Returns from genetic improvement on indices that include production, longevity, mastitis and fertility in UK circumstances

摘要: In the UK, two selection indexes are in use by dairy industry, they PIN (Profit Index; production only) and £PLI (Profitable Lifetime plus lifespan). Expected economic returns over a twenty year period were calculated for addition to when is on hypothetical index based assuming that PTAs (predicted transmitting abilities) mastitis calving interval available (£PLI+M+C). Selection responses single round of using methodology. Genetic covariance matrices constructed published genetic phenotypic parameter estimates sire progeny groups 75 daughters available. Economic values per standard deviation were: £-12, £7, £49, £29, £28 £7 milk, fat, protein, lifespan, mastitis, respectively. Annual as 0.22 change £5.41, £7.66 £9.63 PIN, £PLI+M+C. Responses £PLI+M+C sensitive heritability assumed (between 0.02 0.05). Discounted progress will continue at around 1.6% year. The accumulated discounted from alone UK industry years time estimated be £457m, £653m £813m (2 million cows) Comparisons between results differing complicated fact there have been several generations or criteria close it, whereas has only become recently not yet Also, practice, different pathways may give equal emphasis these indexes, especially relies 80% imported semen. Thus breeding programmes other countries influential. However, it clear (i) last decade (e.g. PIN) led major benefits industry; (ii) substantial cost continuing terms an increased susceptibility decline fertility; (iii) negative consequences can very effectively mitigated broadening with expected animal welfare benefits.