부산대학교 도서관

The aim of the trial was to assess the effect of palm oil (PO; Elaeis guineensis Jacq.) in a basal ration of low-quality Pennisetum purpureum grass on DMI, enteric CH 4 emissions, rumen fermentation and apparent digestibility in hair sheep. Eight non-castrated male Pelibuey sheep with an average live weight (LW) of 28 ± 1.1 kg housed in metabolic crates inside respiration chambers, were used in a replicated 4 × 4 Latin square design. Each period lasted 18 days (13 days for adaptation to handling and rations, and 5 days for measurements of response variables). A control (CON) ration and three PO levels were evaluated: 20, 40 and 60 g/kg as a percentage of dry matter (DM) in the ration. The basal ration had a 70:30 forage:concentrate ratio (DM basis). Individual DMI was measured daily. Measurement of apparent digestibilities of nutrients was carried out by total collection of feces. Samples of rumen liquor were taken postprandial from sheep, subsequently, the molar proportion of VFA was determined. Enteric CH 4 production (L/d) was measured using head boxes. Average intakes of DM per day (855 g/d), DM/kgW0.75 (64 g/d), organic matter (OM; 809 g/d) and crude protein (CP; 106 g/d) were not affected by treatment (P > 0.05). Neutral detergent fiber (NDF) and crude fat (CF) intake were reduced linearly (P < 0.05) as the percentage of PO in the ration was increased. Apparent digestibilities of DM, OM and NDF were not affected by the inclusion of PO (P > 0.05). Molar proportion of propionic acid in the rumen increased linearly as the level of PO inclusion in the ration was augmented (P < 0.05). The acetic:propionic acid ratio decreased linearly (P < 0.01) from 2.02 for the control ration to 1.66 for the ration with 60 g/kg PO. Enteric CH 4 emissions decreased with increasing levels of PO in the ration (P < 0.01). Energy loss (MJ/d) as CH 4 was reduced (P < 0.01), as well as methane energy loss as a proportion of gross energy intake (Ym; P < 0.01) and CH 4 emission per year (EF; P < 0.01). Results demonstrate that PO is a promising by-product for mitigating CH 4 emissions in hair sheep fed low-quality tropical grasses, with reductions of up to 14.1 %, without negative effects on DMI, nutrient intake and ration digestibility. • Palm oil can mitigate enteric methane emissions in tropical sheep production systems. • Enteric CH 4 emissions decreased 14 % by the inclusion of 60 g/kg DM of palm oil in ration. • Voluntary feed intake in sheep is not affected by the inclusion of palm oil in the ration. • Palm oil increases the molar proportion of propionic acid in the rumen. [ABSTRACT FROM AUTHOR]