Comparative Performance and Carcass compsition of two Groups of Pekin Ducks Reared Mixed or Sex-segregated

The lack of clear sexual dimorphism in Pekin ducks as well as the cost of sexing duckling at day of hatching are reasons that justify rearing males and females together. However, many factors tend to favour segregate rearing of duckling including the consumer demand for uniformity of carcass and further processed items, the difference in body weight between males and females, the low feed efficiency during the 7th wk of growth, and the possibility of reducing the growth period. Pekin males possess a faster growth rate than females, better feed efficiency, and lower fat content in their carcass. In previous studies, we observed that the growth rate of the 2 sexes starts to be different at 5 wk of age.[...

Assessment of Feeding Program During the Rearing Period of Pekin Ducks Selected as Breeders for Lean Meat Production

Pekin ducks are known to deposit a thick layer of subcutaneous fat in the breast area, a characteristic that is less pronounced in the chicken. In previous studies, it was observed that Pekin ducks show a great variability in live body weight and leanness (as measured by breast muscle thickness) at market age. This observation provides a good basis for possible improvements of the carcass through selection and breeding of leaner ducks. Ultrasound scanning is a useful technique to assess the carcass merit of the live animal. It has been widely and successfully used in beef cattle and swine for the estimation of carcass yield. It is well recognized that the feed intake of Pekin ducks must be restricted during the development period before sexual maturity (24 weeks of age) to prevent excess body fat deposition which significantly reduces their reproductive performance. Ducks being raised for market reach their approximate adult size at around 8 weeks of age and thereafter require mainly enough food for maintenance plus a small amount for activity and growth.[...

Performance and Carcass characteristics of Pekin and Muscovy Ducks Fed diets Based on Food Wastes

Throughout the world, there is a strong agreement over the necessity for enhancement of environmental protection and achievement of a sustainable agriculture. The world's growing human population and its demand for more food production have to fall within the capacity of the earth's ecological systems. Approximately 40% of the world's grain production is consumed by livestock and that percentage increases up to 70% in certain countries. As the green revolution is no longer enough to cope with the population explosion, experts urge the search for alternative feeding systems because the only grain reserve in case of an emergency is the grain used in animal production.[...

Reproductive Performance of F1 Pekin Duck Breeders Selected with Ultrasound Scanning for Breast Muscle Thickness and the Effect of Selection on F2 Growth and Muscle Measurement

Reducing fatness in farm animals has been most successful with pigs by selective breeding because the body fat in the pig is mainly subcutaneous and its measurement on live animals can be assessed. Duck fat distribution follows closely a similar pattern as in the pig since the body fat presence in this poultry species is the subcutaneous deposits that cannot be removed during processing. However, reducing body fat content in pigs resulted in poor reproductive performance. In poultry, selection for maximum weight gain has led to increased body fatness which negatively correlates with body protein, which in turn positively correlates with egg production.[...

Energy and Digestibility Values of Food Wastes

There are many important reasons for the determination of the metabolizable energy (ME) values of feed ingredients used in formulating diets for poultry. These reasons include balanced formulation of rations where energy is the reference component, and efficient utilization of feedstuffs when feed accounts for approximately 60 % of the production cost. On the same path, determination of nitrogen retention is also important because of its relation to protein synthesis and to reducing nitrogen excretion for environmental concerns. Bioavailable energy of feedstuffs represents 70 % of the 60 % cost and hence is 40 % of the cost of feed.[...