Application of broken-line analysis to assess floor space requirements of nursery and grower-finisher pigs expressed on an allometric basis.
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Few issues in swine production are as complex as floor space allowances. One method for pork producers to calculate floor space allowance (A) is to convert BW into a 2-dimensional concept yielding an expression of A = k * BW(0.667). Data on ADG, ADFI, and G:F were obtained from published peer-reviewed studies. Five data sets were created: A = grower-finisher pigs, fully slatted floors, and consistent group size; B = grower-finisher pigs and fully slatted floors (group size did not need to be consistent); C = grower-finisher pigs, partially slatted floors, and consistent group size; D = grower-finisher pigs, partially slatted floors (group size did not need to be consistent); and E = nursery pigs, fully slatted or woven wire floors (group size did not need to be consistent). Each data set was analyzed using a broken-line analysis and a linear regression. For the broken-line analyses, the critical k value, below which a decrease in ADG occurred, varied from 0.0317 to 0.0348. In all cases the effect of space allowance on ADG was significant (P < 0.05). Using the linear analyses based on data with k values of < 0.030, the critical k values for the 4 grower-finisher data sets did not differ from those obtained using the broken-line analysis (0.0358 vs. 0.0336, respectively; P > 0.10); however, none of the linear regressions explained a significant proportion of the variation in ADG. The slopes for the nonplateau portion of the broken-line analyses based on percent values varied among data sets. For every 0.001 decrease in k (approximately 3% of the critical k value), ADG decreased by 0.56 to 1.41%, with an average value of 0.98% for the 5%-based analyses. The use of an allometric approach to express space allowance and broken-line analysis to establish space requirements seem to be useful tools for pig production. The critical k value at which crowding becomes detrimental to the growth of the pig is similar in full- and partial-slat systems and in nursery and grower-finisher stages. The critical point for crowding determined in these analyses approximated current recommendations to ensure the welfare of pigs. (+info)
Stall dimensions and the prevalence of lameness, injury, and cleanliness on 317 tie-stall dairy farms in Ontario.
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The study objectives were to provide a province-wide description of stall dimensions and the aspects of cattle welfare linked to stall design in the tie-stall industry. Data on stall design; stall dimensions; and the prevalence of lameness, injury, and hind limb and udder cleanliness in lactating dairy cattle were collected from a sample of 317 tie-stall farms across Ontario. The majority of the study farms (90%) had stalls with dimensions (length, width, tie-chain length, and tie rail height) that were less than the current recommendations. This may explain, in part, the prevalence of lameness measured as the prevalence of back arch (3.2%) and severe hind claw rotation (23%), hock lesions (44%), neck lesions (3.8%), broken tails (3%), dirty hind limbs (23%), and dirty udders (4.6%). Veterinarians and producers may use this information to compare farms with the industry averages and target areas in need of improvement. (+info)
Residential insecticide use and risk of non-Hodgkin's lymphoma.
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Previous studies have linked non-Hodgkin's lymphoma (NHL) with occupational exposure to insecticides, but residential use is largely unexplored. In this population-based case-control study, we examined NHL risk and use of insecticides in the home and garden. We identified NHL cases, uninfected with HIV, diagnosed between 1998 and 2000 among women and men ages 20 to 74 years in Iowa and the metropolitan areas of Los Angeles, Detroit, and Seattle. Controls were selected using random digit dialing or Medicare files. Computer-assisted personal interviews (1,321 cases and 1,057 controls) elicited data on insecticide use at each home occupied since 1970. Insecticide levels were measured in dust taken from used vacuum cleaner bags (682 cases and 513 controls). We previously reported a positive association with dichlorodiphenyldichloroethylene levels in carpet dust residues. Here, we focus on insecticides that were commonly used after 1970, the time period covered by our questionnaire. People whose homes were treated for termites had elevated NHL risk (odds ratio, 1.3; 95% confidence interval, 1.0-1.6). Risk was modestly, although not significantly, elevated in all but one study center and in all sexes and races. The elevation in risk was restricted to people whose homes were treated before the 1988 chlordane ban. There was a significant trend of increasing risk with increasing levels of alpha-chlordane residues in dust (P(trend) = 0.04) and a marginally significant trend for gamma-chlordane (P(trend) = 0.06). We found no evidence of associations for insects overall, for specific types of insects other than termites, or for elevated residues of other insecticides. We concluded that chlordane treatment of homes for termites may increase residents' NHL risk. (+info)
An analysis of factors that influence personal exposure to toluene and xylene in residents of Athens, Greece.
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BACKGROUND: Personal exposure to pollutants is influenced by various outdoor and indoor sources. The aim of this study was to evaluate the exposure of Athens citizens to toluene and xylene, excluding exposure from active smoking. METHODS: Passive air samplers were used to monitor volunteers, their homes and various urban sites for one year, resulting in 2400 measurements of toluene and xylene levels. Since both indoor and outdoor pollution contribute significantly to human exposure, volunteers were chosen from occupational groups who spend a lot of time in the streets (traffic policemen, bus drivers and postmen), and from groups who spend more time indoors (teachers and students). Data on individual and house characteristics were obtained using a questionnaire completed at the beginning of the study; a time-location-activity diary was also completed daily by the volunteers in each of the six monitoring campaigns. RESULTS: Average personal toluene exposure varied over the six monitoring campaigns from 53 to 80 microg/m3. Urban and indoor concentrations ranged from 47-84 microg/m3 and 30 - 51 microg/m3, respectively. Average personal xylene exposure varied between 56 and 85 microg/m3 while urban and indoor concentrations ranged from 53-88 microg/m3 and 27-48 microg/m3, respectively. Urban pollution, indoor residential concentrations and personal exposures exhibited the same pattern of variation during the measurement periods. This variation among monitoring campaigns might largely be explained by differences in climate parameters, namely wind speed, humidity and amount of sunlight. CONCLUSION: In Athens, Greece, the time spent outdoors in the city center during work or leisure makes a major contribution to exposure to toluene and xylene among non-smoking citizens. Indoor pollution and means of transportation contribute significantly to individual exposure levels. Other indoor residential characteristics such as recent painting and mode of heating used might also contribute significantly to individual levels. Groups who may be subject to higher exposures (e.g. those who spent more time outdoors because of occupational activities) need to be surveyed and protected against possible adverse health effects. (+info)
Control of Listeria spp. by competitive-exclusion bacteria in floor drains of a poultry processing plant.
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In previous studies workers determined that two lactic acid bacterium isolates, Lactococcus lactis subsp. lactis C-1-92 and Enterococcus durans 152 (competitive-exclusion bacteria [CE]), which were originally obtained from biofilms in floor drains, are bactericidal to Listeria monocytogenes or inhibit the growth of L. monocytogenes both in vitro and in biofilms at 4 to 37 degrees C. We evaluated the efficacy of these isolates for reducing Listeria spp. contamination of floor drains of a plant in which fresh poultry is processed. Baseline assays revealed that the mean numbers of Listeria sp. cells in floor drains sampled on six different dates (at approximately biweekly intervals) were 7.5 log(10) CFU/100 cm(2) for drain 8, 4.9 log(10) CFU/100 cm(2) for drain 3, 4.4 log(10) CFU/100 cm(2) for drain 2, 4.1 log(10) CFU/100 cm(2) for drain 4, 3.7 log(10) CFU/100 cm(2) for drain 1, and 3.6 log(10) CFU/100 cm(2) for drain 6. The drains were then treated with 10(7) CE/ml in an enzyme-foam-based cleaning agent four times in 1 week and twice a week for the following 3 weeks. In samples collected 1 week after CE treatments were applied Listeria sp. cells were not detectable (samples were negative as determined by selective enrichment culture) for drains 4 and 6 (reductions of 4.1 and 3.6 log(10) CFU/100 cm(2), respectively), and the mean numbers of Listeria sp. cells were 3.7 log(10) CFU/100 cm(2) for drain 8 (a reduction of 3.8 log(10) CFU/100 cm(2)), <1.7 log(10) CFU/100 cm(2) for drain 1 (detectable only by selective enrichment culture; a reduction of 3.3 log(10) CFU/100 cm(2)), and 2.6 log(10) CFU/100 cm(2) for drain 3 (a reduction of 2.3 log(10) CFU/100 cm(2)). However, the aerobic plate counts for samples collected from floor drains before, during, and after CE treatment remained approximately the same. The results indicate that application of the two CE can greatly reduce the number of Listeria sp. cells in floor drains at 3 to 26 degrees C in a facility in which fresh poultry is processed. (+info)
Self-reported moisture or mildew in the homes of Head Start children with asthma is associated with greater asthma morbidity.
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This study used results from a cross-sectional survey of parents of 3- to 5-year-old children with asthma to assess the frequency of self-reported home environmental conditions that could contribute to worsening asthma and examined the relationship between these factors and the child's asthma morbidity. Participants were 149 parents drawn from the two largest agencies that provide subsidized preschool childcare services in East and Central Harlem, inner-city communities with high prevalence of asthma. The sample represented 77% of eligibles determined by a validated case-identification instrument. Data were collected on demographics, symptoms, medication use, Emergency Department visits and hospitalization, and environmental conditions in the home. One or more of these home environmental conditions were reported by 92% of participants. Controlling for other environmental conditions and demographics, associations were found between self-reported presence of moisture or mildew on ceilings, walls, or windows and higher frequency of hospitalizations for breathing-related problems (OR = 3.31; 95% CI 1.62-6.75), frequent episodes of wheezing (OR = 3.25; 95% CI 1.8-6.0), and higher frequency of night symptoms due to asthma (OR = 2.19; 95% CI 1.4-3.41). Having a carpet or rug in the child's bedroom or the living room was also associated with hospitalizations (OR = 3.23; 95% CI 1.53-6.8), and male gender was marginally associated with the frequency of night symptoms (OR = 1.51; 95% CI .95-2.4). Asthma is prevalent in the Head Start population, and exposure to home environmental conditions that may worsen asthma is common in the socially disadvantaged populations served by Head Start programs. (+info)
Effectiveness of house dust mite acaricide tri-n-butyl tin maleate on carpets, fabrics and mattress foam: a standardization of methodology.
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The aim of this study was to determine the effectiveness of the acaricide tri-n-butyl tin maleate, industrially applied to samples of carpets, mattress foam, and fabrics used for furniture upholstery, soft toys and shoe uppers. Approximately 100 adult house dust mites of the species Dermatophagoides pteronyssinus were inoculated into a Petri dish containing the sample (a piece of carpet, mattress foam, or fabric), treated with the acaricide, randomly collected. Mite-maintenance culture medium was added on top of each sample. After one, two, three, seven and 30 days of incubation at 25 degrees C and 75% relative humidity, each dish was examined using a 40X stereoscopic microscope (40X). One hundred percent acaricide effectiveness was obtained in treated materials by the end of the 30th-day postinoculation period, under optimal conditions for mite maintenance. (+info)
Sow shoulder lesions: risk factors and treatment effects on an Ontario farm.
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The objectives of this study were to identify risk factors for the development of shoulder lesions in lactating sows and to determine if an effective, economical, and practical treatment could be designed. The study was conducted at a 300-sow farrow-to-finish swine farm in Ontario between July and December 2004. Sow data were recorded on either the day of or 1 d after entering the farrowing crate and before farrowing had occurred. The right and left shoulders of the sows were assigned a score between 0 (normal) and 4 (lesion > 2.3 cm in diam.) on d 1 of the study and weekly thereafter throughout lactation. If a lesion developed, sows were randomly placed into 1 of 3 treatment groups. Groups consisted of a control group that received no treatment, a group that had a 0.2-cm thick, 60 x 60-cm, stainless steel plate attached to the bottom of the farrowing crate, and a group that had a 3.8-cm thick, 60 x 60-cm rubber mat attached to the bottom of the farrowing crate. Of the 310 sows involved in the study, 107 (34%) developed a lesion with a score of 3 or 4. Multivariate regression analysis identified body condition at weaning, flank-to-flank measurements at weaning, breed, parity, farrowing room section, and weaning weight of the litter as significantly associated with development of a shoulder lesion of score 3 or 4. The average number of days for the lesions to be completely resolved was 25 for sows receiving rubber mats, 32 for the controls, and 39 for the sows receiving stainless steel plates. Rubber mats attached to the bottom of the farrowing crates decreased the time required to heal the lesions when compared with controls. The low cost per mat (less than 0.90 dollars factoring in repeated use) makes it an economical and effective treatment. (+info)