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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. [ABSTRACT FROM AUTHOR]

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., (Copyright © 2013 Elsevier B.V. All rights reserved.)

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.

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.

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<0.01) and psychrotrophic, lactobacillus, anaerobic and aerobic counts than from nonstressed carcasses. Lactobacilli did not dominate the microbial population. Electrical stimulation (ES) and the cuts used had an influence on shear force values (P<0.05). ES cuts were significantly more tender than controls. Results suggest that animals should be well rested before slaughter.

Beef plate meat was sprayed with sodium hypochlorite (pH 6.0) from two sources, commercial and electroytically generated. Variables studied in two experiments were rate of flow of sanitizer, line pressure, speed of movement of meat through the sprays, and method and time of sanitization. Hypochlorite sprays reduced microbial counts significantly more than did water applied under the same conditions, but type of hypochlorite was unimportant. Maximum reductions in counts made immediately after sanitization approximated 97 and 93% as measured by swab and core sampling methods, respectively. Sprays were most effective when delivered in a single passage over meat at a rate of 2 rather than 10 cm/sec or in about seven successive passages at 10 cm/sec. Samples collected by coring and swabbing estimated microbial populations different from each other when the samples were taken after sanitized meat had been stored at 3 C for 48 h. Based on our findings we recommend the coring method.

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.

Our previous studies suggested the need to study absorption and evaporation of water from meat during cleaning with water sprays. This article describes the effects of type of meat surface, line pressure, size and configuration of nozzle, and speed of meat travel past the nozzle on water absorption and percent shrinkage after 24 h. Cut meat surfaces had a higher percent gain and lower percent shrinkage than did uncut surfaces. Pressure had no significant effect on percent shrinkage. Solid stream nozzles caused a higher percent gain and a lower percent shrinkage than did flat fan nozzles. As the size of the nozzle was increased, the percent gain increased and the percent shrinkage decreased. The slowest speed of meat travel past the nozzles (5 cm/s) caused the highest percent gain in weight.

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.

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 10 8 bacteria per cm 2 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/cm 2 , 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/cm 2 ) were sanitized with 3% acetic acid. This sanitizer was sprayed at the rate of 6.8 liters/min (1.9 ml/cm 2 ) at a pressure of 14.0 kg/cm 2 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.

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 log 10 colony forming units (CFU)/200 cm 2 and counts of aerobic bacteria 0.87 log 10 CFU/200 cm 2 . All combinations of SP and CS were similar in effectiveness of reducing Enterobacteriaceae counts. However, the low SP tended (P<0.102) to be more effective in reducing aerobic counts. Forequarters possessed greater (P<0.051) aerobic counts (5.44 vs 5.29 log 10 CFU/200 cm 2 ) than hindquarters, but washing eliminated this differential. Automated carcass washing reduced bacterial counts of carcass beef, but within treatments applied, SP and CS had no effect on variation in carcass weight or variation in reduction of microflora. Research indicated that automated carcass washing was a useful procedure for reducing bacterial counts on carcass beef without affecting carcass weights.

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.

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.

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.

Samples taken from dressed beef carcasses by swabbing surfaces or excising tissues were plated to produce counts of aerobic bacteria, Enterobacteriaceae , and Escherichia coli . Counts were compared to determine efficiencies of the two sampling methods. Excised tissues produced much higher counts than did swabs, especially when washed and sanitized carcasses were sampled. Percentages recovered by swabbing appeared to be influenced by characteristics of the area sampled on the carcass. Numbers of Enterobacteriaceae and E. coli recovered by swabbing washed and sanitized carcasses were usually too few to be countable, whereas excision usually produced countable plates. The excision sampling method permitted differentiation among treatment effects of washing and sanitizing.