Abstract

The New Zealand dairy goat industry consists of 187 herds (33,500 does), from which 60 herds (12,600 does) supply milk for the Dairy Goat Co-operative. Most of the milk is used to manufacture whole milk powder for niche markets. Farm profitability can be increased through identifying and selecting superior animals for traits of financial importance such as milk yield. Across-breed estimated breeding values (EBVs) for milk yield adjusted for days in milk (MYA), unadjusted milk yield (MYU) and days in milk (DIM) of Saanen, Nubian, British, Toggenburg and crossbred dairy goats spread across 20 herds were estimated by Best Linear Unbiased Prediction (BLUP) procedures. A repeatability model was used to analyse the first eight lactation yields and included effects of herd-year-month, parity, additive genetic and permanent environment. Coefficients of breed composition and heterosis (assuming equal heterosis among any of the breeds) and days in milk were considered as covariables. Heritability and repeatability were 0.36 and 0.63 respectively. Evaluations were based on 6,517 lactation records of 3,856 does and 83 sires. Average milk production was 548 litres over an average lactation spanning 200 days. Pure-bred Saanen does had longer lactations (DIM) and out-produced other breeds in MYA and MYU. Two year old does produced an extra 150 litres of milk compared to one year old does. Peak production was at 5 years of age then production declined gradually. Young does had longer lactations than old does. Average EBVs for different breeds compared to a Saanen base were for MYU Nubian -291, British -242 and Toggenburg -106 litres, MYA -177, -193 and -51 litres and DIM -40, -17 and -19 days for each breed respectively. First cross heterosis was 105 litres (19%) for MYU, 52 litres (9.5%) for MYA and 18 days (9%) for DIM. This first prototype evaluation allows the selection of does and bucks based on their estimated genetic merit and provides for routine genetic evaluation in the future.

SR, Singireddy, N Lopez-Villalobos, and DJ Garrick

Proceedings of the New Zealand Society of Animal Production, Volume 57, , 43-45, 1997