Poultry viscera and bone meal in broiler pre-starter and starter diets

Abstract

The use of viscera and bone meal in poultry pre-starter and starter diets and its effects on performance, digestive organ development and digestibility and nutrient retention were evaluated. In the first assay, 280-day-old Avian Cobb® chicks were allotted in four experimental groups with five replicates of 14 birds each, in the pre-starter phase; in the second assay, 280 eight-day-old Avian Cobb 48® chicks were allotted in four experimental groups with five replicates of 12 birds each. The experimental diet consisted of increasing levels of viscera and bone meal: 0% (control diet), 3%, 6% and 9% in pre-starter (Assay 1) and starter (Assay 2) diets, to meet nutritional requirements and feed composition proposed by the Brazilian Tables, all of them isonutritive and isoenergetic. A metabolic assay was developed and the total excreta collection was performed from the 4th to the 7th days in Assay 1 and from the 14th to the 17th days in Assay 2. On these days, one chick per experimental unit, representing the mean body weight of the parcel, was euthanized to perform digestive organ morphometry. Mean body weight was 45.4±0.4 on the 1st day in Assay 1 and 179.5±0.8 at 8 days of age in Assay 2. In Assay 1, a negative linear effect was observed for weight gain. Levels of viscera and bone meal influenced quadratically nitrogen digestibility index (Y = 66.0101 + 0.482425X - 0.0481086X2) and linearly the digestibility of dry matter (Y = 71.7775 - 0.615792X) and ether extract (Y = 78.3678 - 0.309136X). Morphometric measures of digestive organs were not influenced by viscera and bone meal levels. For Assay 2, negative and linear effect was observed for viscera and bone meal levels on weight gain (Y = 551.667 - 5.08341X) and feed intake (Y = 955.961 - 7.48435X). Quadratic effect was observed for ether extract digestibility (Y = 82.557 + 1.12021X - 0.150117X2) and maximum point was obtained at 3.7% viscera and bone meal inclusion for ether extract retention. Mortality was not affected by treatments in either of the assays. Viscera and bone meal can be used at 3 or 4% inclusion in broiler pre-starter and starter diets.