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Sunn hemp (SH; Crotalaria juncea L.) is a fast-growing, annual, warm-season tropical legume that could complement less productive cool-season forages such as tall fescue during summer. Little is known about seasonal forage mass and nutritive value partitioning in SH plant components when SH is managed for forage. We determined partitioning of forage mass and nutritive value (crude protein (CP), in vitro true digestibility (IVTD), neutral detergent fiber (NDF), acid detergent fiber (ADF), and neutral detergent fiber digestibility (NDFD)) concentrations in SH leaves and stems harvested 35, 45, and 55 days after planting (DAP) at Bradford Research Center, Columbia, MO, in a 2-year field study. Leaf and stem mass increased with increasing DAP and was greatest ( P ≤ 0.05 ) at 55 DAP followed by 45 and 35 DAP. Stems contributed most to the total forage mass beyond 45 DAP. Across years, CP was greatest ( P ≤ 0.05 ) in leaves (281 g kg−1 DM) and lowest for stems (81 g kg−1 DM) at 55 DAP. The lowest NDF ( P ≤ 0.05 ) was observed in leaves (251 g kg−1 DM) and stems (585 g kg−1 DM) at 35 DAP. Acid detergent fiber was lowest ( P ≤ 0.05 ) for SH leaves (178 g kg−1 DM) and stems (484 g kg−1 DM) at 35 DAP. Digestibility of leaves was greater than that of stems and generally decreased with maturity. The nutritive value of leaves was consistently greater than that of stems and decreased with maturity, except for CP of leaves, which was maintained throughout the season. Results suggested that SH leaves can maintain forage mass and greater quality than its stem throughout the growing season.

How do you teach a plant-based course focused on forage physiology, production and management to an animal science student? How do you engage them and keep them engaged? Empathy. Put yourself in the shoes of the animal science student who is sitting in a plant-science course. Make it applied and relatable to the animal scientist. In this talk I will take a case-study approach to sharing my experience as an animal science student tasked with knowing something about plants and how I use that experience to guide my teaching methods in a Forages course at the University of Missouri.

An experiment was conducted to evaluate the effects of different proportions of ‘Au Grazer’ sericea lespedeza [SL, Lespedeza cuneata (Dum. Cours.) G. Don], a legume rich in condensed tannins (CT), on nutrient intake and digestibility, and to estimate methane (CH4) emissions and 13C isotopic composition (δ13CCH4) from beef steers consuming a forage-based diet. Twenty-five Angus-crossbred steers were distributed in a randomized complete block design (344 ± 48 kg initial BW), and randomly assigned to one of five treatments: 0SL, 25SL, 50SL, 75SL, and 100SL, diets containing 0%, 25%, 50%, 75%, and 100% of SL hay, respectively, mixed with ‘Tifton-85’ bermudagrass hay (Cynodon spp.). The study was carried out for two experimental periods of 21-d each. The statistical model included the fixed effect of treatment and random effects of block, experimental period, and their interaction. Apparent total tract digestibility of crude protein, neutral detergent fiber, and acid detergent fiber was linearly decreased (P < 0.001) by the inclusion of SL. No effects were observed for total CH4 emissions per day, nor for CH4 relative to organic matter intake or digestible organic matter with the inclusion of SL. However, emission of CH4 in relation to intake of CT was affected by treatment (P < 0.001). A linear (P < 0.001) decrease and a quadratic effect (P < 0.001) were observed for δ13C of diets and gas, respectively, in which diets and enteric CH4 with greater inclusion of SL were more depleted in 13C. Moreover, the difference in δ13C between diets and gas (Δδ13C) had a linear decrease (P = 0.001) with the inclusion of SL. The model developed to predict the C3 proportions in the enteric CH4 fitted to predicted values (P < 0.0001). Therefore, greater proportions of SL resulted in lesser CH4 emission when CT intake was considered and the isotopic composition from enteric CH4 was able to predict the contribution of SL in the emissions.

Low productivity and nutritive value of cool-season perennial forages, such as tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] during summer necessitates the identification of warm-season forages that improve nutritive value and yield of cool-season-based forage systems. A fast-growing, warm-season tropical legume sunn hemp (Crotalaria juncea L.) has the potential to accomplish this. Our objectives were to evaluate herbage accumulation and nutritive value (crude protein [CP], in vitro true digestibility [IVTD], neutral detergent fiber [NDF], acid detergent fiber [ADF], and NDF digestibility [NDFD, 48 h]) of sunn hemp harvested 35, 45, and 55 d after planting (DAP) at 10- and 15-cm heights and to determine regrowth potential when harvested 20 d after each initial harvest over two consecutive years. Sunn hemp herbage accumulation averaged 1.9 and 3.1 Mg ha⁻¹ at 45 and 55 DAP, respectively. Herbage accumulation of initial harvest increased linearly from 35 to 45 to 55 DAP by 119 and 57%, respectively. Herbage accumulation of regrowth after the 35 DAP initial harvest was 262 and 303% greater than the 45 and 55 DAP initial harvests, respectively. Cutting height did not affect (P > 0.05) any variables. The greatest CP (154 g kg⁻¹ dry matter) was observed at 35 DAP and decreased linearly with DAP. Both NDF (P < 0.01) and ADF (P = 0.01) concentrations increased linearly with DAP for both initial and regrowth harvests. The IVTD of initial and regrowth harvests averaged 794 and 624 g kg⁻¹ dry matter, respectively. Forage NDFD for initial and regrowth harvests averaged 487 and 392 g kg⁻¹ NDF, respectively. Nutritive value and herbage accumulation of sunn hemp can be optimized by initially harvesting between 35 and 45 DAP, and leaving at least 10 cm of residue to allow for regrowth.

Nutritional characteristics of Juniperus species are now well known and suitability as an abundant, low-cost feedstuff for ruminant animal production is a possibility. Juniperus species produce plant secondary metabolites including condensed tannins (CT) and volatile oils. Maturity of Juniperus species has been shown to affect the concentration of plant secondary metabolites produced. The objectives of this study were to determine the effects of Juniperus species (Juniperus ashei, J. monosperma, J. pinchotii and J. virginiana) and maturity on protein precipitating polyphenolic (PPP) compounds, their biological activity and relatedness of these effects to rumen digestibility characteristics. We found a species by maturity interaction for PPP (P

This review provides an update of ecologically relevant phytochemicals for ruminant production, focusing on their contribution to advancing nutrition. Phytochemicals embody a broad spectrum of chemical components that influence resource competence and biological advantage in determining plant species' distribution and density in different ecosystems. These natural compounds also often act as plant defensive chemicals against predatorial microbes, insects, and herbivores. They may modulate or exacerbate microbial transactions in the gastrointestinal tract and physiological responses in ruminant microbiomes. To harness their production-enhancing characteristics, phytochemicals have been actively researched as feed additives to manipulate ruminal fermentation and establish other phytochemoprophylactic (prevent animal diseases) and phytochemotherapeutic (treat animal diseases) roles. However, phytochemical-host interactions, the exact mechanism of action, and their effects require more profound elucidation to provide definitive recommendations for ruminant production. The majority of phytochemicals of nutritional and pharmacological interest are typically classified as flavonoids (9%), terpenoids (55%), and alkaloids (36%). Within flavonoids, polyphenolics (e.g., hydrolyzable and condensed tannins) have many benefits to ruminants, including reducing methane (CH4) emission, gastrointestinal nematode parasitism, and ruminal proteolysis. Within terpenoids, saponins and essential oils also mitigate CH4 emission, but triterpenoid saponins have rich biochemical structures with many clinical benefits in humans. The anti-methanogenic property in ruminants is variable because of the simultaneous targeting of several physiological pathways. This may explain saponin-containing forages' relative safety for long-term use and describe associated molecular interactions on all ruminant metabolism phases. Alkaloids are N-containing compounds with vast pharmacological properties currently used to treat humans, but their phytochemical usage as feed additives in ruminants has yet to be exploited as they may act as ghost compounds alongside other phytochemicals of known importance. We discussed strategic recommendations for phytochemicals to support sustainable ruminant production, such as replacements for antibiotics and anthelmintics. Topics that merit further examination are discussed and include the role of fresh forages vis-à-vis processed feeds in confined ruminant operations. Applications and benefits of phytochemicals to humankind are yet to be fully understood or utilized. Scientific explorations have provided promising results, pending thorough vetting before primetime use, such that academic and commercial interests in the technology are fully adopted.

Achieving high animal productivity without degrading the environment is the primary target in pasture-based dairy farming. This study investigated the effects of changing the forage base in spring from grass-clover pastures to forb or legume-based pastures on milk yield, N utilization, and methane emissions of Jersey cows in Western Oregon. Twenty-seven mid-lactation dairy cows were randomly assigned to one of three pasture treatments: grass-clover-based pasture composed of festulolium, tall fescue, orchardgrass, and white clover (Grass); forb-based pasture composed of chicory, plantain, and white clover (Forb); and legume-based pasture composed of red clover, bird’s-foot trefoil, berseem clover, and balansa clover (Legume). Pastures were arranged in a randomized complete block design with three replicates (i.e., blocks) with each replicate grazed by a group of three cows. Production and nutritive quality of the forages, animal performance, milk components, nitrogen partitioning, and methane emissions were measured. Feed quality and dry matter intake (DMI) of cows were greater (P ≤ 0.05) for Legume and Forb vs. Grass, with consequent greater milk and milk solids yields (P < 0.01). Cows grazing Forb also had more (P < 0.01) lactose and linoleic acid in milk compared with cows grazing the other pastures, and less (P = 0.04) somatic cell counts compared with Grass. Cows grazing Forb had substantially less (P < 0.01) N in urine, milk, and blood compared with cows grazing the other pastures, with not only a greater (P < 0.01) efficiency of N utilization for milk synthesis calculated using milk urea nitrogen but also a larger (P < 0.01) fecal N content, indicating a shift of N from urine to feces. Both Forb and Legume had a diuretic effect on cows, as indicated by the lower (P < 0.01) creatinine concentration in urine compared with Grass. Methane emissions tended to be less (P = 0.07) in cows grazed on Forb vs. the other pastures. The results indicate that Forb pasture can support animal performance, milk quality, and health comparable to Legume pasture; however, Forb pasture provides the additional benefit of reduced environmental impact of pasture-based dairy production.

Semiarid rangeland plays an important multifunctional agricultural system and plant nutritive value can vary according to soil and climate conditions, and land use such as grazing pressure. This study investigated the impact of four forage allowances (2, 2.5, 3 and 3.5 kg dry matter per kg body weight) on condensed tannin biological activity and nutritional value of Bauhinia cheilantha (Bong) Steud.). The experiment was conducted in a manipulated shrub-tree tropical rangeland under sheep grazing in a two-year field trial, during the rainy season. Forage allowance and time influenced condensed tannin biological activity and nutritional value. B. cheilantha with up to 167 g kg−1 condensed tannins inhibited up to 38.3% rumen methane, indicating possible sheep metabolizable energy intake increases and also reduced up to 29% larval motility, which may reduce gastrointestinal parasite infections. B. cheilantha nutritional values vary over years and have a negative relationship with forage allowance. Forage allowance can be manipulated depending on management goals as forage or environmental mitigation. Low forage allowance promotes great condensed tannins which impacts on great larval motility and less methane production, but great nutritive value. The findings suggest that the legume B. cheilantha can contribute to meeting the nutritional requirements of ruminants.

Optimizing mineral supplementation is critical to maximizing production in a forage-based beef production system. The effect of nitrogen fertilization on mineral accumulation in tall fescue (TF) is not well understood. We evaluated the differences in mineral composition in nitrogen fertilized (TF+N) and unfertilized (TF-N) tall fescue pastures. The experiment was conducted at the University of Missouri Forage Systems Research Center during 2017 and 2018. A randomized complete block design was arranged in novel-endophyte TF pastures. All pastures were mechanically harvested in May. Nitrogen was applied to TF+N in June and again in August (45 kg ha-1 and 90 kg ha-1, respectively). Treatments were rotationally grazed from July to November using yearling cattle. Randomly selected 10 m2 strips were harvested biweekly and 300 g subsamples were dried. Nitric acid digestion was performed followed by ICP-MS to determine mineral content. Data were normalized using rank transformation and analyzed by treatment and month. Analysis of variance was conducted using PROC GLIMMIX (SAS 9.4); slice command was used to determine interactions within month by treatment and within treatment by month. Calcium and magnesium concentration decreased throughout the season with the lowest concentrations observed in both treatments during November (P = 0.0043 and P = 0.0007, respectively). Greater potassium concentrations were observed in June compared to November in both treatments (P < 0.0334). We observed a within month by treatment interaction for sodium. Nitrogen fertilization resulted in greater sodium concentration in all months from August to November compared to TF-N (P < 0.0074). Greater sodium concentrations resulted in decreased K:Na ratios during September, October, and November in TF+N (P = 0.0013, P = 0.0036, and P = 0.0024, respectively). Our results suggest nitrogen fertilization reduced K:Na ratio in TF pastures, which could negatively affect magnesium absorption in recticulo-rumen.

Tannins represent one of the most abundant polyphenolic compounds in plants. Tannins exist as a multitude of chemically unique entities in nature. The most commonly occurring tannins are typically divided into two major classes based on chemical structure: hydrolysable (HT) or condensed tannins (CT). Hydrolysable tannins are esters of gallic or ellagic acid linked to a polyol core, typically glucose. Condensed tannins or proanthocyanidins consist of flavan-3-ol subunits linked together to form oligomers and polymers. Both HT and CT are defined as astringent, medium-to-high-molecular weight polyphenolic compounds that characteristically bind and precipitate soluble proteins. The objective of this paper was to present recent advances in CT-ruminant interactions, the limitations associated with understanding and using CT in ruminant animal production, and future needs for research to further advance our knowledge of the role of CT in optimization of ruminant animal production. Condensed tannins pose some anti-nutritional problems to ruminants due to their astringent property that reduces feed intake and, consequently, animal performance. Ruminants can, however, tolerate CT by slowly adapting the ruminal microbes to the toxic effects of CT and by releasing CT-binding salivary proteins. The protein-binding ability of CT has some benefits to the ruminant due to complexes formed with essential amino acids, preventing their degradation in the rumen, but releasing them in the lower gut for absorption by the animal. Recent data have suggested increased N retention when CT is given to growing animals. There are potential benefits of using CT and HT for anthelmintic purposes due to their ability to inhibit egg hatching and larval motility of gastrointestinal nematode parasites, especially in small ruminants. Condensed tannins also bind to minerals (Al, Ca, Co, Cu, Fe, Mg, Mn, P, and Zn). Although studies with ruminants have been contradictory, it has been reported that because the CT-metal ion complex is stable over a wide pH range, CT may reduce the bioavailability of minerals. Methane mitigation by feeding CT might be the most impactful benefit for ruminant production. Many empirical equations have been developed to predict ruminal methane emissions, but very few have included CT. Future research should focus on the improvement of methodology to assess CT biological activity, interaction with other plant-specialized metabolites, and associated physiological and nutritional impacts on ruminants.

This study evaluates the sanitizing effectiveness of applying, by spraying or dipping, 1.5 or 3.0% acetic acid at either 25°C or 55°C to freshly slaughtered lamb carcasses. After vacuum packaging and during extended storage at 0°C, samples were examined for microbial populations. Each treatment reduced counts significantly compared with counts of untreated controls. Numbers of gram negative bacteria and lactobacilli were affected significantly by the temperature of acid solutions. Other variables caused insignificant differences in the amounts that counts were reduced by sanitization. Overall, dipping in 3% acetic acid at 55°C was the most effective treatment.

Two tests were developed for detecting protein on food contact surfaces. Wetted swabs rubbed over surfaces on which 3 μg of protein was dried became visibly blue when reacted with Folin's test reagents. Wetted Chemstrips, available to test for protein in urine, became visibly colored on rubbing on surfaces with 0.25 μg of protein. Sensitivity of the tests varied with type of protein.

Two wholesale cuts, the silverside ( M biceps femoris ) and bolo, (outside round and clod) from 8 steers were used in this study. Four steers were artificially stressed and the right side of all carcasses was electrically stimulated. Primals were cut into 3 equal portions after 72 h post slaughter, chilling at approximately 4°C, and were vacuum packaged. No microbial differences (P>0.05) were found between primals within treatments. Primals from stressed carcasses had higher pH values (P

The bacteriology of boneless pork loins that were either spray-washed (SW) with water, spray-washed and sanitized with a 200 ppm sodium hypochlorite solution (SSCL) or spray-washed with water and sanitized with a 2% acetic acid solution (SSAA) before being vacuum packaged and stored for up to 28 d at 4.0°C was studied. Aerobic, anaerobic and lactobacilli bacterial counts immediately after treatment and at 14, 21 and 28 d were significantly lower on loins receiving the SSAA treatment than loins receiving the SW and SSCL treatment. SSCL loins had lower bacterial counts than untreated controls during 14 d of storage. SW loins had significantly lower bacterial counts than control loins only immediately after treatment. The SSAA treatment resulted in some discoloration. If this discoloration can be prevented, this treatment should be useful in extending the storage life of fresh pork.

Beef was stored aerobically for 2 or 6 d at 1 ± 1°C before vacuum packaging. Total numbers of aerobic bacteria, Pseudomonas spp., Brochothrix thermosphacta and lactic acid bacteria were determined by selectively plating stored samples. Meat color was evaluated with a color difference meter and a color panel. Aerobic plate counts, numbers of pseudomonads and B. thermosphacta , and pH each were higher in samples held aerobically for 6 d compared with those held aerobically for 2 d. The major effect of delayed vacuum packaging was to slow the growth of lactic acid bacteria and minimize the number of pseudomonads. The variation among treatments was similar in Pseudomonas spp. population for 21 d and in pH for 7 d, and there was no significant effect of packaging treatment in color. Results indicate that the initial treatment variations were lost as storage time progressed.

An experimental cleaning and sanitizing unit was used in cleaning and sanitizing (3.0% acetic acid) beef carcasses. It cleaned the carcasses sufficiently that they would pass the Acceptable Quality Level test of the Food Safety and Quality Service, U.S. Department of Agriculture. The sanitizing unit reduced the microbial population on the surface of the meat by an initial 1.49 logs; the difference between washed and washed and sanitized carcasses after 1 week (168 h) was 0.92 log. A slight gray cast developed within the top 1 mm of fat almost immediately after the acid was applied. Sensory panel members detected no adverse effects on the lean portion of steaks from sanitized carcasses. However, they detected a slight off-flavor in treated fat.

Plate beef was washed and/or sanitized with cold water, hot water, steam, sodium hypochlorite, or acetic acid before being stored for up to 28 days at 3.3 C and 90% relative humidity. Microbial counts initially and at regular intervals thereafter disclosed that, compared with untreated controls, time to reach counts of 108 bacteria per cm2 were (a) 1 day less with steam- or water-treated samples, (b) 2 to 3 days more with hypochlorite-treated samples, (c) 5 days more with hot-water-treated samples, and (d) 16 to 17 days more with acetic acid-treated samples. Re-sanitization with acetic acid extended time to reach equivalent counts by 7 additional days.

Strips of plate meat were sprayed with acetic acid, sodium hypochlorite, or tap water after they were washed with 0, 12.7, or 25.4 liters of tap water/min. Washing before sanitizing lowered bacteria counts significantly only when the higher volume of water, 1.4 ml/cm2, was applied, and this difference existed for samples taken immediately but not 48 h after treatment. Reductions in counts exceeded 99.9% when samples washed with 25.4 liters/min (1.4 ml/cm2) were sanitized with 3% acetic acid. This sanitizer was sprayed at the rate of 6.8 liters/min (1.9 ml/cm2) at a pressure of 14.0 kg/cm2 from a distance of 40 cm as the meat moved at 2 cm/sec through the spray. Under comparable conditions of application, both sodium hypochlorite (200 to 250 mg/liter) and tap water reduced counts by about 90%. Acetic acid had a much greater residual effect on numbers of viable bacteria than did hypochlorite. No effect of air drying was observed.

Summary The domestic horse is used as a nutritional model for rhinoceros maintained under human care. The validity of this model for browsing rhinoceros has been questioned due to high prevalence of iron overload disorder (IOD) in captive black rhinoceros (Diceros bicornis), which is associated with high morbidity and mortality. Iron chelators, such as tannins, are under investigation as dietary supplements to ameliorate or prevent IOD in prone species. Polyphenolic compounds variably affect microbial fermentation, so the first objective of this experiment was to evaluate the effects of grape seed extract (GSE; a concentrated source of condensed tannins; CT) on black rhinoceros hindgut fermentation. Equine nutrition knowledge is used to assess supplements for rhinoceros; therefore, the second objective was to evaluate the domestic horse model for black rhinoceros fermentation and compare fermentation responses to GSE using a continuous single-flow in vitro culture system. Two replicated continuous culture experiments were conducted using horse and black rhinoceros faeces as inoculum sources comparing four diets with increasing GSE inclusion (0.0%, 1.3%, 2.7% and 4.0% of diet dry matter). Diet and GSE polyphenolic compositions were determined, and sodium sulphite effect on neutral detergent fibre extraction of CT-containing forages was tested. Increasing GSE inclusion stimulated microbial growth and fermentation, and proportionally increased diet CT concentration and iron-binding capacity. Horse and black rhinoceros hindgut microflora nutrient digestibility and fermentation responses to GSE did not differ, and results supported equine fermentation as an adequate model for microbial fermentation in the black rhinoceros. Interpretation of these results is limited to hindgut fermentation and further research is needed to compare foregut digestibility and nutrient absorption between these two species. Supplementation of GSE in black rhinoceros diets up to 4% is unlikely to adversely affect hindgut nutrient digestibility or microbial viability and fermentation.

Trees that maintain some leaves throughout dry seasons become important ruminant browse depending on nutritive and antinutritive values. Leaves from seven tree species that maintained some leaves during the dry season were collected during dry and wet seasons and analysed for nutritive and antinutritive values. Neutral detergent fibre of leaves was either not different or less (P ≤ 0.05) during the dry season as compared to the wet season depending on species. Acid detergent fibre was either not different or greater (P ≤ 0.05) during the dry season as compared to the wet season. Crude protein and condensed tannins (CT) were either not different or less (P ≤ 0.05) during the dry season than during the wet season for the seven species. The biological activity (protein-binding ability; PB) of the CT was highly species specific and was either not different between seasons, more bioactive during the wet season, or more bioactive during the dry season depending on the species. Based on combinations of low fibre, high protein and potentially beneficial levels of bioactive CT, Senegalia caffra, Vachellia karoo and Searsia lancea may be the most promising dry-season browse of the species studied.

The objective of this experiment was to evaluate mesquite extract as a phytogenic additive or supplementation for improving nutrient digestibility, carcass traits, physical composition, and meat quality in finished sheep on rangeland. The experiment was conducted in a Caatinga rangeland composed of herbaceous, shrub, and tree species. Santa Ines × Dorper F1 crossbred lambs (n=24) were used, with an average initial body weight of 23.1 ± 1.83 kg. A completely randomized design with a 2 × 2 factorial arrangement of supplementation and phytogenic additive was used. Lambs had access to pasture with Caatinga vegetation from 07:00h to 17:00h and then were collected and kept in individual pens. Treatments consisted of four diets: supplementation (non-supplemented or supplemented) and phytogenic additive (not administered or administered). Supplementation consisted of Tifton 85 hay, corn meal, soybean meal and mineral salt offered at 1% of body weight. The additive consisted of 600 mg/mL mesquite pods (Prosopis juliflora (Sw.) DC) provided orally (6 mL/day) to each group receiving the additive. The additive was prepared and administered fresh each day of the feeding period. The phytogenic additive and supplementation increased nutrient digestibility, carcass weight, performance, commercial cuts, external carcass measurements, leg weight, and femoral muscles (p 0.05) for meat quality parameters. Administration of a phytogenic additive or supplementation are recommended to improve nutrient digestibility, carcass weight, animal performance, commercial cuts, external carcass measurements, leg weight, and femoral muscles in Santa Ines × Dorper F1 crossbred sheep finished on rangeland.

Interest in the condensed tannin-containing legume sericea lespedeza (Lespedeza cuneata) as a nutraceutical (bioactive) forage for livestock has been increasing in the United States but other Lespedeza species have not been adequately evaluated. A study was completed to determine the nutritional and bioactivity potential of Lespedeza species obtained from the USDA Plant Genetic Resources Conservation Unit in Griffin, GA. Accessions from 15 Lespedeza species were planted in small plots at Fort Valley State University in Fort Valley, GA. After establishment, forage was harvested, freeze-dried, ground and analyzed for neutral detergent fiber (NDF), acid detergent fiber (ADF), in vitro true digestibility (IVTD), total phenolics (TP), and protein precipitable phenolics (PPP). Species differences were significant (P < 0.01) for all parameters measured. Lespedeza cuneata accessions, including “AUGrazer,” the cultivar most commonly used as an anti-parasitic crop in the United States had NDF, ADF, and IVTD values of 35.7±0.4%, 26.8±0.4%, and 74.3±1.2%, while L. virginica, a native species, had 34.9±3.0%, 26.0±2.5%, and 74.9±4.2%, respectively. The L. cuneata accessions averaged 179.6±4.3 and 133.6±3.5 mg/g of forage material for TP and PPP, while L. virginica averaged 564.2±24.6 and 306.5±19.9 mg/g, respectively. Other species varied from 30.5±3.0 to 47.4±4.2% NDF, 22.9±1.6 to 36.4±3.6% ADF, 55.2±5.9 to 81.6±3.4% IVTD, and 107.7±17.4 to 283.5±34.7 and 55.2±14.0 to 139.4±28.1 mg/g of forage for TP and PPP, respectively. Based upon these results, Lespedeza species tested in this study, particularly L. virginica, have potential as nutraceutical forages for livestock production systems. As L. cuneata accessions established and grew much better than other Lespedeza species in this study, agronomic testing of this germplasm collection in other environments is warranted. In addition, determining potential anti-parasitic properties of these species using in vitro and in vivo testing would be beneficial.

Methane (CH) is a potent greenhouse gas that is normally produced by microbial fermentation in the rumen and released to the environment mainly during eructation. Prediction of ruminal CH production is important for ruminant nutrition, especially for the determination of ME intake to assess the amount of total GE available for metabolism by an animal. Equations have been developed to predict ruminal CH production based on dietary constituents, but none have considered condensed tannins (CT), which are known to impact CH production by ruminants. The objective was to develop an equation to predict ruminal CH, accounting for CT effects. Methane production data were acquired from 48-h in vitro fermentation of a diverse group of warm-season perennial forage legumes containing different concentrations of CT over the course of 3 yr ( = 113). The following nonlinear exponential decay regression equation was developed: CH₄ = 113.6 × exp (-0.1751 x CT) - 2.18), [corrected] in which CH is expressed in grams per kilogram of fermentable organic matter and CT is in percentage of the DM. This equation predicted that CH production could be reduced by approximately 50% when CT is 3.9% DM. This equation is likely more accurate when screening CT-containing forages for their potential ability to mitigate in vitro CH production by ruminants when the CT concentration is greater than 3% DM. Therefore, despite the degree of variability in ruminal CH production, this equation could be used as a tool for screening CT-containing forages for their potential to inhibit ruminal CH. Future research should focus on the development of predictive equations when other potential reducers of ruminal CH are used in conjunction with CT.

Rising feed costs and recurring feed shortages necessitate the investigation into alternative and underutilized feed resources. Nutritional characteristics of species are either unknown or limited to leaves and ground material from small stems. Therefore, the objective was to quantify nutritional characteristics, 48-h true IVDMD (tIVDMD), microbial gas production, and secondary compound characteristics of entire woody plant material of 4 species-, , , and -at immature and mature stages of growth. Immature plants had greater CP concentrations and lower NDF concentrations ( < 0.001) than mature plants regardless of species. Mature plants also had greater ( < 0.001) concentrations of ADF compared with immature plants with the exception of . In general, immature , , and had greater ( < 0.02) tIVDMD and total 48-h and asymptotic gas production than mature plants. Immature and plants were more digested (tIVDMD; < 0.001) than immature and , but tIVDMD did not differ in mature plant material across species. Condensed tannins (CT) were greater ( < 0.001) in immature and than mature plants; differences in CT concentrations among immature species were also detected ( < 0.04). Volatile oil yields were similar across maturity and species with 1 exception: immature yielded more ( < 0.02) volatile oil than mature material. Volatile oil composition across species varied and contained a range of 65 to 70 terpene compounds. The dominant terpenes across species were generally greater ( < 0.05) in immature vs. mature plant material with the exception of . Labdane acids were negligible in , , and and greater in ( < 0.001). Ground material from mature juniper species, although inferior in nutritional quality compared with immature plants, is comparable to traditional low-quality roughage ingredients. Given that has been successfully fed in lamb feedlot diets, the similarities of , and suggest that all three species have potential to be effective roughage ingredients.

The objective of this research was to evaluate effects of replacing sorghum × Sudangrass hay with ground juniper in gestating ewe supplements on pre- and postpartum growth performance, serum metabolites and hormonal concentrations, milk fatty acid composition, and progeny preweaning performance. In a completely randomized design, commercial Rambouillet ewes (age = 3 to 5 yr; initial BW = 65.2 ± 1.6 kg) on a base diet of long-stem sorghum × Sudangrass hay were assigned to 1 of 4 dietary supplements in which ground juniper replaced 0% (CNTL), 33% (18JUN), 66% (36JUN), or 100% (54JUN) of the ground sorghum × Sudangrass hay in a pelleted supplement with ground juniper from d 38 ± 4 of gestation to 2 d postpartum. Treatment DM diet intake overall (g/kg BW) in ewes receiving no juniper was similar ( ≥ 0.38) to that of those receiving increasing concentrations of juniper. Changes in ewe BW and BCS were similar ( ≥ 0.24) in ewes throughout gestation. All serum metabolites and hormones were within normal clinical ranges; however, serum IGF-1 decreased linearly ( = 0.003), alanine increased (linear; = 0.003), and serum Na decreased (linear; = 0.049) as the percentage of juniper increased in the diet. Ewe milk fatty acid composition was similar (0.05) for the majority of fatty acids across treatment groups, with the exception of arachidonic acid (C20:4n6) being greater (0.02) in 54JUN vs. CNTL ewe milk. Lamb birth weights were similar ( = 0.13), whereas lamb ADG tended to differ (quadratic; = 0.06) from d 0 to 14, with 18JUN being the least. At weaning, BW tended ( = 0.09) to linearly decrease in lambs born to ewes consuming greater concentrations of juniper but were not different ( = 0.26) between CNTL and 18JUN, 36JUN, and 54JUN. Results indicated that feeding increasing levels of ground juniper in supplements did not negatively alter ewe performance or serum metabolites and hormones measured pre- and postpartum. Lamb birth weight and preweaning performance appeared unaffected by maternal consumption of ground juniper containing supplements. Results also provide novel information regarding the effects of plant secondary compound consumption throughout pregnancy on ewe and progeny performance and health.

A study was conducted to determine how total phenolic (TP), protein precipitable phenolic (PPP), C, and N concentrations, and amount of protein bound (PB) by PPP in leaves of Desmodium paniculatum (panicled tick-clover; PTC) and Lespedeza cuneata (sericea lespedeza; SL) were affected by simulated herbivory and plant ontogeny. All PTC treatments resulted in a decrease (P ≤ 0.05) in TP, PPP, C, and N concentrations and PB between vegetative and seed set stages. All SL treatments resulted in increased (P ≤ 0.05) or stable TP and PPP concentrations from vegetative stage to seed set. The amount of PB was greatest (P ≤ 0.05) in SL plants submitted to 25% defoliation, and flowering and seed set stages had greater (P ≤ 0.05) PB than the vegetative stage. Ontogenesis and defoliation did not (P > 0.05) affect SL N and C concentrations. The protein binding characteristics of PPP from PTC, but not that of SL, appear to be altered in response to stress. Results might correspond with seed dispersal strategies of the tw...

The objectives of the present study were to determine if the molecular weight of condensed tannins (CT) from warm-season perennial legumes affects the biological activity of CT relative to suppression of methane (CH4) production by ruminants, and to identify potential North American native forage plants to use for mitigation of enteric CH4 emission. Eight North American native warm-season perennial legumes were evaluated: Leucaena retusa Benth. (littleleaf leadtree), Desmanthus illinoensis (Michx.) MacMill. Ex B.L. Rob. & Fernald (Illinois bundleflower), Lespedeza stuevei Nutt. (tall lespedeza), Mimosa strigillosa Torr. & A. Gray (powderpuff), Neptunia lutea (Leavenworth) Benth. (yellow puff), two ecotypes of Acacia angustissima var. hirta (Nutt.) B.L. Rob (prairie acacia), and Desmodium paniculatum (L.) DC. var. paniculatum (panicledleaf ticktrefoil). Two introduced legumes were also included: Arachis glabrata Benth. (rhizoma peanut) and Lespedeza cuneata (Dum. Cours.) G. Don (sericea lespedeza). Forages were fermented with cattle rumen fluid for 48 h anaerobically using an in vitro gas production technique. D. paniculatum, L. stuevei, and M. strigillosa were high in CT, ranging from 11.7 to 12.5%. D. illinoensis, L. cuneata, N. lutea, and two ecotypes of A. angustissima var. hirta had less CT (P

The beneficial effects of forages containing condensed tannins (CTs) on ruminants are well documented, but the chemical features of CT that yield benefits have not been defined. Some evaluations of limited numbers of highly purified compounds have resulted in positive correlations between CT molecular weight (MW) and biological activity, while others have failed to show a correlation. The objectives of this study were to determine if MW of CT could predict biological activity relative to protein precipitability. MW of condensed tannin, protein-precipitable phenolics (PPP), and the amount of protein bound (PB) were determined for nine species of warm-season perennial legumes. There was no correlation between PPP or PB and MW (R2 0.11 and R2 0.02, respectively). However, CT concentration did correlate with PPP and PB (R2 0.81 and R2 0.69, respectively). It was concluded that CT MW does not explain the variation in protein precipitation by CT from the forage legumes surveyed.

Methane (CH) is a potent greenhouse gas that is normally produced by microbial fermentation in the rumen and released to the environment mainly during eructation. Prediction of ruminal CH production is important for ruminant nutrition, especially for the determination of ME intake to assess the amount of total GE available for metabolism by an animal. Equations have been developed to predict ruminal CH production based on dietary constituents, but none have considered condensed tannins (CT), which are known to impact CH production by ruminants. The objective was to develop an equation to predict ruminal CH, accounting for CT effects. Methane production data were acquired from 48-h in vitro fermentation of a diverse group of warm-season perennial forage legumes containing different concentrations of CT over the course of 3 yr ( = 113). The following nonlinear exponential decay regression equation was developed: CH₄ = 113.6 × exp (-0.1751 x CT) - 2.18), [corrected] in which CH is expressed in grams per kilogram of fermentable organic matter and CT is in percentage of the DM. This equation predicted that CH production could be reduced by approximately 50% when CT is 3.9% DM. This equation is likely more accurate when screening CT-containing forages for their potential ability to mitigate in vitro CH production by ruminants when the CT concentration is greater than 3% DM. Therefore, despite the degree of variability in ruminal CH production, this equation could be used as a tool for screening CT-containing forages for their potential to inhibit ruminal CH. Future research should focus on the development of predictive equations when other potential reducers of ruminal CH are used in conjunction with CT.

Previous studies showed that a series of purified condensed tannins (CTs) from warm-season perennial legumes exhibited high variability in their modulation of methane production during in vitro rumen digestion. The molecular weight differences between these CTs did not provide correlation with either the in vitro CH4 production or the ability to precipitate bovine serum albumin. In an effort to delineate other structure-activity relationships from these methane abatement experiments, the structures of purified CTs from these legumes were assessed with a combination of methanolysis, quantitative thiolysis, 1H-13C HSQC NMR spectroscopy and ultrahigh-resolution MALDI-TOF MS. The composition of these CTs is very diverse: procyanidin/prodelphinidin (PC/PD) ratios ranged from 98/2 to 2/98, cis/trans ratios ranged from 98/2 to 34/66, mean degrees of polymerization ranged from 6 to 39, and % galloylation ranged from 0 to 75%. No strong correlation was observed between methane production and the protein precipitation capabilities of the CT towards three different proteins (BSA, lysozyme, and alfalfa leaf protein) at ruminal pH. However, a strong non-linear correlation was observed for the inhibition of methane production versus the antioxidant activity in plant sample containing typical PC- and PD-type CTs. The modulation of methane production could not be correlated to the CT structure (PC/PD or cis/trans ratios and extent of galloylation). The most active plant in methane abatement was Acacia angustissima, which contained CT, presenting an unusual challenge as it was resistant to standard thiolytic degradation conditions and exhibited an atypical set of cross-peak signals in the 2D NMR. The MALDI analysis supported a 5-deoxy flavan-3-ol-based structure for the CT from this plant.

The objective of this research was to evaluate effects of replacing sorghum × Sudangrass hay with ground juniper in gestating ewe supplements on pre- and postpartum growth performance, serum metabolites and hormonal concentrations, milk fatty acid composition, and progeny preweaning performance. In a completely randomized design, commercial Rambouillet ewes (age = 3 to 5 yr; initial BW = 65.2 ± 1.6 kg) on a base diet of long-stem sorghum × Sudangrass hay were assigned to 1 of 4 dietary supplements in which ground juniper replaced 0% (CNTL), 33% (18JUN), 66% (36JUN), or 100% (54JUN) of the ground sorghum × Sudangrass hay in a pelleted supplement with ground juniper from d 38 ± 4 of gestation to 2 d postpartum. Treatment DM diet intake overall (g/kg BW) in ewes receiving no juniper was similar ( ≥ 0.38) to that of those receiving increasing concentrations of juniper. Changes in ewe BW and BCS were similar ( ≥ 0.24) in ewes throughout gestation. All serum metabolites and hormones were within normal clinical ranges; however, serum IGF-1 decreased linearly ( = 0.003), alanine increased (linear; = 0.003), and serum Na decreased (linear; = 0.049) as the percentage of juniper increased in the diet. Ewe milk fatty acid composition was similar ( > 0.05) for the majority of fatty acids across treatment groups, with the exception of arachidonic acid (C20:4n6) being greater ( < 0.02) in 54JUN vs. CNTL ewe milk. Lamb birth weights were similar ( = 0.13), whereas lamb ADG tended to differ (quadratic; = 0.06) from d 0 to 14, with 18JUN being the least. At weaning, BW tended ( = 0.09) to linearly decrease in lambs born to ewes consuming greater concentrations of juniper but were not different ( = 0.26) between CNTL and 18JUN, 36JUN, and 54JUN. Results indicated that feeding increasing levels of ground juniper in supplements did not negatively alter ewe performance or serum metabolites and hormones measured pre- and postpartum. Lamb birth weight and preweaning performance appeared unaffected by maternal consumption of ground juniper containing supplements. Results also provide novel information regarding the effects of plant secondary compound consumption throughout pregnancy on ewe and progeny performance and health.

Methane emissions from ruminant livestock contribute to total anthropogenic greenhouse gas emissions and reduce metabolizable energy intake by the animal. Condensed tannins (CT) are polyphenolic plant secondary compounds commonly produced by some perennial forage legumes that characteristically bind to protein, carbohydrates, and minerals. The degree to which CT may affect ruminant nutrition depends upon the concentration, structural composition, and biological activity of the CT. The objective of our experiment was to determine the effect of replacing alfalfa in a corn-alfalfa-based substrate with a legume containing CT on in vitro CH4 production and the dynamics of fermentation using an in vitro gas production technique. All fermented substrates contained 50% ground corn as the energy concentrate portion, whereas the forage portion (50%) of each diet was comprised of alfalfa (control) or some combination of alfalfa and sericea lespedeza (SL) or panicled-tick clover (PTC). Our treatments consisted of PTC or SL 15, 30, and 45, which corresponded with 15, 30, or 45% replacement of the diet (alfalfa component) with either PTC or SL. Substrates containing 45% PTC or SL reduced in vitro CH4 production. Treatments did not affect total gas production as compared with that of the control. Replacement of alfalfa with SL or PTC increased fermentable organic matter (FOM). The PTC treatment increased FOM by as much as 1.8% at the 45% replacement level, whereas FOM of SL 45 was increased by less than 1%. The replacement of alfalfa with PTC increased substrate nutritive value greater than replacement with SL. There were no correlations between any physicochemical constituent of the substrates and CH4 production. A combination of factors associated with the inclusion of PTC and SL contributed to the in vitro CH4 production, and CT in these forages was likely a major contributing factor. Further confirmation of these results on in situ or in vivo animal systems is required. If proven effective in an in vivo production scenario, replacement of commonly fed non-CT-containing legumes, such as alfalfa, with legumes containing CT might be a viable method to decrease the effect of animal agriculture on greenhouse gas production.

The effect of molecular weight of condensed tannins (CT) from a variety of warm-season perennial legumes commonly consumed by sheep and goats on anthelmintic activity has not been previously explored. The objectives of this study were to determine if molecular weight of CT from warm-season perennial legumes could predict the biological activity of CT relative to anthelmintic activity against ivermectin resistant L3 stage Haemonchus contortus (HC) using a larval migration inhibition (LMI) assay. A second objective was to determine if CT from warm-season perennial legumes possess anthelmintic properties against L3 stage (HC). Lespedeza stuevei had the greatest concentration of total condensed tannin (TCT; 11.7%), whereas, with the exception of Arachis glabrata, a CT-free negative control, Leucaena retusa had the least TCT (3.3%). Weight-average molecular weight of CT ranged from 552 Da for L. stuevei to 1483 Da for Lespedeza cuneata. The treatments demonstrating the greatest percent LMI were L. retusa, L. stuevei and Acacia angustissima var. hirta (65.4%, 63.1% and 42.2%, respectively). The ivermectin treatment had the smallest percent LMI (12.5%) against ivermectin resistant L3 HC. There was a weak correlation (R(2)=0.34; P=0.05) between CT MW and percent LMI, suggesting that molecular weight of CT is a weak contributing factor to CT biological activity as it relates to LMI of L3 stage HC. L. stuevei, L. retusa and A. angustissima var. hirta STP5 warrant further evaluation of anthelmintic properties in vivo.

Enteric methane (CH4) emissions by ruminants represent a decrease in energy availability to the animal. Forages containing condensed tannins (CT) may suppress enteric CH4 emissions and bind to proteins, allowing protein to escape microbial degradation in the rumen resulting in ruminal bypass protein. Objectives of this study were to evaluate the ability of CT from warm-season perennial legumes commonly consumed by ruminants to suppress CH4 emissions and bind to protein, and to assess the potential use of these forages in sustainable ruminant production systems.

Endocellular enzymes from Pseudomonas fragi (ATCC 4973) had a significant (P < 0.05) effect on the color of sterile beef and sterile aqueous beef extract stored at 21°C and 4°C. There was no evidence of protein degradation or lipid oxidation in samples treated with endocellular enzymes. Our findings indicate that glucose oxidase present in the endocellular enzyme preparations from P. fragi may be an important factor in causing oxidation of the meat pigment oxymyoglobin to metmyoglobin.

Extracellular protease and lipase from Pseudomonas fragi significantly (P < 0.05) decreased color stability of sterile beef at 4°C and sterile beef extract at 4°C and 21°C. Concentrations of free fatty acids (FFA) in enzyme-treated sterile beef samples were significantly (P < 0.05) higher than in sterile controls held at 4°C indicating hydrolysis of glycerides by lipase from P. fragi. Concentrations of nonprotein nitrogen (NPN) and free amino acids in sterile beef extract treated with extracellular enzyme and held at 4°C and 21°C were significantly (P < 0.05) higher than in controls indicating proteolysis by protease from P. fragi. This was confirmed by SDS-polyacrylamide gel electrophoresis of enzyme-treated beef extract stored at 4°C for 6 days. Sephadex G-100 gel filtration and poly-acrylamide disc electrophoresis indicated that the molecular size and electrophoretic mobility of the protease and lipase were similar.

Acetic acid (4%) solution reduced significantly (P < 0.05) the microbial load on the surface of the beef short loins. Steaks cut from spray sanitized loins had significantly (P < 0.05) lower microbial counts than steaks from control loins. Statistical analysis revealed that the acetic acid spray sanitation did not adversely affect color desirability, color score of the prepackaged beef steaks or cause any discoloration. Hence, this could be employed under normal processing conditions to reduce the surface contamination and to retard microbial growth on the surface of steaks cut from beef short loins. Gaseous atmosphere containing 15% CO2 plus 85% O2 was significantly (P < 0.05) effective in controlling the growth of microogranisms on the surface of the prepackaged beef steaks and in maintaining the desirable bright red color of fresh prepackaged beef steaks for at least 20 days.

Growth of Pseudomonas fragi had a significant (P > 0.05) effect on the color of beef stored at 1°± 1°C. Beef color was measured with a Hunter Color/Difference Meter and percentages of myoglobin (Mb), oxymyoglobin (O2 Mb), and metmyoglobin (MMb) on meat surfaces were determined using a Beckman DU Spectrophotometer with a reflectance attachment. As surface growth of P. fragi increased from log 2.2 to 7.2/cm2 during 20 days storage at 1°± l°C, the pH increased from 5.5 to 6.6, free fatty acid values (FFA) increased from 0.62 to 2.60 and percent O2 Mb decreased from 100% to 0%. Data indicated that proteolytic and lipolytic degradation products of P. fragi may be important in decreasing the color stability of beef stored at 1°± 1°C.

Efficacies and optimum application conditions of three sanitizers (chlorine, 200–250 ppm; acetic acid, 4.0%; and quaternary ammonium, 3.78 g/liter) were determined. Variables were three rates of flow of sanitizer (1.7, 3.4 and 6.8 liters/min), washed and unwashed meat, warm (38°C) and cold meat (3.3°C), and two pressures of sanitizer application (3.5 and 14.0 kg/cm2). Results were averaged over other variables providing the following data for individual variables. Acetic acid gave a high initial average decrease in counts (−1.47 log), and counts decreased (−1.79 log) up to 48 hr after sanitization. Chlorinated solution caused an initial mean difference of −0.31 log and a difference after 48 hr of 0.53. The quaternary ammonium compound produced differences of −0.79 and −0.03 log in immediate and 48-hr counts. Acetic acid and hypochlorite were nonselective, but the quaternary sanitizer allowed more oxidase positive, nonfermentative bacteria to survive.

Growth of Pseudomonas fragi had a significant (P < .05) effect on the color of aqueous beef extract stored at 1 ± 1 C. As numbers of P. fragi increased from log 5 to 7.9/ml during 10 days of storage at 1 ± 1 C, the pH increased from 5.5 to 6.0. At the end of 10 days there was a 76% loss of oxymyoglobin in samples inoculated with P. fragi . There was a 45% loss of oxymyoglobin in sterile-control samples. A possible mechanism for conversion of oxymyoglobin to metmyoglobin is suggested.

Eight steers, of which four were exercised prior to slaughter, were slaughtered and one side of each carcass electrically stimulated (ES). Steaks from combined wingrib and sirloin were packaged in two types of plastic foam trays, overwrapped with PVC and displayed in refrigerated display cabinets either at 0°C or 5°C meat surface temperature. Display temperature and period of display significantly influenced shelflife and overall appearance of steaks. ES enhanced tenderness and improved muscle color but caused more weight loss during display when compared with steaks from unstimulated carcasses. All factors investigated had a significant influence on percentage weight loss during display while stress and tray depth also negatively influenced cooking weight loss encountered during cooking.

Carcasses were obtained from 56 heifers that were fed a corn-corn silage diet to determine the effects of automated washing water spray pressures (SP) of 2412 kilopascal (kPa) or 4134 kPa and chain speeds (CS) of 3.9, 5.9 or 7.9 m/min on microflora and weight changes of carcass beef. Carcass beef sides were weighed before washing, 5 min after washing and 20 h after washing and storage at 0°C. Enterobacteriaceae and aerobic counts of forequarters and hindquarters were determined before and 20 h after washing. Carcass sides shrank 1.52 kg after 20 h of storage. This shrinkage was similar among all treatment groups. Washing reduced Enterobacteriaceae counts 1.57 log10 colony forming units (CFU)/200 cm2 and counts of aerobic bacteria 0.87 log10 CFU/200 cm2. All combinations of SP and CS were similar in effectiveness of reducing Enterobacteriaceae counts. However, the low SP tended (P

Our objective was to develop basic design criteria for use in fabricating a functional chamber for a red meat carcass cleaning unit. Emphasis was placed on eliminating the doors. A model carcass cleaning chamber was constructed to test effects of selected design parameters on direction and velocity of airflow. Based on data from the tests using the model, a full-scale chamber with no doors was designed, fabricated, and installed in a commercial packing plant for testing. The air moves into the chamber at both the entrance and the exit. This movement of air into the chamber prevents water droplets entrained in the air from escaping into the slaughtering area and causing condensation on the walls and roof.

SUMMARY —The tenderness of beef was improved by aging. Tenderness decreased with increasing maturity for the cattle evaluated in this investigation. During the early stages of aging, samples were more tender from control animals than from ante-mortem-stressed cattle, but this difference was eliminated by the end of the aging periods. Water-holding capacity and juiciness scores were increased by ante-mortem stress treatments. WHC and juiciness scores decreased during aging. Tenderness scores were correlated significantly with WHC values and juiciness scores at the termination of the low-temperature aging period. Transfer of moisture and mineral ions during aging appeared to be associated with the changes involved in the development and resolution of rigor mortis and improved tenderization of the meat. AS tenderness improved during aging, extractable sodium, magnesium, and calcium were released from the muscle proteins, while potassium, phosphate, and nitrogen were retained. These components changed radically during the early stages of aging, with movement and transfer more uniform during the latter stages. Magnesium was the only mineral component present in the exudate of the water-holding-capacity determination that appeared to be related to tenderness. A relationship existed between physiological cell maturity and the ability of the meat to transfer and bind cellular magnesium. Tenderness decreased as the quantity of magnesium decreased in the exudate from the water-holding-capacity determination. The pH of meat was increased by broiling, while the pH of the exudate decreased when meat samples were cooked in the water-holding-capacity tubes.

SUMMARY Paper and ion-exchange chromatography were used to determine qualitatively certain constituents in lyophilized diffusates from cold-water extracts of beef, lamb, and pork muscles. The qualitative contents of low-molecular-weight diffusible organic constituents in tissue from these three species were remarkably similar. Involvement of constituents studied as flavor and odor precursors is discussed.

SUMMARY Quantitative analyses were made of water-extractable amino nitrogen and carbohydrate constituents of beef, lamb, and pork before and after heating. In all three species, taurine, anserine-carnosine, and alanine were present in relatively large quantities, and losses of these were large during heating. Other important amino acids degraded during heating were: glutamic acid, glycine, lysine, serine, cystine, methionine, leucine, isoleucine, and methyl histidine. Heating caused marked increases of phosphoethanolamine in samples from the three animal species studied. Ribose was the carbohydrate most labile to heating, and glucose was the most stable. The importance of these constituents as odor and/or flavor precursors of meat is discussed.