Introduced forage productivity and quality in the smallholder environment

摘要

Cambodian smallholder cattle farmers operating a traditional mixed farm system (underpinned by rice cultivation) provide limited quality feed to cattle due to year-round feed deficits and climatic seasonal impacts. This study has three primary aims: (1) to evaluate the preharvest productivity of targeted forage species; (2) to establish and evaluate the chemical composition and large ruminant digestibility of targeted forages; and (3) to evaluate the growth rate response of cattle that consumed targeted forages. Three experiments were conducted using established introduced forage plots and cattle at the Phnom Tamao Breeding Station, and involved split plot design and Weende analysis, a cattle feeding 4 × 4 Latin square experimental design with four forage species treatments, and a cattle feed and weight trial. Results showed that forages are typically ready for harvest 2 months after planting to yield 6.2-7.4 kg/m~2 for fresh grasses and 3.2 kg/m~2 for fresh legume. The crude protein ranged from 11.7% to 15.9% for the four grass forages, and the legume (Stylo 184) recorded the highest crude protein (as expected) of 17.8%. The digestibility of all forages was more than 60%. The average daily weight gain ranged from 0.33 kg to 0.52 kg; higher gains were achieved in cattle that were fed Mulato Ⅱ and Terenos, with a daily consumption of approximately 21 kg of fresh forage. These results show that the forages provide improved nutrition for cattle. An additional benefit lies with the capacity to extend the fattening period through use of irrigation, and to conserve fodder as silage. This study provides evidence that introduced forage species can be used to increase the quantity and quality of nutrition available to feed cattle and result in increased cattle liveweight gains.