by Cate L Williams, Farming Connect Knowledge Exchange Hub, IBERS, Aberystwyth University
DIeT (alongside genetics) plays a key role in dictating the fat content of meat and milk products. The ruminant diet is rich in unsaturated fats (UFAs), considered beneficial for human health, yet some meat and dairy product varieties contain a high proportion of saturated fats (SFAs), the amount of which should be limited in a healthy diet.
This is due to a complex process where microbial communities in the rumen convert UFAs to SFAs for the purposes of fat storage and to avoid potentially toxic effects.
As the global population continues to expand, a healthy and nutritious food supply is becoming a central concern, especially in the face of the UK’s exit from the eU. Farmers are expected to improve productivity and quality to compensate for the loss of eU markets, so the result is a drive to improve the nutritional profile of meat and milk products in line with guidelines provided for a healthy, balanced diet.
A substantial body of research exists, investigating the manipulation of the fat profile of meat and milk to alter the balance of UFA: SFA in favour of healthier products.
Studies often involve a regime of supplementation using ingredients which are rich in UFAs such as oils (sunflower, rapeseed, flax, fish oils etc.), or to reduce the conversion rate of UFA: SFA in the rumen including plant-derived chemicals (saponins and tannins) and live microbial supplements (yeast and microalgae). Supplementation with oil increases the calorie content of the diet and ruminal fermentation via antimicrobial effects.
The addition of seed oils in particular, increases the amount of UFAs, but not all, since the UFA profile of the oil is reflected in the end product. These trials are generally lab-based, using in vitro rumen simulation techniques and as such, the consequences of manipulating the rumen microbiota on animal function and digestion will require further study.
Another solution, direct-fed microbials (DFMs) present an interesting alternative to UFA supplementation, with additional benefits, including increased feed efficiency, reduced methane emissions and improved immune status. DFMs are provided in early life, prior to rumination, to establish a population of beneficial gut microbes that produce a higher proportion of UFAs. however, at present, DFM supplementation trials are producing inconsistent results as factors such as delivery mode, dose and duration, and environmental interactions are understood and refined.
The impact of Brexit on the agricultural sector may be significant and unpredictable, although changes in market conditions can be expected. Improving the fat profile of ruminant products will allow UK farmers to deliver high quality products that may contribute to their ability to mitigate the risks associated with a changing political landscape.