Determination of Nutrient Mass Balance in Turkeys

Abstract

Retention and excretion of phosphorus and nitrogen were determined for turkeys fed 2 diets at 3 ages, via mass balance based on the nutrient content of consumed feed, carcasses, and litter. The 2 diets consisted of an industry diet (IND) and a low phosphorus + 600 U of phytase/kg (LP) diet. A subsample of birds was weighed and killed at 12, 15, and 18 wk of age for nutrient retention (via whole carcasses) and excretion (via litter). Diet did not affect BW or feed intake from 12 to 18 wk of age. The mass of phosphorus excreted from 0 to 12, 0 to 15, and 0 to 18 wk of age was 37, 46, and 40% greater for birds fed the IND diets compared with birds fed the LP diets. Phosphorus retained as the percentage of phosphorus consumed was greater at 12, 15, and 18 wk for birds fed the LP diets (67.0, 63.8, and 53.8%) than for birds fed the IND diets (47.3, 44.0, and 32.8%). The difference between the mass of phosphorus excreted, as calculated from litter, compared with feed intake minus carcass retention was less than 5% at 18 wk. The nitrogen retained averaged 90.7, 136.7, and 184.2 g/bird, whereas nitrogen excreted averaged 377.6, 620.7, and 921.8 g/bird at 12, 15, and 18 wk of age, respectively. Additionally, with an 18-wk average litter DM of 78.0%, the unaccounted for nitrogen at 18 wk was 427 and 405 g/bird for birds fed the IND and LP diets, respectively (40 and 37% of excreted nitrogen).

The response in jejunal and ileal nutrient and energy digestibility and the expression of markers of intestinal inflammation in broiler chickens to coccidial vaccine challenge and phytase supplementation

“…Phytase has been used extensively in poultry to improve digestibility of phytate-bound P and to minimize P excretion into the environment (Adedokun et al 2004;Applegate et al 2008;Adeola and Cowieson 2011). However, the amount of improvement as a result of exogenous phytase supplementation differs between studies as a result of feed ingredient types, diet matrix, and age of birds (Adeola and Cowieson 2011).…”

Influence of rearing conditions and manure management practices on ammonia and greenhouse gas emissions from poultry houses

“…with increasing age and weight, N excretion per day per bird increases due to higher daily feed intake (NRC, 1994;Smith et al, 2000;Pope et al, 2004;Applegate et al, 2008). with increasing age and weight, N excretion per day per bird increases due to higher daily feed intake (NRC, 1994;Smith et al, 2000;Pope et al, 2004;Applegate et al, 2008).…”