Survey of Bali bull fattening practices in central Lombok, eastern Indonesia, based on feeding of Sesbania grandiflora

Abstract
A longitudinal survey was conducted in 2013 to document the productivity of the Sesbania grandiflora feeding system for cattle fattening in central Lombok. Sesbania is integrated into the intensive rice-growing region by planting it along the rice bunds surrounding the rice fields. The hamlet of Nyerot in the subdistrict of Jonggat was chosen for the study as it had a long history of successful use of sesbania for fattening Bali bulls. Parameters measured included: area of rice paddy where sesbania could be planted; forage establishment, harvesting and feeding practices; cattle purchases and sales; and monthly liveweight gain. Farmers planted an average of 406 sesbania trees on bunds surrounding 0.6 ha of rice paddy. The median values for the main forages fed (dry matter offered) were harvested elephant grass (78% of diet), sesbania (12% of diet) and other feeds (mainly rice bran) (5% of diet). Sesbania was harvested by lopping the lower side branches of ~6 trees per bull per day and never completely defoliating single trees. The farmers fattened an average of 1.6 bulls at a time achieving a yearly mean liveweight gain of 0.41 kg/bull.day. New bulls were purchased with an average liveweight of 203 kg while the average sale weight was 260 kg. Purchase and sale prices were high at A$3.27 and A$3.29, respectively, while the average fattening period was 5 months. Bull liveweight gains were related to total amount of forage fed. No direct statistically significant link between liveweight gains and amount of sesbania fed was obtained due to the multiple factors that influenced forage and bull management. This survey has provided new insights into the practice of bull fattening in central Lombok. The survey has confirmed the high productivity of the feeding system and has highlighted the opportunity to scale out the use of system to other regions.