No abstract

SUMMARYTitan broiler chickens kept in batteries at the Universidad Agraria, Lima, were fed diets containing duckweed (Lemna gibba) in proportions of 0, 10, 15 and 25%. The weight gain of broilers fed 15% duckweed was similar to that of the controls; 25% duckweed in the diet resulted in a significant decrease in feed consumption and weight gain.To determine if Titan and Arbor Acres broiler chickens could be maintained on duckweed diets under commercial conditions, birds were fed diets containing 0 and 5% duckweed. Female birds (Titan and Arbor Acres) fed diets containing 5 % duckweed showed increased final weights. The pigmentation of all birds receiving the diet containing duckweed was significantly increased.Duckweed used at levels of up to 15 % in the diets of broiler chickens could represent an important protein source for poultry feed in developing countries where soyabean meal or fish-meal are not available.

~~ ___ ~-The growth of broiler chickens on diets containing various levels of Lemna gibba was evaluated. Groups of broiler chicks were fed on diets containing 0-400 g Lemna gibbalkg for 3 weeks. These chickens were then changed to standard diets for a further 2 weeks. As the level of Lemna gibba increased, feed consumption and weight gain decreased. However, when diets were changed to the standard diet, compensatory growth was observed. In a second experiment, diets were formulated with a metabolizable energy of 5.02 MJ (1200 kcal)/kg Lemna gibba and included a finer-milled Lemna gibba. Chickens were fed on diets containing 0-300 g Lemna gibbalkg for 4 weeks. Each group was then divided into two subgroups. For the next 2 weeks one of these sub-groups was maintained on the experimental (Lemna gibba) diets (LL), while the other sub-group was changed to a standard diet (LS). Bird fed at levels above 150 g Lemna gibbalkg had decreased consumption and weight gain. These birds when changed to a standard diet tended to have increased weight gain compared with chickens continuously fed standard rations. LS birds had significantly higher weight gains and feed consumption and lower feed conversion than LL birds. In contrast to older birds, chicks fed on Lemna gibba a t high concentrations showed growth retardation. When changed back to a standard diet they demonstrated normal or compensatory growth.

Efecto de un concentrado proteico a base de subproductos de camal avícola sobre el comportamiento productivo de pollos de carne Effect of a protein concentrate based on poultry by-products on the productive performance of broiler chickens

Objectives: To evaluate the inclusion of acidulated soybean oil in diets for rainbow trout alevins (Oncorhynchus mykiss) on its performance under commercial conditions. Methodology: Forty thousand and five hundred rainbow trout alevins were used and raised in ponds. Three levels of acidulated soybean oil included in the diet of 0.0, 2.5 and 5.0 % were evaluated. The study was conducted for 60 days. The variables evaluated were weight gain, feed intake, feed conversion, length gain, survival, growth rate, protein efficiency retention and feed cost / kg of weight. The data obtained were analyzed using the analysis of variance of a completely randomized design. Results: The levels of acidulated oil used in the diets for trout alevins had a similar effect on the evaluated variables . (P > 0.05). Conclusions: The acidulated soybean oil can partially or totally replace the crude soybeanoil, up to 5.0 % in diets for rainbow trout alevinsKeywords: Soybean oil, alevins, trout, performance.