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991.
992.
993.
Weanling pigs (n = 160) were used to evaluate dietary essential microminerals (Cu, Fe, Mn, Se, and Zn) on performance, tissue minerals, and liver and plasma enzymatic activities during a 35-d postweaning period. A randomized complete block design with 5 treatments and 8 replicates was used in this study. Organic microminerals were added to complex nursery diets at 0 (basal), 50, 100, or 150% of the requirements of microminerals listed by the 1998 NRC. A fifth treatment contained inorganic microminerals at 100% NRC and served as the positive control. Pigs were bled at intervals with hemoglobin (Hb), hematocrit (Hct), glutathione peroxidase, and ceruloplasmin activities determined. Six pigs at weaning and 1 pig per pen at d 35 were killed, and the liver, heart, loin, kidney, pancreas, and the frontal lobe of the brain were collected for micromineral analysis. The liver was frozen in liquid N for determination of enzymatic activities. The analyzed innate microminerals in the basal diet met the NRC requirement for Cu and Mn but not Fe, Se, and Zn. Performance was not affected from 0 to 10 d postweaning, but when microminerals were added to diets, ADG, ADFI, and G:F improved (P < 0.01) from 10 to 35 d and for the overall 35-d period. Pigs fed the basal diet exhibited parakeratosis-like skin lesions, whereas those fed the supplemental microminerals did not. This skin condition was corrected after a diet with the added microminerals was fed. When the basal diet was fed, Hb and Hct declined, but supplemental microminerals increased Hb and Hct values. Liver catalase activity increased (P < 0.01) when microminerals were fed. The Mn superoxide dismutase activity tended to decline quadratically (P = 0.06) when supplemental microminerals were fed above that of the basal diet. Liver plasma glutathione peroxidase activities were greater (P < 0.01) when dietary organic and inorganic micromineral were fed. Liver concentrations of microminerals increased linearly (P < 0.01) as dietary microminerals increased, indicating that the liver was the primary storage organ. Micromineral tissue concentrations were least in pigs fed the basal diet and increased (quadratic, P < 0.01) to the 50% level of organic microminerals in the various tissues collected. The results indicated that innate microminerals, Cu and Mn, from a complex nursery diet may meet the micromineral needs of the weaned pig, but the need for Fe, Se, or Zn was not met by the basal diet. 相似文献
994.
The objective of the study was to evaluate the dietary effects of distillers dried grains with solubles (DDGS) with either inorganic or organic trace mineral sources on air emissions. Three diets were compared: a corn- and soybean meal-based control diet (Con), a diet containing 20% DDGS with inorganic trace mineral sources (20In), and a diet containing 20% DDGS with organic trace mineral sources (20Org). Groups of 6 pigs were allocated randomly to 1 of 12 environmentally controlled rooms for a 98-d experiment. A total of 72 pigs were blocked into 3 light and 3 heavy BW groups to minimize BW variation. Average initial BW for the light and heavy blocks were 22.6 kg and 27.0 kg, respectively. Concentrations and airflow of NH?, H?S, N?O, CH(4), CO?, and nonmethane total hydrocarbons (NMTHC) were measured in the exhaust air from each room. Body weight gain (94 kg per pig; P = 0.36) and G:F (0.39; P = 0.79) were not different as a result of diet, although a reduced feed intake was observed in pigs offered 20Org (P < 0.05). Total daily H?S emission mass was greater (P = 0.03) in rooms where the 20In diet was offered (462.26 mg) compared with rooms where the Con (354.62 mg) and 20Org (323.10 mg) diets were offered. No dietary effect (P = 0.47) was observed when H?S emissions were adjusted for S consumption (14.38 mg of H?S emitted daily per gram of S consumed). Compared with NH? emitted on the Con diet, the daily mass of NH? emitted decreased by 7.6% when pigs were fed 20In and increased by 11.0% in rooms where the 20Org was fed (P < 0.05). On a N consumption basis, feeding swine 20In significantly reduced NH? emissions compared with 20Org and Con, whereas NH? emissions from pigs fed 20Org were significantly greater than emissions from pigs fed the Con diet (P < 0.01). The NH? emission mass from rooms offered the Con, 20In, and 20Org diets was 120.1, 109.8, and 142.8 mg/g of N consumed/d, respectively (P < 0.01). Feeding DDGS with either inorganic or organic trace mineral sources increased the daily emission masses of CH? and NMTHC (P < 0.01), but not N?O emissions. Plasma urea N (P = 0.64), albumin (P = 0.39), globulin (P = 0.75), and total bilirubin concentrations (P = 0.82) were not different between diet groups. Results demonstrated that DDGS will increase H?S, CH?, NH?, and NMTHC emissions from pigs, but organic sources of trace minerals are a promising mitigation strategy to alleviate the adverse effect of DDGS on H?S emissions. 相似文献
995.
996.
Sepúlveda MA Muñoz-Zanzi C Rosenfeld C Jara R Pelican KM Hill D 《Veterinary parasitology》2011,175(1-2):60-65
American mink (Neovison vison) is a widely distributed invasive species in southern Chile. Thirty four feral minks were trapped at two distinct sites (rural and peri-urban), diet analyzed and Toxoplasma gondii exposure compared using PCR and specific antibodies. Serum samples were evaluated using a commercial latex agglutination test where a titer ≥ 1:32 was considered positive. Of 30 mink analyzed, 21 (70%) were positive to T. gondii antibodies, with titers ranging from 1:32 to 1:2048. As expected, adult mink showed higher seroprevalence of exposure to T. gondii (18/21) than young mink (3/9) (P=0.008). There was not statistically significant difference between sex groups (P=0.687). Differences in seroprevalence were observed between the two sample sites with a higher proportion of positive individuals in the peri-urban area, and therefore, closer to human settlements (35.7% vs. 100%, P=0.0001). Individuals positive to T. gondii using PCR and/or serology showed similar differences by site with higher infected individuals in peri-urban areas (58.8% vs. 100%, P=0.007). Diet of American mink based in fecal composition analyses was mainly based on crustaceans (frequency of occurrence: crustaceans=100%, birds and rodents<7%), suggesting that the high observed prevalence of T. gondii infection might be more associated with its aquatic behavior (e.g. ingestion of oocysts in contaminated fresh water) than with their trophic behavior (e.g. preying over species that can have T. gondii cysts in their tissues). As an invasive species potentially subject to routine culling to maintain population sizes under control, minks could be used as a sentinel species to monitor pathogens of public and wildlife health importance, such as T. gondii, in aquatic environments. 相似文献
997.
An expert opinion workshop was held on the subject of the cause, identification and control of new and emerging Salmonella strains. Experts were invited to complete questionnaires, contribute to structured discussions and take part in cluster group tasks. Outputs of the workshop included that, with current surveillance methods, it might take up to 2.5 years from the first introduction of a new strain into the UK livestock population to its identification as a human epidemic strain. In order to reduce the time to detection and provide more effective control options, several recommendations were made, including better back-tracing of human cases to their source, which would require more effective communication between those responsible for human and veterinary surveillance. 相似文献
998.
The effect of 0.2% emamectin benzoate (SLICE; Intervet/ Schering-Plough Animal Health, Roseland, New Jersey) administered in top-dressed, pelleted commercial fish feed was evaluated for control of freshwater Argulus sp. in goldfish Carassius auratus and koi carp, a variant of common carp Cyprinus carpio, in freshwater aquaria at 24-25 degrees C. Sixteen individually housed goldfish were each exposed to 37 Argulus. The number of fish lice attached to each fish at the start of the experiment was not determined; however, the total number of motile fish lice in each aquarium (on fish and in the water) was determined at the start and end of each experiment. Eight goldfish were fed the control diet (0 microg x kg fish biomass(-1) x d(-1)) and eight were fed the medicated diet (50 microg x kg fish biomass(-1) x d(-1)) for seven consecutive days. After treatment, fish louse infestation in controls was 20.5 +/- 1.5 (mean +/- SE) lice per fish. No Argulus were found on fish in the treated group. In a separate experiment, 10 individually housed koi were each exposed to 128 Argulus. Five koi were fed the control diet and five were fed a low-dose medicated diet (5 microg x kg fish biomass(-1) x d(-1)) for 7 d. After treatment, fish louse infestation among the controls was 14.6 +/- 3.8 lice per koi. No Argulus were found on koi in the treated group. Hence, a 7-d regimen of oral emamectin benzoate controlled experimental infestation of Argulus when administered to goldfish at 50 microg x kg fish biomass(-1) x d(-1) and to koi at 5 microg x kg fish biomass(-1) x d(-1). 相似文献
999.
Salmonella enterica is an important zoonotic agent and nosocomial infections and epidemics have occurred in animal facilities. The objective of this study was to estimate the prevalence of Salmonella in the environment in animal shelters. From 12 to 25 samples were taken from each shelter to represent environmental contamination. Samples were collected from surfaces in areas used by animals and in public access areas including animal receiving rooms, kennels, paediatric wards, treatment, visitation rooms, isolation, euthanasia, outdoor runs and play areas, reception rooms, animal transport vehicles, offices, break rooms and restrooms. Samples were tested for Salmonella and compared within shelters to identify high- and low-risk areas; and between shelters to identify differences in environmental contamination by geographical location, infection control policies, and shelter size characteristics. Twenty-eight per cent of sampled Colorado shelters had environmental Salmonella contamination. Two regions in the eastern 1/3 of the state had prevalences of 30% and 100%. Within-shelter sample prevalence ranged from 0 to 100%. Results of this study indicate that animal shelters can be frequently contaminated with Salmonella spp., a variety of Salmonella species may be present, contamination can be widespread within a facility and recovered isolates may harbour antibiotic resistance The findings from this study may influence and help focus educational policy on issues of infection control and zoonotic disease awareness in animal shelters. 相似文献
1000.
W. W. Wallender K. K. Tanji J. R. Gilley R. W. Hill J. M. Lord C. V. Moore R. R. Robinson E. C. Stegman 《Irrigation and Drainage Systems》2006,20(4):361-387
The principles of irrigation and drainage in cracking soils differ markedly from non-cracking soils, and are not thoroughly
understood. This paper presents a conceptual model to simulate water and salt flows in cracking soils of the Imperial Valley,
CA, in the presence of ground water that contributes partially to ET demand of crops. A salt reactivity function is introduced
in the model to account for mineral precipitation (salt deposition) and mineral dissolution (salt pick up). The conceptual
water flow model assumes that surface irrigation water moves into the cracks, infiltrates horizontally to wet the soil profile
and a fraction bypasses below the root zone into the shallow ground water and is retained for later crop extraction via upflow.
Then, water drains vertically through the soil profile step by step, and root water extractions are calculated. When ET exceeds
available water upflow of ground water is calculated. Provision for reclamation leaching before the next crop is also made.
The associated conceptual salt transport model involves complete mixing of invading and resident soil water. Salt concentration
from ET is subjected to a salt reactivity function to obtain salt deposition of calcite and gypsum to obtain salt concentration
after precipitation. This reactivity function is also used in the inverse when two or more waters mix to transform salt after
precipitation to salt concentration after ET. The flow of salts follows the water transport algorithum. The model has been
applied to a point in the Imperial Valley and observed data from Bali et al. (2001) was used for calibration. Simulated point data from four successive years of alfalfa, reclamation leaching, wheat and lettuce
are evaluated in this paper. 相似文献