Effects of increasing concentrations of glycerol in concentrate diets on nutrient digestibility, methane emissions, growth, fatty acid profiles, and carcass traits of lambs

A Short-Term Supplementation with a Polyphenol-Rich Extract from Radiata Pine Bark Improves Fatty Acid Profiles in Finishing Lambs

The aim of this study was to evaluate the effects of a short-term supplementation with a polyphenol-rich extract from radiata pine bark (PBE) on animal performance, blood parameters, and fatty acid (FA) profiles in finishing lambs. Twenty-seven Suffolk lambs (4 months old) fed a finishing diet were randomly assigned to one of the following treatments: diet without PBE or diet supplemented with PBE on a 1 or 2% dry matter (DM) basis, for 35 d (14 d adaptation and 21 d of experimental period). Data were compared using Tukey's test and orthogonal and polynomial contrasts. The results indicated that the supplementation with PBE increased (p = 0.008) relative growth rate (RGR) and improved (p = 0.003) protein conversion (CPC), whereas weight gain, carcass characteristic, and blood parameters were unaffected (p ≥ 0.106). Total mono- and polyunsaturated FAs, conjugated linoleic acid (CLA), and vaccenic and oleic acids were linearly increased (p ≤ 0.016) by PBE supplementation. In contrast, total saturated FAs (ΣSFA), Σn-6/Σn-3 ratio, atherogenicity index (AI), thrombogenic index (TI), and the proportion of elaidic acid were linearly decreased (p ≤ 0.018). In conclusion, the supplementation with 1 or 2% DM of PBE improves subcutaneous FA profiles by increasing CLA and reducing ΣSFA, Σn-6/Σn-3 ratio, AI, and TI. Additionally, PBE supplementation has the potential to improve RGR and CPC, with unaffected intake, growth performance, blood parameters, or carcass characteristics.

Nutritional Interventions to Reduce Methane Emissions in Ruminants

Methane is the single largest source of anthropogenic greenhouse gases produced in ruminants. As global warming is a main concern, the interest in mitigation strategies for ruminant derived methane has strongly increased over the last years. Methane is a natural by-product of anaerobic microbial (bacteria, archaea, protozoa, and fungi) fermentation of carbohydrates and, to a lesser extent, amino acids in the rumen. This gaseous compound is the most prominent hydrogen sink product synthesized in the rumen. It is formed by the archaea, the so-called methanogens, which utilize excessive ruminal hydrogen. Different nutritional strategies to reduce methane production in ruminants have been investigated such as dietary manipulations, plant extracts, lipids and lipid by-products, plant secondary metabolites, flavonoids, phenolic acid, statins, prebiotics, probiotics, etc. With the range of technical options suggested above, it is possible to develop best nutritional strategies to reduce the ill effects of livestock on global warming. These nutritional strategies seem to be the most developed means in mitigating methane from enteric fermentation in ruminants and some are ready to be applied in the field at the moment.

Using glycerin with chitosan extracted from shrimp residue to enhance rumen fermentation and feed use in native Thai bulls

Background and Aim:

Crude glycerin is changed to propionate in the rumen, while chitosan can be used as a feed supplement to increase propionic acid concentration and decrease methane (CH₄) production. We hypothesized that supplementation with a combination of a high level of crude glycerin with chitosan could have a beneficial effect on ruminal fermentation and mitigate CH₄ production. This study aimed to explore the combined effects of crude glycerin and chitosan supplementation on nutrient digestibility, rumen fermentation, and CH₄ calculation in native Thai bulls.

Materials and Methods:

Four 2-year-old native Thai bulls, weighing 150±20 kg, were kept in a 2×2 factorial arrangement in a 4×4 Latin square design. Factor A represented the incorporation of crude glycerin at 10.5% and 21% of the dry matter (DM) of a total mixed ration (TMR), and factor B represented the supplementation of chitosan at 1% and 2% DM of a TMR.

Results:

Increasing levels of crude glycerin at 21% decreased DM intake by 0.62 kg/day compared with 10.5% crude glycerin (p<0.05), whereas nutrient digestibility did not change (p>0.05). The incorporated crude glycerin and supplemented chitosan levels did not affect the pH, temperature, concentrations of ammonia-nitrogen, microbial population, and blood urea nitrogen (p>0.05). Supplemented chitosan and incorporated crude glycerin did not show any interaction effects on the molar portions and total volatile fatty acids (VFAs), except estimated CH₄. Increasing the incorporated crude glycerin levels increased propionate and decreased the ratio of acetate to propionate ratio, whereas levels of butyrate, acetate, and total VFAs were unchanged. The combination of crude glycerin at 21% in the TMR with chitosan at 2% reduced CH₄ estimation by 5.08% compared with the other feed treatment.

Conclusion:

Increasing incorporated crude glycerin levels in a TMR significantly elevated the propionate concentration, whereas combining 21% crude glycerin in the TMR diet with 2% chitosan supplementation could depress CH₄ estimation more effectively than adding one of these supplements alone.

Modulating the lipid profile of beef using cottonseed and crude glycerin

The search for healthy food leads to demand for functional foods that do not harm the health of the consumers. The objective was to evaluate the impact of the supply of cottonseed and crude glycerin as modulators of the lipid profile of the beef produced on pasture. The concentrated supplement was formulated with two levels of cottonseed (0 and 25%) and/or two levels of crude glycerin (0 and 15%), totaling four experimental groups. Two experiments were conducted; the first experiment was outlined in a 5 × 5 Latin square design, contrasting the protein-energy supplementation with the mineral supplementation. The concentrate supplementation allowed the increase in intake and digestibility of the dry matter (P = 0.03), ether extract, crude protein, and non-fibrous carbohydrate (P < 0.01). However, the results showed no effect of crude glycerin or cottonseed inclusion on intake or nutrients digestibility. The second experiment evaluated the protein-energy supplementation and its impact on the lipid profile of meat produced, carcass characteristics, and animal performance. There was no influence of cottonseed or crude glycerin in performance or carcass characteristics. However, the use of the cottonseed reduced the content of short-chain fatty acids, omega 3 linolenic acid, conjugated linoleic acid (CLA) C18: 2 cis 9 trans 11 (P < 0.01), and the inclusion of crude glycerin led to increased conjugated linoleic acid (CLA) C18: 2 cis 9 trans 11 (P = 0.04). An important result is given by illustrating the impact of these fatty acids in the nutritional quality of the meat. Thus, it is possible to manipulate the lipid profile of meat produced by cottonseed or crude glycerin supplementation, without affecting the animal performance.

Effects of dietary grapeseed extract on performance, energy and nitrogen balance as well as methane and nitrogen losses of lambs and goat kids

The influence of phenol-rich dietary grapeseed extract on performance, energy and N balance and methane production was determined in sixteen lambs and thirteen goat kids (body weight 20·5 and 19·0 kg, 2 months of age, day 1 of study). Half of the animals received a concentrate containing grapeseed extract, and the others received concentrate without grapeseed extract (total extractable phenols analysed 27 v. 9 g/kg dietary DM; concentrate and hay 1:1). Diets were fed for 7 weeks with 1 week for determining intake, excretion and gaseous exchange in metabolism crates and respiration chambers. Overall, there was an adverse effect of the phenolic diet on apparent N digestibility and body N retention. Faecal N loss as proportion of N intake increased while urinary N loss declined. Relative to N intake, total N excretion was higher and body N retention lower in goat kids than lambs. Diets and animal species had no effect on methane emissions. The saliva of the goat kids had a higher binding capacity for condensed tannins (CT). Goat kids on the phenolic diet had higher CT concentrations in faeces and excreted more CT compared with the lambs (interaction species × diet P < 0·001). The lambs had overall higher (P < 0·001) urinary phenol concentrations than the goat kids (2·19 v. 1·48 g/l). The negative effect on body N retention and lack of effect on methane emissions make the use of the extract in the dosage applied not appealing. Species differences need to be considered in future studies.

Linseed and glycerol in forage diets effect methane production and rumen fermentation parameters in a Rusitec semi-continuos system

Context The use of oilseeds as a feed ingredient has been proposed to improve fatty acid profiles and reduce methane (CH4) emissions. Glycerol has been used as a common additive in ruminant feeding systems with variable effects on CH4 production. The effects of the combination of these ingredients remain unknown. Aims The aim of this study was to assess the effects of feeding linseed and increasing concentrations of glycerol in forage diets supplemented with corn grain on nutrient disappearance, CH4 production and rumen fermentation parameters. Methods Experimental diets were: control (70:30% hay:corn); linseed (70:15 :15% hay:corn:linseed); 5% glycerol (70:10:15:5% hay:corn:linseed:glycerol); 10% glycerol (70:5:15:10% hay:corn:linseed:glycerol). Diets were incubated in a completely randomised design with four replicates per treatment in a Rusitec apparatus for 15 days (10 days adaptation, 5 days sampling). Key results Total VFA production (VFA, mmol/day) was quadratically increased due to glycerol concentration in the diets (P = 0.009). Acetate:propionate (A:P) decreased by the inclusion of linseed (P &lt; 0.001) and glycerol into the diets (P &lt; 0.001). Linseed inclusion in the diet reduced CH4 production, mg/DM disappeared (P = 0.004) by up to 36%. These effects were not altered by the addition of glycerol into the diets. Ammonia nitrogen (NH3-N) production increased 2-fold in the linseed-added diets, but this effect was partially reverted by increasing glycerol concentrations in the diets (P &lt; 0.001). Crude protein (CP) disappearance increased (P &lt; 0.001) in the linseed added diets, with no effect of glycerol addition. Neutral detergent fibre (aNDFom; P = 0.005) disappearance was increased by the addition of linseed to the diet. Conclusions The use of linseed in ruminant diets reduces CH4 emissions but increases NH3-N production in a Rusitec system. This latter effect is partially reverted by glycerol inclusion in the diet. Propionate production increases with the inclusion of glycerol, but does not alter CH4 production. Including linseed increases the in vitro CP disappearance without affecting DM total disappearance. Implications Care should be taken with the use of oilseeds in ruminant diets as it can reduce CH4 emissions but may cause important increases in NH3 emissions. Inclusion of glycerol may partially overcome this latter issue.

Methane emissions, feed intake, and total tract digestibility in lambs fed diets differing in fat content and fibre digestibility

This study determined enteric methane (CH4) emissions, intake, and apparent total tract digestibility of diets varying in fibre digestibility and fat content. A Latin square design with two levels of fat [2.0% and 6.0% dry matter (DM); low and high] and two levels of fibre digestibility [low fibre digestibility (LFbD) or high fibre digestibility (HFbD)] was used. Higher dry matter intake (DMI) was observed (P < 0.01) for LFbD versus HFbD diets (2.56 vs. 2.14 kg d−1, respectively), with no effect of fat. Fibre, DM, and organic matter digestibility were higher (P < 0.01) for HFbD than LFbD diets. Increasing fat did not affect intake or digestibility of DM or dietary constituents but there was a fibre digestibility × fat content interaction (P < 0.01) for fat digestibility. There was also a fat content × fibre digestibility interaction (P < 0.05) for CH4 (g kg−1 DMI, organic matter intake, neutral detergent fibre intake, and percent gross energy intake), with emissions being higher when fat was added to the HFbD than the LFbD diet. The CH4 emissions per kilogram of neutral detergent fibre (NDF) digested were higher (P < 0.01) for the HFbD than the LFbD diet. Methane emissions were increased by the HFbD diet, but inclusion of fat had a differential impact on CH4 emissions as a proportion of DMI or NDF intake in diets differing in fibre digestibility.

In vivo evaluation of garlic (Allium sativum) supplementation to rice straw-based diet on mitigation of CH4 and CO2 emissions and blood profiles using crossbreed rams

BACKGROUND

Two experiments were implemented using three cannulated crossbreed rams (Corriedale × Suffolk) fed rice straw-based diet. In vivo evaluation of garlic powder (GP) supplementation to rice straw-based diet on CH₄ and CO₂ emissions and blood profiles of the rams (body weight = 52 ± 3 kg) was performed. The design was a triplicate 3 × 3 Latin square. Groups were the control (no GP) and two GP groups, which were given supplementation for 0.1 (GP0.1) and 0.5% (GP0.5) of concentrate. The differences between two experiments were data missing of GP0.1 and uncontrolled environment in Experiment 1. Blood profiles were added in Experiment 2.

RESULTS

In Experiment 1, supplementation of GP to the rams reduced CH₄ production significantly (P < 0.05) by 38%. Dry matter intake was not different among the groups in both experiments. In Experiment 2, CH₄ was lower in the GP0.5 group than the control group by 7%, whereas CO₂ showed no difference among the groups. Serum glutamic oxaloacetic transaminase was significantly (P > 0.05) lower in the GP0.5 group than the control group, whereas glutamic pyruvic transaminase, total protein, urea N, total cholesterol, low-density lipoprotein, calcium, phosphorus, magnesium and non-esterified fatty acids were not significantly (P > 0.05) different.

CONCLUSIONS

GP supplementation, particularly GP0.5, decreases CH₄ emissions in rams fed rice straw-based diets. © 2018 Society of Chemical Industry.

The combined effects of supplementing monensin and 3-nitrooxypropanol on methane emissions, growth rate, and feed conversion efficiency in beef cattle fed high-forage and high-grain diets

The study objective was to evaluate the combined effects of supplementing monensin (MON) and the methane (CH4) inhibitor 3-nitrooxypropanol (NOP) on enteric CH4 emissions, growth rate, and feed conversion efficiency of backgrounding and finishing beef cattle. Two hundred and forty crossbred steers were used in a 238-d feeding study and fed a backgrounding diet for the first 105 d (backgrounding phase), transition diets for 28 d, followed by a finishing diet for 105 d (finishing phase). Treatments were as follows: 1) control (no additive); 2) MON (monensin supplemented at 33 mg/kg DM; 3) NOP (3-nitrooxypropanol supplemented at 200 mg/kg DM for backgrounding or 125 mg/kg DM for finishing phase); and 4) MONOP (33 mg/kg DM MON supplemented with either 200 mg/kg DM or 125 mg/kg DM NOP). The experiment was a randomized complete block (weight: heavy and light) design with 2 (NOP) × 2 (MON) factorial arrangement of treatments using 24 pens (8 cattle/pen; 6 pens/treatment) at the main feedlot and 8 pens (6 cattle/pen; 2 pens/treatment) at the controlled environment building (CEB) feedlot. Five animals per treatment were moved to chambers for CH4 measurements during both phases. Data were analyzed using a Mixed procedure of SAS with pen as experimental unit (except CH4). Location (Main vs. CEB) had no significant effect and was thus omitted from the final model. Overall, there were few interactions between MON and NOP indicating that the effects of the 2 compounds were independent. When cattle were fed the backgrounding diet, pen DMI was decreased by 7%, whereas gain-to-feed ratio (G:F) was improved by 5% with NOP supplementation (P < 0.01). Similarly, MON improved G:F ratio by 4% (P < 0.01), but without affecting DMI. During the finishing phase, DMI tended (P = 0.06) to decrease by 5% with both MON (5%) and NOP (5%), whereas ADG tended (P = 0.08) to decrease by 3% with MON. Gain-to-feed ratio for finishing cattle was improved with NOP by 3% (P < 0.01); however, no effects were observed with MON. 3-Nitrooxypropanol decreased CH4 yield (g/kg DMI) by 42% and 37% with backgrounding and finishing diets (P ≤ 0.01), respectively, whereas MON did not lower CH4 yield. Overall, these results demonstrate efficacy of NOP in reducing enteric CH4 emissions and subsequently improving feed conversion efficiency in cattle fed high-forage and high-grain diets. Furthermore, effects of NOP did not depend on whether MON was included in the diet.

Does partial replacement of corn with glycerin in beef cattle diets affect in vitro ruminal fermentation, gas production kinetic, and enteric greenhouse gas emissions?

Five in vitro experiments were conducted with the following objectives: 1) To evaluate the ruminal fermentation of three different single ingredients: corn, glycerin, and starch (Exp. 1 and 2); 2) To assess effects of partially replacing corn with glycerin in beef cattle diets on ruminal fermentation pattern (Exp. 3 and 4); and 3) To evaluate the effects of glycerin inclusion on the extension of ruminal DM digestibility of feeds with high (orchard hay) and low (corn) fiber content (Exp. 5). For Exp. 1 and 2, two in vitro systems (24-bottle AnkomRF and 20-serum bottles) were used in four consecutive fermentation batches to evaluate gas production (GP), fermentation profiles, enteric methane (CH4), and carbon dioxide (CO2) of corn, glycerin, and starch. The 24 h total GP, acetate concentration, and acetate: propionate ratio decreased only when glycerin was added to the diet (P < 0.01). The 48-h total GP and metabolizable energy were greatest for corn (P < 0.01), and similar between glycerin and starch. The starch treatment had the lowest total volatile fatty acids concentration (P = 0.01). Glycerin had greatest CH4 production, lag time, and maximum gas volume of the first pool (P < 0.05). However, the maximum gas volume of the second pool was greatest for corn (P < 0.05), and similar between glycerin and starch. The starch treatment had the greatest specific rates of digestion for first and second pools (P < 0.05). Production of CO2 (mL/g) was greater for corn (P < 0.01), but similar for glycerin and starch. For Exp. 3 and 4, the same systems were used to evaluate four different levels of glycerin [0, 100, 200, and 300 g/kg of dry matter (DM)] replacing corn in beef cattle finishing diets. Glycerin levels did not affect 24 and 48 h total GP, CH4, and CO2 (P > 0.05). The inclusion of glycerin linearly decreased acetate concentration (P = 0.03) and acetate: propionate ratio (P = 0.04). For Exp. 5, two DaisyII incubators were used to evaluate the in vitro dry matter digestibility (IVDMD) of the following treatments: orchard hay; corn; orchard hay + glycerin; and corn + glycerin. Glycerin inclusion decreased orchard hay IVDMD (P < 0.01) but did not affect corn IVDMD (P > 0.05). We concluded that, under these experimental conditions, glycerin has similar energy efficiency when used in replacement of corn and included at up to 300 g/kg in beef cattle diets.

Optimal dose of 3-nitrooxypropanol for decreasing enteric methane emissions from beef cattle fed high-forage and high-grain diets

The objective of the present study was to determine the dose response of the methane (CH4) inhibitor 3-nitrooxypropanol (NOP) on enteric CH4 production and dry matter intake (DMI) for beef cattle fed a high-forage or high-grain diet. Fifteen crossbred yearling steers were used in two consecutive studies (high-forage backgrounding, high-grain finishing), each designed as an incomplete block with two 28-day periods with a 7-day washout in between and treatments corresponding to six doses of NOP (0 (Control), 50, 75, 100, 150, 200 mg/kg DM). The NOP was provided in the ration daily with the dose increased gradually over the first 10 days of each period. No treatment effects were observed on overall DMI or DMI of cattle when they were in the chambers either for the high-forage (P ≥ 0.54) or high-grain (P ≥ 0.26) diet. With the high-forage diet, NOP supplementation lowered total CH4 emissions (g/day) (P = 0.05), with the response at 200 mg NOP/kg DM different from Control (P < 0.05). Similarly, CH4 emissions corrected for DMI (g/kg DMI) and as a percentage of gross energy intake were linearly reduced in the high-forage diet with supplemental NOP (P < 0.01) and responses observed at 100, 150 and 200 mg NOP/kg DM differed from Control (P < 0.05). For the high-grain diet, total CH4 emissions decreased with incremental increases in the concentration of NOP supplemented (P = 0.04) and responses observed at 150 and 200 mg/kg DM differed from Control. Similarly, linear responses were observed with CH4 emissions corrected for DMI (P = 0.04) and gross energy intake (P = 0.02), with 100–200 mg NOP/kg DM differing from Control. Overall, results from the present study demonstrated that for beef cattle fed high-forage and high-grain diets, supplementation of 100–200 mg NOP/kg DM lowered enteric CH4 emissions without inducing any negative effects on DMI.

Intake, feeding behaviour, digestibility, performance, carcass characteristics and meat quality of lambs fed different levels of semi-purified glycerine in the diet

The aim of this study was to evaluate the effect of different inclusion levels of semi-purified glycerine in the diet of feedlot lambs on feeding behaviour, nutrient intake and digestibility, carcass characteristics, meat quality and in vitro degradability. Thirty-two Dorper × (Texel × Suffolk) crossbred intact male lambs (22.2 ± 5.51 kg) were fed glycerine (90% purity) at 0, 120, 240 or 360 g/kg dry matter (DM) in a total mixed ration with a roughage to concentrate ratio of 40:60 for 84 d. In vitro degradability was not affected by glycerine supplementation. Feeding behaviour and digestibility of DM, crude protein and fibre and production performance were similar among treatments. Ether extract digestibility was lower at the highest inclusion level. Glycerine level had no effect on ruminal pH, carcass characteristics and meat quality, except for subcutaneous fat thickness which was lower for lambs fed glycerine at 240 and 360 g/kg DM. Scores for unpleasant taste, unpleasant odour, succulence and softness of meat were not affected by dietary glycerine level. These data suggest that there are no adverse effects on carcass quality and performance when semi-purified glycerine is provided up to 360 g/kg DM in the diet of growing lambs fed a forage to concentrate ratio of 40:60.

Effects of crude glycerin from waste vegetable oil in diets on performance and carcass characteristics of feedlot goats

OBJECTIVE

This experiment was conducted to investigate the effects of crude glycerin from waste vegetable oil (CGWVO) on performance, carcass traits, meat quality, and muscle chemical composition.

METHODS

Twenty-four crossbred (Thai Native×Anglo Nubian) uncastrated male goats (16.8± 0.46 kg body weight [BW]) were assigned to a completely randomized design and subjected to four experimental diets containing 0%, 2%, 4%, and 6% of CGWVO (63.42% of glycerol and 47.78% of crude fat) on a dry matter (DM) basis. The diets were offered ad libitum as total mixed rations twice daily. The feed intake, feeding behavior, growth performance, carcass and meat traits, and muscle chemical composition were evaluated.

RESULTS

Based on this experiment, there were significant differences (p>0.05) among groups regarding DM intake, growth performance, and carcass traits where goats receiving 6% of CGWVO had lower daily DM intake, growth performance, and carcass traits than those fed on 0%, 2%, and 4% of CGWVO. There were no effects of CGWVO on carcass length, carcass width, Longissimus muscle (LM) area, Warner-Bratzler shear force, pH and color of LM at 45 min after slaughter, as well as on other carcass cut and muscle chemical composition.

CONCLUSION

In conclusion, the addition of up to 4% of DM in the diets for crossbred finishing goats seems to be the most interesting strategy, since it promotes greatest animal performance. Moreover, this study was a suitable approach to exploit the use of biodiesel production from waste vegetable oil for goat production.

Growth performance and digestion of growing lambs fed diets supplemented with glycerol

Two experiments were conducted to evaluate the effects of replacing corn with an increasing concentration of high-purity glycerol (>99%) on growth performance, economical efficiency, blood constituents and nutrient digestibility of growing lambs. In experiment one, 24 male lambs (initial BW=33.6±6.0 kg; age=6.75±0.75 months) were randomly assigned to one of the three experimental treatments containing 0%, 5% or 10% glycerol to replace corn in concentrate. In experiment two, nine lambs (initial BW=44.7±2.2 kg, age=8.84±0.32 months) were used in a digestion trial with three treatments (three lambs per treatment) with glycerol replacing corn at 0%, 5% or 10% in the concentrate. Total dry matter (DM) intake decreased quadratically (P=0.003) with increasing concentration of glycerol in the diet. Lambs fed glycerol diets had greater average daily gain (P=0.005) and better feed efficiency (P=0.002) compared with the control. Feed costs were also reduced with glycerol inclusion. Glycerol supplementation did not affect serum concentrations of total protein, albumin, globulin, total lipid, cholesterol and glucose concentrations. Glycerol supplementation had no effect (P>0.05) on organic matter and CP digestion, but improved DM (P=0.0003), crude fiber (P=0.10), ether extract (P=0.0002) and nitrogen-free extract (P=0.05) digestion. In conclusion, glycerol can replace corn up to 10% of DM in the diets of growing lambs.

Effects of crude glycerin from waste vegetable oil supplementation on feed intake, ruminal fermentation characteristics, and nitrogen utilization of goats

This experiment was evaluation of the effects of increasing concentrations of crude glycerin from waste vegetable oil (CGWVO) in diets on feed intake, digestibility, ruminal fermentation characteristics, and nitrogen balance of goats. Four crossbred male (Thai Native × Anglo Nubian) goats, with an average initial body weight (BW) of 31.5 ± 1.90 kg, were randomly assigned according to a 4 × 4 Latin square design. The dietary treatments contained 0, 2, 4, and 6 % of dietary dry matter (DM) of CGWVO. Based on this experiment, there were significantly different (P > 0.05) among treatment groups regarding DM intake and digestion coefficients of nutrients (DM, OM, CP, EE, NDF, and ADF), which goats receiving 6 % of CGWVO had lower daily DMI and nutrient intake than those fed on 0, 2, and 4 % of CGWVO. Ruminal pH, NH3-N, and blood urea nitrogen (BUN) concentration were unchanged by dietary treatments, except that for 6 % of CGWVO supplementation, NH3-N, and BUN were lower (P < 0.05) than for the diets 0 % of CGWVO, while the differences between the diets 0, 2, and 4 % of CGWVO were not significant. The amounts of N absorption and retention were similar among treatments, except that for 6 % of CGWVO which N absorption was lower (P < 0.05) than among treatments while the difference between the diets 0, 2, and 4 % of CGWVO were not significant. Based on this study, CGWVO levels up to 4 % in total mixed ration could be efficiently utilized for goats. This study was a good approach in exploiting the use of biodiesel production from waste vegetable oil for goat production.

Effects of Elevated Crude Glycerin Concentrations on Feedlot Performance and Carcass Characteristics in Finishing Steers

Twenty crossbred steers (400±40.1 kg of initial body weight) were used to assess the effects of a dietary supplementation with crude glycerin (CG) as a substitute for corn grain on performance, carcass traits, and meat quality. Four isocaloric and isonitrogenous diets were offered to the experimental animals (5 steers per treatment) for 121 days using randomized complete block design. The steers individually received dietary treatments containing 0%, 7%, 14%, and 21% of CG (88.91% pure) on a dry matter (DM) basis. The diets were offered ad libitum as total mixed rations twice daily. Weight gain and carcass traits were determined. At the end of the experimental period, the harvest data and carcass characteristics of the steers were recorded, and meat quality was determined. No significant effect of CG inclusion was observed in any of the growth performance and carcass characteristics traits studied. Also, there were no apparent effects of diets (p>0.05) on meat quality (pH, water holding capacity, drip losses, and cooking losses). The study concluded that CG could be used as a substitute for corn grain up to the level of approximately 21% of DM in the diets of finishing steers.

Enteric methane emissions in response to ruminal inoculation of Propionibacterium strains in beef cattle fed a mixed diet

The objective of this study was to test the efficacy of Propionibacterium strains to mitigate enteric methane (CH4) emissions in beef heifers fed a mixed diet. An experiment was conducted with 16 ruminally cannulated beef heifers fed a basal diet consisting of 60 : 40 barley silage : barley grain (DM basis). Treatments included: (1) Control, (2) Propionibacterium freudenreichii T114, (3) P. thoenii T159, and (4) P. freudenreichii T54. Strains (1 × 1011 colony forming units) were administered daily directly into the rumen before feeding. No treatment effects were observed for DM intake (P = 0.90), mean ruminal pH (P = 0.50) and total volatile fatty acids (P = 0.44). However, compared with the Control, proportions of individual volatile fatty acids changed with acetate being less with Propionibacterium T159 (P = 0.02), whereas ruminal isobutyrate (P < 0.01) and acetate : propionate ratio (P = 0.04) were greater with Propionibacterium T114. Total daily enteric CH4 production averaged 188 g/day and was not affected by Propionbacterium strains (P = 0.51). Methane yield averaged 22 g/kg of DMI intake and tended to be greater with Propionibacterium strains (P = 0.08). The relative abundance of total Propionibacteria was greater with the inoculation of Propionibacterium T159 relative to the Control heifers (P = 0.04). In conclusion, inoculation of Propionibacterium T159 decreased ruminal acetate proportion and Propionibacterium T114 increased acetate : propionate ratio. However, inoculated strains failed to lower total CH4 emissions possibly due to the inability of Propionibacterium strains to elevate ruminal propionate concentrations.

Crude glycerin combined with sugar cane silage in lamb diets

This study aimed to evaluate the effect of the level of crude glycerin (CG) on in vitro fermentation kinetics (0, 20, 40, 60, and 80 g/kg DM of sugar cane silage), on in vitro neutral detergent fiber (NDF) degradation (0, 30, 60, and 90 g/kg DM of sugar cane silage), and intake and digestibility of nutrients and nitrogen balance (0, 20, 55, 82, and 108 g/kg DM of sugar cane silage) in lambs. The in vitro trials were conducted in a completely randomized design with three repetitions. The in vivo trial was conducted in a Latin square design with five repetitions (5 × 5). For variables in which the F test was considered significant, the statistical interpretation of the effect of CG substitution levels was carried out through regression analyses. Kinetic parameters were not affected by CG inclusion. On in vitro NDF degradation, a significant effect of CG levels was observed on the potentially degradable fraction of NDF, the insoluble potentially degradable fraction of NDF, and the undegradable NDF fraction. The intake and digestibility of nutrients and nitrogen balance were not affected by CG inclusion. The CG levels change in vitro NDF degradability parameters; however, there were no changes in animal intake, digestibility, and nitrogen balance with the inclusion levels used.

Carcass characteristics and meat quality of lambs fed high concentrations of crude glycerin in low-starch diets

In this study, we evaluated the effects of total corn replacement with crude glycerin on carcass characteristics and meat quality of feedlot lambs fed high-concentrate diets with low starch. Forty non-castrated Santa Ines lambs (23.5 ± 3.56 kg BW) were assigned to a randomized complete block design with five dietary treatments: 0%, 7.5%, 15%, 22.5%, or 30% crude glycerin, replacing corn. Animals were slaughtered at a BW of 38 kg after 72 ± 20 days. The addition of up to 30% crude glycerin reduced carcass weight and yield (P ≤ 0.02). Odd-chain fatty acids, oleic, palmitoleic, total unsaturated, and monounsaturated fatty acids were increased (P ≤ 0.01) while CLA tended to increase in glycerin-fed lambs (P = 0.06). Crude glycerin decreased stearic, palmitic, transvaccenic, total saturated fatty acids, and atherogenicity index (P < 0.01). High concentrations of crude glycerin in low-starch diets reduced carcass weights, nevertheless improved meat quality by increasing unsaturated and odd-chain fatty acid contents.

Effect of breed and pasture type on methane emissions from weaned lambs offered fresh forage

To investigate the extent to which enteric methane (CH₄) emissions from growing lambs are explained by simple body weight and diet characteristics, a 2 × 2 Latin square changeover design experiment was carried out using two sheep breeds and two fresh pasture types. Weaned lambs of two contrasting breed types were used: Welsh Mountain (WM, a small, hardy hill breed) and Welsh Mule × Texel (TexX, prime lamb) (n = 8 per breed). The lambs were zero-grazed on material cut from recently reseeded perennial ryegrass and extensively managed permanent pasture. In each experimental period, individual ad libitum dry matter intake (DMI) was determined indoors following an adaptation period of 2 weeks, and CH₄ emissions were measured individually in open-circuit respiration chambers over a period of 3 days. Although total daily CH₄ emissions were lower for the WM lambs than for the TexX lambs (13·3 v. 15·7 g/day, respectively) when offered fresh forage, the yield of CH₄ per unit DMI was similar for the two breed types (16·4 v. 17·7 g CH₄/kg DMI). Total output of CH₄ per day was higher when lambs were offered ryegrass compared with permanent pasture (16·1 v. 12·9 g/day, respectively), which was probably driven by differences in DMI (986 v. 732 g/day). Methane emissions per unit DMI (16·4 v. 17·7 g CH₄/kg DMI) and proportion of gross energy intake excreted as CH₄ (0·052 v. 0·056 MJ/MJ) were both higher on the permanent pasture. No forage × breed type interactions were identified. The results indicate that forage type had a greater impact than breed type on CH₄ emissions from growing weaned lambs. It can be concluded that when calculating CH₄ emissions for inventory purposes, it is more important to know what forages growing lambs are consuming than to know what breeds they are.

Effects of dietary glycerin inclusion at 0, 5, 10, and 15 percent of dry matter on energy metabolism and nutrient balance in finishing beef steers

Expansion of the biodiesel industry has increased the glycerin (GLY) supply. Glycerin is an energy-dense feed that can be used in ruminant species; however, the energy value of GLY is not known. Therefore, the effects of GLY inclusion at 0, 5, 10, and 15% on energy balance in finishing cattle diets were evaluated in 8 steers (BW = 503 kg) using a replicated Latin square design. Data were analyzed with the fixed effects of dietary treatment and period, and the random effects of square and steer within square were included in the model. Contrast statements were used to separate linear and quadratic effects of GLY inclusion. Glycerin replaced dry-rolled corn (DRC) at 0, 5, 10, and 15% of dietary DM. Dry matter intake decreased linearly (P = 0.02) as GLY increased in the diet. As a proportion of GE intake, fecal energy loss tended to decrease linearly (P < 0.07), and DE also tended to increase linearly (P = 0.07) as dietary level of GLY increased. Urinary energy loss was not different (P > 0.31) as a proportion of GE as GLY increased in the diet. Methane energy loss as a proportion of GE intake tended to respond quadratically (P = 0.10), decreasing from 0 to 10% GLY inclusion and increasing thereafter. As a proportion of GE intake, ME tended to respond quadratically (P = 0.10), increasing from 0 to 10% GLY and then decreasing. As a proportion of GE intake, heat production increased linearly (P = 0.02) as GLY increased in the diet. Additionally, as a proportion of GE intake, retained energy (RE) tended to respond quadratically (P = 0.07), increasing from 0 to 10% GLY inclusion and decreasing thereafter. As a proportion of N intake, urinary and fecal N excretion increased linearly (P < 0.04) as GLY increased in the diet. Furthermore, grams of N retained and N retained as a percent of N intake both decreased linearly (P < 0.02) as GLY increased in the diet. Total DM digestibility tended (P < 0.10) to respond quadratically, increasing at a decreasing rate from 0 to 5% GLY inclusion. Overall, RE tended to decrease as GLY increased in the diet in conjunction with a decrease in N retention, which could indicate an increased metabolic cost to the animal associated with feeding GLY. Based on RE, the feeding value of GLY in high-concentrate diets is greater than DRC at 5 and 10% of DM but less at 15% of DM.

Effects of dietary crude glycerin supplementation on nutrient digestibility, ruminal fermentation, blood metabolites, and nitrogen balance of goats

This experiment was conducted to evaluate the effects of increasing concentrations of crude glycerin (CGLY) in diets on nutrient utilization, ruminal fermentation characteristics, and nitrogen utilization of goats. Four male crossbred (Thai Native×Anglo Nubian) goats, with an average initial weight of 26±3.0 kg, were randomly assigned according to a 4×4 Latin square design with four 21 days consecutive periods. Treatments diets contained 0%, 5%, 10%, and 20% of dietary DM of CGLY. Based on this experiment, there were no significant differences (p>0.05) among treatment groups regarding DM intake and digestion coefficients of nutrients (DM, OM, CP, EE, NDF, and ADF). Likewise, mean serum glucose, BHBA, and PCV concentrations were not affected (p>0.05) by dietary treatments, whereas serum insulin concentration linearly increased (L, p = 0.002) with increasing the amount of CGLY supplementation. Ruminal pH, NH₃-N, and BUN concentration were unchanged by dietary treatments, except for 20% of CGLY, NH₃-N, and BUN were lower (p<0.05) than for the diets 10% of CGLY, while the difference between the diets 0%, 5%, and 20% of CGLY were not significant. The amount of N absorption and retention were similar among treatments. Based on this study, CGLY levels up to 20% in total mixed ration could be efficiently utilized for goats and this study elucidates a good approach to exploiting the use of biodiesel production for goat production.

Effects on enteric methane production and bacterial and archaeal communities by the addition of cashew nut shell extract or glycerol-an in vitro evaluation

The objective of the study was to evaluate the effect of cashew nut shell extract (CNSE) and glycerol (purity >99%) on enteric methane (CH4) production and microbial communities in an automated gas in vitro system. Microbial communities from the in vitro system were compared with samples from the donor cows, in vivo. Inoculated rumen fluid was mixed with a diet with a 60:40 forage:concentrate ratio and, in total, 5 different treatments were set up: 5mg of CNSE (CNSE-L), 10mg of CNSE (CNSE-H), 15mmol of glycerol/L (glycerol-L), and 30mmol of glycerol/L (glycerol-H), and a control without feed additive. Gas samples were taken at 2, 4, 8, 24, 32, and 48h of incubation, and the CH4 concentration was measured. Samples of rumen fluid were taken for volatile fatty acid analysis and for microbial sequence analyses after 8, 24, and 48h of incubation. In vivo rumen samples from the cows were taken 2h after the morning feeding at 3 consecutive days to compare the in vitro system with in vivo conditions. The gas data and data from microbial sequence analysis (454 sequencing) were analyzed using a mixed model and principal components analysis. These analyses illustrated that CH4 production was reduced with the CNSE treatment, by 8 and 18%, respectively, for the L and H concentration. Glycerol instead increased CH4 production by 8 and 12%, respectively, for the L and H concentration. The inhibition with CNSE could be due to the observed shift in bacterial population, possibly resulting in decreased production of hydrogen or formate, the methanogenic substrates. Alternatively the response could be explained by a shift in the methanogenic community. In the glycerol treatments, no main differences in bacterial or archaeal population were detected compared with the in vivo control. Thus, the increase in CH4 production may be explained by the increase in substrate in the in vitro system. The reduced CH4 production in vitro with CNSE suggests that CNSE can be a promising inhibitor of CH4 formation in the rumen of dairy cows.

Fatty acid profile, carcass and meat quality traits of young Nellore bulls fed crude glycerin replacing energy sources in the concentrate

Carcass and meat quality traits of 60 Nellore young bulls fed diets without crude glycerin (CG); with CG replacing corn (CGc; 10% of dry matter - DM) in the concentrate; and with CG replacing soybean hull (CGsh; 10% of DM) in the concentrate were evaluated. Diets were evaluated at two concentrate levels (CLs). The CL did not affect cold carcass weight (CCW; P=0.6074), cold carcass dressing (CCD; P=0.9636), rib fat thickness (RFT; P=0.8696) and longissimus muscle area (LMA; P=0.7524). Animals fed diets with CGc or CGsh showed meat with greater deposition of monounsaturated fatty acid (MUFA; P=0.0022) and CLA (18:2 cis-9, trans-11) contents (P=0.0001) than animals fed diets without CG. The inclusion of 10% of CG in diets CGc or CGsh does not affect the carcass and meat quality traits; however, it increases the MUFA and CLA contents in beef, although these changes are very small in nutritional terms.

Inclusion of glycerol in forage diets increases methane production in a rumen simulation technique system

We hypothesised that the inclusion of glycerol in the forage diets of ruminants would increase the proportion of propionate produced and thereby decrease in vitro CH₄ production. This hypothesis was examined in the present study using a semi-continuous fermentation system (rumen simulation technique) fed a brome hay (8·5 g) and maize silage (1·5 g) diet with increasing concentrations (0, 50, 100 and 150 g/kg DM) of glycerol substituted for maize silage. Glycerol linearly increased total volatile fatty acids production (P<0·001). Acetate production was quadratically affected (P=0·023) and propionate and butyrate production was linearly increased (P<0·001). Glycerol linearly increased (P=0·011) DM disappearance from hay and silage. Crude protein disappearance from hay was not affected (P=0·789), but that from silage was linearly increased (P<0·001) with increasing glycerol concentrations. Neutral-detergent fibre (P=0·040) and acid-detergent fibre (P=0·031) disappearance from hay and silage was linearly increased by glycerol. Total gas production tended to increase linearly (P=0·061) and CH₄ concentration in gas was linearly increased (P<0·001) by glycerol, resulting in a linear increase (P<0·001) in mg CH₄/g DM digested. Our hypothesis was rejected as increasing concentrations of glycerol in a forage diet linearly increased CH₄ production in semi-continuous fermenters, despite the increases in the concentrations of propionate. In conclusion, this apparent discrepancy is due to the more reduced state of glycerol when compared with carbohydrates, which implies that there is no net incorporation of electrons when glycerol is metabolised to propionate.

Carcass characteristics of feedlot lambs fed crude glycerin contaminated with high concentrations of crude fat

Thirty non-castrated male lambs with 20±2.3 kg average body weight (BW) were randomly assigned to five treatments consisted of different dietary concentrations of crude glycerin (CG; 0, 3, 6, 9 and 12% on DM basis) to evaluate the effects on performance, carcass and meat quality traits. A quadratic effect was observed for performance (P=0.04), final BW (P<0.01) and hot carcass weight (P<0.01). No effects of CG were observed (P>0.05) on carcass pH neither on shear-force, cooking loss and ether extract content in longissimus. The inclusion of CG tended to reduce the Zn content in meat (P=0.09). The data suggests that CG (36.2% of glycerol and 46.5% of crude fat) may be used in diets of finishing lambs with concentrations up to 3% without negative effects on performance and main carcass traits. Moreover, inclusion of CG seems to not affect quality and safety of meat for human consumption.