Plant Oils Add To Diets Reduce Methanes
Adding plant oils to grass-based diets can reduce cow methane production and have beneficial effects on certain fatty acids in milk.
This is concluded from research done by the Natural Resources Institute Finland (Luke).The results were published in the Journal of Dairy Science.
Nutrition approaches on methane reduction
It is well known that ruminants contribute to the total amount of greenhouse gases in the form of methane (CH4) emissions (bel gas and fart).
Several nutrition and management strategies can be used to minimize the effects of cattle. Early experiments also included the use of plant oils and oilseeds. One or more mechanisms are thought to help reduce the production of CH4 into dietary lipid supplements, including the reduction of digestion of organic matter in the rumen, the transfer of ruminal fermentation from acetate to propionate production, and the Direct inhibition of animals. However, earlier experiments also showed that at higher oil levels, feed intake is often compromised, and changes in rumen microflora associated with reduced rumen CH4 production to lipid supplements are not well characterized. Coupled with the fact that milk fatty acid content in milk is beneficial to humans, a group of Finnish researchers decided to set up a test to test all these elements.
The Finnish research team wanted to test the suitability of dietary supplemented fats as a CH4 mitigation strategy and it could use a diet based on restricted fermented silage while improving milk fatty acid composition. Photo: PXhere
4 different plant oils tested in Nordic Red Bull
The research team wanted to test the suitability of dietary supplemented fat as a CH4 mitigation strategy that could use a diet based on restricted fermented silage while improving the fatty acid composition of milk. In this study, four lipid supplements with varying chain length or unsaturation were used and supplemented with five Nordic Red Bull (with rumen ducts) diet. The diet consisted of total mixed rations based on grass silage with a forage to concentrate ratio of 60:40 supplemented with no lipid (CO) or 50g/kg of diet dry matter (DM) of myristic acid (MA), rapeseed oil (RO), safflower oil (SO), or linseed oil (LO).
Effect on DMI and milk composition
The results showed that compared with CO, feeding MA resulted in the lowest DM intake, and RO intake decreased DM intake. Feeding MA reduced the yields of milk,milk constituents, and energy-corrected milk.Compared to CO, plant oils do not affect the production of milk and milk components, but reduce milk protein content. In addition to the increase in ammonia nitrogen concentration due to feeding of MA, RO and SO had no effect on the characteristics of ruminal fermentation, but with CO. Supplementing lipids reduces daily rumen CH4 emissions; however, this response is the result of reducing feed intake in some extent. Lipid-modified microbial community structure does not affect the total number of bacteria, archaea, and ciliate protozoa.
Dietary treatments had no significant effect on the apparent digestibility of organic matter, fiber, and total energy. reatment does not affect the energy secreted in milk as part of energy intake or as part of dietary nitrogen utilization efficiency. All lipids lowered de novo fatty acid synthesis in the mammary gland. Plant oils increased proportions of milk fat 18:0, cis 18:1, trans and monounsaturated fatty acids, and decreased saturated fatty acids compared with CO and MA. Both SO and LO increased the proportion of total polyunsaturated fatty acids, total conjugated linolenic acid, and cis-9,trans-11 conjugated linoleic acid. Feeding MA clearly increased the Δ9 desaturation of fatty acids.
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Based on these results, the researchers point out that these insights provide compelling evidence that plant oils supplemented with forage silage can reduce rumen CH4 emissions and milk saturated fatty acids and increase the ratio of unsaturated fatty acids and total conjugated linoleic acid. It does not interfere with digestibility, rumen fermentation, rumen microbial count or milk production.