Browsing by Person "Bashar, Muhammad Khairul"

Now showing 1 - 1 of 1

Approaches to increase digestibility of Bangladesh ruminant feed resources in order to mitigate enteric methane production
(2024) Bashar, Muhammad Khairul; Rodehutscord, Markus
Multiple analyses have shown that the rising human population, urbanization, and consumer preferences affect the demand for livestock products in developing countries. Concurrently, human population and urbanisation growth are reducing the likelihood of newly cultivated land producing feeds or restoring damaged pastures. Using low-quality roughage more efficiently is an option, but such roughages have drawbacks, including high structural carbohydrate and low nitrogen contents, which lead to poor palatability and nutrient utilisation including emission of methane (CH4) that is harmful to the environment and a loss of energy to the animal. Using commonly accessible legumes and tree foliage could be a possibility to address the need for N and CH4 mitigation due to their high crude protein and secondary compound contents. In order to evaluate the potential of specific combinations of roughages, concentrates, and other feeds, it is necessary to determine the feeding values, in vitro ruminal fermentation, and CH4 production of single feeds, as well as the promising interaction (associative) effects between single feeds when combinded in a ration. This may allow for formulating a better balanced total mixed ration (TMR) for ruminants, which was the main goal of the present doctoral study. Eighteen feedstuffs from Bangladesh were chosen, including roughages such as crop residues (rice straw, urea molasses treated straw and maize stover), silages (Napier silage and Maize silage), common grasses (German grass, Para grass and Napier grass) and leguminous fodder (Ipil-ipil, Glicidia, Alfalfa hay and Moringa tops) and concentrates (crushed wheat, crushed maize, Wheat bran, Kashari bran, and Rice bran). In Study 1, the single feeds were characterized by comprehensive chemical analysis and in vitro production of total gas and methane using the Hohenheim gas test. Based on the results of Study 1, rice straw, German grass, Napier silage, and maize silage were used in Study 2 and incubated in vitro alone or after substitution by Ipil-ipil and Gliricidia at levels of 10%, 20%, 30%, and 40%, respectively. In Study 3, mixtures of roughages and leguminous fodder (rice straw + 40% Ipil-ipil, German grass + 10% Ipil-ipil, Napier silage + 30% Ipil ipil, and maize silage + 30% Ipil-ipil) were combined with single concentrates in order to identify the most promising mixtures in regard to digestibility and methane production. Eventually, 24 TMR were formulated using six for each type of roughage in Study 4. These TMR were comprised of 60% of the same combination of roughage as used in Study 3 and 40% of various combinations of concentrates including TMR-1 (60% rice bran + 10% wheat bran + 30% kashari bran), TMR-2 (30% rice bran + 10% wheat bran + 60% kashari bran), TMR-3 (10% rice bran + 60% wheat bran + 30% kashari bran), TMR-4 (10% rice bran + 30% wheat bran + 60% kashari bran), TMR-5 (60% rice bran + 30% wheat bran + 10 kashari bran), and TMR-6 (30% rice bran + 60% wheat bran + 10% kashari bran) in order to identify suitable TMR for maximising ruminal fermentation and reducing the CH4 production in vitro. In all studies, the total gas production (GP), digestibility of organic matter (dOM), metabolisable energy (ME), and net energy for lactation (NEL) were determined after incubating 200 mg of feed with a rumen fluid-buffer solution for 72 hours. In addition, the CH4 concentration in the produced gas was measured after incubating 120 mg of feed for 24 hours. Measured values of the mixed feed were compared to estimated values, where the estimated values were weighted means of the values of the individual feeds, to determine the associative effects between the feed ingredients (Study 2 and Study 4). In Study 1, the concentration of acid detergent fibre (ADF), neutral detergent fibre (NDF), and acid detergent lignin (ADL) was the lowest in leguminous fodder while the crude protein (CP) concentration was the hightest, followed by the common grasses and the silages. The crop residues showed the lowest CP and the highest cell wall fraction concentrations. The dOM, ME, and NEL of crushed wheat and crushed maize were significantly higher (p<0.05) than those of other feedstuffs. The same differences were found (p<0.05) for CH4 concentration (% of GP) and CH4 production (L CH4/kg dOM). The dOM and ME of German grass and Ipil-ipil were higher (p<0.05), whereas the CH4 concentration and CH4 production were lower compared to that of crop residues and other common grasses. The CH4 production of single feeds decreased with increasing concentrations of CP, ADF, and ADL, whereas it increased with NDF concentration. These findings enabled development of more balanced diets for ruminants with the aim of improved digestibility and reduced CH4 emission while making use of widely available feed resources in Bangladesh. Study 2 aimed to evaluate the in vitro ruminal fermentation, CH4 production, and associative effects between low-quality roughages and CP supplements. The gas production after 24 hours (GP24) and rumen fermentation rate increased (p<0.05) with increasing addition of Ipil-ipil to rice straw. It also resulted in a gradual increase of dOM and ME (p<0.05) of the mixture, reaching maximum values (59.1% and 7.60 MJ ME/kg DM) and maximum reductions in CH4 concentration and CH4/dOM (6.9% and 11.7%) compared to the control with Ipil-ipil addition at 40% of DM. When Ipil-ipil was added at 30% to Napier silage, the same trend was observed for dOM and ME (56.5%, and 7.55 MJ ME/kg DM) and CH4 concentration and CH4/dOM (5.3% and 13.3%). Ipil-ipil did not significantly interact with high quality roughages such as German grass and maize silage. Increasing the addition of Gliricidia to the roughages in Study 2 led to a decrease in GP24, dOM, ME, and CH4 production. The highest levels of the associative effects (p<0.05) were seen when 40% Ipil-ipil was added to rice straw and 30% was added to Napier silage. In conclusion, adding Ipil-ipil to low-quality roughages is superior to Gliricidia and showed promising results, with the ranking as follows: rice straw + 40% Ipil-ipil > Napier silage + 30% Ipil-ipil > maize silage + 30% Ipil-ipil > German gras + 10% Ipil-ipil. Study 3 and Study 4 had the overarching purpose to determine which combination of single concentrates and combinations of concentrates with roughage produced the best mixed feed in terms of rumen fermentation, CH4 reduction potential, and associative effect. The CP and non-stach carbohydrate contents of the Ipil-ipil-based mixed feed was enhanced by adding Wheat bran and Kashari bran as single concentrates, which had a favourable effect on rumen fermentation and gas production but had the opposite effect on CH4 production when compared to the addition of Rice bran. In Study 4, TMR were formulated using roughages and Ipil-ipil and addition of Wheat bran, Kashari bran, and Rice bran in various combinations. The TMR based on German grass and maize silage with specific bran combinations showed significant reductions in in vitro CH4 production, CH4 concentration, and CH4/dOM while maximising GP, dOM, ME, and the associative effects. To conclude, the results of chemical analyses and in vitro fermentation studies showed that specific combinations of roughages, protein feeds, and by-products available in Bangladesh have the potential to formulate rations for cattle that help making livestock production more sustainable. The results may be also relevant for other developing nations. It is suggested to verify the results of the present project by animal trials at local conditions.