Methane Emission Factor at Different Total Digestible Nutrients and Feeding Level in Ram

Abstract
Description
Effect of total digestible nutrients (TDN) and feeding level on methane emission factor was discussed. Methane which is a trace gas that formed from feed fermentation process in the rumen and is influenced by many factors such as feed quality and feed intake levels. Forty four individual data of methane emission and feed intake level and TDN of rams were used in this study. The TDN was determined by total collection method, and was separated into low (TDN less than 55%) and high (TDN higher than 55%), while the feeding level was calculated as the percentage of dry matter intake (DMI) to the body weight and was grouped into low (DMI less than 4%body weight; BW) and high (DMI higher than 4%BW). Methane production was measured by Facemask method. The result showed that level of TDN did not affect (P>0.05) methane production per unit dry matter intake (DMI) with an average of30.92 g/kgDMI, but significantly affected (P<0.05) methane production per unit TDN (low TDN = 0.06 vs. high TDN = 0.04 gCH4/gTDN; P = 0.019) and total methane production (low TDN = 28.82 vs. high TDN = 27.04 g/d; P = 0.043). In the other hand, the high feeding level significantly affected (P<0.01) methane production per unit DMI (low feeding level = 32.89 vs. high feeding level: 26.96 g/kg; P = 0.001) and methane production per unit average daily gain (ADG) (low feeding level = 0.98 vs. high feeding level = 0.35 g; P = 0.007), but did not affect (P>0.05) total methane production (average 27.37 g/d). It can be concluded that methane emission factor for rams must be calculated based on their TDN and DMI levels.
Keywords
Methane emission factor; total digestible nutrient; dry matter intake
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