The first observation of milkability of the sheep breeds Tsigai, Improved Valachian and their crosses with Lacaune

Abstract

The aim of this study was to evaluate the milkability of two purebred breeds Tsigai (TS, <i>n</i> = 14) and Improved Valachian (IV, <i>n</i> = 15), their crosses with Lacaune 50% TS × 50% LC (<i>n</i> = 13), 50% IV × 50% LC (<i>n</i> = 9) and purebred Lacaune (LC, <i>n</i> = 19). The measurements of the milk flow were performed on day 90 ± 10 of lactation during evening machine milking. The recording of milk flow was carried out by the equipment for graduated electronic recording of milk level in a jar in one-second intervals. The milk flow curves were classified into four types: 1 peak (1P), 2 peaks (2P), plateau I (maximal milk flow over 0.4 l/min (PLI)), plateau II (maximal milk flow less than 0.4 l/min (PLII)). The last two types refer to ewes with steady milk flow during milking. Udder morphology traits were measured (cisternal depth, teat angle) and subjectively assessed by the use of linear scores (cistern depth, teat position). The average total milk yield was 0.335 ± 0.043, 0.392 ± 0.042, 0.407 ± 0.042 l in purebred TS, IV, LC resp. and 0.397 ± 0.046, 0.434 ± 0.056 l in crosses TS × LC and IV × LC, resp. The frequency of occurrence of different types of milk flow /1P:2P:PLI:PLII/ was 27, 47, 22, 4%, resp. The highest milk yield was observed in ewes with PLI (0.481 ± 0.045 l), followed by 2P (0.401 ± 0.029 l) and 1P (0.293 ± 0.036 l) type of milk flow curve (<i>P</i> = 0.0112). An opposite effect was observed in the percentage of machine stripping yield where 1P had 41.94 ± 3.83%, 2P 21.29 ± 3.04% and PLI 15.90 ± 4.70% (<i>P</i> < 0.0001). LC and TS × LC, IV × LC had the more horizontal teat position than TS and IV. It can be supposed that at least during around 69% milkings the sheep released oxytocin in response to machine milking and that TS, IV and their crosses with LC also have a suitable potential for machine milking.

Effect of ewes entry order into milking parlour on milkability and milk composition

“…However, while the frequency of occurrence of individual milk flow types was similar (P = 0.75) in LG, this was not the case in FG (P = 0.02). In FG, the lowest occurrence (5.3%) was observed by PLII and therefore by the milk flow type mostly with the longest milking time according to Macuhova et al (2008). Moreover, almost all of the ewes with PLII were in LG (7 out of 8; exact χ² test, χ² value = 4.50, df = 1, P = 0.07).…”

“…Machine stripping yield, the percentage machine stripping yield from total milk yield, and milking time were not affected (P > 0.05) by the milking group (Table 1). Milking time can be influenced by the frequency of occurrence of particular types of milk flow (Macuhova et al 2008). Ewes with 1P milk flow needed shorter time for machine milking than ewes with 2P or PL, PLII milk flow (Tancin et al 2015).…”

“…The milk level was measured continuously by the transmitter that recorded the position of the float in the jar on a computer once per second. The milk flow patterns were drawn by using a formula by Macuhova et al (2008):…”

“…Milk flow curves were evaluated according to Marnet et al (1998), Rovai et al (2002), and Macuhova et al (2008) and divided into 4 types: 1 peak (1P; without notable milk flow after 40 s of milking), 2 peaks (2P), plateau (PL; represents milk flow by ewes with longer duration of steady phase and peak flow rate during plateau phase > 0.4 l/min at least for 20 s), and plateau low (PLII; represents also milk flow curves with steady milk flow during milking, but at peak milk flow rate at plateau phase 0.4 l/min or > 0.4 l/min shorter than for 20 s).…”

“…The analysis of the milk flow curves shows that the milk ejection reflex does not occur every time during milking in sheep (Mayer et al 1989;Bruckmaier et al 1997;Marnet et al 1998;Dzidic et al 2004;Macuhova et al 2008). One-peak milk flow curves can represent milk flow without (when only cisternal milk fraction is removed in response to machine milking and no notable milk flow is observed after 40 s of milking (Marnet et al 1998)) or with alveolar milk (Bruckmaier et al 1997;Marnet et al 1998).…”