Genetic variation in meat production related traits in reindeer (Rangifer t. tarandus)

Abstract

In reindeer husbandry, animal breeding could offer tools for improving productivity by selection. The traits affecting meat production efficiency are primarily related to calf growth and survival, and to dam’s longevity and lifetime ability to raise heavy calves. Information on genetic (co)variation in these traits is scarce but needed in estimating the potential and effectiveness of selection as well as biological constraints. The objectives of the study were to estimate these genetic parameters from the data of an experimental reindeer herd at Kutuharju (Inari, Finland). Heritabilities (h2) and genetic correlations (rg) among the average daily gain of calves (ADG), dams’ age at maturity, individual fitness (λind) and the cumulative sum of her calves’ weaning weight over seven years (WW7) were studied with AS-Reml software using the dataset from the experimental herd. The pedigree included also sire information to allow the separation of the maternal effects. Direct and maternal heritabilities of ADG were moderate (0.24±0.09 and 0.18±0.05, respectively) and the direct-maternal correlation was highly negative (-0.73±0.17). Indeed, selection on growth necessitates information on both calf and dam. The genetic correlation of growth with birth date and birth weight could not be detected with the data. The age at maturity and λind had a small heritable component (0.07±0.12 and 0.10±0.06, respectively), whereas the heritability value of WW7 was 0.23±0.07. Reindeer herders’ empirical selection on calf’s autumn weight favours fast growth (rg between growth and autumn weight = 0.35±0.24). Dam’s weight in her first autumn was strongly correlated with her lifetime production expressed by her individual fitness (rg = 0.71±0.23) and the cumulative sum of her calves’ weaning weight (rg = 0.63±0.12). Hence, the early information on the dam (her weight in her first autumn or her first calf’s autumn weight) works as useful selection criteria for the traits related to lifetime production.