The Research Column

Milk fat depression is a costly and complex disorder of mostly high-producing TMR fed dairy cows, with milk fat sometimes declining up to 50%. It occurs primarily on high carbohydrate fermentable diets and/or with unsaturated fat supplements. Although known and studied for many years, there is still no way to address the root cause directly; the problem being rumen microbes that synthesize so-called antilipogenic fatty acids on these diets.

The aim of the study by the authors cited was to identify subclinical mastitis in the udder through zootechnical data, infrared thermography (IRT) and machine learning techniques.

The ability of a dairy cow to perform similarly across time is clearly important and should be included in breeding programmes if feasible and heritable, since this would be linked to resilience. Consistency, defined as the quality of performing as expected each day of lactation, could be highly associated with resilience, where resilience is the animal’s ability to maintain health and performance in the presence of environmental challenges such as pathogens, heat waves and nutritional changes.

Increased data routinely collected by modern milking machine sensors and software has occurred together with increased cow attached sensor data, usually applied for fertility and health monitoring. To increase milking efficiency and gentle, quick and complete milking, it makes sense to investigate how various milking machine settings will impact on gentleness of milking through a proxy measurement of cow comfort during milking.

The introduction of concentrates in the diet has contributed markedly to increasing milk production per cow and limiting the effect of the negative energy balance during the period when dry matter intake (DMI) is comparatively low. A wide range of concentrate feeding approaches are used including total mixed rations (TMR), or presenting the concentrate portion separately from the forage via in-parlour or out-of-parlour feeding systems, or a combination of these approaches.

The controversy regarding animal products and human health and environmental concerns has not yet subsided, despite recent evidence which on the one hand shows that the relationship with cardiovascular disease, cancer and diabetes is largely inconclusive, and on the other hand environmental damage can be managed by production system management, such as regenerative management techniques.

Fresh whey cheeses are susceptible to the growth of mainly moulds and yeasts, due to their high moisture, protein and lactose contents, low salt concentration, and pH around 6.0. Even with good hygienic practices and effective cooling, they have limited shelf life. Thus, the investigation of post-production decontamination methods, preferably alternatives to thermal and chemical treatments, is required to ensure the safety and quality of whey cheeses during delivery and storage.

Genetics are inextricably linked to reproductive physiology and performance of dairy cows. In this context strong associations have been reported for genomic enhanced PTA for fertility and reproductive outcomes (PTA meaning the predicted difference of a parent animal’s offspring from the average, due to genes transmitted from that parent).

Milk is a valuable source of nutrients in human nutrition, but the composition could be altered as a result of physical interventions. Due to safety requirements, shelf life and consumer preferences, milk is normally pasteurised, homogenised and sometimes spray dried. Homogenisation is done using pressure and heat, and this causes changes in the location of proteins in the milk as well as protein modifications which can affect nutritional characteristics. The intention of the study cited was to investigate these proteomic changes further and to what extend they are variable.

Methane is a greenhouse gas which because of climate change expectations should be mitigated. Its production in the rumen also results in 4 to 12% loss in potential energy to the cow, and therefore mitigation may improve production performance, at least theoretically. There are several feeding and management strategies to exploit methane mitigation, and more recently genetic variability, which is the subject of this investigation, has also been explored.