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Mastitis remains the most expensive disease of dairy cows, and antibiotic dry cow therapy (DCT) at dry-off is an important part of mastitis control. Regardless of the infection status, blanket DCT is administered to all quarters of all cows, which is controversial due to the worldwide problem of antimicrobial resistance. Even though selective DCT of only infected cows is a more sustainable approach, choosing animals for treatment is not always straightforward. Our aim was to evaluate whether the herd-level DCT approach is associated with early lactation udder health problems, taking into account the cow characteristics. The information source was 2015?2017 Dairy Herd Improvement data with 7461 multiparous cows from 241 Finnish dairy herds. Information on the herd-level DCT approach was obtained from farmers? questionnaire responses in 2017, and the three different approaches were selective DCT, blanket DCT, and no DCT. The statistical tool for the data analysis was a generalized linear mixed model with a random herd effect for binary outcomes and a linear mixed model with a random herd effect for a continuous outcome. The two binary outcomes were the odds of having high milk somatic cell count (SCC ? 200 000 cells/mL) on the first test-day within 5?45 days in milk (DIM) and the odds of mastitis treatment in early lactation up to 45 DIM. The third outcome was the mean milk lnSCC (? 1000 cells/ mL) within 120 DIM. Selective DCT was the prevailing treatment practice in our data. Blanket DCT was associated with lower SCC after calving. Cows more likely to have high SCC after calving were older cows, cows with high average SCC during the previous lactation, and cows with high milk yield near dry-off. A mastitis treatment in the early lactation was more likely if, during the previous lactation, the cow had high average SCC, high peak milk production, or high milk yield near dry-off. Our findings indicate that DCT is still effective in mastitis control. Cows with high milk yield, especially near dry-off, and cows with persistently high SCC require attention when considering next lactation udder health. Mastitis remains the most expensive disease of dairy cows, and antibiotic dry cow therapy (DCT) at dry-off is an important part of mastitis control. Regardless of the infection status, blanket DCT is administered to all quarters of all cows, which is controversial due to the worldwide problem of antimicrobial resistance. Even though selective DCT of only infected cows is a more sustainable approach, choosing animals for treatment is not always straightforward. Our aim was to evaluate whether the herd-level DCT approach is associated with early lactation udder health problems, taking into account the cow characteristics. The information source was 2015?2017 Dairy Herd Improvement data with 7461 multiparous cows from 241 Finnish dairy herds. Information on the herd-level DCT approach was obtained from farmers? questionnaire responses in 2017, and the three different approaches were selective DCT, blanket DCT, and no DCT. The statistical tool for the data analysis was a generalized linear mixed model with a random herd effect for binary outcomes and a linear mixed model with a random herd effect for a continuous outcome. The two binary outcomes were the odds of having high milk somatic cell count (SCC ? 200 000 cells/mL) on the first test-day within 5?45 days in milk (DIM) and the odds of mastitis treatment in early lactation up to 45 DIM. The third outcome was the mean milk lnSCC (? 1000 cells/ mL) within 120 DIM. Selective DCT was the prevailing treatment practice in our data. Blanket DCT was associated with lower SCC after calving. Cows more likely to have high SCC after calving were older cows, cows with high average SCC during the previous lactation, and cows with high milk yield near dry-off. A mastitis treatment in the early lactation was more likely if, during the previous lactation, the cow had high average SCC, high peak milk production, or high milk yield near dry-off. Our findings indicate that DCT is still effective in mastitis control. Cows with high milk yield, especially near dry-off, and cows with persistently high SCC require attention when considering next lactation udder health.

A widespread management practice in commercial dairy farms is to stop milk production artificially commonly 2 months before expected calving, in a process termed drying-off. Dry-off management normally encompasses dietary changes as well as abrupt or gradual changes in daily milking frequency, which can compromise the welfare of modern cows. This study investigated the effects of various dry-off strategies comprising feed energy density (normal lactation diet versus energy-reduced diet, both fed for ad libitum intake) and daily milking frequency (twice versus once) from seven days prior to the day of last milking (i.e. dry-off day - D0) on the feeding motivation, feed-related attention bias and visual lateralisation towards feed of dairy cows. During two separate days (D-5 and D-2) prior to dry-off, cows on the energy-reduced diet started feeding much earlier than cows on the normal diet. No effect of daily milking frequency or interaction with feed energy density on feeding motivation were found. The increased feeding motivation induced by a low energy feed did not reflect changes in neither feed-related attention bias nor visual lateralisation towards feed. In agreement with the literature, the majority of the cows showed right eye dominance towards a feed source when feeding, corresponding to the left-brain hemisphere. Our study supports the suggestion that cows offered low energy diets show signs of hunger prior to dry-off, even when fed for ad libitum intake. The current study sheds light on the relevance of developing more animal-friendly dry-off management, as well as the importance of developing existing feed-related attention bias tests for nonhuman animals.

The objectives of this study were to investigate different feeding strategies of high-yielding dairy cows during dry-off. With a 12- to 13-mo calving interval and increasing milk yield, metabolic and health problems during the dry-off period will increase. Twenty-two dairy primiparous and multiparous cows were randomly assigned to 2 feeding treatments. One group was fed straw ad libitum (straw), and the other group was fed silage (4 kg/d of dry matter) daily and straw ad libitum (silage). At the dry-off point (d 0), the cows had an average milk yield of 17.1 +/- 0.8 kg/d. All cows were milked in the morning on d 3 and 5 during the dry-off period. Rumen fluid was analyzed for volatile fatty acids (VFA), pH, NH3-N, and protozoa were counted from samples collected at d -3, 4, and 17. Total VFA concentration decreased at dry-off in both treatments and the drop was most pronounced among cows fed straw. Rumen pH increased significantly in both groups, and cows fed straw had significantly higher pH during dry-off. Ammonia N in rumen decreased significantly at dry-off and there was a tendency to lowered NH(3)-N in cows fed straw at dry-off. The plasma concentration of nonesterified fatty acids was markedly elevated during the dry-off period among cows in the straw treatment group, but was less pronounced among the cows fed silage with straw. The glucose level in plasma was not significantly affected during the dry-off period, and the insulin concentration was markedly reduced in both treatment groups. Plasma leptin concentration was lower in the lactating state than in the dry period. Both the beta-hydroxybutyrate and urea concentrations in plasma were significantly reduced during dry-off. Our results indicate that dry-off markedly affected the metabolism in the blood and in the rumen of the cows, and that the cows offered only straw during the dry-off were most affected.

Dissertação de Mestrado Integrado em Medicina Veterinária O potencial genético das vacas leiteiras para a produção de leite tem aumentado nas últimas décadas, tornando-se num desafio cada vez maior interromper a lactação no momento da secagem. São vários os fatores de risco associados à secagem que podem predispor para o aparecimento de infeções intramamárias durante o período seco, manifestando-se sob a forma de mastite clínica ou subclínica após o parto. Pretendeu-se com este estudo analisar a influência do gotejamento de leite à secagem na ocorrência de mastites clínicas após o parto. Para além do gotejamento de leite, outros fatores de risco durante o período seco, para a ocorrência de mastites após o parto foram estudados, entre os quais a hiperqueratose dos tetos, a produção de leite total e à secagem, a paridade das vacas, a metodologia de secagem e a contagem de células somáticas antes da secagem e após o parto. Foram registados dados de 82 vacas de duas explorações da região centro de Portugal continental desde setembro de 2015 a abril de 2016. Observou-se uma incidência de gotejamento de leite de 10,9% e o estudo demonstrou haver associação (p