Effects of particle size of processed barley grain, enzyme addition and microwave treatment on in vitro disappearance and gas production for feedlot cattle

Effect of Cellulase Enzyme Produced from Penicilliumchrysogenum on the Milk Production, Composition, Amino Acid, and Fatty Acid Profiles of Egyptian Buffaloes Fed a High-Forage Diet

Simple Summary

Exogenous fibrolytic enzymes can improve nutrient digestibility of feeds high in fibrous content offered to Egyptian lactating buffaloes. The proposed cellulase exclusively produced in-farm using Penicillium Chrysogenum showed higher activity in previous in vitro studies. That is why it was chosen to get tested against a well-known commercial source of cellulase enzyme from the Egyptian markets for its efficiency in increasing milk productivity and composition. Profiles of amino acids and fatty acids were also recorded. The initial results highlighted a superiority of the produced enzyme (FENZ) against the commercial source (CENZ). It was also clear that FENZ can preserve higher proportions of fatty acids in the milk, primarily conjugated linoleic acid. Based on the idea rationale, our conclusion is to promote setting a small cellulase production unit in each farm in Egypt to decrease the cost of feeding by using agricultural and agro-industrial waste during the cellulase production and feeding process.

Abstract

The experiment was conducted to study the effects of supplementing a cellulase enzymes cocktail to lactating buffaloes’ diet, on the nutrient intake, nutrient digestibility, and milk production performance and composition. Twenty-four lactating Egyptian buffaloes were assigned into one of the following treatments: CON—control consisted of a total mixed ration, CENZ—the total mixed ration supplemented by a commercial source of cellulase enzyme, FENZ—the total mixed ration supplemented with cellulase enzyme cocktail produced in-farm. Supplementing the diet with the in-farm source of cellulase (FENZ) had a significantly higher impact on crude protein, neutral detergent fiber, and acid detergent fiber digestibility. However, FENZ tended to increase the EE digestibility compared to CENZ. FENZ showed significantly higher nutrient digestibility percentages compared to other groups. Supplementing the diet with cellulase enzymes (CON vs. ENZ) significantly increased the daily milk yield and the fat correct milk yield; both yields were significantly higher with FENZ than all groups. Oleic, linoleic, and linolenic acid concentration were significantly higher with cellulase enzymes supplementation (CON vs. ENZ) and the conjugated linoleic acid concentration. Supplementing fungal cellulase enzyme produced on a farm-scale has improved milk productivity, fat yield, and milk fat unsaturated fatty acids profile in lactating buffaloes.

Estimation of the net energy value of barley for finishing beef steers

The objective of this study was to identify barley grain characteristics measured by laboratory procedures that could be used to predict barley energy content for finishing beef steers. Twenty-eight different barley genotypes were evaluated including 18 cultivars and 10 experimental lines. Laboratory analysis of barley samples included bulk density, particle size, N, ADF, starch, and ISDMD (in situ DM disappearance after 3 h of ruminal incubation). Animal performance data (BW, DMI, ADG, steer NE_m, and NE_g requirements) were collected from 26 feedlot experiments conducted in Montana and Idaho during a 10-yr period and were used to estimate barley NE_m and NE_g content. A total of 80 experimental units were available with each experimental unit being a diet mean from an individual feedlot experiment. Fifty-eight of the 80 experimental units were randomly selected and used in the development data set and the remaining 22 experimental units were used in the validation data set. Forward, backward, and stepwise selection methods were used to identify variables to be included in regression equations for NE_m using PROC REG of SAS. Barley samples in the model development data set represented a wide range in concentrations (DM basis): N (1.6% to 2.8%), ISDMD (25.7% to 58.7%), ADF (3.6% to 8.0%), starch (44.1% to 62.4%), particle size (1,100 to 2,814 µm), and bulk density (50.8 to 69.4 kg/hL). The barley grain characteristics of particle size, ISDMD, starch, and ADF were the most important variables in six successful models (R ² = 0.48 to 0.60; P = 0.001). The six prediction equations gave mean predicted values for NE_m ranging from 1.99 to 2.05 Mcal/kg (average 2.04 Mcal/kg; 0.45% CV). The mean actual NE_m values from animal performance trials ranged from 1.75 to 2.48 Mcal/kg (average 2.03 Mcal/kg; 6.5% CV). The mean bias or difference in predicted vs. actual values ranged from -0.001 to 0.005 Mcal/kg. Barley NE_g values calculated from animal performance ranged from 1.13 to 1.78 Mcal/kg (average 1.39 Mcal/kg; 8.4% CV). Average predicted barley NE_m and NE_g were 0.02 and 0.01 Mcal/kg less, respectively, than the 2.06 Mcal/kg NE_m and 1.40 Mcal/kg NE_g reported by NRC. Barley NE can be predicted from simple laboratory procedures which will aid plant breeders developing new feed varieties and nutritionists formulating finishing rations for beef cattle.

Short communication: In vitro rumen gas production and starch degradation of starch-based feeds depend on mean particle size

Our objective was to model the effect of mean particle size (mPS) on in vitro rumen starch degradation (IVSD) and the kinetics of gas production for different starch-based feeds. For each feed, 2 batches of the same grains were separately processed through 2 different mills (cutter or rotor speed mills), with or without different screens to achieve a wide range of mPS (0.32 to 3.31 mm for corn meals; 0.19 to 2.81 mm for barley meals; 0.16 to 2.13 mm for wheat meals; 0.28 to 2.32 mm for oat meals; 0.21 to 2.36 mm for rye meals; 0.40 to 1.79 for sorghum meals; 0.26 to 4.71 mm for pea meals; and 0.25 to 4.53 mm for faba meals). The IVSD data and gas production kinetics, obtained by fitting to a single-pool exponential model, were analyzed using a completely randomized design, in which the main tested effect was mPS (n = 6 for all tested meals, except n = 7 for corn meals and n = 5 for sorghum meals). Rumen inocula were collected from 2 fistulated Holstein dairy cows that were fed a total mixed ration consisting of 16.2% crude protein, 28.5% starch, and 35.0% neutral detergent fiber on a dry matter basis. The IVSD, evaluated after 7 h of rumen incubation, decreased linearly with increasing mPS for corn, barley, wheat, rye, pea, and faba meals, and decreased quadratically with increasing mPS for the other meals. The y-axis intercept for 7-h IVSD was below 90% starch for corn, barley, and rye feeds and greater than 90% for the other tested feeds. The mPS adjustment factors for the rate of rumen starch degradation varied widely among the different tested feeds. We found a linear decrease in starch degradation with increasing mPS for barley, wheat, rye, and pea meals, whereas we noted a quadratic decrease in starch degradation for the other tested meals. Further, we observed a linear decrease in the rate of gas production with increasing mPS in each tested feed, except for pea meal, which had a quadratic relationship. For each 1 mm increase in mPS, the gas production was adjusted by -0.009 h^-1 for corn, -0.011 h^-1 for barley, -0.008 h^-1 for wheat, and -0.006 h^-1 for faba, whereas numerically greater adjustments were needed for oat (-0.022 h^-1), rye (-0.017 h^-1), and sorghum (-0.014 h^-1). These mPS adjustment factors could be used to modify the starch-based feed energy values as a function of mean particle size, although in vivo validation is required.