Growth rate and body composition
1993
Kastelic, M. | Salehar, A. (Biotechnical Faculty, Ljubljana (Slovenia). Zootechnical Dept.)
Growth rate, body composition and feed efficiency are the most important traits of fattening pigs. The body mass increase has the shape of asymptotic growth curve. Final (mature) size in mammals is limited. Daily gains increase rapidly in the first growth phase. In the second growth phase they decrease with a slower rate. There is a point between these two growth phases, where the animal reaches the highest daily gain. During growth there is a decrease in proportion of ash and water in the body, protein proportion remains more or less stable and fat proportion increases. Feed efficiency decreases with growth. Heritabilities for daily gain, food efficiency and backfat thickness have middle values. Phenotypic and genotypic correlations between daily gain and proportion of meat in carcass are negative and between daily gain and backfat thickness positive. Animals with higher mature body mass have lower proportion of fat than animals with the same body mass, but with lower mature body mass. Animals fed restrictly have lower proportion of fat than animals of the same age fed ad libitum. However they have lower body mass at the same age. All these factors should be taken in consideration in order to achieve optimal results during fattening
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