Effects of molasses supplementation on animal performance and carcass parameters of beef cattle: a meta-analysis.

Molasses must be one of the most used foods in the diet of ruminant animals; however, there is no consensus on the effect of including molasses on carcass parameters. In this context, the objective was to evaluate the effect of including molasses in the diet of feedlot cattle on performance and carcass parameters. Thirteen peer-reviewed publications with 45 treatment means were included in the dataset. The effect of molasses in beef cattle diets was evaluated by examining the weighted mean differences (WMD) between molasses treatment (diet with molasses) and control diet (diet without molasses). Heterogeneity was explored by meta-regression and subgroup analysis using genetic type and experimental period, molasses in diet (g/kg dry matter (DM)), molasses type, concentrate in diet (g/kg DM), and forage type. The inclusion of molasses in the diet increased dry matter digestibility, but reduced NDF digestibility, carcass weight, subcutaneous, and visceral fat. The main sources of variation for the responses with molasses inclusion on intake, digestibility, performance, and carcass parameters were the level of molasses inclusion and the experimental period. In general context, the inclusion of molasses in the diet between 100 to 150 g/kg of DM did not affect performance and carcass parameters. However, the inclusion of molasses above 200 g/kg reduces the average daily gain and carcass weight.

Does distillers' grains supplementation affect beef cattle performance, carcass characteristics, and meat quality? A meta-analysis study.

This study evaluated, through meta-analysis, the effect of distillers' grains (DG) supplementation to beef cattle on their performance, carcass parameters, and meat fatty acid profile. Eighty-one peer-reviewed publications with 439 treatments means were included in the data set. The effects of DG supplementation to beef cattle were evaluated using weighted mean differences (WMD) between the control group (diets with no DG) and DG group (diets with DG). Heterogeneity was explored by meta-regression and subgroup analysis using genetic type, treatment period, DG type, amount of DG in diet (g DG/kg DM), sulfur in diet (g S/kg DM), ether extract in diet (g EE/kg DM), feed systems (pasture or total mixed ration), and concentrate level in the diet (g/kg DM). Meat fatty acid profile was more affected when DG was fed to crossbreed animals. In Angus animals, DG inclusion to the diets had little effect on meat fatty acid profile whereas, a pronounced reduction was reported in meat omega-6/omega-3 ratio. In response to DG inclusion to the diets, an increase in diet sulfur content up to 6.0 g/kg and ether extract content up to 110 g/kg had no adverse effects on performance, carcass parameters, and meat physicochemical characteristics. Distillers' grains inclusions in amounts between 500 and 600 g DG/kg provided the greatest responses when evaluating carcass parameters and meat fatty acid profile. Increased CLA c9 t11, linolenic acid, and total PUFA and reduced myristic acid concentration in meat were reported when animals were fed diets containing DG.

Effects of rumen undegradable protein sources on nitrous oxide, methane and ammonia emission from the manure of feedlot-finished cattle.

The effects of sources of rumen undegradable protein (RUP) in diets on methane (CH4), nitrous oxide (N2O) and ammonia (NH3) emissions from the manure of feedlot-finished cattle were evaluated. We hypothesized that the use of different RUP sources in diets would reduce N loss via urine and contribute to reduced N2O, CH4 and NH3 emissions to the environment. Nellore cattle received different diets (18 animals/treatment), including soybean meal (SM, RDP source), by-pass soybean meal (BSM, RUP source) and corn gluten meal (CGM, RUP source). The protein source did not affect the N and C concentration in urine, C concentration in feces, and N balance (P > 0.05). The RUP sources resulted in a higher N2O emission than the RDP source (P = 0.030), while BSM resulted in a higher N2O emission than CGM (P = 0.038) (SM = 633, BSM = 2521, and CGM = 1153 g ha-2 N-N2O); however, there were no differences in CH4 and NH3 emission (P > 0.05). In conclusion, the use of RUP in diets did not affect N excretion of beef cattle or CH4 and NH3 emission from manure, but increased N2O emission from the manure.

The effect of dietary inclusion of crude glycerin on performance, ruminal fermentation, meat quality and fatty acid profile of beef cattle: Meta-analysis.

This meta-analysis was carried to evaluate the effect of the use of crude glycerin in diets for beef cattle on the ruminal fermentation, animal performance, physical and chemical characteristics, and fatty acid profile of meat through meta-analysis. Data from forty-eight peer-reviewed publications with 170 treatments means was included in the data set. The effect glycerin in diet were evaluated by examining the weighted mean differences (WMD) between glycerin treatment (diets with crude glycerin) and control diet (without crude glycerin). Heterogeneity was explored by meta-regression and subgroup analysis using genetic type, treatment period, crude glycerin in the diet (g/kg DM), feed systems (pasture or total mixed ration), and concentrate in the diet (g/kg DM). The inclusion of crude glycerin had no effect on the average daily gain, but increased feed efficiency by 3.15% while reducing subcutaneous fat thickness by 3.13%. Inclusion of crude glycerin reduced meat cholesterol by 9.13%, and total saturated fatty acids by 1.05%, and increased total unsaturated (2.02%), monounsaturated (3.17%) fatty acids. However, it did not affect the concentrations of conjugated linoleic acid and omega-3. Crude glycerin inclusions up to 200 g/kg DM did not promote a negative effect on animal performance, carcass and physical-chemical characteristics of meat, and supported an increase in total monounsaturated (1.73%), oleic acid (12.29 mg) and palmitoleic acid (1.24 mg), while reducing myristic acid (3.08 mg), stearic acid (12.00 mg) in beef cattle meat.