Modifications caused by tedding and evolution during storage of the quality of hay made from Brachiaria decumbens and Digitaria swazilandensis in French Guiana

Abstract

In French Guiana, livestock farmers have chosen hay making as the best technique for storing forage and dealing with seasonal variations in its availability. The climatic conditions and the availability of this biomass during the short and long rainy seasons (November-December and April- June, respectively) mean that this technique can be used during limited periods, distributed bimodally over the year. However, to optimize the use of this hay, it must be of good nutritional quality. The study shows the incidence of factors linked to the plant (age and nature of the forage) on the quality of hay produced. The effect of the storage duration on the nutritional value of the end-product is also examined. Hay produced with Digitaria swazilandensis cut when it is 30 days old is of greater nutritive value than hay made with Brachiaria decumbens cut at the same age. Under the trial conditions, the change in the nutritive value is significant from the 5th month of storage onwards, with a considerable reduction in  in vitro dry matter digestibility and total nitrogen content. The authors conclude that it is possible in practice to produce hay of satisfactory nutritional value from Digitaria swazilandensis if it is cut a 4 weeks after receiving 80 units of nitrogen at the beginning of regrowth.