Crop by-products satisfy the winter feed gap for beef cattle ensuring sustainable grazing of native pastures

Cattle production in the northern mountainous areas of Vietnam utilizes 31% of total land area for natural grazing. A study conducted in Sơn La Province in 2012/13 quantified the productivity of natural pastures and availability of agricultural by-products as feed sources to fill the winter feed gap in beef cattle production. Natural pasture species of Cynodondactylo, Apludavaria var. Mutica Hos, Digitariaabludens, Centostecalappacea and Cymbopogoncaesiu were identified as preferentially fed by grazing ruminants during summer and autumn due to their palatability and digestibility and provided adequate animal nutrition for this period. Conversely, the long dry winter persistent species of Mimosa pudica, Imperatacylindrica, Saccharumarundinaceum and Melastomasanguineum were shown to be less digestible, and clearly demonstrated a feed gap during the winter. The research showed that rice straw, corn by-products and banana trunk were available in sufficient quantities to satisfy this winter feed gap, and although the biomass production of these by-products was shown to be very high, the study found that the utilization of them was limited due to farmer knowledge and awareness of these by-products as an important feed source for their cattle during the period of feed gap. The outcomes of this study may be used to develop and implement strategies for optimal use of these feed sources, contributing to the improvement of beef cattle production in the area, and ensuring sustainable grazing of native pastures.