Summary The aim of this study was to evaluate the effects of different timing for frozen–thawed b... more Summary The aim of this study was to evaluate the effects of different timing for frozen–thawed bovine ampullary epithelial cell (BAEC) and bovine oviductal epithelial cell (BOEC) co-culture on the development and quality of bovine embryos produced in vitro. Embryo development was assessed by day 8 blastocyst yield, whereas embryo quality was determined using blastocyst differential cell count, cryotolerance and the expression of selected genes related to embryo quality. The results showed that the presence of BAECs during the last 6 h of in vitro maturation (IVM) increased blastocyst yield and survival of the vitrified-warmed blastocysts. In addition, embryos produced in the presence of BAECs during the last 6 h of IVM or in the presence of BOECs during the first 4 days of in vitro culture (IVC) showed a greater number of trophectoderm cells and a greater inner cell mass. In terms of gene expression, IFN-T was downregulated and PLAC8, AQP3 and ATP1A1 were upregulated in the presenc...
Vets often use key performance indicators (KPIs) to evaluate the actual performance status of a d... more Vets often use key performance indicators (KPIs) to evaluate the actual performance status of a dairy herd. Basic knowledge of data analysis is necessary to interpret these KPIs correctly, but unfortunately vets often lack the training and knowledge required to do this. This article aims to make vets aware of common data interpretation errors and discusses four data misinterpretation pitfalls – variation, momentum, lag and bias – as well as introduces the concept of data visualisation, such as the use of graphs and charts, to help vets avoid these pitfalls.
The liver fluke Fasciola hepatica is a parasite of ruminants with a worldwide distribution and an... more The liver fluke Fasciola hepatica is a parasite of ruminants with a worldwide distribution and an apparent increasing incidence in EU member states. Effective control in dairy cattle is hampered by the lack of flukicides with a zero-withdrawal time for milk, leaving the dry period as the only time that preventive treatment can be applied. Here, we present the results of a blinded, randomized and placebo-controlled trial on 11 dairy herds (402 animals) exposed to F. hepatica to 1) assess the effect of closantel treatment at dry-off (or 80-42 days before calving in first-calving heifers) on milk production parameters and 2) evaluate if a number of easy-to-use animal parameters is related to the milk production response after treatment. Closantel treatment resulted in a noticeable decrease of anti-F. hepatica antibody levels from 3-6 months after treatment onwards, a higher peak production (1.06 kg) and a slightly higher persistence (9%) of the lactation, resulting in a 305-day milk pr...
In practice, many veterinarians inseminate cows ‘blindly’ 72 hours following a single injection o... more In practice, many veterinarians inseminate cows ‘blindly’ 72 hours following a single injection of prostaglandin F2α (PGF2α). In this paper we describe the results of a study in which we examined follicular growth dynamics following PGF2α induced luteolysis, aiming at a better insight into the chances for pregnancy when cows are inseminated in a timed manner. A total of 62 dairy cows (CL>25 mm and largest follicle >12 mm) were enrolled in the study and divided over three treatment groups. On day 0 (start of the experiment) all animals received an intramuscular injection of 500 μg cloprostenol, while 42 cows were subjected to ultrasound-guided trans-vaginal follicle aspiration of the largest follicle and were further subdivided into ablation ≤8.5 mm (n = 31) and ablation >8.5 mm (n = 11), according to the size (<8.5 vs. 8.5 to 12 mm, respectively) of the second largest follicle present at the moment of aspiration. The remaining cows (n = 20) were allocated as controls, re...
The objective of this study was to determine the fatty acid (FA) profile and assess desaturase in... more The objective of this study was to determine the fatty acid (FA) profile and assess desaturase indices of nonesterified fatty acids (NEFA) in the blood, as well as in the abdominal (ABD) and subcutaneous (SUBC) fat stores, in dairy cows with left displacement of the abomasum (LDA). Blood, ABD, and SUBC samples were taken from 50 Holstein cows offered for surgery to correct LDA. The FA profile of the 3 compartments was determined by gas chromatography after lipid extraction, methylation, and, in the case of blood plasma, separation of lipid classes. The most abundant FA in all 3 compartments were 16:0, 18:0, and 18:1 cis-9, with a total proportion of 82.5, 68.0, and 74.1g/100 g of FA in ABD, NEFA, and SUBC, respectively. A principal component analysis was performed on the entire FA profile as well as on the Δ(9)-desaturase indices (14:1 cis-9/14:0, 16:1 cis-9/16:0, 18:1 cis-9/18:0). The principal component analysis extracted 2 principal components (PC), representing 51.6% (PC1) and 2...
The effects of metabolic diseases (MD) occurring during the transition period on milk production ... more The effects of metabolic diseases (MD) occurring during the transition period on milk production of dairy cows have been evaluated in many different ways, often with conflicting conclusions. The present study used a fitted lactation model to analyze specific aspects of lactation curve shape and magnitude in cows that avoided culling or death in the first 120 d in milk (DIM). Production and health records of 1,946 lactations in a 1-yr follow-up study design were collected from a transition management facility in Germany to evaluate both short- and long-term effects of MD on milk production. Milk production data were fitted with the nonlinear MilkBot lactation model, and health records were used to classify cows as healthy (H), affected by one MD (MD), or by multiple MD (MD+). The final data set contained 1,071 H, 348 MD, and 136 MD+ cows, with distinct incidences of 3.7% twinning, 4.8% milk fever, 3.6% retained placenta, 15.4% metritis, 8.3% ketosis, 2.0% displaced abomasum, and 3.7%...
The objective of the present study was to evaluate environmental and dam factors associated with ... more The objective of the present study was to evaluate environmental and dam factors associated with birth size of Holstein calves. Data of 1,594 births from dairy herds in Belgium and Germany were analyzed in a retrospective cross-sectional study. Immediately after birth, the birth weight of the calves was measured. On the next day, the heart girth (HG), withers height, and diagonal length of the dams and calves were measured. Parity, body condition score, gestation length (GL), and age at calving were recorded for all dams. For the cows, days open, lactation length, length of the dry period, and calving interval were also calculated. The magnitude and shape of the lactation that took place during gestation was quantified using the MilkBot model based on monthly milk weights. Using the same procedure, cumulative milk production from conception to drying off (MGEST) was calculated. After descriptive analyses, mixed models were used to identify factors that are significantly associated with the birth weight (most consistent measure of size at birth) of the calves born to both heifers and cows. Of the variables offered to the offspring birth weight model in heifers (n=540), calf sex, season of calving, GL, HG, withers height, diagonal length, and age at calving were significant. The mean birth weight of the calves born to heifers was estimated to be 41.3±1.01kg. In comparison to calves born to old (25.5 to 37.3mo; n=99) heifers, the birth weight was estimated to be 2.75, 3.29, and 2.35kg heavier when the calves were born to very young (20.3 to &amp;amp;amp;amp;lt;22mo; n=98), young (22 to &amp;amp;amp;amp;lt;23.5mo; n=145), and standard aged (23.5 to &amp;amp;amp;amp;lt;25.5mo; n=198) heifers, respectively. Of the variables offered to the offspring birth weight model in cows (n=1,054), calf sex, season of calving, GL, parity, dry period, and MGEST were significant. The mean birth weight of the calves born to cows was estimated to be 44.1±0.99kg. For cows having an identical HG, the birth weight of the calves was estimated to be 0.97 and 1.11kg higher in cows with low (1,400 to &amp;amp;amp;amp;lt;5,400kg) and high (6,500 to &amp;amp;amp;amp;lt;7,200) MGEST, respectively, compared with cows with very high (7,200 to 11,600kg) MGEST. The decisive effects of age at calving in heifers and of high milk production levels during gestation in cows on the birth weight of their calves may provide a basis for developing managerial interventions to improve long-term health and productivity of the offspring.
Summary The aim of this study was to evaluate the effects of different timing for frozen–thawed b... more Summary The aim of this study was to evaluate the effects of different timing for frozen–thawed bovine ampullary epithelial cell (BAEC) and bovine oviductal epithelial cell (BOEC) co-culture on the development and quality of bovine embryos produced in vitro. Embryo development was assessed by day 8 blastocyst yield, whereas embryo quality was determined using blastocyst differential cell count, cryotolerance and the expression of selected genes related to embryo quality. The results showed that the presence of BAECs during the last 6 h of in vitro maturation (IVM) increased blastocyst yield and survival of the vitrified-warmed blastocysts. In addition, embryos produced in the presence of BAECs during the last 6 h of IVM or in the presence of BOECs during the first 4 days of in vitro culture (IVC) showed a greater number of trophectoderm cells and a greater inner cell mass. In terms of gene expression, IFN-T was downregulated and PLAC8, AQP3 and ATP1A1 were upregulated in the presenc...
Vets often use key performance indicators (KPIs) to evaluate the actual performance status of a d... more Vets often use key performance indicators (KPIs) to evaluate the actual performance status of a dairy herd. Basic knowledge of data analysis is necessary to interpret these KPIs correctly, but unfortunately vets often lack the training and knowledge required to do this. This article aims to make vets aware of common data interpretation errors and discusses four data misinterpretation pitfalls – variation, momentum, lag and bias – as well as introduces the concept of data visualisation, such as the use of graphs and charts, to help vets avoid these pitfalls.
The liver fluke Fasciola hepatica is a parasite of ruminants with a worldwide distribution and an... more The liver fluke Fasciola hepatica is a parasite of ruminants with a worldwide distribution and an apparent increasing incidence in EU member states. Effective control in dairy cattle is hampered by the lack of flukicides with a zero-withdrawal time for milk, leaving the dry period as the only time that preventive treatment can be applied. Here, we present the results of a blinded, randomized and placebo-controlled trial on 11 dairy herds (402 animals) exposed to F. hepatica to 1) assess the effect of closantel treatment at dry-off (or 80-42 days before calving in first-calving heifers) on milk production parameters and 2) evaluate if a number of easy-to-use animal parameters is related to the milk production response after treatment. Closantel treatment resulted in a noticeable decrease of anti-F. hepatica antibody levels from 3-6 months after treatment onwards, a higher peak production (1.06 kg) and a slightly higher persistence (9%) of the lactation, resulting in a 305-day milk pr...
In practice, many veterinarians inseminate cows ‘blindly’ 72 hours following a single injection o... more In practice, many veterinarians inseminate cows ‘blindly’ 72 hours following a single injection of prostaglandin F2α (PGF2α). In this paper we describe the results of a study in which we examined follicular growth dynamics following PGF2α induced luteolysis, aiming at a better insight into the chances for pregnancy when cows are inseminated in a timed manner. A total of 62 dairy cows (CL>25 mm and largest follicle >12 mm) were enrolled in the study and divided over three treatment groups. On day 0 (start of the experiment) all animals received an intramuscular injection of 500 μg cloprostenol, while 42 cows were subjected to ultrasound-guided trans-vaginal follicle aspiration of the largest follicle and were further subdivided into ablation ≤8.5 mm (n = 31) and ablation >8.5 mm (n = 11), according to the size (<8.5 vs. 8.5 to 12 mm, respectively) of the second largest follicle present at the moment of aspiration. The remaining cows (n = 20) were allocated as controls, re...
The objective of this study was to determine the fatty acid (FA) profile and assess desaturase in... more The objective of this study was to determine the fatty acid (FA) profile and assess desaturase indices of nonesterified fatty acids (NEFA) in the blood, as well as in the abdominal (ABD) and subcutaneous (SUBC) fat stores, in dairy cows with left displacement of the abomasum (LDA). Blood, ABD, and SUBC samples were taken from 50 Holstein cows offered for surgery to correct LDA. The FA profile of the 3 compartments was determined by gas chromatography after lipid extraction, methylation, and, in the case of blood plasma, separation of lipid classes. The most abundant FA in all 3 compartments were 16:0, 18:0, and 18:1 cis-9, with a total proportion of 82.5, 68.0, and 74.1g/100 g of FA in ABD, NEFA, and SUBC, respectively. A principal component analysis was performed on the entire FA profile as well as on the Δ(9)-desaturase indices (14:1 cis-9/14:0, 16:1 cis-9/16:0, 18:1 cis-9/18:0). The principal component analysis extracted 2 principal components (PC), representing 51.6% (PC1) and 2...
The effects of metabolic diseases (MD) occurring during the transition period on milk production ... more The effects of metabolic diseases (MD) occurring during the transition period on milk production of dairy cows have been evaluated in many different ways, often with conflicting conclusions. The present study used a fitted lactation model to analyze specific aspects of lactation curve shape and magnitude in cows that avoided culling or death in the first 120 d in milk (DIM). Production and health records of 1,946 lactations in a 1-yr follow-up study design were collected from a transition management facility in Germany to evaluate both short- and long-term effects of MD on milk production. Milk production data were fitted with the nonlinear MilkBot lactation model, and health records were used to classify cows as healthy (H), affected by one MD (MD), or by multiple MD (MD+). The final data set contained 1,071 H, 348 MD, and 136 MD+ cows, with distinct incidences of 3.7% twinning, 4.8% milk fever, 3.6% retained placenta, 15.4% metritis, 8.3% ketosis, 2.0% displaced abomasum, and 3.7%...
The objective of the present study was to evaluate environmental and dam factors associated with ... more The objective of the present study was to evaluate environmental and dam factors associated with birth size of Holstein calves. Data of 1,594 births from dairy herds in Belgium and Germany were analyzed in a retrospective cross-sectional study. Immediately after birth, the birth weight of the calves was measured. On the next day, the heart girth (HG), withers height, and diagonal length of the dams and calves were measured. Parity, body condition score, gestation length (GL), and age at calving were recorded for all dams. For the cows, days open, lactation length, length of the dry period, and calving interval were also calculated. The magnitude and shape of the lactation that took place during gestation was quantified using the MilkBot model based on monthly milk weights. Using the same procedure, cumulative milk production from conception to drying off (MGEST) was calculated. After descriptive analyses, mixed models were used to identify factors that are significantly associated with the birth weight (most consistent measure of size at birth) of the calves born to both heifers and cows. Of the variables offered to the offspring birth weight model in heifers (n=540), calf sex, season of calving, GL, HG, withers height, diagonal length, and age at calving were significant. The mean birth weight of the calves born to heifers was estimated to be 41.3±1.01kg. In comparison to calves born to old (25.5 to 37.3mo; n=99) heifers, the birth weight was estimated to be 2.75, 3.29, and 2.35kg heavier when the calves were born to very young (20.3 to &amp;amp;amp;amp;lt;22mo; n=98), young (22 to &amp;amp;amp;amp;lt;23.5mo; n=145), and standard aged (23.5 to &amp;amp;amp;amp;lt;25.5mo; n=198) heifers, respectively. Of the variables offered to the offspring birth weight model in cows (n=1,054), calf sex, season of calving, GL, parity, dry period, and MGEST were significant. The mean birth weight of the calves born to cows was estimated to be 44.1±0.99kg. For cows having an identical HG, the birth weight of the calves was estimated to be 0.97 and 1.11kg higher in cows with low (1,400 to &amp;amp;amp;amp;lt;5,400kg) and high (6,500 to &amp;amp;amp;amp;lt;7,200) MGEST, respectively, compared with cows with very high (7,200 to 11,600kg) MGEST. The decisive effects of age at calving in heifers and of high milk production levels during gestation in cows on the birth weight of their calves may provide a basis for developing managerial interventions to improve long-term health and productivity of the offspring.
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