Consequences of reduced protein supply from weaning to slaughter

A. Samson, D. Guillou, C. Launay. Conséquences des apports réduits en protéines du sevrage à l’abattage. 43e Journées de la Recherche Porcine, 2011.

14-Mar-2011 (15 years 2 months 24 days ago)
The reduction of protein levels from weaning till slaughter, in keeping with the current French recommendations to reduce pollution (CORPEN, 2003), was evaluated in a feeding trial. The experiment was designed as a split‐split‐plot with 3 consecutive periods (post‐weaning, growing, finishing) and 2 protein levels (‘High’ and ‘Low’) in each period. ‘Low’ protein diets were formulated with 2 percentage points less protein than ‘High’ protein diets, the latter corresponding to the current ‘low pollution’ recommendations, while maintaining constant the levels of the top 4 limiting essential amino acids (lysine, threonine, methionine and cystine) and controlling the tryptophane level, expressed in standardized ileal digestible values.

The trial started with 256 piglets, 112 of which were selected for individual follow‐up in the grow‐finish phase with measurements recorded on: growth rate, feed conversion ratio, and carcass grade. Nitrogen excretion was calculated using actual performance data and feed analysis data.

Reducing the feed protein content below the current ‘low pollution’ recommendations succeeded in further reducing the nitrogen excretion by 5 to 17%, depending on the feed sequence. However, significant production losses were associated with the reduction of protein content: increased duration to reach market‐weight, increased feed conversion ratio, and increased carcass fatness. Imposing further reductions in swine feed protein content would increase the cost of producing pork in current production systems.