Toxicity of DDT to Laying Hens
White Leghorn hens were fed diets containing 0, 300, 600, or 1200 ppm technical grade DDT for three 28-day periods. The 1200 ppm diet caused tremors and 33% mortality in the final period, but no gross toxicity symptoms were seen in birds fed the other diets. Egg production was decreased during the third period by 600 or 1200 ppm. Egg weight was decreased during the third period by 600 or 1200 p...متن کامل
DURING 2007, all laying hen producers within the McDonald’s Restaurants UK supply base (McDonald’s Restaurants UK source eggs from free-range UK producers) were required to plant, if not present already, 5 per cent of the total range area in trees. Noble Foods supply free-range eggs into a variety of food retailers not all of which require tree cover on the range. In this study, the authors inv...متن کامل
The bacterium Erysipelothrix rhusiopathiae can infect a wide range of mammals (including humans) and birds. Disease outbreaks (erysipelas) have been considered unusual in chickens internationally, but outbreaks with high mortality and egg production losses have been diagnosed in Swedish laying hen flocks every year since 1998. Different aspects of E. rhusiopathiae infection in chickens were exa...متن کامل
Comparative gonadotrophic potency of anterior pituitaries from cocks, laying hens and non-laying hens in molt.
A bulk of studies on the assay of gonadotrophic hormone content of the anterior pituitary from the animals in various reproductive conditions has been done. Riley and Fraps(1942b) assayed pituitary glands from chickens in various reproductive stages, judging the gonadotrophic potency by the increment of uterine weights of immature mice, and concluded that glands from non-laying hens produced a ...متن کامل
Expression of peroxisome proliferator-activated receptor-alpha (PPARalpha) has been shown in liver of chicks, but effects of its activation have not yet been investigated. In this study, laying hens were treated with clofibrate, a synthetic PPARalpha agonist, to investigate the effects of PPARalpha activation on liver lipid metabolism. Hens receiving a diet containing 5 g of clofibrate/kg had a...متن کامل
عنوان ژورنال: Poultry Science