Only the milk stored in the cisternal part of the udder is available for machine milking before milk ejection. Due to a high portion of milk stored in the alveolar part (more than 80%) the occurrence of milk ejection induced by tactile stimulation of the udder before milking is required for complete and fast milk removal. The normal milking liner pulsation also induces the milk ejection reflex during milking. However, the full milking vacuum after the removal of cisternal milk and before milk ejection causes the occurrence of bimodal milk flow curves and often a prolongation of milking time at simultaneously reduced milk flow rates (Bruckmaier and Blum, 1998) resulting in a higher risk of mastitis incidences (Rittershaus et al., 2001).The effect of tactile stimulation on the milk flow profile is mainly studied at the whole udder level (Bruckmaier and Blum, 1996). However, the most effective study to see the effects of milk ejection reflex on milk flow should be done at a quarter level (Tančin et al., 2003(Tančin et al., , 2006. Recently we have found a positive relationship between the duration of the decline phase of milk flow and somatic cell counts (Tančin et al., 2002). In the case of bimodal quarter milk flow a longer duration of the decline phase occurred as compared with non-bimodal curves (Tančin et al., 2005). However, there is no detailed study on how premilking stimulation influences the duration of the decline phase. The composition of milk including SCC changes in the course of milking (Bruckmaier et al., 2004). The milk ejection reflex induced before milking by tactile pre-stimulation could also influence the composition of milk in the course of milking. We expect that the pre-stimulation of the udder will improve the distribution of milk constituents during milking, which could be exactly described at a quarter level.The aim of this study was to investigate the milk flow patterns and the composition of milk in the Effect of pre-stimulation on milk flow pattern and distribution of milk constituents at a quarter level ABSTRACT: The aim of this study was to investigate milk flow patterns and milk composition in relation to premilking udder stimulation. The milk of one quarter of each of the sixteen cows was removed separately and in the course of milking it was divided into six fractions (P -cisternal milk during milking without stimulation and the first 300 ml during milking with pre-stimulation, 0-25%, 25-50%, 50-75%, 75-100%, 75-100%, MS-machine stripping) and into five portions (25%, 50%, 75%, 100%, 100% + MS). Two milkings were performed during two consecutive evening milkings with or without manual stimulation. Pre-stimulation resulted in a reduction of milking time, duration of the increase and decline phase of milk flow, stripping yield, but it increased the peak flow rate as compared to milking without pre-stimulation (P < 0.05). In both fractions and portions the content of fat increased steadily during milking and reached a maximum at MS. Lactose increased from P to 50-75% and then it decr...

Under the practical conditions, it is important to evaluate the factors affecting milk performance. Data from test day yield and milk components should be useful for such evaluation. The aim of the experiment was to study the effect of season, udder health (by somatic cell counts SCC), parity, stage of lactation on milk production, milk components, and SCC under the practical conditions. Also, the frequency of incidence of high SCC during the season was observed. The experiment was realized on one dairy farm in dairy practice. The experiment lasted from December 2015 to October 2017. We examined 481 Holstein dairy cows (6910 milk samples). Milk samples were collected once per month – performed by recording test day. Only cows with 9 – 11 test days were evaluated. The effect of season, parity, stage of lactation, and SCC influenced most of the studied traits. The milk yield was highest at 2nd lactation. In the following lactations, the milk yields were decreasing. The SCC significantly increased with advanced parity. The elevated SCC was found in the beginning and in the final part of lactation. SCC as a factor significantly reduced milk yield, lactose content but increased fat and protein content. In conclusion, under practical conditions, the management should use the data from test days and analyze them for a better understanding of the performance efficiency at the farm level and for implementing more sophisticated decision making in farming.

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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.

The aim of paper review is to describe the influence of somatic cell count (SCC) in the milk of ewes on the composition and milk production associated with the presence of mastitis pathogens as well as the assessment of the effects of non-infectious factors such as breed, number of lambs, order and stage of lactation, age, oestrus, livestock management, the impact of the month, the season to change the SCC in the milk of ewes. It also points to the possible physiological value of SCC in sheep milk for udder health assessment as it is generally accepted for dairy cows. The important part of this paper is to show antimicrobial resistance of mastitis pathogens. The more complex results obtained in Slovakia under experimental and practical conditions are discussed. In conclusion, taking into account all mentioned factors and studies, SCC could play important role in management of dairy ewes breeding to get acceptable milk performances and good udder health at comparable physiological levels as in dairy cows. Regular milk recording could significantly contribute to effort of farmers in mastitis control program.