Yazar "Antanaitis, Ramunas" seçeneğine göre listele

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    Evaluation of automatic milking system variables in dairy cows with different levels of lactation stage and reproduction status
    (Cambridge Univ Press, 2019) Juozaitiene, Vida; Juozaitis, Arunas; Zymantiene, Judita; Spancerniene, Ugne; Antanaitis, Ramunas; Zilaitis, Vytuolis; Tusas, Saulius
    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.
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    Impact of Calving Difficulty on Lameness in Dairy Cows
    (Mdpi, 2022) Malasauskiene, Dovile; Antanaitis, Ramunas; Juozaitiene, Vida; Paulauskas, Algimantas; Urbonavicius, Gediminas; Televicius, Mindaugas; Urbutis, Mingaudas
    The aims of our study were to evaluate the associations between calving difficulty and lameness and their effects on milk yield and quality traits. A total of 4723 calving cases were evaluated for calving difficulty using a 4-point scoring system. Lameness was diagnosed with a visual locomotion score system from 1 to 30 days after calving in 333 fresh dairy cows. Cows were divided into non-lame cows and lame cows. Milk quality traits were registered using Lely Astronaut (R) A3 milking robots. The normal distribution of all indicators was assessed using the Shapiro-Wilk normality test. Normally distributed milk indicators were expressed as mean +/- standard error of the mean. Differences between the mean values of their groups were determined using the Fisher's least significant difference test. We categorized cows by health status, i.e., lame (LA) and non-lame (HL) cows, and according to calving difficulty (CD) (on a 4-point scale: 1-no problem, 2-slight problem, 3-problems requiring assistance, 4-considerable force and extreme difficulty). In the present study, calving difficulty increased the risk of lameness in cows by 2.09-fold (95% CI = 1.644-2.650, p < 0.001). It was found that the mean standard milk yield in fresh dairy cows with calving difficulty was lower (-6.14 kg, p < 0.001) than in the group where no assistance was required at calving. Similarly, herd affected milk fat (%) and the calving process-herd and the interaction between calving difficulty and herd-and lameness impacted the quantity of milk protein and lactose in cows. We found that severe lameness (3-4 points) (3.88-5.92% of cows) became more prevalent in those cows that had dystocia than those that did not (0.27-2.37% of cows).
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    The Association between Blood ?-Hydroxybutyric Acid Concentration in the Second Week of Lactation and Reproduction Performance of Lithuanian Black and White Cows
    (Mdpi, 2022) Mecionyte, Indre; Palubinskas, Giedrius; Anskiene, Lina; Antanaitis, Ramunas; Yilmaz, Ayhan; Tapio, Ilma; Zilaitis, Vytuolis
    Simple Summary Determination of BHB concentration in the second week of lactation (WK 2) may allow us to predict the fertility properties of cows and help better manage farms. BHB concentration can be considered as a predictor trait of reproduction success. High BHB concentration requires a higher amount of insemination. The season in which the cows calve and the parity must be considered in the assessment as these factors affect BHB concentration in WK 2. Hyperketonemia is a very common metabolic state in dairy cows, which result in lower milk production, impaired fertility, and increased frequency of other diseases. In this study, we aimed to determine the influence of season, parity, and milk yield of cows on beta-hydroxybutyrate (BHB) concentration in the second week of lactation (WK 2) and establish the relationship between BHB concentration in WK 2 and reproduction performance traits such as insemination rate and first insemination day of Lithuanian Black and White dairy cows. The study included clinically healthy Lithuanian Black and White cows (n = 692). Blood BHB concentration was measured using capillary blood samples collected after morning milking when cows were 7-10 DIM. The impact of WK 2 blood BHB concentration on the insemination rate and first insemination day were investigated. The effect of BHB was evaluated according to the season, parity, and milk yield per lactation (305 DIM). Significant differences were observed in BHB concentration in WK 2 due to season and parity, but no statistically significant differences were observed for milk yields (305 d). Increased blood BHB concentration in WK 2 negatively affected insemination rate (p < 0.001) and first insemination day (p < 0.001). The study findings indicate that BHB concentration in WK 2 depends on season and parity, while the milk yield is not associated with BHB concentration. High BHB concentration in WK 2 increases insemination rate and delays the first insemination day for high milk-yielding Lithuanian Black and White dairy cows.