Impact of nutrition on nitrogen, phosphorus, Cu and Zn in pig manure, and on emissions of ammonia and odours

Abstract

In order to reduce N, P and trace elements in pig manure, research toward a better agreement between supply and requirement has been undertaken in recent years, and ways to improve the biological availability of these elements in feedstuffs have been investigated. Substantial reduction in N excreted by pigs can be achieved by phase feeding combined with a better adjustment of the dietary amino acid balance. Feeding pigs with low N diets also allows a reduction of ammonia emission and to some extent the production of malodorous compounds. Phase feeding is also effective in reducing P excretion. However, low digestibility of P in feeds remains the main problem, although it is partly alleviated by the supplementation of pig diets with microbial phytase and the use of highly digestible mineral phosphates. In the same way, lowering Cu and Zn dietary supply is obviously an efficient way to reduce pigs' excretion of Cu and Zn. In a whole-farm perspective, improving the efficiency of nutrient utilisation by the animals is an efficient way to reduce import of nutrients from outside the farm and decrease the environmental risks.

Nutritive value of ensiled pig excreta, poultry litter or urea with molasses or bakery by-products in diets for lambs

“…In pig production systems, faecal nitrogen (N) excretion, which amounts to 17% of the intake, consists of the undigested protein fraction and endogenous N losses, mainly digestive secretions and desquamation of intestinal cells. The remaining amino acids, after protein deposition and obligatory losses, are catabolized and excreted mainly as urea (Dourmad & Jondreville, 2007). In poultry litter (PL), crude protein (CP) content is about 20%, mainly as uric acid (Deshck et al, 1998), though Van Ryssen (2011) recorded broiler litter containing ca.…”

Productive Response of Duroc x Large White and Commercial Hybrid x Large White Crosses Fed High and Low Protein Diets

“…The need of pigs for the essential amino acids was widely studied and the researches confirm their inefficacity in satisfying the non-specific N requirements (Adkins et al, 1966;Allen and Baker, 1974;Featherstone, 1976); furthermore the essential amino acids must be supplied with the diet in certain amounts and proportions to obtain optimum efficiency of utilization of the proteins. Several authors report values of efficiency of dietary protein utilization between 18-40 % (de Lange et al, 1999;Della Casa, 2006;Dourmad et al, 1994;Monteiro et al, 2010;Mordenti et al, 1995, Rossi et al, 2005; according to Dourmad et al 2007, in pigs fed diets based on cereals and soybean flour during breeding-fattening, the N retention is of about 32%. The different protein utilization depends on several factors: composition of the diet, physiological state, growth intensity of the animals, breed and genotype, sex and slaughter weight (Bittante et al, 1990).…”

Life cycle assessment as a tool to evaluate the impact of reducing crude protein in pig diets

“…According to this principle, and as reviewed by DOURMAD & JONDREVILLE (2007), reducing the dietary CP while balancing the diet with feed-use (FU) AA is an effective way of reducing N excretion, as long as pig performance and carcass composition are not adversely affected. These authors reported about 9% reduction in N excretion by growingfinishing pigs per percentage unit of CP reduction, when the dietary CP level was reduced from 178 to 136g kg -1 , without affecting energy efficiency, carcass lean percentage or average daily gain.…”