The main objective of this research communication was to explore the extent of milkability changes caused by the incidence of clinical mastitis. Our second objective was to investigate if the ...milkability of cows shortly before mastitis incidence significantly differed in comparison with healthy cows. Milk yield, milking time, average milk flow, partial milk flows and the occurrence of bimodal milk flows were monitored during the first 120 d in milk for all cows that calved on the farm during the experimental period (n = 127). A veterinarian diagnosed 27 cows with clinical mastitis, while the remaining healthy cows served as a control group. The period surrounding the mastitis was monitored in a timeline from 2 weeks before to 4 weeks after the diagnosis. We did not observe any significant differences in milkability between the healthy cows and the cows in the pre-mastitis period, which suggests that monitoring these might not be useful for early mastitis detection. Milk yield and milk flow were significantly decreased in the week of mastitis diagnosis compared to the pre-mastitis period. Milking time was not affected in the week of diagnosis, but was significantly increased in the following week, because milk yield returned to pre-mastitis values, but average milk flow was still significantly decreased. Milk yield was normalized to pre-mastitis values as the first of monitored parameters. Milk flow returned to pre-mastitis values in the fourth week after mastitis diagnosis. Milking time was the only parameter that was significantly affected up to a month after diagnosis. Our results showed that milkability changes caused by mastitis are significant and should not be ignored. The ability to adjust milking settings for cows diagnosed with mastitis could become a useful tool for improving mastitis treatment.
ABSTRACTThe aim of this study was to propose and verify a scoring system for the evaluation of udder susceptibility to mastitis, which combined five influential teat traits into one overall score for ...the udder. The traits included barrel diameter, apex diameter, canal length, the change in wall thickness, and the change in apex diameter. Teat morphology of 38 Holstein cows were measured twice during lactation by ultrasonography. Each teat was scored for the presence of traits with negative implications for the udder health at the start (ScoreLactStart) and the end of lactation (ScoreLactEnd). Results showed that cows with higher score had significantly worse udder health. The number of mastitis warning days was significantly correlated to both scores. In addition, ScoreLactEnd was correlated to somatic cell count (SCC) and lactose content. Each increase of ScoreLactEnd by 1 point represented an increase in SCC by 17,745 cells mL−1, 9.4 more days with mastitis warning, and 4.6 more days with SCC above 400,000 cells mL−1 during observed lactation. Only ScoreLactStart was significantly related to blood content, but relations to SCC were weaker compared to ScoreLactEnd. Ranking udders based on teat morphology traits show potential for detection of mastitis susceptible cows in commercial herds.
The aim of this study was the evaluation of heat stress in milk production in dairy cows (daily milk yield; milk production in 1st lactation). The comparison was performed between fraternal twins ...(full sisters), produced on the same farm and same parity. One of the twins produced in a hot period whereas her sister produced in a cooler period. Also, there can be differences in milk production between fraternal twins. Therefore, a second group of fraternal twins was also created that produced without heat stress. Databases of fraternal twins were analysed using PROC GLM analysis of Statistica® with selected effects. In conclusion, a negative effect of heat stress on milk production was found. There was an obvious tendency (in some cases insignificant) for worse milk production during heat stress in both the daily milk yield during hot days and in 1st lactation started in the hot season. Fat content (in %) was also lower in the hot period but differences were insignificant. On the other hand, there was found very low differences in milk production (and milk components) between fraternal twins produced in season without heat stress.
The objective of this study was to estimate lamb birth weight based on body dimensions. We monitored 101 lambs (61 Charollais lambs, 27 Kent lambs, and 13 their crossbreds) at a selected commercial ...flock. Birth weight, chest circumference (CC), head circumference (HC), and shin circumference (SC) were measured immediately after birth using a tape measure. Correlation analysis indicated the promising use of CC (r = 0.795; p < .001) or HC (r = 0.679; p < .001) for estimating body weight. Statistical models with one body measurement indicated that a model with CC as a covariate had the highest coefficient of determination and the lowest Akaike’s information criterion, corrected Akaike’s information criterion, and Bayesian information criterion. The defined criteria generally identified that models with SC, HC, and CC and models with HC and CC as covariates were the best. Residual analyses verified our results, but more extensive analyses of other breeds under different breeding conditions should be conducted to confirm and generalise our results.HighlightsStatistical models have been proposed to predict the birth weight of lambs.Tape measure can be successfully used for birth weight estimation.Model with chest, head, shin circumferences as covariates were suggested.
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