Effect of maturity stage on sorghum silage production: intake, digestibility, energy partition, and methane production in sheep

Abstract

The objective of the study was to evaluate the intake, digestibility, energy partition, and methane production of sheep fed with BRS 610 sorghum silage produced from plants harvested at different stages of maturity. Sorghum was harvested at the milk, soft mass, hard mass, and mature stages of development, corresponding to 100, 107, 114, and 121 days after planting, respectively. Twenty uncastrated adult rams were utilized, with five rams per treatment. There was a linear increase in voluntary intake expressed as a function of metabolic weight for dry matter (DM), organic matter (OM), non-fibrous carbohydrates (NFC), and the NDF/CP ratio. The apparent digestibility of DM and OM increased linearly with increasing plant maturity at harvest. The energy content in sorghum silage exhibited a quadratic effect. No significant effect was observed on methane losses, caloric increment (CI), and enteric methane production. BRS 610 sorghum is recommended to be harvested for silage production when the plants reach the hard dough stage. This results in silage with higher energy values, improved voluntary intake, digestibility, and nitrogen use efficiency, without impacting methane production by animals.