In order to evaluate the adaptation of a newly introduced breed and of a pr
oduction system, the effects of herd-year, season of kidding, parity, and,
where appropriate, prolificacy on milk yield, lactation length and prolific
acy of Alpine goats in the Italian region of Lombardy were investigated. An
alysis of two consecutive years, 1298 lactation records, from 34 herds, gav
e mean values (+/-SE) of 567+/-6 kg for milk yield, 231+/-1 days for lactat
ion 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 manage
ment. 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, parti
al R-2 0.01). Lactation length was also affected by parity (p<0.001 R-2 0.1
6) and season of kidding (p<0.001 R-2 0.06). Prolificacy was affected by pa
rity 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 prolifica
cy 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 th
at performances of Alpine goats in Lombardy can be successfully improved wi
th an adequate management. Our findings confirm that litter size should not
be ignored when establishing correction factors in order to compare milk y
ields. (C) 1999 Elsevier Science B.V. All rights reserved.