The Research Column

Since mastitis resistance and milk SCC have a close relationship with udder and teat conformation features, selecting cows with ideal udder and teat shape may be a proposition. Also, the use of technologies such as sonography to detect udder health should be pursued. Ultrasound is commonly used in human medicine to check the mammary glands, for example to differentiate between cystic and solid lesions using 5-13 MHz scanners. Ultrasound is a non-invasive and non-destructive diagnostic tool which could provide real time images of the healthy and mastitic organ.

Heat stress occurs when animals are unable to effectively dissipate heat from metabolism associated with digestion, maintenance and production, plus any heat gained from the environment, the latter being more prominent if the temperature-humidity index (THI) exceeds the comfort zone. In high producing (Holstein) dairy cows, the condition is exaggerated because of the high metabolic load associated with the elevated metabolic demands of lactation.

New-born calves are susceptible to disease due to an under-developed immune system, which at this stage is only supported by an inadequate intestinal microbiota. If healthy, the microbiota nevertheless protects against harmful gut micro-organisms, activates the immune system and assists in initial calf nutrition. Colostrum at this stage is crucial to allow large-molecule immunoglobulins to pass through the short-lived comparatively large pores in the intestinal wall.

Soybean meal is globally probably the most favoured protein supplement in dairy cow diets, but increased demand has elevated its price, which necessitates evaluating other options. One such option is canola meal, with limited research suggesting that canola meal is used as efficient or more efficiently for milk production than soybean meal. Some research showed that the inclusion of canola meal increased DMI, milk yield and milk protein compared to soybean meal and other protein sources.

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.