Pig feeding for lean meat production : recent developments and prospects

Abstract

During the last decades, pig production has gained important and continuous progress from selection for constantly increasing lean tissue gain and decreasing fat deposition, in order to meet the increasing demand of market and consumer. The present report is intended to examine the changes that have been introduced in pig feeding to bring the necessary adaptations for optimizing growth performance, by considering the recent development and the trends for the future, in relation to the predictable shift in production performance and technological innovations. The unceasingly changing contribution of animal related factors has made it necessary to consider prediction modelling of nutritional requirements (energy, protein and amino acids), with a general trend to lower energy needs than in the past and higher amino acid requirements relative to energy. This modelling approach allows to implement new feeding strategies (feeding scale, type of feed for a given phase of production) that are adapted to lean meat production, according to specific production conditions and with sufficiently discriminating feed evaluation systems (net energy, ileal amino acid digestibility). In addition, the steady increase in some dietary inputs (nitrogen, phosphorus) for expanded lean meat production implies a sound management of nutrient supply, in order to prevent excessive loss to the environment (water, atmosphere). The observed trend to some degradation of meat quality with intense selection for muscular growth, particularly with regard to technological and organoleptic characteristics, necessitates to take into account these constraints in feeding, whether one considers fat deposition or lean tissue gain (extent of intramuscular fat). Finally, after examining the effects of feeding on carcass conformation, we have considered the incidence of excessive leanness in sows on reproduction performance, in relation to mobilization and restauration of body lipid reserves. This problem of optimum balance between lean and fat is an important challenge for future evolution of feeding lean pigs. From practical standpoint, the new nutritional approaches based on establishing dose - response relationships that integrate the diversity of available genotypes (from the fattest to the leannest), along with production and environmental conditions, should contribute, in each case, to fix the optimum conditions for producing a given type of pig.