A Demonstration Project in New York and Virginia: Retrofitting Cost-Effective Roll-over Protective Structures (CROPS) on Tractors.

The NIOSH cost-effective roll-over protective structure (CROPS) demonstration project sought to determine whether three prototype roll-over protective structures (ROPS) designed to be retrofitted on Ford 8N, Ford 3000, Ford 4000, and Massey Ferguson 135 tractors could be installed in the field and whether they would be acceptable by the intended end users (farmers). There were a total of 50 CROPS. demonstrators (25 in New York and 25 in Virginia), with 45 observers attending the New York CROPS demonstrations and 36 observers attending the Virginia CROPS demonstrations, for a total of 70 participants in New York and 61 in Virginia. The oldest retrofitted tractors were 77 to 62 years old, while the newest retrofitted tractors were 40 to 37 years old. The most frequently retrofitted tractor in the CROPS demonstration project was a Ford 3000 series tractor (n = 19; 38%), followed by Ford 4000 (n = 11; 22%), Massey Ferguson 135 (n = 11; 22%), and Ford 8N (n = 9; 18%). A major issue of CROPS retrofitting was the rear wheel fenders. The effort involved in disassembling the fenders (removing the old bolts was often faster by cutting them with a torch), modifying the fender mounting brackets, and then reinstalling the fenders with the CROPS generally required the most time. In addition, various other semi-permanent equipment attachments, such as front-end loaders, required additional time and effort to fit with the CROPS. Demonstrators were asked to rank the reasons why they had not retrofitted their tractors with ROPS until they had enrolled in the CROPS demonstration program. ROPS "cost too much" was ranked as the primary reason for participants in both states (80% for New York and 88% for Virginia). The second highest ranked reasons were "ROPS wasn't available" for Virginia (80%) and "hassle to find ROPS" for New York (69%). The third highest ranked reasons were "not enough time to find ROPS" for New York (67%) and "hassle to find ROPS" for Virginia (79%). All demonstrators and observers indicated that they were glad to have participated in the CROPS project.

Adoption of rollover protective structures (ROPS) on U.S. farm tractors by state: 1993-1995, 2001, and 2004.

This research compares state-level rollover protective structure (ROPS) prevalence rates from the early and mid-1990s to those observed in the years 2001 and 2004. In addition, state-level ROPS prevalence rates are compared to state-level tractor overturn fatality rates. Tractor data for 1993-1995 and for 2001 and 2004 for all tractors and ROPS-equipped tractors in use on U.S. farms were derived from surveys conducted for NIOSH by the USDA-NASS. Changes in ROPS prevalence rates at the state level between the two time periods were assessed using a two-sample paired t-test with unequal sample sizes. Poisson regression was used to assess the association between ROPS prevalence rates and tractor overturn fatality rates at the state level. Overall, 49 of the 50 states had an observed increase in the percentage of farm tractors equipped with ROPS from 1993-1995 to 2001 and 2004. This increase was statistically significant for 34 states. Large shifts in ROPS prevalence were found within individual states and in clusters of states. These include a major increase in the southeastern U.S. and some western states. However, a core of states in the northeast (many of them in or near the Appalachian Mountains) through the upper midwest remain in the bottom quartile for ROPS prevalence. For the years 1992 through 2004, the highest fatality rates were observed in many of the same states that were identified previously as having persistently low ROPS prevalence rates. There is a clear relationship between low state-level ROPS prevalence rates and high state-specific tractor overturn fatality rates. While progress has been made in increasing the percentage of ROPS-equipped farm tractors, it is projected that ROPS prevalence rates will not reach a protective level nationally until after 2015. Regionally, the northeast and midwest will not reach protective levels of ROPS-equipped tractors until after 2020. Based on the adoption rates observed, tractor overturn rates will likely continue to be a more localized, but significant, public health issue for several states beyond the year 2020. The results of this study show the geographic areas of the U.S. where the greatest need exists, and where a greater emphasis should be placed on ROPS promotion activities. However, addressing this public health issue on a large scale will require resources and an organized commitment, which have historically been lacking.

Evaluation of an occupational injury intervention among Wisconsin dairy farmers.

OBJECTIVES: Dairy farming injury rates are high. Previous agricultural research has shown that better information flow can speed adoption of more profitable practices. We conducted and evaluated an intervention to increase voluntary adoption of three production practices that were safer and more profitable than typical practices: barn lights, bag silos, and a mixing site for calf feed. METHODS: Print mass media, public events, university Extension, and dairy farmers already using the practices were all enlisted to disseminate information to 4,300 northeast district Wisconsin dairy farmers. Evaluation questionnaires were mailed to independent samples of farm managers before (n = 582) and after (n = 572) the 12 month long intervention. RESULTS: After the intervention, more managers reported getting information about barn lights from public events (12% vs. 23%) and private consultants (8% vs. 17%) and about silo bags from print media (79% vs. 87%) and private consultants (9% vs. 14%). More managers were aware of barn lights (48% vs. 72%) and the calf feed mixing site (44% vs. 56%). There was a nonsignificant tendency for more managers to report adopting barn lights (12% vs. 23%). CONCLUSIONS: Improving information flow to operation managers about safer, more profitable production practices may be a relatively easy way to supplement conventional injury control efforts in high-hazard industries.

Effect of method of application of a fibrolytic enzyme product on digestive processes and milk production in Holstein-Friesian cows.

Four multiparous cows with cannulas in the rumen and proximal duodenum were used in early lactation in a 4 x 4 Latin square experiment to investigate the effect of method of application of a fibrolytic enzyme product on digestive processes and milk production. The cows were given ad libitum a total mixed ration (TMR) composed of 57% (dry matter basis) forage (3:1 corn silage:grass silage) and 43% concentrates. The TMR contained (g/kg dry matter): 274 neutral detergent fiber, 295 starch, 180 crude protein. Treatments were TMR alone or TMR with the enzyme product added (2 kg/1000 kg TMR dry matter) either sprayed on the TMR 1 h before the morning feed (TMR-E), sprayed only on the concentrate the day before feeding (Concs-E), or infused into the rumen for 14 h/d (Rumen-E). There was no significant effect on either feed intake or milk yield but both were highest on TMR-E. Rumen digestibility of dry matter, organic matter, and starch was unaffected by the enzyme. Digestibility of NDF was lowest on TMR-E in the rumen but highest postruminally. Total tract digestibility was highest on TMR-E for dry matter, organic matter, and starch but treatment differences were nonsignificant for neutral detergent fiber. Corn silage stover retention time in the rumen was reduced by all enzyme treatments but postruminal transit time was increased so the decline in total tract retention time with enzymes was not significant. It is suggested that the tendency for enzymes to reduce particle retention time in the rumen may, by reducing the time available for fibrolysis to occur, at least partly explain the variability in the reported responses to enzyme treatment.

Effect of feeding supplemental fibrolytic enzymes or soluble sugars with malic acid on milk production.

Two trials were conducted to evaluate effects of feeding supplemental fibrolytic enzymes or soluble sugars and malic acid on milk production. In trial 1, 257 cows at four sites were fed a basal diet consisting of no more than 60% of forage DM as corn silage and less than 40% as alfalfa hay. Cows were assigned randomly within site, parity, and two stages of lactation to: 1) control; 2) enzyme A; 3) enzyme B; and 4) soluble sugars and malic acid. There was a 14-d pretreatment and an 84-d treatment period. Enzyme solutions were sprayed on either the forage component or the TMR each day while mixing feed. Trial 2 was similar, except 122 cows at one site in the United Kingdom were fed diets containing forage that was 75% corn silage and 25% grass silage, and all cows began the study between 25 to 31 DIM. Mean milk productions for 233 cows that completed trial 1 were 32.9, 32.5, 32.4, and 32.9 kg/d for control, enzyme A, enzyme B, and soluble sugars and malic acid, respectively. Mean milk productions for 116 cows that completed trial 2 were 28.2, 27.9, 28.8, and 28.4 kg/d, respectively. In vitro analyses of the activities of enzyme solutions indicated that all major cellulose and hemicellulose degrading activities were present; however, the pH optima (approximate pH = 4 to 5) were more acidic, and the temperature optimum (approximately 50 degrees C) was greater than normal pH and temperature in the rumen. If fibrolytic activity in the rumen is a major mechanism of action of supplemental fibrolytic enzymes, it appears that considerable activity of these preparations was lost due to conditions in the rumen. In conclusion, feeding supplemental fibrolytic enzymes or malic acid with soluble sugars had no effect on milk production under the conditions used in this study.

Traumatic injuries in agriculture.

The National Coalition for Agricultural Safety and Health (NCASH) in 1988 addressed issues in agriculture and noted "a sense of urgency... arose from the recognition of the unabating epidemic of traumatic death and injury in American farming . . ." This article provides an update to the NCASH conference on traumatic injuries in agriculture, a history on how the facts and figures were arrived at for the NCASH conference, and a current report on the status of traumatic injuries in agriculture in the U.S. Fatal and nonfatal injuries are addressed along with national and regional surveillance systems. The Census of Fatal Occupational Injuries (CFOI) was used for reporting national agricultural production fatal injuries from 1992-1998 (25.8 deaths per 100,000 workers), the Traumatic Injury Surveillance of Farmers (TISF) 1993-1995 was used to report nonfatal injuries occurring nationally (7.5/100 workers), and Regional Rural Injury Studies I and II (RRIS-I and RRIS-II) were used to illustrate a regional approach along with in-depth, specific analyses. Fatality rates, which showed some decline in the 1980s, were fairly constant during the 1990s. Changes in nonfatal injury rates for this sector could not be assessed due to a lack of benchmark data. The main concerns identified in the 1989 NCASH report continue today: tractors are the leading cause of farm-related death due mostly to overturns; older farmers continue to be at the highest risk for farm fatalities; and traumatic injuries continue to be a major concern for youth living or working on U.S. farms. Fatal and nonfatal traumatic injuries associated with agricultural production are a major public health problem that needs to be addressed through comprehensive approaches that include further delineation of the problem, particularly in children and older adults, and identification of specific risk factors through analytic efforts. Continued development of relevant surveillance systems and implementation of appropriate interventions are the primary challenges for the current decade.

Evaluation of the effectiveness of educational interventions in the Pennsylvania Central Region Farm Safety Pilot Project.

BACKGROUND: Evaluation of agricultural safety interventions has frequently been identified as an area requiring further research. This study prospectively evaluates the effectiveness of three specific educational safety interventions in reducing farm hazards. METHODS: Farm characteristics and hazard conditions at 216 farms in Pennsylvania were assessed through a questionnaire and objective audit, respectively, at both pre- and post-intervention time points. Counties were assigned to one of the following interventions: youth education, community coalition, self-audit, pre/post control, or post-only control group. Changes in hazard were analyzed through linear regression. RESULTS: Self-audit was the most effective intervention, leading to a 20% reduction in hazard scores. The community coalition and pre/post control group also showed reductions. CONCLUSIONS: Intervention effectiveness significantly differed depending on initial hazards, indicating the need to target specific interventions for more or less hazardous farms. Findings of this prospective evaluation differed from the initial cross-sectional results, thus underscoring the need for longitudinal investigations.

Secretion of dopamine and norepinephrine in hypophyseal portal blood and prolactin in peripheral blood of Holstein cattle.

The objective was to test the hypothesis that dopamine regulates prolactin (PRL) secretion by determining acute changes in catecholamine concentrations in hypophyseal portal blood of cattle, and their relation to peripheral blood concentration of PRL in hypophyseal stalk-transected (HST) and sham-operated controls (SOC). Holstein heifers (606 +/- 21 kg BW; mean +/- SE) were subjected to neurosurgery for 8 h to collect hypophyseal portal blood with a stainless steel cannula designed with a cuff placed under the pituitary stalk and peripheral blood via a jugular vein catheter. PRL plasma concentration was measured by radioimmunoassay, and dopamine and norepinephrine in portal plasma by radioenzymatic assay. During anesthesia before HST or SOC, PRL plasma concentration ranged from 20-40 ng/ml throughout 255 min. PRL abruptly increased and remained above 90 ng/ml after HST compared with a steady decrease to <20 ng/ml in SOC heifers throughout 440 min. Within 5 min after severing the hypophyseal stalk, dopamine in portal blood (>8 ng/ml) was significantly increased (P < 0.05) compared with peripheral blood (<2 ng/ml). Norepinephrine concentration in portal blood was significantly greater (P < 0.05) than in peripheral blood during the first 60 min. The sustained high PRL level in peripheral plasma after severing the hypophyseal stalk stimulated hypothalamic dopamine secretion from hypophyseal portal vessels during the prolonged period of blood collection. Norepinephrine concentration in these cattle was greater in hypophyseal portal than in peripheral blood, implicating both an important hypothalamic source of the catecholamine as well as an adrenal gland contribution during anesthesia.

Pregnancy, parturition, and lactation in hypophyseal stalk-transected beef heifers.

Progesterone secretion is crucial for maintaining pregnancy to parturition in mammalian species, and in cattle the corpus luteum is the primary source of this hormone. This study determined the roles of prolactin (PRL), growth hormone (GH) and luteinizing hormone (LH) in the luteotropic process in beef heifers hypophyseal stalk-transected (HST, n=7) or sham operated (sham operated controls, SOC, n=9) during midgestation. The main finding was that endogenous PRL and GH maintained progesterone secretion in HST heifers in a similar manner to that in SOC throughout pregnancy. Serum PRL averaged 37 vs 187 and GH 2 vs 4 ng/ml in HST heifers compared with SOC, whereas LH abruptly decreased to undetectable levels after HST compared with a modest 0.4 ng/ml in SOC heifers. The second finding was that parturition and lactation occurred in HST heifers with calf delivery induced to occur at the same time as SOC. Milk production in HST animals was severely limited, and postpartum estrus obliterated compared with SOC. The suckling stimulus sustained milk ejection in HST heifers in spite of diminished PRL, GH, thyroid stimulating hormone, thyroxine and tri-iodothyronine secretion. The results suggest that PRL, GH and possibly placental lactogen are luteotropic during pregnancy in cattle.