Polyurethane Adhesives for Wood Based on a Simple Mixture of Castor Oil and Crude Glycerin.

Developing a new type of polyurethane is essential because conventional options often exhibit shortcomings in terms of environmental sustainability, cost-effectiveness, and performance in specialized applications. A novel polyurethane adhesive derived from a simple mixture of castor oil (CO) and crude glycerin (CG) holds promise as it reduces reliance on fossil fuels and harnesses renewable resources, making it environmentally friendly. Simple CO/CG mixtures, adjusted at three different weight fractions, were used as bio-based polyester polyols to produce polyurethane adhesive for wood bonding. The resulting products are yellowish liquids with moderate-to-high viscosity, measuring 19,800-21,000 cP at 25 °C. The chemical structure of the polyester polyols was characterized using infrared spectroscopy (FTIR), thermogravimetry (TG), and differential scanning calorimetry (DSC). These polyols reacted with polymeric 4,4-methylene diphenyl diisocyanate (p-MDI) at a consistent isocyanate index of 1.3, resulting in the formation of polyurethane adhesives. Crucially, all final adhesives met the adhesive strength requirements specified by ASTM D-5751 standards, underscoring their suitability for wood bonding applications. The addition of CG enhanced the surface and volumetric hydrophobicity of the cured adhesives, resulting in adhesive properties that are not only stronger but also more weather-resistant. Although the thermal stability of the adhesives decreased with the inclusion of CG, FTIR analysis confirmed proper polyurethane polymer formation. The adhesive adjusted for a 2:1 CO:CG weight ratio promoted wood-wood bonding with the highest shear strength, likely due to a higher formation of urethane linkages between hydroxyl groups from the blend of polyols and isocyanate groups from the p-MDI.

Effect of substitution of distillers grains and glycerin for steam-flaked corn in finishing cattle diets on growth performance and carcass characteristics.

An experiment was conducted to determine the effect of substituting modified corn distillers grains with solubles (DGS) or crude soy glycerin (CG) for steam-flaked corn (SFC) in finishing diets on growth performance and carcass characteristics. Treatments were arranged as a 2 × 2 factorial with DGS (0% or 40%) and CG (0% or 10%) replacing dietary SFC in a basal diet. Growth performance and carcass traits were measured on 48 individually fed crossbred yearling cattle (21 steers and 27 heifers; 380 ± 37 kg). Cattle were randomly allotted to 48 Calan gate bunks. After the first 28 days, nine animals were removed from the study for health reasons or observed confirmation of consumption of feed from unassigned Calan gate bunk (n = 39). After the feeding period, cattle were harvested in two groups on day-124 and day-173. No DGS × CG interactions were observed (P > 0.10) for any dependent growth performance or carcass characteristic variable tested. Cattle-fed DGS as 40% of diet dry matter (DM) had greater (P< 0.01) dry matter intake (DMI), while CG inclusion at 10% of diet DM did not affect DMI (P = 0.16). Carcass-adjusted average daily gain (ADG) was not affected by DGS (P = 0.73) or CG (P = 0.28). Decreased (P = 0.03) carcass-adjusted gain-to-feed (G:F) was observed as the main effect of DGS. Greater DMI resulting from feeding DGS as 40% of diet DM appears to have driven the tendency for reduced G:F. Hot carcass weight, longissimus muscle area, 12th rib fat depth, yield grade, and marbling score were not (P> 0.10) influenced by DGS or CG. However, kidney, pelvic, fat (KPH) was increased (P = 0.01) when cattle were fed DGS as 40% of diet DM. Based on the findings presented, it is concluded that CG can substitute up to 10% of SFC in the diet without negatively affecting cattle growth performance or carcass characteristics, regardless of DGS inclusion as 40% of the diet DM.

Livestock producers have an opportunity to improve sustainably through the utilization of co-products of the bio-fuel industry through cattle feeding. Crude glycerin, although less commonly fed compared to distillers grains, provides an opportunity for cattle feeders to increase the versatility of feed ingredient sources without compromising performance. The present study examined the effect of substituting modified corn distillers grains and crude soy glycerin for steam­flaked corn in beef cattle finishing diets on cattle growth performance and carcass characteristics. Growth performance was not influenced by treatment suggesting that crude glycerin and modified corn distillers grains in finishing diets were effective substitutions for steam­flaked corn when market price permits.

Up-recycling oil produced water as the media-base for the production of xanthan gum.

Produced water (PW) and crude glycerin (CG) are compounds overproduced by the oil and biodiesel industry and significant scientific efforts are being applied for properly recycling them. The aim of this research is to combine such industrial byproducts for sustaining the production of xanthan by Xanthomonas campestris. Xanthan yields and viscosity on distinct PW ratios (0, 10, 15, 25, 50, 100) and on 100% dialyzed PW (DPW) in shaker batch testing identified DPW treatment as the best approach for further bioreactor experiments. Such experiments showed a xanthan yield of 17.3 g/L within 54 h and a viscosity of 512 mPa s. Physical-chemical characterization (energy dispersive X-ray spectroscopy, scanning electron microscopy and Raman spectroscopy) showed similarities between the produced gum and the experimental control. This research shows a clear alternative for upcycling high salinity PW and CG for the generation of a valued bioproduct for the oil industry.

Agroindustrial wastes as a substrate for the cultivation of Eruca sativa Miller seedlings: physical-chemical and phytometric parameters assessment.

Evaluation was made of the use of organic substrates obtained from the composting of poultry industry wastes, together with crude glycerin, for the production of arugula seedlings (Eruca sativa Miller). The raw materials included hatchery waste, chicken litter, and flotation tank sludge, in combination with other materials such as tree pruning, sugarcane bagasse, crude glycerin (at 0, 1.5, 3.0, 4.5, and 6.0%), and boiler charcoal. Analysis of the organic substrates included determination of nitrogen, phosphorus, and potassium (NPK), pH, electrical conductivity, functional groups, and carboxylic acids. Physical parameters determined were water retention capacity, solids volume, porosity, density, and granulometry. For the arugula seedlings, determinations were made of the ease of removal of the root ball from the tray, the effect of free drop on the root ball, phytometric parameters, and total phenolic compounds. Decreased concentrations of carboxylic acids, together with the presence of aromatic functional groups, indicated maturation/stabilization of the organic substrates. The phytometric measurements indicated that the use of the organic substrates with addition of 3.0, 4.5, and 6.0% of crude glycerin favored arugula production and led to higher contents of total phenolic compounds in the seedlings, with values of 3657.54, 3602.13, and 3232.92 mg GAE g-1, respectively. The results demonstrated that the use of these organic substrates with the addition of crude glycerin provided satisfactory development of arugula seedlings.

Crambe meal and crude glycerin from biodiesel production in diets for finishing of crossbred cattle in feedlot.

Our hypothesis is that crambe meal can totally substitute soybean meal and crude glycerin can partially replace the corn in the diet without leading to losses of nutrient intake and productive performance. Two assays were performed using heifers and steers. In the first assay, 24 Beefalo-Nellore heifers with 18 months old with 311.5 ± 5.5 kg, and in the second assay, 24 Beefalo-Nellore steers with 18 months old with 317.0 ± 6.4 kg were evaluated. The experiment was carried out in a randomized complete design, in a 2 × 2 factorial scheme, consisting of two energy sources (corn and crude glycerin) and two protein sources (soybean meal and crambe meal). Both assays had 104 experimental days of feedlot. There was no interaction between the variation sources. There was an effect of protein source on nutrient intake for heifers except to neutral detergent fiber intake, which presented effect of energy source. Heifers fed soybean meal showed higher results for total weight gain and daily weight gain. There was observed effect of energy source on rib eye area and subcutaneous fat thickness. Steers fed soybean meal showed higher neutral detergent fiber intake and non-fibrous carbohydrates. Steers fed corn + crude glycerin showed higher results for total weight gain and daily weight gain. The steers fed soybean meal showed higher averages for subcutaneous fat thickness. Crambe meal and crude glycerin can be used as alternative sources of energy and protein to replace 100% of soybean and 50% of corn, respectively, for finishing Beefalo-Nellore cattle in a feedlot.

Feeding Crude Glycerin to Finishing Iberian Crossbred Pigs: Effects on Growth Performance, Nutrient Digestibility, and Blood Parameters.

A total of 192 Iberian × Duroc pigs kept under intensive conditions were used to investigate the effects of feeding crude glycerin on growth performance, nutrient digestibility, and blood parameters. Animals were blocked by initial body weight (96.0 ± 11.3 kg) and allotted to pens (16 pigs per pen). Pens were assigned randomly to one of three dietary treatments (four pens per treatment). Dietary treatments contained 0, 5, or 10% of crude glycerin proportionally substituting for wheat (G0, G5, and G10, respectively). Diets were formulated to be isoenergetic and isoaminoacidic. No significant effect of crude glycerin was observed on average daily gain, average feed intake, or feed conversion ratio. The apparent total tract digestibility of dry matter, organic matter, and crude protein was no different between treatments. Total serum protein, albumin, glucose, insulin, and IGF-1 were not affected by glycerin inclusion. In conclusion, crude glycerin up to 100 g/kg can be included in the diets of finishing Iberian crossbred pigs without any negative effect on growth performance, digestibility, or serum metabolic parameters.

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.

The Effect of the Dietary Inclusion of Crude Glycerin in Pre-Starter and Starter Diets for Piglets.

The aim of this study was to evaluate the effect of the inclusion of crude glycerin in post-weaning diets for piglets on growth performance and digestibility. The study was carried out with a total of 360 piglets over a 39 day period. Animals were blocked by body weight (7.7 ± 0.86 kg) and allotted randomly to one of three dietary treatments containing 0, 2.5 or 5% glycerin (G0, G2.5 and G5, respectively). Considering the whole period, glycerin did not affect the average daily gain. However, the average daily feed intake (ADFI) and the feed conversion ratio (FCR) tended to decrease or decreased linearly as the amount of glycerin increased, respectively (p = 0.060 and p = 0.039). The apparent total tract digestibility (ATTD) of dry and organic matter (DM, OM) increased linearly with increasing glycerin in both periods (p ≤ 0.05). At the end of the study, there were no differences between treatments for any of the hormones measured. In conclusion, the FCR and digestibility of DM and OM were improved although the ADFI tended to be lower when glycerin was included at 5%. Consequently, crude glycerin could be used as an alternative ingredient to partially replace sweet whey and wheat in post-weaning diets.

Feeding behavior of feedlot lambs fed diets with different energy and protein sources.

This study aimed to evaluate the effect of the replacement of ground corn by crude glycerin and soybean meal by cottonseed cake, in association or not, on feedlot lambs' feeding behavior. Thirty-two non-castrated crossbred ½ Dorper ½ Santa Inês lambs, with an average body weight of 18.52 ± 3.24 kg (mean ± standard deviation), were distributed in a completely randomized design, into four treatments and eight replicates per treatment, in a 2 × 2 factorial scheme. Four experimental diets were tested with different sources or combinations of energy and protein ingredients in the concentrate, respectively: (1) ground corn + soybean meal; (2) ground corn and cottonseed cake; (3) crude glycerin and soybean meal; and (4) crude glycerin and cottonseed cake. The glycerin decreased dry matter (DM) and neutral detergent fiber (NDF) (P < 0.001) intakes, whereas it increased times spent in feeding (P = 0.009; from 21.8 to 28.6), rumination (P = 0.006; from 56.2 to 67.2), and chewing (P < 0.001; from 79.4 to 97.2), in minutes/100 g of DM. Feeding efficiencies of DM (P = 0.003) and NDF (P = 0.008) were decreased by the diets. Protein sources increased (P = 0.018) the times spent in chewing and per period in rumination (P = 0.014). Cottonseed cake, as a protein source, up to a 112 g/kg DM level, can totally replace soybean meal in diets for feedlot lambs without effects on the intake, behavioral activities, and feeding efficiencies. In contrast, the crude glycerin energy source is not adequate to replace ground corn in lambs' diets.

Carcass Characteristics and Meat Quality of Betong Chicken Fed with Diets Supplemented with Crude Glycerin.

Experiments were conducted to evaluate the effect of crude glycerin inclusion in the diets of Betong chicken on the characteristics of their carcasses, internal organs, meat quality, lipid oxidation, and fatty acid profiles. One hundred 1-day-old chicks were raised for 8 weeks. Subsequently, the birds were sexed based on their morphological features, and weighed. Forty-eight male chickens, with comparable body weights, were randomly allotted to receive any of the three experimental diets, containing 0, 50 or 100 g crude glycerin/kg feed, on an as fed basis until they were 20 weeks old. A total of 24 chickens were slaughtered and their carcass characteristics and meat quality were studied. Results showed that carcass characteristics and internal organ parameters were not affected by crude glycerin supplementation (P>0.05). After chilling for 24 h, pH of the meat decreased in all groups (P>0.05), while shear force and cooking loss were not affected (P>0.05). Furthermore, crude glycerin did not affect the parameters such as crude protein, ether extract, ash, moisture and proportions of different fatty acid contents of meat of the Betong chicken (P>0.05). However, breast meat color and lipid oxidation were influenced by crude glycerin in diet (P<0.05). These results suggest that crude glycerin can be used at concentrations up to 10% in Betong chicken diet from 8 to 20 weeks of age. Nevertheless, its effect on breast meat color and lipid oxidation need to be considered.

Environmentally friendly rhamnolipid production for petroleum remediation.

Biosurfactants have potential applications in the remediation of petroleum-contaminated sites. Several strategies can be used to reduce the production costs of these surfactants and make the process more environmentally friendly. In this study, we combined some of these strategies to produce the rhamnolipid-type biosurfactant, including the use of the genetically modified strain Pseudomonas aeruginosa-estA, an industrial coproduct as a carbon source, a simple and low-cost medium, and a simple downstream process. The process resulted in a high yield (17.6 g L-1), even using crude glycerin as the carbon source, with substrate in product conversion factor (YRML/s) of 0.444. The cell-free supernatant (CFS) was not toxic to Artemia salina and selected mammalian cell lineages, suggesting that it can be used directly in the environment without further purification steps. Qualitative analysis showed that CFS has excellent dispersion in the oil-displacement test, emulsifying (IE24 = 65.5%), and tensoactive properties. When salinity, temperature and pressure were set to seawater conditions, the values for interfacial tension between crude oil and water were below 1.0 mN m-1. Taken together, these results demonstrate that it is possible to obtain a nontoxic crude rhamnolipid product, with high productivity, to replace petroleum-based surfactants in oil spill cleanups and other environmental applications.

Development and validation of HILIC-UHPLC-ELSD methods for determination of sugar alcohols stereoisomers and its application for bioconversion processes of crude glycerin.

The recent increase in the production of crude glycerin through the manufacture of biodiesel has imputed a commercial issue, the excess of this raw material in the market and its constant devaluation, which resulted in the need for new technologies for its use. Crude glycerin can be used in biotechnological processes for the production of high value-added compounds. This study presents novel, simple and fast methods based on ultra-high performance liquid chromatography (UHPLC) using evaporative light scattering detection (ELSD) for simultaneous analysis of ten sugar alcohols with a hydrophilic interaction chromatography (HILIC) column. The selected compounds and their possible stereoisomers have major commercial importance and they can be obtained by biotechnological routes. Under optimized conditions, threitol, erythritol, adonitol, xylitol, arabitol, iditol, sorbitol, mannitol, dulcitol and volemitol can be analyzed simultaneously within 15.0 min. The use of different column temperatures was a key parameter to reach the selectivity during the separation of some stereoisomers. Regression equations revealed a good linear relationship (R > 0.995) over the range from 50.0 to 800.0 ng. Limits of detection (LOD) and quantification (LOQ) ranged from 30.0 to 45.0 ng and 50.0-75.0 ng, respectively. The HILIC-UHPLC-ELSD methods showed good precision with low coefficient of variation (CV%) for the intra- and inter-assays experiments (≤ 5.1%) and high repeatability in terms of retention times for each analyte (≤ 0.5%). The accuracy was confirmed with an average recovery ranging from 92.3 to 107.3%. The developed methods employ an analytical technique more accessible and suitable for routine analyzes and have shown to be suitable for simultaneous analysis of sugar alcohols present in crude bioconverted glycerin samples using different classes of microorganisms.

Feedlot of lambs fed biodiesel co-products: performance, commercial cuts and economic evaluation.

The aim of this study was to evaluate the animal performance, commercial cuts, and their yields within the production system, and economics of sheep production, of lambs finished in feedlots and fed with or without biodiesel co-products. A total of 40 lambs were divided into four biodiesel co-product treatment groups: a no-treatment control; peanut meal; crude glycerin; and peanut meal + crude glycerin. Animal performance did not differ (P > 0.05) among the treatment groups, where the average daily gain was close to 0.26 kg/day. Likewise, the quantitative carcass characteristics did not differ (P > 0.05) and the biological mean yield was 54.92%. Similarly, the commercial cuts and their yields did not differ (P ≥ 0.09) among the treatments. These results took into consideration the standard, age, and slaughter body weight of the animals. The economic evaluation determined that peanut meal was the best co-product for use in finishing lambs in a feedlot. Hence, all the biodiesel co-products evaluated can be used at feedlots to finish lambs without changing the variables measured.

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.

Effects of partial replacement of maize in the diet with crude glycerin and/or soyabean oil on ruminal fermentation and microbial population in Nellore steers.

The objective of this study was to determine whether a combination of crude glycerin (CG) and soyabean oil (SO) could be used to partially replace maize in the diet of Nellore steers while maintaining optimum feed utilisation. Eight castrated Nellore steers fitted with ruminal and duodenal cannulas were used in a double 4×4 Latin square design balanced for residual effects, in a factorial arrangement (A×B), when factor A corresponded to the provision of SO, and factor B to the provision of CG. Steers feed SO and CG showed similar DM intake, DM, organic matter and neutral-detergent fibre digestibility to that of steers fed diets without oil and without glycerine (P>0·05). Both diets with CG additions reduced the acetate:propionate ratio and increased the proportion of iso-butyrate, butyrate, iso-valerate and valerate (P<0·05). Steers fed diets containing SO had less total N excretion (P<0·001) and showed greater retained N expressed as % N intake (P=0·022). SO and CG diet generated a greater ruminal abundance of Prevotella, Succinivibrio, Ruminococcus, Syntrophococcus and Succiniclasticum. Archaea abundance (P=0·002) and total ciliate protozoa were less in steers fed diets containing SO (P=0·011). CG associated with lipids could be an energy source, which is a useful strategy for the partial replacement of maize in cattle diets, could result in reduced total N excretion and ruminal methanogens without affecting intake and digestibility.

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.

Effects of high concentrations of dietary crude glycerin on dairy cow productivity and milk quality.

An increasing worldwide interest in alternative fuel sources and in a more diversified energy matrix has provided incentives for the biodiesel industry, generating large amounts of the by-product crude glycerin, a potential alternative feed for dairy cows. A replicated 3×3 Latin square study was conducted to evaluate the effects of high concentrations of crude glycerin on dry matter intake, milk yield and composition, milk fatty acid profile, and blood metabolites of medium-yield cows. Ruminally cannulated Holstein cows (n=6; 587 ± 39 kg of body weight; 114 ± 29 d in milk; and 20 ± 1.5 kg/d milk yield) were used in the study. The experimental period included 2 wk for adaptation and 1 wk for data collection. Cows were fed diets containing 0 (control), 15, or 30% crude glycerin (83% glycerol). Cows were milked, milk weights were recorded twice daily, and milk samples were collected for milk quality analyses at d 18 and 19 in each experimental period. Feeding cows with crude glycerin linearly decreased dry-matter intake, the 3.5% fat-corrected milk, and the solid-corrected milk yield. Hepatic enzymes were not affected by dietary treatments, except gamma-glutamyl transferase, which was decreased with the 15% crude glycerin diet. Serum glucose and albumin showed quadratic effect with increasing inclusion of crude glycerin. Plasma cholesterol as well as total protein linearly decreased with increasing inclusion of crude glycerin. Milk fat concentration and yield showed a quadratic effect of treatments. Solid yield decreased linearly with increasing inclusion of crude glycerin. Odd-chain fatty acids and conjugated linoleic acid in milk fat linearly increased with addition of crude glycerin in the diets. Together, these results suggest that crude glycerin has potential to replace corn; however, feeding diets in which corn is replaced with crude glycerin at 30% of dietary DM greatly reduces animal performance.

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.