VetSRev
Database of veterinary systematic reviews
Database of veterinary systematic reviews
Agriculture, Ecosystems & Environment (2020) 289:
DOI: 10.1016/j.agee.2019.106748
Inappropriate management of pig manure contributes considerably to pollution of waterbodies by nitrogen (N) and phosphorus (P), and to air pollution by ammonia (NH_\textrm3) and hydrogen sulfide (H_\textrm2S) emissions. Dietary manipulation is recognized as a possible pollution mitigation measure, but it may affect pig growth and thereby production costs. Here we present a global meta-analysis of the effects of dietary manipulation on nutrient (N and P) excretion, gaseous (NH_\textrm3 and H_\textrm2S) emissions from manure, and growth performance of pigs, using data from 245 published studies. Four groups of dietary manipulation were distinguished, namely (i) lowering dietary crude protein (CP) content, (ii) supplementing exogenous enzymes, (iii) supplementing fermented feed ingredients, and (iv) supplementing other additives (e.g. fermentable carbohydrates, acidifying agent/salts and probiotics) in feed. In addition, the cost-effectiveness of dietary manipulations was evaluated, expressed as US per kg N excretion abated. Results show that lowering CP content significantly reduced both total N excretion (28.5%) and NH_\textrm3 emissions (34.4%). Addition of protease reduced N excretion (18.2%) but did not affect NH_\textrm3 emissions. Supplementing other additives simultaneously reduced NH_\textrm3 emissions (21.5%) and H_\textrm2$S emissions (23.2%). Adding phytase to feed significantly decreased total P excretion by 31.4%. Diets with fermented feed ingredients tended to decrease N excretion and emissions, but this effect was not statistically significant. All dietary manipulations significantly improved the growth performance regarding the weight gain and feed efficiency, except for lowering CP content. But lowering dietary CP content within a moderate level in combination with adding additional amino acids did not impair pig growth. The cost-effectiveness analysis indicated that various diary manipulation measures were economically beneficial to farmers through improved feed-to-meat conversion efficiency. Our results can support to the design of proper dietary formulations so as to simultaneously reduce N and P excretion and associated emissions, meanwhile enhance the growth performance of pigs with lower economic cost.
Wang, H. L., Long, W. T., Chadwick, D., Velthof, G. L., Oenema, O., Ma, W. Q., Wang, J. J., Qin, W., Hou, Y., & Zhang, F. S. (2020). Can dietary manipulations improve the productivity of pigs with lower environmental and economic cost? A global meta-analysis. Agriculture, Ecosystems & Environment, 289(106748). https://doi.org/10.1016/j.agee.2019.106748 hogs, pigs, swine, meta-analysis, Animal Nutrition (Production Responses) [LL520], effects, liveweight gain, liveweight gains, Animal Nutrition (General) [LL500], carbohydrates, diets, saccharides, data analysis, research, studies, composition, crude protein, feeding stuffs, feeds, Forage and Feed Products (Non-human) [RR000], ammonia, productivity, growth rate, feed conversion efficiency, amino acids, emissions, performance, excretion, weight gain, enzymes, additives, production costs, sustainability, probiotics, emission, Nutrition related Disorders and Therapeutic Nutrition [VV130], phosphorus, environmental pollution, pollution, Pollution and Degradation [PP600], adjuncts, Animal Wastes [XX100], cost benefit analysis, farmers, phytases, pig manure, proteases, proteinases, salts