Malic acid salt improves digestion of cassava chip diets

Cassava (Manihot esculenta) chips, CC, has a strong potential as an energy source for ruminants in tropical areas. However, it’s a source of quick ruminal-fermentable energy, therefore it leads to risk for subclinical acidosis. Malate has shown to be effective in preventing acidosis as it increases ruminal pH and decreases lactate (Martin et al.,1999 and Carro and Ranilla,2003).Khampa et al.,2006a and 2006b performed two experiments to evaluate the benefits of malate in CC diets. The first experiment was carried out with dairy steers receiving a high CC (70%) concentrate diet with various levels of malic acid salt and ad libitum urea as well as treated rice straw roughage.

Malate showed changes on dry matter intake, increased and stabilized ruminal pH, increased ammonia-nitrogen, blood urea nitrogen and total volatile fatty acids. It also changed the proportion of fatty acids in favour of propionate, resulting in more available energy. The second experiment was carried out with lactating dairy cows receiving high CC concentrate (70 and 75%) with various levels of urea and malate. Malate improved the digestibility of organic matter, crude protein and fiber. As well, higher doses of malate resulted in lesser ruminal lactic acid and faecal N. Microbial N supply also increased along with malate dose. Finally, the study showed that malate improved rumen ecology.

In conclusion: malate improves ruminal digestion in CC diets for steers and lactating dairy cows.