Sheep are potential animals to be raised in Indonesia, but their production is influenced by various factors such as; feed quality, rearing system, sheep condition and environment. The most important factor is feed quality, which affects nutrient consumption and protein utilization.
Feed is needed for maintenance, growth, production and reproduction. Increasing animal production should be accompanied with the availability of forage because forage is the main feed for ruminants. The availability of forage fluctuates and depends on the season and it is mostly limited during the dry season.
Leguminous crops are one of the forage sources that are a potential feed for animal because it contains high protein. Leucaena commonly known as river tamarind is one such potential legume that is a source of protein feed for ruminants1.River Tamarind contains high protein content. It also contains an anti-nutrient chemical compound that is toxic to animals, namely, mimosine. The structure of mimosine is similar to tyrosine (an amino acid). Mimosine, on a molecular level, interferes with the functions of tyrosine and enzymes2.
Thyroid hormones regulate the rate of metabolism, protein synthesis and the body’s sensitivity to other hormones, so that they can influence the metabolism processes in the body. There were limited reports on the fate of mimosine and its effect on thyroid hormones in sheep3. In this context a new study was carried out to evaluate the mimosine concentration in the rumen, blood, faces and urine as well as its effects on blood metabolites and thyroid hormones of sheep fed with different levels of river tamarind leaf meal4.
The detection of mimosine in the blood means that under-graded mimosine can be absorbed from the rumen. The increasing level of lriver tamarind leaves in the ration from 15-30% did not increase the mimosine content in the faces and urine. This outcome may indicate that the rumen of sheep fed with leucaena harbor bacteria that are able to degrade mimosine.
The increasing level of leucaena in diets did not affect blood glucose, cholesterol and protein. Blood albumin was also not affected by leucaena in diets. The similar levels of T3 and T4 hormones among treatments indicated that the absorption of iodium mineral and thyroid hormones production are not affected by the inclusion of leucaena leaf meal (up to 30%) in the diet.
It was established that Mimosine disappearance in the body of sheep was approximately 34-68%. Undegraded mimosine was excreted through the faeces and urine. The inclusion of leucaena leaf meal (up to 30%) in the diet as a replacement of glyricidia did not affect blood metabolites (glucose, cholesterol, protein and albumin) and thyroid hormones in local sheep.
Mimosine, leucaena, gliricidia, sheep, blood metabolites, river tamarind leaf meal, metabolism processes, Thyroid hormones, anti-nutrient, chemical compound, forage availability, Leguminous crops.
- Haque, N., S. Toppo, M.L. Saraswat and M.Y. Khan, 2008. Effect of feeding Leucaena leucocephala leaves and twigs on energy utilization by goats. Feed Sci. Technol., 142: 330-338.
- Xuan, T.D., A.A. Elzaawely, F. Deba, M. Fukuta and S. Tawata, 2006. Mimosine in leucaena as a potent bio-herbicide. Sustain. Dev., 26: 89-97.
- TerMeulen U. and E.A. El Harith, 1985. Mimosine-a factor limiting the use of Leucaena leucocephala as an animal feed. Der Tropenlandwirt-J. Agric. Trop. Subtrop., 86: 109-118.
- Suharti, S., Kurnia, F.X.S., Pambudi, B. and Wiryawan, K.G., 2018. Fate of Mimosine, Concentration of Blood Metabolites and Thyroid Hormones of Sheep Fed with Leucaena and Glyricidia Leaf Meal. J. Nutri., 17: 268-273.