THE EFFECT OF EWES RELOCATION ON MILK COMPOSITION AND MILK FLOW KINETICS

The investigation of an influence of ewes relocation and milking in other parlour (treatment) on milk flow kinetics, milkability and milk composition was the aim of this study. In total 34 ewes of two breeds and crosbreeds Tsigai (14 heads) and Improved Valachian (20 heads) with Lacaune were tested. Two weeks after lamb weaning the ewes were milked in parallel milking parlour (1x16 stalls) under shelter. On the last evening milking (first experimental milking, EB) before relocation of flock to another parlour


INTRODUCTION
For fast and complete milk removal, in of spite larger volume of cistern in ewes, the milk ejection reflex occurrence is also needed (Labusiere, 1981) as it is well presented for dairy cows (Tančin and Bruckmaier, 2001). In ewes of lower milk yield the milk ejection is often observed as a second emission of milk during milking causing a bimodal milk flow kinetics Under the various milking conditions and manipulation with ewes the milk ejection reflex could be disturbed causing inhibition of second emission occurrence (Kulinová et al., 2012). Inhibition of second emission causes lower milk and fat yield (Antonič et al., 2013). It was also confirmed that despite of larger cisternal volume in ewes, milk ejection reflex and also complete milk removal from udder is very important to keep milk production due to the effect of milk born feedback mechanisms (Silanikove et al., 2010). we could expect different response of ewes to milking under stress conditions. The aim of the work was to study the effect of relocation and milking in other parlour on milk flow kinetic, milkability parameters and milk composition. The importance of differed milk flow kinetic of ewes under the control milking conditions to mentioned stress load was evaluated as well.

Experimental conditions and design
Experiment was performed on 34 experimental ewes of two breeds and crossbreeds Tsigai (14 heads, two of them pure Tsigai, and others were crosbreed with Lacaune from 25-75) and Improved Valachian (20 heads, three of them pure IV, and others were crosbreed with Lacaune from 25-75). Ewes were randomly selected from the flock and used for experimental purposes two weeks after lambs weaning in April. During these two weeks the flock was milked in parallel milking parlour (1x16 stalls) under shelter with following parameters: pulsation rate 120 cycles per min., milking vacuum 52 kPa, pulsation ratio 50:50. On the last evening milking, (first experimental milking, evening before relocation -EB) before relocation of flock to another milking parlour, the milk flow kinetics of experimental ewes were measured using electronic collection jar (described below). After the following morning milking the flock was moved on a pasture and milked in another milking parlour (1x24-stalls) with 12 standard milking units and with following parameters: pulsation rate 180 cycles per min., milking vacuum 40 kPa and pulsation ratio 50:50. Milk flow kinetic of experimental ewes was recorded during the next three continuous evening milkings after relocation (E0 -second, E1 -third and E2 -fourth milking of experiment). Thus data from four continuous evening milkings (one before and three after relocation) were available for statistical evaluation.
During the whole experiment the ewes were fed by concentrate 0.5 kg and 0,2 kg oat grain at milking parlour and before relocation they received oat silage (6 kg) and hay (0,5 kg) and after relocation they were on meadow pasture (7 kg). On the basis of milk flow kinetics during EB the ewes were divided into three groups for statistical evaluation. The first group was represented by animals with bimodal (2 emissions) milk flow curve (BG, n=12), in the second group were animals with non-bimodal (1 emission) milk flow curve (NG, n=10) and the last one was represented by animals with plateau (steady) milk flow curve (PLG, n=12) to test the importance of differed milk flow kinetics of ewes under the control milking conditions to mentioned stress -relocation and milking in another parlour.

Milk flow recording and parameters
Milk flow kinetics was recorded individually by using four electronic jars (1.5 L each) collecting total milk produced at the milking. Within each jar there was a 2-wire compact magnetostrictive level transmitter (Nivotrack, Nivelco Ipari Elektronika Rt, Budapest, Hungary) connected with the computer. Milk level in the jar was continuously measured by a transmitter recording signal on the computer every second. Measured changes of height level of milk were transformed into values, from which were detected parameters of milkability (TMY -total

Statistical analysis
Data from four evening milkings were evaluated statistically using mixed model (Mixed procedure; SAS/STAT 9.1, [2002][2003]. This model was applied to study the influence of the sources of variation in studied traits (milk production and milk emission/milkability).

RESULTS AND DISCUSSION
Relocation and milking in another parlour significantly influenced the TMY between EB (evening before) and E0 (evening after morning ewes relocation) what pointed to stress from changed milking conditions (Table 1). Next two milkings showed adaptation to milking conditions. A statistically significant increase was also in E1 compared to E0 for MMY (Table 1). Statistically significant differences were also recorded in MT. Thus relocation of ewes and their milking in another place significantly influenced milkability. The effect of ewes' relocation on TMY was also confirmed by others authors in ewes or cows (Sevi et al., 2001; Mačuhová et al., 2002). MS and MMF were also significantly influenced by treatment but changes did not corresponded to the changes of above mentioned parameters. The volume of milk obtained by machine stripping and maximal milk flow are significantly positively influenced by the vacuum level (Sinapis et al., 2000,2006). Thus higher MS and MMF were caused by higher vacuum level at EB milking. Therefore we are aware of possible effect of changed milking parameters on the response of ewes to the relocation and milking in another parlour.
As it was mentioned above TMY was significantly lower in E0 in comparison to EB and E2 (Figure 1). This physiological response of ewes to the change of milking place supports also high occurrence of N milk flow type in E0 milking (Figure 1). High occurrence of N milk flow type could indicate inhibition of oxytocin release as a consequence of stress effect. The higher occurrence of N type of milk flow during stress response in ewes was found by other authors as well (Marnet et al., 1998; Kulinová et al., 2012) or in cows during milking in unfamiliar surroundings (Mačuhová et al., 2002). Relatively higher frequency of N milk flow type during EB milking could be explained by higher vacuum level at parallel milking parlour under shelter causing faster milk flow from cistern.  , 2003). Therefore we expected that ewes with B milk flow at EB milking will response more clearly due to inhibition of oxytocin release and thus changing of milk flow from B to N type. This was clearly confirmed in ewes in BG. It seams that ewes with B milk flow type could be considered as suitable animals because they represent the ewes with physiological response to machine milking and also with pathophysiological response to the change of milking conditions. Therefore these animals could be used forthe study the effect of milking management on milkability of ewes (Mačuhová et al., 2012).  In milk composition, no significant differences were found between machine milkings for fat content, lactose content, dry matter and log SCC (Table 2). There was a significant increase of protein content in E1 and E2 compared to EB and increase of SNF in E2 compared to EB. In E0 we did not evaluate milk composition but when we take into account the fact that N milk flow types were high we could assume that percentage of fat content could be lower as compared with EB milking as reported

CONCLUSION
The responses of ewes to stress from relocation and adaptation to other milking conditions were studied in ewes of Tsigai and Improved Valachian breed. Treatment significantly negatively influenced the milkability of ewes

DM (%)
18.04 ± 0.24 -18.32 ± 0.24 18.44 ± 0.25 0.106 log SCC 5.37 ± 0.11 -5.53 ± 0.11 5.46 ± 0.11 0.346 SNF -Solid non fat, DM -dry matter, SCC -somatic cell counts A,B Means differ at P <0.01 a,b , Means differ at P <0.05 Figure 2A, B, C Frequency of distribution of milk flow types in groups differed by milk flow type during first experimental milking (EB) influenced by change of milking conditions and milking parlour (EO, E1, E2) but a more clear response was found in ewes with bimodal milk flow response to machine milking before treatment. From obtained results the response of ewes was partially influenced by technical parameters of the milking machine. However ewes have soon adapted to other milking conditions.