In vitro digestibility study was conducted to determine the effectsof supplementing fractionated Refined,Bleached and Deodorized Palm Stearin(RBDPST) on ruminal digestion. Fractionated RBDPST was soaked in incubation medium consisting of distilled water, buffer solution, trace element solution, micro and macro mineral solution, as well as rumen liquor that was collected from slaughtered cattle. This experiment was conducted at 39°C with an incubation period of 24 hours. Dried napier grass was used as control treatment. Gas producedwas recorded and collected to measure the methane gas produced. Methane gas produced from fractionated RBDPST was found to be relatively lower than control. This indicates that fractionated RBDPST had the ability to function as rumen bypass fat as it was not fully digested in the rumen.

The present investigation was carried out to evaluate three potential complete rations made from locally available ingredients through in vitro digestibility (DM, CP, NDF and ADF) and in vitro total volatile fatty acids (TVFA) production. Three iso-nitrogenous complete rations comprising of maize stover (T1), red gram straw (T2) or black gram straw (T3) and concentrate in 60:40 ratio were prepared and the cost/kg diets were 5.2, 5.5 and 5.7 rupees/Kg diet, respectively. Three fistulated buffalo bulls (5 yrs, 350 ± 9.36 kg BW) used as donors of rumen inoculums were fed the same three complete rations (T1, T2 and T3) after proper adaptation. The three complete rations were iso-nitrogenous with CP content ranging from 12.62 to 12.82, while T3 contained higher EE (1.68 %) and TA (9.75 %) and higher NFE (34.38 %) in T1 than in other complete rations. However, variation was apparent in the fiber fractions of the three complete rations attributable to varying sources of the fibrous crop residues. Overall in vitro DM digestibility (IVDMD) and in vitro NDF digestibility (IVNDFD) % was higher (p<0.05) in T1 (58.59 ± 1.55 and 56.33 ± 0.24) followed by T3 (57.75 ± 0.46 and 54.20 ± 0.64) and in T2 (55.45 ± 0.69 and 53.23 ± 1.25). However, the differences for in vitro CP digestibility (IVCPD) and in vitro ADF digestibility (IVADFD) % were higher in T1 than in other complete rations, the values did not differ statistically. Overall TVFA (meq/L) production was higher in T1 (87.65 ± 7.17) than in T2 (83.00 ± 5.74) and T3 (84.00 ± 5.52). It is concluded that T1 is superior to T2 or T3 in terms of in vitro digestibility (DM, CP, NDF and ADF), in vitro TVFA production and cost of formulation.

Objective: This research aimed to evaluate in vitro ruminal fermentation, methane (CH4) emissions, and the relationship between the nutritional content and CH4 emissions of tropical feedstuffs to formulate low CH4-emitting feeds for ruminants. Materials and Methods: Eighteen feedstuffs, including roughages (3 crop residues, 2 silages, 3 common grasses, and 4 leguminous fodder) and 6 concentrates, were evaluated using the Hohenheim Gas Test. Approximately 200 mg of feed were incubated with a rumen fluid-buffer solution for 72 h to test gas production (GP) and 120 mg for 24 h to determine the CH4 con-centration in the gas. Digestibility of organic matter (dOM) and metabolizable energy (ME) were calculated using GP data. Results: Leguminous fodder contained the highest crude protein (CP) concentration (166–314 gm/kg dry matter (DM)), followed by common grasses (52–147 gm/kg DM) and silages (94–106 gm/kg DM), but the lowest concentration of detergent fiber fractions. Crushed wheat and maize had higher dOM and ME (87.8% and 90.9%, and 14.4 MJ/kg DM and 13.8 MJ/kg DM, respectively), and their CH4 concentration (% of GP) and CH4 emissions (L CH4/kg dOM) followed a similar trend as the other feedstuffs. The dOM and ME of German grass and Ipil-ipil were higher, whereas the CH4 concentration and CH4 emissions were lower compared to crop residues and other common grasses. The CH4 emissions originating from the feedstuffs were positively correlated with the concentration of neutral detergent fiber and GP and negatively correlated with CP. Conclusion: Our result provides an opportunity to select feed ingredients with higher digestibility and concurrently less CH4 emissions in formulating diets for ruminants when using commonly available feed resources in many tropical countries. This may enhance animal productive performances while reducing the impact of animal production on the environment. [J Adv Vet Anim Res 2024; 11(4.000): 924-935]