Objective: This study was conducted to evaluate the use of <i>Megasphaera elsdenii</i> (<i>M. elsdenii</i>) as a probiotic on rumen fermentation, production performance, carcass traits and health of ruminants by integrating data from various related studies using meta-analysis.Methods: A total of 32 studies (consisted of 136 data points) were obtained and integrated into a database. The parameters integrated were fermentation products, rumen microbes, production performance, carcass quality, animal health, blood and urine metabolites. Statistical analysis of the compiled database used a mixed model methodology. Different studies were considered random effects, while <i>M. elsdenii</i> supplementation doses were considered fixed effects. p-values and the Akaike information criterion were employed as model statistics. The model was deemed significant at p<0.05 or had a tendency to be significant when p-value between 0.05〈p〈0.10.Results: Supplementation with <i>M. elsdenii</i> increased (p<0.05) some proportion of fermented rumen products such as propionate, butyrate, isobutyrate, and valerate, and significantly reduced (p<0.05) lactic acid concentration, acetate proportion, total bacterial population and methane emission. Furthermore, the probiotic supplementation enhanced (p<0.05) livestock production performance, especially in the average daily gain and body condition score. Regarding the carcass quality, hot carcass weight and carcass gain were elevated (p<0.05) due to the <i>M. elsdenii</i> supplementation. Animal health also showed improvement as indicated by the lower (p<0.05) diarrhoea and bloat incidences as well as the liver abscess. However, <i>M. elsdenii</i> supplementation had negligible effects on blood and urine metabolites of ruminants.Conclusion: Supplementation of <i>M. elsdenii</i> is capable of decreasing ruminal lactic acid concentration, enhancing rumen health, elevating some favourable rumen fermentation products, and in turn, increasing production performance of ruminants.

Supplementation of oil rich in unsaturated fatty acids (FAs) such as canola, soybean, and palm oils improved the quality of milk fatty acids. However, the unprotected unsaturated oil might impair rumen fermentation, feed, and fiber digestibility. A study was conducted to determine the best type of oil supplementation (factor A) including canola (A1), soybean (A2), or palm (A3) and level oil supplementation (factor B) including B0 = 0%, B1 = 1%, B2 = 2% or B3 = 3%) on the in-vitro feed fermentation and digestibility. The study used a 3 x 4 factorial block design. Two-stages were used to measure the pH, ammonia (NH3), volatile fatty acids (VFAs), protozoal number, dry matter (DMD), organic matter (OMD), neutral detergent fiber (NDFD), and acid detergent fiber (ADFD) digestibility. The results showed that oil type did not significantly influence the fermentability (pH, NH3, VFAs, and protozoa) and feed's digestibility (DMD, OMD, NDFD, and ADFD) but oil level influence the fermentability and digestibility significantly. In addition, an increase above 1% in oil levels reduced protein fermentability, protozoal number, DMD, and OMD, but increased VFA. It is concluded that the addition of unprotected canola, soybean, or palm oil in dairy cattle ration could be applied in a concentration not more than 1%.

This study aimed to compare calcium oxide (CaO) and calcium chloride (CaCl₂) as calcium sources for coconut fatty acid distillate (CFAD) calcium soap (Ca-soap) production and to evaluate the supplementation ratios of unprotected and protected CFAD in dairy rations to optimize rumen function. This research included two steps: (1) assessing the protection strength of Ca-soap made with CaO and CaCl₂ at mole ratios of Ca to CFAD of 1, 1.5, 2, and 2.5; (2) evaluating CFAD supplementation in an in vitro dairy ration study using a 5 × 4 randomized factorial block design. Factor A compared unprotected and protected CFAD ratios of A1 = 100:0, A2 = 75:25, A3 = 50:50, A4 = 25:75, and A5 = 0:100, and factor B compared supplementation levels of B1 = 0%, B2 = 1%, B3 = 2%, and B4 = 3%. CaCl₂ at a 2.5-mole ratio to CFAD produced the lowest acid value and the carboxylic acid (C=O) chemical bond. Complete protection (0:100) exhibited the highest densities of Bacteroides and nutrient digestibility (p < 0.05) without significantly affecting rumen fermentability (p > 0.05). Higher CFAD levels significantly reduced methanogens and protozoa (p < 0.05) without significantly affecting estimated methane production. In conclusion, CaCl₂ at a 2.5-mole ratio to CFAD provided the best protection, and its complete protection in CFAD supplementation optimized rumen function.

A study was conducted to determine the protein degradation characteristics of 27 tropical feedstuffs for dairy rations. Twenty-two tropical feedstuffs were grouped into A1 (local low fiber and low protein sources: corn, rice bran, cassava, cassava waste, wheat, pollard), A2 (local low fiber and low protein sources: palm kernel meal, tofu waste, tempe waste), and A3 (local high fiber sources: acacia, alfalfa, narra, gliricidia, indigofera, calliandra, bauhinia, leucaena, albizia, agati, piper, moringa, jack leaves), and compared to A4 (imported low fiber high protein sources: soybean, roasted soybean, DDGS, CGM, CGF) using the in sacco method. The study revealed that A1, A2, and A3 had lower protein content but higher crude fiber than A4. Protein solubility (a) was higher in A1 and A2, while the potentially degraded fraction (b) was higher in A2 and A3. A1 and A2 had higher RDP fractions than A3 and A4. High RDP feedstuffs include pollard, wheat, soybean, CGF, tempe waste, alfalfa, gliricidia, indigofera, agati, and moringa. In contrast, high RUP feedstuffs include corn, palm kernel meal, narra, calliandra, leucaena, albizia, tamarind, piper, jack leaves, roasted soybean, soybean meal, and CGM. Tropical feedstuffs exhibit diverse protein degradation characteristics, making them valuable for strategic ration formulation in dairy cattle.

Dietary fat provides an efficient energy supply due to its high energy density and low heat increment. This strategy is particularly effective during early lactation, when negative energy balance (NEB) commonly occurs, but the results regarding improvements in dairy performance have been inconsistent. Therefore, this study aimed to evaluate the effect of dietary protected fat in early lactation dairy cows on dairy performance, energy balance, and blood metabolites. A total of 14 articles were selected for the meta-analysis, integrating 31 data points into the database. The data were analyzed using the random effects meta-analysis method, with effect size calculated based on Hedges’d. The parameters were analyzed, including dry matter intake, nutrient digestibility, body weight (BW) and body condition score (BCS) changes, milk yield and composition, energy balance, and blood metabolites. The results showed that dietary protected fat significantly enhanced dry matter (DM) digestibility (65.90% vs. 67.66%, p<0.01), organic matter (OM) digestibility (70.96% vs 72.33%, p<0.01), BW changes (60.47 vs 153.17 g/day, p<0.01), and milk yield (27.79 vs. 29.20 kg/day, p<0.01), while reducing milk fat content (4.04% vs. 3.80%, p<0.05). Dietary protected fat reduced NEFA concentrations (-1.024 vs. -1.527 mmol/L, p<0.01), but it did not significantly affect overall energy balance. In conclusion, protected fat supplementation improved dairy performance and body reserves during early lactation without altering energy balance.