Prenatal programming of later performance in dairy cattle = Prenatale programmering van latere prestaties bij melkvee

Prenatal programming refers to the fact that insults during pre- and early postnatal life can have long-term consequences on the health and performance. In diary cattle, physiological conditions, such as maternal body growth, milk yield and parity, and environmental conditions during gestation can create a suboptimal environment for the developing fetus. As a consequence, adaptations of the placental and newborn phenotype take place. In addition, potential long-term effects of prenatal programming influence body growth, fertility, milk yield and longevity in dairy cows. These results suggest that the current management systems may pose a risk for the long-term health and performance of dairy cattle. Hence, in management practices, all pre- and postnatal aspects should carefully be considered in order to raise healthier and more productive dairy cows

Het effect van het toedienen van een orale elektrolytenoplossing op de zuur-basebalans en vitaliteit van pasgeboren Belgisch witblauwe kalveren

In the present study, the effect was investigated of administering an oral electrolyte solution (Glutellac(R)) to newborn Belgian blue calves on their vitality, the acid-balance in the blood, and their passive immunity. Twenty newborn calves were incorporated in the study, of which ten were administered a placebo and ten were administered Glutellac(R). Only three calves showed metabolic acidosis. The group, which was administered Glutellac(R), showed a significant higher base excess at two hours (p < 0.05), six hours (p < 0.001) and twelve hours (p < 0.001) after birth. Clinically and in terms of IgG absorption capacity, there were no significant differences between both groups. In conclusion, it can be stated that the administration of Glutellac(R) to Belgian blue calves without metabolic acidosis immediately following birth by caesarean section beneficially influences the base excess

Maternale en omgevingsfactoren die significant geassocieerd zijn met het geboortegewicht van holsteinkalveren

The objective of the present study was to determine factors that are associated with the birth size of Holstein calves. A retrospective cross-sectional study was set up, and data of 1594 calf births from four dairy herds in Belgium and one in Germany were analyzed. Of the variables offered to the offspring birth weight (BW) model in heifers, calf gender, gestation length, season of calving, age at calving and heart girth, wither height and diagonal length of the dam were retained as significant. The BW was significantly lower in heifers that calved at a very old age (25.5 to 37.3 months) (P < 0.001). Calves born out of young (20.3 to <22 months) and old (23.3 to 25.5 months) heifers were lighter than calves born out of intermediately aged (22 to <23.5 months) heifers. Of the variables offered to the offspring BW model in cows, calf gender, season of calving, gestation length, parity, length of the dry period and the milk production during gestation (MGEST) were significant. For cows having the same heart girth, the BW of the calves was 0.97 and 1.11 kg higher in cows with low (1,400 to < 5,400 kg) and high (6,500 to < 7,200) MGEST, respectively, than in cows with very high MGEST (7,200 to 11,600 kg) (P < 0.05). The negative effects of young and older age at calving in heifers and of very high milk production levels during gestation in cows on the BW of their calves, provide a basis for further research in nutritional and managerial interventions to improve the long-term health and productivity of the offspring

Effect of β-hydroxybutyric acid, parity, and body condition score on phenotype and proliferative capacity of colostral mononuclear leukocytes of high-yielding dairy cows

In neonatal calves, the ingestion of colostrum is imperative for preventing infectious diseases. Investigations into the transfer of passive immunity of cattle have primarily focused on the importance of colostral immunoglobulins, with a recent increase in focus on understanding the role of colostral leukocytes. The main objective of the present study was to measure the influence of parity, body condition score, serum nonesterified fatty acids, and serum beta-hydroxybutyrate concentrations of periparturient cows on phenotype and mitogen-and antigen-induced proliferative capacity of bovine colostral leukocytes. Holstein-Friesian cows (n = 141) were intramuscularly vaccinated at 60 and 30 d before the expected parturition date with a tetanus toxoid vaccine. Of these 141 animals, 28 primiparous and 72 multiparous cows were sampled immediately. after parturition. Colostrum mononuclear cell populations were identified by flow cytometry using bovine cluster of differentiation markers, and the proliferative capacity of these cells was determined using a H-3-thymidine proliferation assay. Under-conditioned cows had a significantly higher percentage of colostral macrophages than normal-conditioned animals, whereas over-conditioned cows had significantly more colostral B-lymphocytes. Serum beta-hydroxybutyrate was significantly associated with higher numbers of colostral T-lymphocytes and macrophages. Heifers had significantly higher mitogen- and antigen-induced proliferation of their colostral leukocytes than third parity or older cows. In conclusion, body condition score, parity, and serum beta-hydroxybutyrate concentration of periparturient high-yielding dairy cows were shown to influence the number of colostral macrophages or the mitogen-and antigen-induced proliferation of colostral leukocytes, possibly influencing the cellular immunity of the newborn calf

Het inschatten van energiereserves onder de vorm van vet bij hoogproductieve melkkoeien

The aim of the present study was to examine the correlation between the subcutaneous and intra-abdominal fat deposits in dairy cows and, furthermore, to determine how these fat deposits can be accurately measured in the living cow using methods applicable in the field. In 74 dairy cows, the amount of subcutaneous fat was measured just before slaughter, using three different techniques: determination of the body condition score (BCS), measurement of the ultrasonographic back fat thickness (BFT), and measurement of the bio-electrical impedance (bioelectrical impedance analysis, BIA). After slaughter, the amount of fat stored in the omentum was determined using a new omental fat score (OFS) based on a 5-point scale. The results revealed that there is significant correlation between the different methods tested to measure the amount of subcutaneously stored fat (BCS-BFT: r = 0.71; p < 0.001; BCS-BIA: r 0.39; p < 0.01; BFT-BIA: r = 0.57; p < 0.001). Remarkably, however, no correlation was found between the OFS and the amount of fat stored in the subcutis as measured by the BCS and the BFT (r = 0.20; p = 0.08 and r = 0.10; p = 0.39, respectively). Also, the BIA results were not correlated with the OFS (r = 0,10; p = 0,40), a fact which could be due to the electrode placement along the dorsal midline of the cow instead of on the limbs. The conclusion of this study is that both farmers and veterinarians should be aware that, although the BCS and the BFT may be scored as optimal in relation to their stage in lactation, some cows may hide a significant amount of fat in their omentum, which may put them at a higher risk of suffering from metabolic diseases. More research is required in order to develop new techniques to measure accurately and in a practically applicable way the total amount of fat stored in the body of a living cow

'Thunder Measure Vet Device' : een praktische en objectieve methode om de lichaamsconditie van melkvee te schatten

The scoring of the body condition at specific time points during the lactation cycle has proven to be essential in the nutritional management of modern dairy herds. The 'Thunder Measure (TM) Vet Device' has recently been developed by Ingenera SA, Switzerland to accurately and objectively measure the body condition score (BCS) of dairy cows in the field. Based on a smartphone app linked to a laser device, the system makes an analysis of three dorsal view photographs taken, for example, when cows are lined up in the feed alley. In the present study, the correlation and repeatability of the system were examined in comparison with the conventional visual measurement of BCS and ultrasonographic measurement of the backfat thickness (BFT). The conventional measurement of the BCS was done by a veterinary surgeon experienced in body condition scoring and by less experienced veterinary undergraduate students. The results obtained via the TM Vet Device were only moderately correlated with the BFT measurements (r=0.38, P<0.001), but were highly correlated (r=0.82, P<0.001) and showed good agreement with the BCS results obtained by the experienced veterinary surgeon. The BCS results obtained by the undergraduate students were highly variable, leading to a highly variable correlation with the results gathered using the TM Vet Device (r=0.23 (P<0.05) to r=0.74 (P<0.001)). The repeatability of the results obtained by the device was very high (91%). Only the repeatability of the results obtained by the experienced veterinarian (93%) and the BFT measurement (96%) were higher. In lean animals, some overscoring by the device was noted in comparison with the scores given by the experienced veterinary surgeon, although this overscoring diminished as the body condition score assigned by the veterinary surgeon increased. The ease to use and the accuracy of the results obtained allow the TM Vet Device to be considered a useful tool in the nutritional management of a modern dairy herd

Interpretation and visualisation of data from dairy herds

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

Bovi-Analytics : a platform to educate veterinary students Big Data in dairy cows : an initiative to create the veterinary stethoscope version 3.0?

C

Genome-wide association for milk production and lactation curve parameters in Holstein dairy cows

The aim of this study was to identify genomic regions associated with 305-day milk yield and lactation curve parameters on primiparous (n = 9,910) and multiparous (n = 11,158) Holstein cows. The SNP solutions were estimated using a weighted single-step genomic BLUP approach and imputed high-density panel (777k) genotypes. The proportion of genetic variance explained by windows of 50 consecutive SNP (with an average of 165 Kb) was calculated, and regions that accounted for more than 0.50% of the variance were used to search for candidate genes. Estimated heritabilities were 0.37, 0.34, 0.17, 0.12, 0.30 and 0.19, respectively, for 305-day milk yield, peak yield, peak time, ramp, scale and decay for primiparous cows. Genetic correlations of 305-day milk yield with peak yield, peak time, ramp, scale and decay in primiparous cows were 0.99, 0.63, 0.20, 0.97 and -0.52, respectively. The results identified three windows on BTA14 associated with 305-day milk yield and the parameters of lactation curve in primi- and multiparous cows. Previously proposed candidate genes for milk yield supported by this work include GRINA, CYHR1, FOXH1, TONSL, PPP1R16A, ARHGAP39, MAF1, OPLAH and MROH1, whereas newly identified candidate genes are MIR2308, ZNF7, ZNF34, SLURP1, MAFA and KIFC2 (BTA14). The protein lipidation biological process term, which plays a key role in controlling protein localization and function, was identified as the most important term enriched by the identified genes

Expert-based development of a generic HACCP-based risk management system to prevent critical negative energy balance in dairy herds

The objective of this study was to develop a generic risk management system based on the Hazard Analysis and Critical Control Point (HACCP) principles for the prevention of critical negative energy balance (NEB) in dairy herds using an expert panel approach. In addition, we discuss the advantages and limitations of the system in terms of implementation in the individual dairy herd. For the expert panel, we invited 30 researchers and advisors with expertise in the field of dairy cow feeding and/or health management from eight European regions. They were invited to a Delphi-based set-up that included three inter-correlated questionnaires in which they were asked to suggest risk factors for critical NEB and to score these based on 'effect' and 'probability'. Finally, the experts were asked to suggest critical control points (CCPs) specified by alarm values, monitoring frequency and corrective actions related to the most relevant risk factors in an operational farm setting. A total of 12 experts (40 %) completed all three questionnaires. Of these 12 experts, seven were researchers and five were advisors and in total they represented seven out of the eight European regions addressed in the questionnaire study. When asking for suggestions on risk factors and CCPs, these were formulated as 'open questions', and the experts' suggestions were numerous and overlapping. The suggestions were merged via a process of linguistic editing in order to eliminate doublets. The editing process revealed that the experts provided a total of 34 CCPs for the 11 risk factors they scored as most important. The consensus among experts was relatively high when scoring the most important risk factors, while there were more diverse suggestions of CCPs with specification of alarm values and corrective actions. We therefore concluded that the expert panel approach only partly succeeded in developing a generic HACCP for critical NEB in dairy cows. We recommend that the output of this paper is used to inform key areas for implementation on the individual dairy farm by local farm teams including farmers and their advisors, who together can conduct herd-specific risk factor profiling, organise the ongoing monitoring of herd-specific CCPs, as well as implement corrective actions when CCP alarm values are exceeded