Feed efficiency in rabbit farming: ways of improvement, technico-economical and environmental impacts

Abstract

Despite substantial advances in breeding efficiency over the last 40 years, feed still represents the majority of production cost (± 60 %). Feed efficiency, mostly expressed as Feed Conversion Ratio (FCR), is a key indicator to judge the financial and environmental performance of a farming system. Moreover, by improving feed efficiency, excretion and gas losses in the environment are reduced. In conventional rabbit farming, the average farm FCR (maternity + fattening units) in European farms was decreased by 10 % (decrease from 3.8 to 3.4) during the past 15 years, as well as nitrogen and phosphorus excretion. This improvement can be attributed to joint progress in health control, feeding strategies (including feed restriction), housing management and genetic potential of animals. This review summarizes the impact of various factors to improve FCR for conventional rabbit farming. To optimize rabbit farm FCR, the reproducing stock as well as the fattening unit must be considered. After the sanitary management, the reproductive performances of the flock are a good leverage to improve FCR. The use of balanced diets preserving digestive health of the growing rabbit, together with an appropriate feeding restriction after weaning, is also a good leverage. Research in genetics also contributes to lowering FCR, by two ways: increasing the growth rate and/or reducing the feed intake for a fixed growth. The environmental impact of rabbit production varies between 7.6 and 10.5 kg of CO₂ equivalent/kg of carcass produced (slightly higher than chicken) and does not differ from that of pork. In perspectives, further improvements of feed efficiency, and reductions in feed input and output in environment, should lead to a farm FCR of 3.0, similar to that of pig production.