Energy supplements for leucaena

Abstract

Keynote paper presented at the International Leucaena Conference, 1‒3 November 2018, Brisbane, Queensland, Australia.Leucaena can be fed as the sole diet to fattening cattle without nutritional problems and it will promote high liveweight gains. The high crude protein concentration in leucaena suggests that energy supplements, which are readily fermented in the rumen, could be used to capture the excess rumen degradable protein and provide more microbial protein and metabolizable energy to the animal, further increasing liveweight gain or milk production. This approach has been tested in grazing cattle and also in cut-and-carry systems in Australia and Indonesia. In both systems, production (liveweight gain or milk production) increased with the addition of supplements containing large amounts of fermentable meta- bolizable energy. The substitution of the basal diet (leucaena or leucaena mixed with grass or crop residues) by the supplement also means that more animals can be carried in the system for a set amount or area of leucaena. The same principles would apply to any tree legume-based system. Energy supplements can come in many forms, viz. fermentable starch (cereal grains and cassava), sugars (molasses), pectins (soybean hulls and pulps) and fibre (rice bran, cassava bagasse), but they have not been compared for their efficacy nor for their economic benefit, if any, in these systems.

International Leucaena Conference 2018: Highlights and priorities

“…Animal productivity. Conference delegates confirmed that leucaena is a highly palatable, productive and profitable forage option used by beef producers in northern Australia (Buck et al 2019a; and by beef, dairy and goat producers in Colombia (Pachas et al 2019;Rivera et al 2019;Zapata Cadavid et al 2019;), Mexico (Ramírez-Avilés et al 2019), Paraguay (Glatzle et al 2019), Argentina (Radrizzani et al 2019a;, Indonesia (Dahlanuddin et al 2019;Waldron et al 2019), Myanmar (Aung 2019), India (Nimbkar 2019), Thailand (Nakamanee et al 2019a;, Venezuela (Escalante 2019) and Cuba (Ruiz et al 2019).…”

“…Cuba; Ruiz et al 2019) and countries of Southeast Asia (Indonesia and Thailand), leucaena is established as a protein bank using single/multiple rows often for cut-and-carry feeding to beef and dairy cattle, goats and dual-purpose animals. In these systems, leucaena is often the major component of the diet, sometimes constituting 100% of the ration, especially during the dry season (Dahlanuddin et al 2019). The arboreal variety cv.…”

“…In Indonesia, Dahlanuddin et al (2019) reported that farmers with an average of 2.8 ha of land and 0.8 ha of planted leucaena fattened Bali bulls in a cut-and-carry system which Waldron et al (2019) reported to be highly profitable. Mean liveweight gains ranged from 0.4 to 0.6 kg/d and were at least double those achieved in the traditional rearing system.…”

“…Energy supplementation of leucaena-fed animals was reviewed by Harper et al (2019). They reported that production (liveweight gain or milk production) from leucaena was increased by the addition of supplements containing fermentable metabolizable energy, such as cereal grains, cassava, molasses, rice bran and crop residues.…”

Herbaceous legumes provide several options for increasing beef cattle productivity in eastern Indonesia

“…Thus, we infer that a source of additional ME is required to increase LWG further. Extra energy could be used both to utilise any excess rumen degradable protein, and to increase overall ME intake (Harper et al 2019). This has been demonstrated in pen-feeding trials and both grazing and cut-and-carry systems using tree legumes, with increases in total DMI and LWG in cattle fed leucaena or sesbania plus rice bran or maize bran (e.g.…”