While the physical nature of calcium salt-type fat supplements may not seem important initially, research findings indicate that granule size has a major impact on the degree of rumen-protection of these products, according to Volac Wilmar Feed Ingredients.
Research by Volac Wilmar conducted at the National University of Singapore has found a significantly higher breakdown of calcium salts of fine granules (less than 0.5 mm in diameter) compared to large granules (3-4 mm in diameter) across a range of different acid conditions to reflect typical rumen pH values, the company said in an announcement.
Because calcium salts are an industry-standard method of delivering C18:1 (oleic) and C16:0 (palmitic) fatty acids to dairy cows, the implications of these findings are clear: the physical nature of calcium salt supplements is a key factor in the success of delivery of fatty acids through the rumen in their active form, the company said.
“Rumen protection is critical to avoid reductions in rumen fiber digestibility and to ensure delivery of unsaturated fatty acids, such as C18:1, through the rumen to the small intestine for absorption,” said Dr. Richard Kirkland, global technical manager for Volac Wilmar Feed Ingredients. “In simple terms, we manufacture rumen-protected fats for two reasons. The first is to protect the rumen from the fat, which allows us to avoid reductions in fiber digestibility. The second is to protect the fat from the rumen to avoid biohydrogenation of unsaturated fatty acids to ensure they pass to the small intestine for functional benefit.”
In order to optimize cow performance and return on investment through fat supplementation, product granule size should be considered, Kirkland said.
“However, particle size varies greatly according to the manufacturing process and different brands display a large range in granule size,” Kirkland noted.
Consider fatty acids, not fat
Ongoing research has highlighted the effects of individual fatty acids on milk yield, milk fat content, body condition score and fertility at different periods of lactation, added Dr. John Newbold, professor of dairy nutrition at Scotland’s Rural College.
“In isolation, C16:0 improves milk fat production and yield and is most beneficial in mid- to late lactation. C16:0 induces insulin resistance to increase the partitioning of nutrients to milk, though [it] appears to have negative effects on egg development leading to reduced fertility,” Newbold explained. “By contrast, C18:1 improves digestibility of total fat, leading to increased energy supply, and is linked to enhanced body condition score. C18:1 also promotes egg development, boosting fertility by improving embryo development. To capture the full benefits of C18:1, supplements with higher proportions should be offered in early lactation.”
To maximize returns from specific milk contracts, fatty acids should be selected depending on the stage of lactation, individual farm challenges and contract requirements, Newbold said. For year-round calving herds, targeting specific fatty acid requirements for individual cows is not a feasible task. However, selecting a multipurpose fat supplement balanced with an optimum C16:0-to-C18:1 ratio is an effective way to overcome this challenge.
“In the correct ratio, C16:0 and C18:1 fatty acids can help balance milk production, body condition and fertility during early lactation. As the cow transitions into later stages of lactation, C16:0 can effectively increase milk fat production,” Newbold said.
Return on investment
According to Kirkland, the granule size of calcium salt fat supplements is a key factor when seeing a return on investment through targeted fat supplementation to ensure that the delivery of active fatty acids through the rumen is maximized for absorption and utilization.
“Rumen-protected fat supplementation not only helps meet energy requirements but also supports specific areas of performance, but remember: not all fatty acids will support cow performance in the same manner, and not all fat supplements will be digested to the same extent due to differences in fatty acid profile,” Kirkland concluded. “Particle size definitely matters, and when it comes to calcium salts, bigger is better.”