Broiler Performance Affected by Nutrients, Not Soybean

Broiler performance was similar when they were fed diets incorporating different sources of soybean meal when these were formulated according to analysed rather than calculated amino acid digestibility, according to new research from Spain.
A previous study by M.P. Serrano and colleagues at Ciudad Universitaria in Madrid showed that pelleting improves the performance of broilers up to 42 days of age, and that the source of soybean meal – US, Brazil or Argentina – can also have a significant impact on growth.
To investigate these effects, they conducted two experiments to determine the apparent ileal digestibility (AID) of the amino acids of four commercial soybean meals from the United States (USA-1, 48.1 per cent crude protein and USA-2, 46.2 per cent crude protein), Brazil (BRA, 47.6 per cent crude protein) and Argentina (ARG, 46.3 per cent crude protein) and the effects of the inclusion of these soybean meals in diets in mash, crumble or pellet form on growth performance, total tract apparent retention of nutrients and digestive organ size in broilers reared in cages from 1 to 25 days of age.
According to their latest paper published recently in Poultry Science, they found that crumbling or pelleting of the diets improved growth performance of broilers and that diets formulated with analysed rather than calculated AID of amino acids in soybean meal sources resulted in similar broiler performance.
In their first experiment, the AID of lysine was higher (P<0.05) for USA-2 than BRA, with USA-1 and ARG being intermediate. For the second experiment, 12 diets were arranged as a 3×4 factorial with three feed forms (mash, crumbles and pellets) and the same four soybean meal sources as before. The feeds were iso-nutritive and the AID of the amino acids in soybean meal obtained in experiment 1 was used for diet formulation. Broilers fed mash had lower (P<0.001) average daily feed intake and average daily gain and poorer (P<0.001) feed-to-gain ratio than broilers fed crumbles or pellets but soybean meal source did not affect performance. Nitrogen retention was higher (P<0.01) in birds fed mash than in birds fed crumbles or pellets at all ages. Total tract apparent retention of nutrients was lower (P<0.05) for the BRA and ARG diets than for the USA-1 and USA-2 diets. Gizzard empty relative weight (as a percentage of bodyweight) was higher and gizzard pH lower for broilers fed mash than for broilers fed crumbles or pellets (P<0.001).