The Effect Of Cysteamine Hydrochloride And Nitrate Supplementation On Methane Emission And Growth Performance Of Beef Cattle

Demand for livestock products and methane mitigation is increasingly stimulating a search for technologies capable of increasing animal productivity while lowering enteric methane emissions.Dietary nitrate(NO3-)has shown this capability in sheep on low nitrogen diets.Cysteamine hydrochloride(CSH)has also been shown to have such dual efficacy,but whether it affects rumen fermentation directly or indirectly by modifying digesta kinetics is unknown.The test ?: It was hypothesized that the administration of CSH to cattle would reduce in-vitro and in-vivo methane production and also increase their average daily liveweight gain(LWG)without affecting their DM intake(DMI).Subsequently,a 42-d in-vivo experiment was conducted using a completely randomised design with 8 yearling cattle(236±49 kg liveweight;LW)to assess LWG,methane production and feed conversion ratio(FCR)on a basal roughage/concentrate diet containing either no additives,80 mg/kg LW of CSH.Daily methane production rate(DMP;g methane/d)was measured over 2×24h periods in open-circuit calorimetry chambers during both weeks 3 and 6 of the study,with nutrient digestibility determined by collecting faecal samples and using acid insoluble ash as an indigestible marker.Relative to cattle fed the control diet CSH supplemented cattle exhibited no change in LWG or FCR(P>0.05).While neither DMP nor methane yield(MY;methane/kg DMI)were reduced by CSH(mean 9.2% reduction),methane production rate was significantly reduced(P<0.05.)for up to 6 h post-feeding relative to control animals.The test ?: Aiming to study the effect of nitrate on methane yield,rumen fermentation and growth of cattle,in vitro and in vivo experiment were conducted.In vitro experiment was designed by single factor including control,1%nitrate and 2%nitrate,which repeated 3 times.In vivo experiment was conducted using 8 cattle,which was single factor randomized design including no additives and 1% nitrate.The experiment was conducted for 56 days: 14 days of dietary adaption period;39 days of ad-libitum feeding growth;3 days of 80% limited feed in chambers.The results showed that administration of 1% nitrate and 2% nitrate decreased respectively the methane production by 15.2% and 46.2% in in vitro experiment,while the methane production was lowed by 28.5% in 1% nitrate at least 5 h after feeding in in vivo.The reduction expressing methane kg/ DMI and methane/gross energy was respectively 31.8% and 12.8%.However,daily weight gain and feed conversion ratio were not different with control,while nitrate significantly inhibited VFA production.Accordingly,nitrate can effectively restrain methane,while did not have a positive impact on production performance.