures, 21 and 30 C, were used during a 28-day experimental period. There were two groups of hens in each temperature treatment. The control groups (C) were given a conventional balanced diet and each dietary self-selection group (S-S) was provided, on an individual hen basis, three diets each one being high in energy, protein, or calcium. The S-S groups had significantly reduced egg production, which probably resulted from the significantly reduced protein intake. Egg weight and energy intake were reduced in the S-S group at 21 C while calcium intake and egg shell strength at 30 C were higher as compared to the corresponding C group. Dietary self-selection did not enable hens to regulate nutrient intake for comparable performance to hens provided one balanced diet. Also, the detrimental effects of high environmental temperature were not overcome by dietary self-selection.
D000818:Animals; D001835:Body Weight; D002136:Calcium, Dietary; D002645:Chickens / Q000502:physiology*; D004044:Dietary Proteins; D002149:Energy Intake; D005260:Female; D005518:Food Preferences; D006358:Hot Temperature; D010058:Oviposition
D002136:Calcium, Dietary; D004044:Dietary Proteins