New research has shed light on milk fat production. We'll be focusing on two promising areas of research the modern dairy farmer should be aware of. One is the recent work revolving around the importance of gut health in animal performance and how to leverage this to increase milk fat production. The second new development shows us how how milk fat is assembled by the cow and presents some new ideas on how we may be able to monitor and manage milk fat production in the future. Lets jump in now to get a better understanding milk fat production:
GIT, microbiome, and calcium gluconate
The human body harbors 100 trillion microgranisms. These microbes, collectively called “the microbiome”, are distributed throughout the body where they perform a number of vital functions that we cannot perform ourselves. The greatest number of microbiome reside in the largest organ: the gastrointestinal tract (GIT).
Dairy cattle also have a microbiome, the largest of which lives in the rumen. The rumen microbiome is a major contributor to animal efficiency; enabling the cow to digest plant materials that cannot be digested by other animals. The role that GIT microbiome play in dairy cow production has not received as much attention. The functional similarities of the GIT microbiome in dairy cows and non-ruminants has brought about a renewed interest in understanding how the GIT influences cow health and productivity. Enhancing the function of GIT and its microbiome may unlock the key to optimal animal efficiency.
Studies in humans and pigs showed calcium gluconate has beneficial effects on the GIT. More specifically calcium gluconate stimulates the growth of good GIT bacteria and these bacteria produce more butyrate. Butyrate is a fatty acid that provides energy to the GIT and strengthens the cells that comprise the defensive barrier. Whether calcium gluconate could be beneficial for dairy cattle has not been examined previously. In our first study, an infusion method was used where a long tube was guided through the rumen and inserted and anchored into the omasum. The approach allowed calcium gluconate to bypass the rumen making it available to the GIT. These infusion experiments demonstrated significant increases in milk fat yield (kg/d). The resulting success of these experiments raised the question about whether calcium gluconate could also be beneficial for rumen bacteria.
However, when tested no animal performance benefits were observed when calcium gluconate was fed in the TMR. Together, these findings provided evidence that calcium gluconate worked best in the GIT of lactating dairy cows. Selko Cremalto was created and tested in a series of feeding experiments. The pivotal study was a full lactation study. Research showed that daily milk fat yield increased 109 g/d and energy corrected milk increased 2.7 kg/d in multiparous Holstein cows.
Importance of the Fatty Acid Profile
The fat in milk is often the component with the highest value; however, it is extremely difficult to increase predictably—usually because we do not fully comprehend the various ways in which nutrition and milk production interact.
When cows are fed energy, they can store it as body condition or release it into the milk—a choice that varies according to stage of lactation. The next issue the form of the energy—fat, protein, and carbohydrates all provide energy; however, cows will divide this energy between fat and milk volume. That stated, although the yield of fat may increase,—with associated benefits in milk cheque payments—the concentration of fat may not change or may even decrease as a result of being diluted by the extra milk volume.
There are ways that milk fat yield can be increased with some certainty: introducing palmitic acid into the diet is the easiest, but far from cost-effective. Palmitic acid, a 16-carbon fatty acid, is found in all vegetable fats, but is particularly high in palm fat (hence the name). Concerns about including palm fat products in the dairy cow diet have been raised with regard to the sustainability of producing palm oils as well as the effects that changing the fatty acid profile might have on the physical/manufacturing properties of milk fat.
Recent developments by Professor Dave Barbano at Cornell University have focused on using a milk fatty acid profile to explain what happens in the rumen and in the cow. Analysing for milk fatty acids has been a slow and costly process, but Barbano has developed calibrations for the mid-infrared milk analyzers routinely used for determining milk composition. This means that he can provide feedback on herd and individual performance both quickly and at a minimal cost. As indicated above, some of the fat in milk comes preformed from the feed but other fatty acids are synthesized (de novo) by the mammary gland. Barbano has determined amounts of de novo fatty acids which relate directly to milk fat concentration and to bunk space per cow, stocking density, peNDF and fat content of the ration. In addition, he showed a correlation with ketosis and other metabolic diseases. This ground-breaking data will allow producers and nutritionists to optimize rations for milk fat and overall cow health once Barbano’s findings become more widely available at milk processing plants and DHIA laboratories.