Milkability assessment of Tsigai, Improved Valachian, Lacaune and F1Crossbred ewes (Tsigai × Lacaune, Improved Valachian × Lacaune) throughout lactation

Abstract

This paper aimed to compare the milking ability of ewes from pure European breeds (Tsigai, Improved Valachian, Lacaune, and their crosses) on the basis of their milk flow kinetics during machine milking throughout lactation. Ewes of the Tsigai (TS, n = 13), Improved Valachian (IV, n = 12), Lacaune (LC, n = 12), TS × LC (50%, n = 12) and IV × LC (50%, n = 12) on their 1–3 lactation were used. The ewes were in their 74 ± 12 d of lactation at the beginning of the experiment. Milk flow data of each ewe were recorded during one evening milking in the middle of four successive months (May, June, July, and August). Milk flow was recorded by means of an automatic collecting jar equipped with an electronic milk meter device working in every 1-s intervals. The milk flow curves were classified into three types: 1 peak (1P), 2 peaks (2P) and plateau (PL). The highest values of repeatability of parameters were found for stripped milk yield (SMY), maximum milk flow, latency time and milk yield at 30 s (over 0.52). The lowest values were recorded for machine milking time (MMT), machine milk yield (MMY) and time to reach maximum milk flow (<0.33). Month of lactation significantly influenced most of the milkability data except latency time and time to maximum flow rate. The effect of genotype showed highly significant influence on most of the analyzed parameters. The lowest total milk yield (TMY) and MMY were measured in pure TS (0.348 ± 0.02 l and 0.266 ± 0.021 l, respectively) and IV breeds (0.320 ± 0.022 l and 0.259 ± 0.021 l, respectively) as compared with Lacaune (0.524 ± 0.022 l and 0.360 ± 0.021 l, respectively). The highest TMY and MMY were measured in ewes with PL milk flow types and the lowest in ewes with 1P. Ewes with 1P showed clearly shorter MMT and higher percentage of SMY as compared to PL and 2P though SMY did not differ among groups. Interaction of milk flow type and stage of lactation influenced TMY and MMY, maximum milk flow, milk yield in 30 s of milking and MMT. A clear effect of milk flow type on TMY and MMY was observed each month.