TECHNICAL Improving dairy cow performance with rumen protected amino acids Utilising rumen protected amino acids in feed rations permits dairy producers to better meet the specific amino acid requirements of the animal. This allows cows to reach their optimum potential for milk production and improve farm profitability, writes Dr. RAZAQ BAOLGUN*. Supplementing ruminant animals functional roles in disease mitigation, supplementing ruminants such as with rumen protected amino acids immune response and reproduction. dairy cows with RPAA results in (RPAA) to balance amino acids is Amino acid supplementation of improved production responses. becoming widely accepted among dairy cows has offered more precise Amino acids and encapsulation nutritionists. This is because there is nutrition of protein and allows the technology increasing evidence of their benefits manipulation of dairy cow diets. It is in replacing expensive protein increasingly becoming necessary to Kemin has developed an effective feeds, ability to lower crude protein minimise the environmental impact encapsulation technology that in the diet and therefore reduce of excess nitrogen in the diet of combines rumen protection of ration cost, and positive production ruminants by targeting and supplying the specific amino acids, lysine or responses, especially in dairy cows. specific amino acids that may be methionine, and their maximum Several reviews on the role of amino limiting in the diet. Methionine release in the small intestine for acids also suggest that apart from and lysine, respectively, are often uptake and utilisation. Kemin being a building block for tissue and regarded as the most limiting amino employs a spray freeze encapsulation milk protein, they also play other acids, and studies have shown that technology for its rumen protected 14 DAIRY SUPPLEMENT – August/September 2016 Figure 1: Electron micrograph of LysiPearl showing its stability through the gastrointestinal tract of cattle. (A) Pre-rumen (B) Post-rumen (C) Post-digestive tract lysine (LysiPearl) and methionine ammonia for microbial protein using MP, it has been shown that (MetiPearl). This spray freezing synthesis; to improve the efficiency of use of technology uses liquid nitrogen (ii) rumen undegraded protein MP, there is a need to also consider for solidification of a hydrogenated (RUP) is the portion of dietary the ratio of the limiting amino acids. palmitic fatty acid matrix in which the protein that escapes microbial Lysine and methionine are the two amino acid of interest is embedded. degradation in the rumen and essential amino acids considered The progressive release of amino flows into the small intestine; to be limiting in the diet and their acids from Kemin’s Pearls using a and concentrations are measured as a proprietary in vitro technology is (iii) a small amount of endogenous percentage in the MP (ie MP-lysine shown in Figure 1. The Pearls are still protein, which is from sloughed and MP-methionine). It is important reasonably intact post rumen and off intestinal epithelial cells. to note that MP includes both were totally disintegrated at the end The contributions of MCP is essential and non-essential amino of the digestive tract demonstrating suggested to be around 55% for a acids. Depending on the computer protection in the rumen followed 25 litre/day cow and decreased to model used, it is suggested that by almost complete release and 45% for a 45 litre/day cow, and it is the ratio of lysine to methionine absorption of the amino acid in the affected by the amount of RDP and should fall in the range of around small intestine. fermentable energy in the rumen. 2.8 to 3.12. Table 1 shows the This suggests that the requirement for recommended optimal MP-lysine The concept of metabolisable RUP will increase with increasing milk and MP-methionine and the ratio in protein production. The amino acid profile various computer models available Metabolisable protein (MP) is the of MCP is close to ideal for milk commercially. The differences in the amount of digestible protein that is production and growth. On the other predicted values are due to different absorbed in the small intestine and hand, the amino acid profile of dietary mathematical constants applied. available to the animal for tissue and RUP can vary depending on the However, the consensus is to stick milk protein synthesis. Contrary to quality and digestibility of the dietary to one model and fine tune its this, crude protein is the proximate crude protein. Therefore the quality application using field observations. amount or concentration of protein of feed proteins and their digestibility Benefits of rumen protected that is present in the diet and it is will affect the amount of MP flow amino acids subject to various digestive changes and absorption in the small intestine. in the gastro intestinal tract before So both feed and animal factors will The benefits of supplementing dairy reaching the small intestine. Therefore affect MP supply and therefore the cows with RPAA are well established the amount and quality of MP in performance of ruminants. If variation in the literature. The ability to target terms of amino acid profile becomes in the quality of RUP using targeted specific amino acids is the biggest critical to the performance of a amino acid supply from RPAA source advantage of supplementation dairy cow. The concept of the ‘ideal can be minimised, you can improve with RPAA as it allows predictable protein’ for animal performance is production and increase profitability delivery of the targeted amino about matching animal requirements of a dairy cow. acid to the duodenum of the cow. for amino acids with supply from the Given the specificity required for Balancing amino acids diet. balancing amino acids, encapsulation Metabolisable protein consists As indicated earlier, the quality and technology offers better and primarily of: quantity of MP can determine the controlled manipulation of diets to (i) microbial protein (MCP), performance of dairy cow. Therefore, achieve optimum performance. resulting from microbial the amount of RUP and MCP (both • Increased milk production degradation of degradable making up most of the MP) reaching in terms of litres and milk protein in the rumen (RDP) the small intestine and their amino solids have been reported in into ammonia and the acid profile are important. While lactating dairy cows, especially subsequent incorporation of predicting dairy cow production in the early stage of lactation v DAIRY SUPPLEMENT – August/September 2016 15 TECHNICAL v when nutrient demand is Table 1: Recommended amino acid requirements as predicted using different high. Depending on the diet, nutritional models. deficiencies of limiting amino acids, usually lysine and methionine can be corrected by Dietary targets of MP lysine and MP methionine and recommended ratio feeding RPAA to improve milk System Percent in Metabolisable Protein Optimal Ratio yield and milk components. Lysine Methionine • Because specific amino acids are targeted, RPAA offers an CNCPS opportunity to reduce the Before v6.1 6.68 2.4 2.78 cost of feed that may not be V6.1 6.97 2.53 2.75 required. For example, we can reduce the cost of protein meal CPM-Dairy by reducing the amount in V3.0.10* 7.46 2.57 2.9 the diet and allowing cheaper ingredients into the least cost NRC formulation. Original release# 6.8 2.29 2.97 • Using conventional feedstuffs to balance amino acids is V1.19** 6.83 2.28 3 challenging and can be almost *Whitehouse et al. 2009, **Whitehouse et al. 2013, #Schwab et al. 2009 impossible because other amino acids or nutrients that are not required are also cows with RPAA. maintaining maximum release and digestibility in the small intestine. supplied, leading to an over- On top application supply of protein and therefore Several studies have shown the inefficient utilisation of protein. This involves adding RPAA to an benefits of supplementing RPAA to By supplementing with RPAA, existing diet to meet requirement lactating cows in terms of improving it is more targeted and can in order to increase animal milk production by meeting specific overcome the oversupply of performance. This is often used to amino acid requirement (on-top proteins that are not required. bridge a deficiency of particular amino approach). Rumen protected amino This will improve the efficiency acids that are limiting production. acids can also be used to reformulate of protein utilisation and The economic significance of this diet to improve the efficiency of improve performance. approach will depend on the prices of nitrogen utilisation by reducing excess • If RPAA are used to balance other feedstuffs and milk price. nitrogen in the diet and reducing nitrogen excretion. This often reduces amino acid supplies and remove Reformulation approach unwanted protein, it creates ration cost and therefore can improve space for other necessary This involves manipulating the diet financial returns. nutrients to be included in the composition, which often requires the It is clear that feeding rumen diet. For example, more starch removal or reduction of a particular protected amino acids offers the dairy or fibre can be incorporated into feedstuff with the addition of specific farmer the opportunity to increase the diet. RPAA. The objectives of reformulation herd performance and profitability. • Removing excess protein from are to reduce ration cost by removing It is important to note that feeding the diet has an environmental or reducing the amount of expensive RPAA is not exclusive as its success benefit as it reduces the feedstuff like protein meals while also depends on optimising rumen excretion of nitrogen into the maintaining or even improving function by ensuring that there environment while maintaining performance, improving efficiency of is adequate rumen degradable or improving milk production. nitrogen utilisation, and creating space protein and fermentable energy to In published studies, reducing for other nutrients such as starch and drive microbial protein yield.