In this study, we hypothesized that differences of automatic milking systems (AMS) variables in dairy cows during estrus and through diverse stages of lactation can be suggested as alternative indicators to support the pregnancy in dairy farms using automatic milking systems. The key objectives were: (1) to determine the variation of automatic milking system indicators during lactation and to estimate the relationship with reproduction status in dairy cows; (2) to test the hypothesis that milking traits of cows can be influenced by estrus and conceiving, and can be used as a predictor of the likelihood of reproductive success in dairy herds. Estrus synchronization was performed in 368 healthy Lithuanian Black and White cows. All cows (n = 368) were synchronized and inseminated for the first time on the 91st day in milk (DIM). Cows not pregnant (17.39%) were synchronized and inseminated again at 132 DIM. After the first insemination pregnant (n = 304) cows were identified as group 1, after the second insemination pregnant (n = 58) cows – as group 2. Overall, 12 01 713 records of udder quarters in cows from 5 to 305 DIM were evaluated. The results revealed the reduction in milk yield during estrus 11.05% on 91 DIM and 13.89% on 132 DIM (P < 0.001) and an increment in milk flow traits in cows after 91 DIM (P < 0.05), also a slight decline in milk flow traits on 132 DIM. Furthermore, milking frequency (MF) of cows decreased significantly (P < 0.001) after conceiving. The interval between milkings (MI) increased (40.30%) during estrus of cows in group 1 (P < 0.001), and thereafter gradually increased, however in group 2 there was a temporary increment (6.06%) on the 91 DIM and steady rise (42.13%) on 132 DIM was noticed. The results highlight that changes in AMS indicators of cows may be considered as an additional tool for improvement of reproductive management in dairy herds, but further research-based studies are necessary before practical application.

The objective of this work was to evaluate the association of bimodality of milk flow curves with microbiological status of mammary glands and parity of cows. We selected 167 primiparous and 148 multiparous Lithuanian Black and White dairy cows in 2nd to 4th month of lactation. The bimodality of milk flow was determined in 22.2% primiparous and in 38.6% multiparous cows (P less than 0.001). The most prevalent pathogens of mastitis were Staphylococcus aureus (15.3%), other staphylococci (22.2%) and streptococci (5.8%). Prevalence of mastitis pathogens in multiparous cows was 1.4 times and the bimodality of milk flow curves –1.7 times higher in comparison with primiparous cows (P less than 0.001). The bimodality of milk flow curve was mostly associated with the prevalence of Streptococcus agalactiae and Staphylococcus aureus (P less than 0.001). The increased frequency of mastitis pathogens (21.5%) in cows with the bimodal milk flow curves supports the negative effect of bimodality on udder health of cows (P less than 0.001).

No abstract

There is an increased interest in using automatic milking systems (AMS) to indirectly assess the welfare of dairy cows, but knowledge on analyzing the association between lameness, milk yield characteristics, and reproductive performance in cows is still insufficient. The main aims of this study were to evaluate the influence of lameness on several AMS variables and reproductive performance indicators during the early stage of lactation and estrus in Lithuanian Black and White dairy cows, as well as to assess the associations between lameness, productivity and reproductive efficiency. A total of 418 milking cows (50.3±1.2 d postpartum) without any apparent reproductive disorder were monitored for hoof health status. Cows were assigned to two groups on the basis of visual locomotion scoring: "non-lame"cows (group 1; 74.20%) and cows presenting "lameness" (lame cows) (group 2; 25.80%).Productive and milking performances of dairy cows were recorded from 50 to 100 days in milk (DIM) and 1 day after the first estrus. The lameness was predominantly localized on the hind feet (79.60%) and less frequently -on the front feet (20.40%; p<0.001). Furthermore, the lameness had a tendency to decrease milk production (4.24%; p<0.05) and increase the difference in milk yield between rear and front quarters of the udder (1.20%; p<0.05). The frequency of milking (5.19%) was lower in lame cows (p<0.05). The lame cows during estrus showed a more pronounced decrement in milk yield and milking frequency (p<0.05), and also higher milk progesterone concentration values (1.55-1.76 time's; p<0.001), and an increasing number of inseminations (11.69%; p<0.05) were observed. The results highlighted that analysis of data from AMS programs can be a successful tool for reducing risk factors related to the effective management of reproductive performance and hoof health of dairy cows.

We hypothesized that lameness has an impact on milk flow traits. The aim of the current study was therefore to investigate the relation between lameness and milk flow traits in dairy cows. For this study 73 healthy and 55 cows with lameness were selected. Lameness was diagnosed by a local specialized veterinarian, according to the standard procedure. The blood samples were collected during clinical examination. The milking properties of cows were evaluated twice in a row—during evening and morning milking. The selected cows in the current lactation did not receive veterinary treatment, and correct hoof trimming was not performed at least four weeks before the experiment. The measurements were taken by two electronic mobile milk flow meters (Lactocorder®®, WMB AG, Balgache, Switzerland). Milk flow data were processed using LactoPro 5.2.0 software (Biomelktechnik Swiss). Cortisol concentration was measured with the automated analyzer TOSOH®® AIA-360 (South San Francisco, CA, USA). We found out that milk flow traits can act as biomarkers of lameness in dairy cows. We determined that the milk yield in the first minute of healthy dairy cows was 1.77 kg higher than that of lame cows. The electrical conductivity during the initial time of milking of healthy cows was 0.24 mS/cm lower than that of the lame group. The milking duration of LA cows was 1.07 min shorter and the time of incline in milk flow from 0.5 kg/min till the reach of the plateau phase was longer. The risk of lameness was most clearly indicated by an increase in blood cortisol concentration; if its blood level in cows exceeds 1 µg/dL, the risk of identifying lameness increases 4.9 times.