Experience during two generations of within lines boar performance testing, using 5α-androst-16-ene-3-one (5α-androstenone) and an olfactory judgement of boar taint

Abstract

The Danish work undertaken within the B.A.A.P. Commission of Pig Production working group on the production and the utilization of meat from entire male animals is presented from the Danish breeding experiment station « Tylstrup » on thelbasis of 845 entire male pigs of the Dconish Landrace breed during the generations 1974-75 and 197 8.76- From the year of herd establishment, 1974-75, are given the means, the frequencies and the variation of a panel judg- ment of boar odour intensity (in boar fat) together with those of two steroid criteria, 5 a-andro- stenone (in boar fat and blood plasma) and testosterone (in blood plasma). For the steroids, the repeatabilities (intra-blood sample) and the correlations between morning and afternoon samples are given. The purpose of this presentation is to forward estimates of genetic parameters for the po- tential selection objective boar taint and of its probable genetic relation to male reproductive performance and growth. The highest estimate of p. 100 additive gene action (h2) is found for a linear biological expression, adding the level of the steroid 5a-androstenone and the olfactory panel score: ’h combined linear boar taint expression 0.46 ! o.18; P < 0.01. The heritability estimate of the important steroid in male reproduction, the testosterone, was found to be similarly high: ’h testosterone = 0.45 t 0.17; P < 0.01 The estimates of the phenotypic (rp) and genetic (YG) correlations between daily weight gain (DWG) and on the one side 5