Factors affecting milk production and prolificacy of Alpine goats in Lombardy (Italy)

Abstract

In order to evaluate the adaptation of a newly introduced breed and of a production system, the effects of herd-year, season of kidding, parity, and, where appropriate, prolificacy on milk yield, lactation length and prolificacy of Alpine goats in the Italian region of Lombardy were investigated. Analysis of two consecutive years, 1298 lactation records, from 34 herds, gave mean values (±SE) of 567±6 kg for milk yield, 231±1 days for lactation length and 1.6±0.01 kids per kidding. Milk yield and lactation length were primarily influenced by the herd-year factor ( p<0.001, partial R 2 0.68 and 0.55, respectively) which mainly reflects differences in herd management. Milk yield was also affected by season of kidding ( p<0.001, partial R 2 0.4), parity ( p<0.001, partial R 2 0.03) and litter size ( p<0.001, partial R 2 0.01). Lactation length was also affected by parity ( p<0.001 R 2 0.16) and season of kidding ( p<0.001 R 2 0.06). Prolificacy was affected by parity and by herd-year factor ( p<0.001, partial R 2 0.09). Kidding early in the year gave higher milk yields, longer lactations and higher prolificacy, but in the choice of the kidding season also the higher prices of kid meat just before Easter have to be considered. Maximum milk yield and prolificacy were attained late (in 4th and 5th lactation), probably due to early age at first kidding. The relevant effect of the herd-year factor indicates that performances of Alpine goats in Lombardy can be successfully improved with an adequate management. Our findings confirm that litter size should not be ignored when establishing correction factors in order to compare milk yields.