Ronidazole in high concentrations in drinking water for treatment and prevention of diarrhea in swine dysentery

The addition of ronidazole to the drinking water at the concentration of 0.003% was effective for the treatment of experimentally induced swine dysentery in swine. Ronidazole at concentrations of 0.0015% and 0.00075% aided in the treatment of swine dysentery and the development of immunity to the disease. In experiment I, in which swine were given concentrations of 0.003, 0.0015, and 0.00075%, there were more survivors, fewer days of hemorrhagic diarrhea, greater feed and water consumption and body weight gain, and more favorable feed efficiency in the medicated swine than in the nonmedicated swine. With the 0.003% concentration, there were no deaths, and the diarrhea receded during or after treatment with the 0.0015% and 0.00075% concentrations, the incidence of nonhemorrhagic diarrhea was greater in medicated than in nonmedicated swine, and the diarrhea did not subside during treatment. In experimetn II, there were more survivors in the groups of swine medicated with the 0.0015% concentration than in the nonmedicated groups of swine. All surviving nonmedicated swine in experiment I were immune to reexposure 3 months after initial exposure. More swine given to the 0.0015% and 0.00075% concentrations in the same experiment were immune to reexposure 3 months after initial exposure than were the swine given the 0.003% concentration. In experiment II, neither the swine previously medicated with the 0.0015% concentration nor the nonmedicated swine were immune to reexposure 5 weeks after initial expsoure. Large spirochetes were observed in fecal smears from all exposed swine which developed either hemorrhagic or nonhemorrhagic diarrhea.     

Comparison of furazolidone and carbadox in the feed for treatment of Salmonella choleraesuis in swine

Furazolidone and carbadox, as feed additives, were only partially effective for the treatment of experimentally induced infections of Salmonella choleraesuis var kunzendorf in swine. There was little difference in mortality between the medicated exposed and the nonmedicated exposed swine, and medication did not markedly decrease rectal temperature. In experiment I, the mortality in groups fed furazolidone was lower than in those fed carbadox, but higher than in the nonmedicated exposed. In experiment II, there was little difference in mortality between the medicated and the nonmedicated exposed swine. In both experiments, however, exposed swine that survived had body weight gains significantly (P less than 0.05) higher in 3 of the 4 medicated exposed groups than in the nonmedicated groups. With the exception of the swine fed carbadox for 2 weeks, the feed and water consumption of the survivors in the medicated exposed groups during the recovery phase was higher (but not significantly (P greater than 0.05) higher) than that of the nonmedicated exposed groups. The problems with medicating in feed for treatment of S choleraesuis were that the infected swine frequently vomited the feed and became partially anorectic.     

Agar immobilized yeast cells in tubular reactor for ethanol production

Saccharomyces cerevisiae cells were immobilized in agar gel and used in a tubular reactor for conversion of cane molasses to ethanol at 30 degrees C, pH 4.5. Reactor was used in a continuous operation to test the operational stability and ethanol productivity. After 100 days of continuous fermentation at a dilution rate of 0.67 hr-1, some deactivation of cells was observed, but ethanol productivity was recovered by reactivating the cells by sparging air intermittently. It was found that intermittent reactivation during continuous operation was very important for satisfactory performance of the reactor. During operation, gel beads maintained their rigidity. Maximum ethanol concentration (94.9 g/L) was obtained with a feed containing 255 g/L reducing sugar, at a dilution rate of 0.2 hr-1. Maximum volumetric productivity (79.5 g ethanol /L/hr), specific ethanol productivity (0.58 g ethanol/g cells/hr), specific sugar uptake rate (1.12 g sugar/g cells/hr) and ethanol yield coefficient (0.43 g ethanol/g sugar) were obtained with a feed containing 195 g/L reducing sugar at a dilution rate of 1.33 hr-1.     

Effects of dietary protein and strain on the growth of broiler breeder pullets from zero to five weeks of age

In a series of four experiments, the effects of differences in dietary protein intake on BW, skeletal growth and the weight of the Pectoralis major muscle was studied in Hubbard Standard and Hubbard Hi-Y broiler breeder pullets. In Experiment 1, pullets were fed diets with either 15, 17, or 19% CP from 1 to 21 d. There was a linear increase in BW gain and feed consumption with each increase in CP and Hubbard Standard pullets consumed significantly more feed than Hubbard Hi-Y pullets. From 21 to 34 d, pullets were subjected to feed restriction every day (ED) or every-other-day (EOD). On Day 35, pullets were given ad libitum access to feed and ED-restricted pullets consumed significantly more feed than EOD-restricted pullets through 3.5 h postfeeding. In Experiment (Exp.) 2, pullets were fed the 19% CP diet for approximately 14 d (300 g) or 20 d (600 g) before being switched to the 15% CP diet. In Experiment 3, the 19% CP diet was fed for exactly 7 or 21 d before switching to the 15% CP diet. In all experiments, Hubbard Standard pullets weighed significantly more than Hubbard Hi-Y pullets and had increased overall skeletal growth. When the pullets from both strains were restricted to only 380 g BW at 28 d, (Exp. 3) the longer period of protein intake significantly enhanced breast muscle weight but there were no significant strain differences. When BW at 28 d was increased to 480 g, (Exp. 2), dietary protein and strain differences were observed.     

Removal of EATX from Waste Gases by a Trickle-Bed Air Biofilter

The trickle-bed air biofilter performance for treating mixtures of ethylacetate (EA), toluene (T), and xylene (X) volatile organic compounds (VOCs) was evaluated under different influent VOC loadings. The EA removal efficiencies were significantly higher than those for T and X, indicating that EA is a preferred substrate in the EATX waste gas. More than 80% removal efficiencies could be achieved under influent loadings below 77 g EA∕m3∕h, 8 g T∕m3∕h, and 10 g X∕m3∕h. The trickle-bed air biofilter appears efficient for controlling EATX emission with medium EA loadings and low TX loadings. The elimination capacities of EA, T, and X for a pure VOC feed were higher than for a mixed VOC feed and the differences increased with increased influent VOC loading.     

Prophylactic effect of dietary zinc in a laboratory mouse model of swine dysentery

Reduced prevalence of diarrhea and mortality has been reported after dietary supplementation with zinc compounds in swine with naturally acquired colibacillosis and those challenge-exposed with Serpulina hyodysenteriae; however, the usefulness of this approach for control of enteric diseases of swine remains to be determined. To examine the effect of dietary zinc-containing compounds on the colonization and development of cecal lesions associated with S hyodysenteriae infection, a defined diet alone or with added ZnO, ZnSO4, or Zn-methionine complex to a final concentration of approximately 6,000 mg of Zn2+/kg of complete feed was fed ad libitum to 156 female mice (strain C3H/HeN) for 10 days prior to oral inoculation either with S hyodysenteriae or sterile trypticase soy broth. Rations were continued for 42 days, while at weekly intervals, 3 mice/group were necropsied for determination of body weight, cecal weight, liver zinc concentration, presence of S hyodysenteriae in the cecum, and gross and histologic assessments of cecal lesions. From postinoculation day 0 to 42, the liver zinc concentration of mice fed the zinc-supplemented diets was approximately twice that of mice fed the basal diet, irrespective of the source of zinc. From postinoculation day 7 through 42, the overall recovery rate of S hyodysenteriae in infected mice fed the basal diet was 77.8%. In contrast, recovery rates of S hyodysenteriae from S hyodysenteriae-inoculated mice fed the zinc-supplemented diets were 0% for Zn-methionine and ZnO and 16.7% for ZnSO4. Mice fed the basal diet had significantly (P < 0.05) higher weight gain than mice fed the zinc-supplemented diets.(ABSTRACT TRUNCATED AT 250 WORDS)     

Temperature and SRT Effects on Aerobic Thermophilic Sludge Treatment

Laboratory-scale experiments were conducted to determine optimum sludge residence time (SRT) and temperature of aerobic thermophilic pretreatment (ATP) of mixed sludge (thickened waste activated sludge and primary sludge) to achieve maximum pathogen reduction and best process performance. 4-L laboratory-scale ATP reactors were operated at SRTs of 0.6, 1.0, and 1.5 days and temperatures of 55, 58, 62, and 65°C. ATP at temperatures ≥62°C and SRT ≥0.6 day reduced the feed sludge fecal coliform density from 107 MPN∕g total solids (TS) to <104 MPN∕g TS. Salmonella in the feed sludge was reduced to <1 MPN∕4 g TS from 2 to 18 MPN∕4 g TS by ATP at temperatures ≥55°C and SRT ≥0.6 day. ATP was able to increase sludge volatile acids concentration by 100–200% over the feed sludge volatile acid concentration and to reduce sludge supernatant chemical oxygen demand from 20,000 to 22,000 mg∕L in the feed to 13,000–17,000 mg∕L in the ATP reactor. Volatile solids reduction by ATP increased from 25 to 40% when SRT was increased from 0.6 to 1.5 days, and a 5% increase in volatile solids reduction was seen at SRTs of 0.6, 1.0, and 1.5 days when ATP temperature was increased from 55 to 65°C.     

Rapid screening test for sulfamethazine in swine feeds

A simple, 10-min qualitative screening test for sulfamethazine (SM) in swine feeds is detailed. The method, which can be run in the field, uses 2 plastic tubes arranged piggyback style. The upper tube contains, from top to bottom, the feed sample (about 1 g), partially deactivated alumina, and an anion exchange resin buffered at pH 5.7. The bottom tube contains a small bed of anion exchanger buffered at pH 7.9, which traps the SM. After percolation of solvent from the pH 7.9 resin and is reacted with Bratton-Marshall reagents to give a pink-to-lavender color. Feeds containing less than or equal to 0.15 ppm can be detected. A simple, additional dye concentration step allows for detection of 0.02 ppm, if desired. Only amphoteric primary aromatic amino-containing compounds with a pKa close to that of SM can theoretically interfere. Preparation of permanent color solutions using cobalt and copper acetates in glacial acetic acid is described for the optional establishment of the minimum concentration of SM in the feed. The method offers a simple way to detect some cross-contaminated withdrawal feeds containing greater than 2 ppm SM, which can lead to violative (greater than or equal to ppm) residues in swine liver.     

Incidence and economics of tuberculosis in swine slaughtered from 1976 to 1988

The Swine Tuberculosis Regulations, revised in 1972, stipulated that all swine carcasses with mycobacterial lesions in more than 2 primary sites should be passed for cooking (PFC). Economic loss from a condemned carcass is 100%, whereas loss from a PFC carcass is 66%. Increased condemned and PFC swine carcass rates in 1972, 1973, and 1974, and the economic losses from them were attributed to changes in the regulations. An industrial organization estimated increased economic losses from swine tuberculosis, but detected decreased rates of condemned and PFC swine carcasses in 1975 and 1986. The federal meat inspection data for 1976 to 1988 indicated that the yearly condemned carcass rate remained < 8.0/100,000 swine slaughtered, whereas the PFC carcass rate decreased by 74.1%, from 52.4 to 13.6/100,000 swine slaughtered. The incidence (condemned + PFC) per 100,000 swine slaughtered decreased by 67.7%, from 58.03 in 1976 to 18.72 in 1988. The Agricultural Statistics indicated that a yearly loss from tuberculosis of $2.3 million in 1976 decreased by 73% to $0.97 million in 1988. A yearly loss of $41,580/$100 million of animal value decreased by 70% to $12,880/$100 million in 1988. The decreased incidence of swine tuberculosis and the economic losses with this disease indicate that the swine industry in the United States was not adversely affected by the change in the Swine Tuberculosis Regulations.     

The African swine fever virus thymidine kinase gene is required for efficient replication in swine macrophages and for virulence in swine

African swine fever virus (ASFV) replicates in the cytoplasm of infected cells and contains genes encoding a number of enzymes needed for DNA synthesis, including a thymidine kinase (TK) gene. Recombinant TK gene deletion viruses were produced by using two highly pathogenic isolates of ASFV through homologous recombination with an ASFV p72 promoter-beta-glucuronidase indicator cassette (p72GUS) flanked by ASFV sequences targeting the TK region. Attempts to isolate double-crossover TK gene deletion mutants on swine macrophages failed, suggesting a growth deficiency of TK- ASFV on macrophages. Two pathogenic ASFV isolates, ASFV Malawi and ASFV Haiti, partially adapted to Vero cells, were used successfully to construct TK deletion viruses on Vero cells. The selected viruses grew well on Vero cells, but both mutants exhibited a growth defect on swine macrophages at low multiplicities of infection (MOI), yielding 0.1 to 1.0% of wild-type levels. At high MOI, the macrophage growth defect was not apparent. The Malawi TK deletion mutant showed reduced virulence for swine, producing transient fevers, lower viremia titers, and reduced mortality. In contrast, 100% mortality was observed for swine inoculated with the TK+ revertant virus. Swine surviving TK- ASFV infection remained free of clinical signs of African swine fever following subsequent challenge with the parental pathogenic ASFV. The data indicate that the TK gene of ASFV is important for growth in swine macrophages in vitro and is a virus virulence factor in swine.     

Effects of rumen-undegradable protein and feed intake on nitrogen balance and milk protein production in dairy cows

An experiment was designed to determine the response of milk protein production and N utilization in dairy cows to supplementation of a predominantly rumen-undegradable protein (RUP) mixture with a fixed amino acid (AA) pattern and the response to the amount of feed intake. The experiment was designed as a 6 x 6 Latin square with a 3 x 2 factorial arrangement of treatments. The factors were three concentrations of RUP supplement (4.5, 14.9, and 29.1% of dry matter intake) and two levels of feed intake restriction (10 and 20%) of the basal diet. The supplement was designed to approximate a postruminal AA pattern that was similar to bovine caseins for Met, Lys, Phe, His, and Thr. Measurements were made during the last 5 d of each 21-d period. Milk protein production responded linearly as the concentration of RUP supplement in the treatment diet increased within the given range. The difference in feed intake restriction did not affect milk protein production. Efficiency of N utilization for milk production exceeded 30% for cows fed the lowest RUP supplement. Results indicated that there is an opportunity to increase milk protein production by using RUP formulations that are balanced for AA while minimizing waste N excretion.     

Effect of duration of feed quality restriction on body dimensions in lambs

We measured the effect of duration of feed quality restriction and the consequent compensatory growth on body dimensions in 18 crossbred Swifter (Texel sire x Flemish dam) male lambs born in March 1994 and weaned at approximately 2 mo of age. The lambs were fed grass straw (46 g CP/kg DM) for ad libitum consumption and 35 g CP x kg(-75) x d(-1) mixed concentrates (173 g/kg DM). At approximately 3.5 mo of age and average live weight of approximately 34 kg, the lambs were allotted to six blocks, each block with three lambs of approximately the same live weight. Within each block, the three lambs were then randomly assigned to two restricted treatments (R1 and R2) and a control (C) treatment. In treatments R1 and R2, feed quality was restricted by withholding concentrates for 3 and 4.5 mo, respectively. A growth model was developed to study the effects of restriction and subsequent compensation after realimentation (6.5 and 8 mo for R1 and R2 groups, respectively). During restriction, live weight and growth in body dimensions were suppressed. Bone length measures such as body length and ulna length were less affected than live weight. The response in testes girth to restriction was almost immediate. At the end of the experiment (age of about 14 mo), R1 animals fully compensated. However, the R1 animals had higher testes girth (P < .001), chest girth (P < .01), and chest depth (P < .05). Extending the duration of feed restriction did not have a significant effect on the rate of losses in live weight and body dimensions during restriction. At the end of the experiment, except for withers height and trunk length, the R2 animals did not compensate fully in live weight and other dimensions. However, the parameter estimates suggested that the R2 animals may need a relatively longer period of realimentation to reach to the same size as R1 and C animals.     

Gender affects rats' central nervous system histaminergic responses to dietary manipulation

The histaminergic system (histamine and its H1-receptor) of the central nervous system has been implicated in control of food intake. The reported studies were designed to examine the effects of food restriction and very low (1%) protein diets on central nervous system H1-receptors in male and female rats. In a series of experiments, groups of rats were freely fed a 25% protein diet, a 1% protein diet, or fed the 25% protein diet at 4 g/100 g body weight for 14-20 d. When freely fed 25% protein diets, females had higher whole-brain H1-receptor binding than males on d 1 (female 122.36 +/- 4.53 and male 65.78 +/- 3.82 pmol/g protein; P < 0.001). Changing diets affected central H1-receptor binding in both males and females (P < 0.003). When rats were fed both restricted levels of food and 1% protein diets, the receptor binding of males increased by d 5 whereas that of females decreased by d 5 (P < 0.001). When fed 1% protein diets, females had decreased H1-receptor binding (98.4 +/- 2.38 pmol/g protein) and that in males increased to 119.81 +/- 5.09 pmol/g protein. After 15 d, females had eaten significantly more food than males: females 166 +/- 4.9 g, males 124 +/- 1.9 g (P< 0.0007). Males had a significantly greater weight loss than females: males -28.8 +/- 2.6 g, females -17.08 +/- 0.97 g (P < 0.0007). When fed restricted diets, females had decreased H1-receptor binding (93.81 +/- 5.58 pmol/g) whereas binding in males increased to 111.27 +/- 8.55 pmol/g. Preliminary saturation binding studies indicated that restricted food intake lowered receptor density (females consuming 25% protein: 715 +/- 30 pmol/g protein; female restricted: 467 +/- 28 pmol/g protein, P < 0.05), while 1% protein increased receptor sensitivity, i.e., lowered KD (males consuming 25% protein: 15.3 +/- 1.8 nmol; males fed low protein: 2.8 +/- 0.27 nmol). This study suggests that dietary manipulation affects central H1-receptor binding in a gender-specific manner, thereby modulating central histaminergic activity during food or protein deficit.     

Contrast-agent gas bodies enhance hemolysis induced by lithotripter shock waves and high-intensity focused ultrasound in whole blood

Fresh canine whole blood was exposed in 1.3-mL disposable pipette bulbs with or without added Albunex contrast agent to lithotripter shock waves (rate: 2 Hz; mean pressure amplitude: 14.8 MPa) or 1.28-MHz high-intensity focused ultrasound up to a mean pressure amplitude of 17.8 MPa. Significant shock-wave-induced hemolysis up to about 10% was detected after 500 or more shock waves without added agent, after 200 with 1% added agent and after 100 with 10% added contrast agent. Hemolysis was increased somewhat with added contrast agent, but this enhancement was not statistically significant. For ultrasound exposure, significant hemolysis approaching 100% was detected for 100-ms continuous exposure at 17.8 MPa without added gas bodies. Addition of 1% contrast agent enhanced the hemolysis by reducing the apparent threshold to 10 MPa. Burst mode exposure with a 100-ms total on-time (20 microseconds, 100 microseconds and 1-ms bursts) also yielded hemolysis enhancement with added contrast agent, with results similar to the 100-ms continuous exposure. The added gas bodies appear to lower cavitation thresholds by serving as cavitation nuclei in the blood.     

Forage characteristics, steer performance, and water quality from bermudagrass pastures fertilized with two levels of nitrogen from swine lagoon effluent

Four .8-ha pastures of bermudagrass (Cynodon dactylon [L.] Pers.) were fertilized with either 456 or 873 kg/ha of nitrogen (N) from swine lagoon effluent (two replicates per treatment) and grazed by steers over two summers. Within each pasture, steers received forage only, an energy source (corn), a mixture of corn and soybean meal, or a mixture of corn and blood meal via electronic Calan feeders. All supplements were offered at a level of 1.36 kg/d, and the soybean meal and blood meal supplements provided similar among quantities of protein. Weight gains were similar among supplemented steers, but supplemented steers gained faster (P < .05) than controls. Nitrogen fertilization level had no effect on steer gains, steer grazing days per hectare, or in vitro dry matter disappearance, NDF, and ADF of clipped forage samples. Plant protein and nitrate ion concentrations were greater (P < .06) in clipped forage samples receiving the higher N application rate. Nitrate ion concentrations were greater in available forage samples from the pastures with the high N application rate. Mean total N and nitrate N concentrations were similar in water samples obtained from monitoring wells for the two N treatments over the 2 yr and there were no year x N interactions. Chloride concentrations were greater (P < .05) and pH and specific conductance were less in water samples collected from the 873 kg than from the 456 kg/ha N treatment. Long-term studies are needed to examine the possible cumulative effects of applying various levels of swine waste to the same land area.     

Effect of feeding blends of Fusarium mycotoxin-contaminated grains containing deoxynivalenol and fusaric acid on growth and feed consumption of immature swine

Experiments were conducted to determine the effect of feeding diets containing combinations of the Fusarium metabolites deoxynivalenol (DON) and fusaric acid (FA) to starter swine. In all experiments, pigs of approximately 8.2 kg initial weight were fed diets containing blends of mycotoxin-contaminated corn, wheat, and barley for 21 d with growth and feed consumption determined weekly. In the first experiment, diets were determined to contain 0 microgram DON/g + 58.9 micrograms FA/g (control), 4.4 micrograms DON/g + 57.1 micrograms FA/g, 6.0 micrograms DON/g + 48.6 micrograms FA/g, and 7.5 micrograms DON/g + 57.4 micrograms FA/g. The feeding of all diets containing DON caused significant linear depressions in growth and feed intake after only 1 wk. Lower concentrations of DON and FA were fed in the second experiment with diets containing 0 microgram DON/g + 16.3 micrograms FA/g (control), .5 microgram DON/g + 14.3 micrograms FA/g, 1.1 micrograms DON/g + 14.1 micrograms FA/g, and 1.9 micrograms DON/g + 13.6 micrograms FA/g. There was a significant linear reduction in feed intake after 1 wk with increasing levels of dietary DON. Weight gains declined significantly only after 3 wk. Increasing amounts of FA combined with relatively constant amounts of DON were fed in the third experiment. By analysis, diets contained .5 micrograms DON/g + 2.9 micrograms FA/g (control), 2.2 micrograms DON/g + 12.2 micrograms FA/g, 2.5 micrograms DON/g + 15.6 micrograms FA/g, and 2.4 micrograms DON/g + 15.9 micrograms FA/g. In the 1st wk, the feeding of increasing amounts of fusaric acid combined with a relatively constant amount of DON caused a significant linear depression in weight gain. We concluded that a toxicological synergism exists between DON and FA when fed to immature swine and that FA concentrations in feeds should be determined whenever DON analysis is conducted.     

Dose- and time-dependent effects of ethanol on functional and structural aspects of the liver sinusoid in the mouse

Two experiments were conducted to investigate the factors responsible for the adverse effects of guanidinated proteins on feed intake in chickens. In Experiment 1, male broiler chicks were fed one of five purified diets containing casein or guanidinated casein (G-casein) as the sole source of protein (230 g crude protein/kg diet) from d 6 to 13 post-hatching. A casein-based diet containing 17.2 g lysine/kg, served as the control. In the experimental diets, casein was substituted by G-casein and lysine was added at 0, 5.6, 11.4 and 17.0 g/kg diet, respectively. Feed intake and weight gains of chicks fed the G-casein diet without added lysine were markedly depressed (P < 0.05), but this depression was largely overcome by additional lysine. The intake and gains of chicks fed the G-casein diet plus 17.0 g lysine/kg were lower (P < 0.05) than those fed the G-casein diet plus 11.4 g lysine/kg and this was associated with a higher plasma lysine:arginine ratio. Tissue analysis showed that homoarginine is distributed throughout body tissues following absorption. Brain lysine concentrations were lower (P < 0.05) in chicks fed diets containing G-casein without added lysine, but increased (P < 0.05) with supplemental lysine. In Experiment 2, the effect of homoarginine per se on feed intake was investigated in two short-term intake studies using 5-wk-old broiler chickens. Significant (P < 0.05) depressions in feed intake were observed within the first hour after oral administration of 400 mg homoarginine-HCl. The results suggest that both lysine deficiency and homoarginine per se were responsible for the adverse effects of guanidinated proteins on feed intake in chickens.     

Hydrogen peroxide is involved in collagen-induced platelet activation

Leptin is a 16-kDa protein secreted by adipocytes that has been proposed to regulate feed intake in mice, rats, and humans. The present study was designed to characterize porcine leptin structure and expression. Successful RT-PCR resulted in development of a cDNA clone to the full length coding region of porcine leptin. Sequence data demonstrate 85% base homology to rodent, 88% to human, and a 92% homology to the bovine sequence. For assessment of porcine leptin gene expression, total RNA was extracted from the subcutaneous adipose tissue of genetically selected high backfat pigs and from contemporary crossbred swine. Total RNA derived from genetically selected high fat pigs contained 113% higher (P < .05) concentrations of porcine leptin mRNA than total RNA derived from contemporary crossbred pigs. Western blotting was used to evaluate serum levels of porcine leptin in genetically selected high backfat and contemporary, crossbred pigs. Relative levels of porcine leptin in sera from obese swine were approximately 306% higher (P < .05) than levels present in sera from contemporary, crossbred swine. These data indicate that leptin is expressed in pigs, the expressed protein is secreted into the bloodstream, and obese swine express higher levels of leptin mRNA and protein than nonobese swine at similar body weight.     

The effect of preservatives based on propionic acid on the fermentation and aerobic stability of corn silage and a total mixed ration

For 3 successive yr, whole-plant corn was ensiled in laboratory silos with low percentages of silage preservatives, the primary active ingredient of which was propionic acid. Preservatives were added to forage just prior to ensiling at rates of 0.1 to 0.2% of the fresh forage weight. In all 3 yr, treatments had minor effects on fermentation end products, except that the concentration of propionic acid was greater because of its addition. The mean low and high percentages of preservatives increased aerobic stability of the treated silages by 19 and 57 h, respectively, in Experiment 1 and by 17 and 38 h, respectively, in Experiment 2. In Experiment 3, aerobic stability was improved by > 90 h by preservatives (0.2% addition). In a lactation study, a total mixed ration (46% dry matter) was mixed without or with (0.2 or 0.3%) a stabilizer that was designed to prevent spoilage in the feed bunk. The high dose resulted in orts with a lower pH and temperature after 24 h in the feed bunk. However, dry matter intake and milk production were unaffected by treatments. Chemical preservatives based on propionic acid added at low rates did not affect fermentation but were effective in the reduction of heating in corn silage and in a total mixed ration.     

Immunological studies in patients with mumps orchitis

A study of the effect of restriction of feed intake on the deiodination, faecal excretion, distribution and secretion of thyroid hormones was carried out in a group of eight young male goats. In the control goats fed ad libitum no changes in the concentration of circulating thyroxine were observed with increasing age or body weight during the experimental period; however, an increase in thyroxine secretion rate per animal was apparent with increasing age or body weight of the goats. In feed-restricted goats, no changes in the peripheral deiodination of [125I]thyroxine were observed, though significantly reduced faecal excretion of [125I]thyroxine was seen in goats restricted to 50 or 20% of their ad libitum feed intake. Both thyroxine turnover rate and thyroxine distribution volume were reduced by feed restriction. The secretion rate of thyroxine was reduced to 45% of the rate in ad libitum fed animals when feed intake was restricted to 20%. Calculation of thyroxine secretion rate per kilogram 0-75 body weight showed a highly significant correlation with feed intake. It was concluded that the marked reduction in thyroid activity occurring when feed restriction was imposed would be expected to cause a physiologically significant reduction in metabolic activity.