York Dairy Research Articles

Estimation of Treatment Effects of Recombinant Bovine Somatotropin Using Matching Samples

The production and profit impacts of recombinant bovine somatotropin (rbST) on select New York dairy farms were estimated using data over the years 1994 through 2004, by comparing matching farms that use and do not use rbST. The use of rbST increases milk production per cow and decreases the cost of production per hundredweight of milk. The cost penalty (cost reduction) is $0.39 per hundredweight for those currently using rbST to stop using rbST, while the average treatment effect is $0.73.

Combined Monitoring and Modeling Indicate the Most Effective Agricultural Best Management Practices

Although water quality problems associated with agricultural nonpoint source (NPS) pollution have prompted the rapid and widespread adoption of a variety of so called "best management practices" (BMPs), there have been few realistic efforts to assess their combined effectiveness in reducing NPS pollution. This study used the Variable Source Loading Function (VSLF) model, a distributed watershed model, to simulate phosphorus (P) loading from an upstate New York dairy farm before and after the implementation of a suite of BMPs. With minimal calibration, the model calculates the dissolved P (DP) losses from impervious surfaces (e.g., barnyards), the plant/soil complex, field-applied manure, and loads associated with baseflow conditions. The simulated DP loads agreed well with measured loads for both the pre-BMP and post-BMP periods. More importantly, results showed that BMPs reduced DP loads by 35%, which is over half of the expected reduction if all manure was removed from the watershed, i.e., approximately 50% reduction. The model results indicate that had no BMPs been installed DP loads would be approximately 37% greater than observed at the watershed outlet. The most effective BMPs were those that disassociated pollutant loading areas from areas prone to generating runoff, i.e., hydrologically sensitive areas. By contrast, attempts to reduce P content in manure were somewhat less effective. This study demonstrates that a combination of distributed, mechanistic modeling and long-term monitoring provides better insights into the effectiveness of water quality protection efforts than either individually.

Dynamics of insecticide resistance alleles in house fly populations from New York and Florida

The frequency of insecticide-resistance alleles for two genes ( Vssc1 and CYP6D1) was studied in field collected populations of house flies from two different climates. While the frequency of these resistance alleles in flies at dairies from four states has recently been reported, there is no information on the relative change of these allele frequencies over time. House flies were collected during the 2003–2004 season from New York and Florida before the first application of permethrin, during the middle of the field season, after the final application, and again the following spring (following months without permethrin use). Bioassay results indicated that homozygous susceptible and extremely resistant flies were rare, while moderately and highly resistant individuals were relatively common at all times in both states. The frequency of resistance alleles at the New York dairy rose during the season and declined over the winter, suggesting an overwintering fitness cost associated with these alleles. The super-kdr allele was detected for the first time in North America at the end of 2003. In Florida the frequency of the resistance alleles did not increase during the spray season or decrease during the winter, suggesting there is substantial immigration of susceptible alleles to the Florida dairy and no overwintering fitness cost associated with resistance alleles in this climate. Resistance to permethrin correlated well with the frequency of the Vssc1 and CYP6D1 resistance alleles in flies from New York, but not as well in the population from Florida. This suggests there may be a new resistance mechanism or allele evolving in Florida.

When to Get In and Out of Dairy Farming: A Real Option Analysis

The Dixit entry/exit real option model was applied to the entry/exit decisions of New York dairy farmers. For the cost structure of a 500-cow farm, the entry milk price is $17.52 per hundredweight (cwt) and the exit milk price is $10.84. For the 50-cow farm cost structure, the entry price is higher at $23.71 per cwt, and the exit price is also higher at $13.48. If infinite numbers of representative farms enter and exit at these prices, the price of milk should range between $13.48 and $17.52 per cwt.

Evaluation of the Efficacy of On-farm Pasteurization of Waste Milk in Seven Western New York Dairies

Whole milk has nutritional and economic benefits over milk replacer as a feed source for calves. Waste milk-non-saleable milk from treated cattle-represents the most affordable source of whole milk on the dairy. Despite its benefits, whole milk contains many pathogens and poses a disease risk to calves. Pasteurization has emerged as a valuable and cost-effective method for reducing the number of pathogenic bacteria present in waste milk on farms, and studies have shown numerous health and economic benefits through feeding pasteurized waste milk over un-pasteurized waste milk. There remains a need for identifying how effective pasteurizers are when operating under on-farm conditions. The objective of this study was to evaluate bacterial load in waste milk before and after on-farm pasteurization.

Field Trial of Vaccination against Leptospira borgpetersenii serovar hardjo bovis in a Single New York Dairy Herd

Dry cows and late gestation heifers were assigned randomly to receive a monovalent vaccine against L. borgpetersenii serovar hardjo-bovis at about 220 days of gestation or nothing. A second dose of vaccine was administered about 28 days later to the vaccinated group. Before the trial, the herd was determined to be infected. Five of 45 lactating animals chosen by convenience were shedding leptospires in urine by fluorescent antibody testing. The herd was milking about 2600 cows during the duration of the trial. There were 1208 animals enrolled in the trial, 601 controls and 607 vaccinates. The reproductive management of the herd was not changed during the study period. Outcome measures were first service conception rate: 27% for controls, and 36% for vaccinates, chi square test, p=0.004. Survival analysis of days to conception: 50% were pregnant at 105 days in controls, and 90 days in the vaccinated group, Wilcoxon rank sum of Kaplan Meir estimates p<.001. Overall pregnancy rate from DC305 for controls was 19%, and 21 % for vaccinates. There were nearly equal abortions after first pregnancy palpation at 35-41 days after breeding, 56 in the control group and 58 in the vaccinates. Vaccination in this herd improved reproductive performance by increasing the apparent conception risk to first service.

Ceftiofur-resistant Salmonella strains isolated from dairy farms represent multiple widely distributed subtypes that evolved by independent horizontal gene transfer.

Salmonella is the leading cause of known food-borne bacterial infections in the United States, with an incidence rate of approximately 15 cases per 100,000 people. The rise of antimicrobial-resistant Salmonella subtypes, including the appearance of subtypes resistant to ceftriaxone, represents a particular concern. Ceftriaxone is used to treat invasive cases of Salmonella in children and is closely related to ceftiofur, an antibiotic commonly used to treat diseases of cattle. In order to develop a better understanding of the evolution and transmission of ceftiofur resistance in Salmonella, we characterized ceftiofur-resistant and -sensitive Salmonella isolates from seven New York dairy farms. A total of 39 isolates from these seven farms were analyzed for evolutionary relatedness (by DNA sequencing of the Salmonella genes fimA, manB, and mdh), antibiotic resistance profiles, and the presence of bla(CMY-2), a beta-lactamase gene associated with resistance to cephalosporins. Our data indicate that (i) resistance to ceftriaxone and ceftiofur was highly correlated with the presence of bla(CMY-2); (ii) ceftiofur-resistant Salmonella strains were geographically widespread, as shown by their isolation from farms located throughout New York State; (iii) ceftiofur-resistant Salmonella strains isolated from farms represent multiple distinct subtypes and evolutionary lineages, as determined by serotyping, DNA sequence typing, and antimicrobial-resistance profiles; and (iv) ceftiofur-resistant Salmonella strains evolved by multiple independent acquisitions of an identical bla(CMY-2) allele and by clonal spread of ceftiofur-resistant subtypes.

Phosphorus Concentrations in Overland Flow from Diverse Locations on a New York Dairy Farm

The National Phosphorus Project rainfall simulator was used to quantify overland flow and P transport from nine sites distributed throughout the watershed of a New York City Watershed Agriculture Program collaborating dairy farm. Observed concentrations of total dissolved phosphorus (TDP) were low (0.007-0.12 mg L(-1)) in flow from deciduous forest, extensively managed pasture, and hillside seeps; moderate (0.18-0.64 mg L(-1)) in flow from intensively managed pastures, a hayfield, and a cow path; and extremely high (11.6 mg L(-1)) in flow from a manured barnyard. Concentrations of TDP from sites without fresh manure were strongly correlated with soil test P (TDP [mg L(-1)] = 0.0056 + 0.0180 x Morgan's soil test phosphorus [STP, mg kg(-1)]; R2 = 84%). Observed concentrations of suspended solids were low (16-137 mg L(-1)) in flow from vegetated sites, but were higher (375-615 mg L(-1)) in flow from sites with little ground cover (barnyard, cow path, plowed field). Under dry summer conditions the time to observed overland flow was shorter (<18 min) for nonfield areas (seeps, barnyard, cow path) than for field and forest areas (27-93 min), indicating that hydrologically active nonfield areas of minor spatial extent but with high soil P (e.g., cow paths and barnyards) can play a significant role in summertime P loading. When soils started from field capacity (second-day) time to overland flow was uniformly less than 23 min, indicating that under wet watershed conditions low-P source areas can dilute overland flow from concentrated sources.

THE IMPORTANCE OF AGRICULTURAL TIRE HABITATS FOR MOSQUITOES OF PUBLIC HEALTH IMPORTANCE IN NEW YORK STATE

The presence of mosquito species breeding in agricultural "bunker tires" on dairy farms in New York state was evaluated. Twelve species of mosquitoes (Aedes vexans, Anopheles barberi, An. punctipenriis, An. perplexens, Culex pipiens pipiens, Cx. restuans, Cx. salinarius, Cx. territans, Toxorhynchites rutilus septentrionalis, Ochlerotatus atropalpus, Oc. japonicus japonicus, and Oc. triseriatus) were collected from 8 New York state dairy farms in 2001 and from 17 dairy farms in 2002. All but 2 of these species have been found naturally infected with arboviruses and could be important vectors affecting human and animal health. Because of the potential public and animal health importance of the invasive species Oc. j. japonicus, active surveillance to identify breeding sites and distribution of this mosquito is essential. In 2001, Oc. j. japonicus was recovered from 5 of 8 central New York dairy farms surveyed. In 2002, Oc. j. japonicus was recovered from 4 of the same dairy farms plus an additional dairy out of 5 surveyed. This species appears to be established on dairy farms in the south, central, and eastern regions of New York state, with greatest abundance in the southeastern region. A single Oc. j. japonicus larva was collected from the northern region on the final sampling date in September 2002. Our data demonstrate that agricultural tire habitats can be productive breeding sites for arbovirus vectors. As a consequence, these habitats should not be ignored in vector control and surveillance programs.

Assessing the impact of economic liberalization across countries: a comparison of dairy industry efficiency in Canada and the USA

This paper examines and compares the technical efficiency measures of Ontario and New York dairy producers for the period 1992 to 1998. A nonparametric stochastic frontier model is introduced to estimate technical efficiency. The backfitting algorithm of Breiman and Friedman is used to estimate the frontier. Empirical results indicate that during the period of study, New York dairy farmers produced milk more efficiently than Ontario dairy producers, but the magnitude of the difference was small. The estimated mean technical efficiency for the former group is 0.602 as compared to 0.532 for the latter. The results also indicated that over time, dairy farms in both regions improved their level of technical efficiency. Furthermore, no correlation was found between farm size and estimated technical efficiency.

Chronic disease risk in central New York dairy farmers: Results from a large health survey 1989-1999

The agricultural workplace presents a variety of health and safety hazards; it is unknown whether farm work may be a risk factor for certain chronic diseases. The health survey data from a large rural population in central New York were used from two studies (1989, 1999) to assess both 1999 prevalence and 10-year incidence of self-reported diabetes, heart disease, hypercholesterolemia, and hypertension among farm (predominantly dairy) and non-farm residents. The 1999 asthma prevalence was also assessed. Multiple logistic regression models for 1999 prevalence found statistically significant protective effects of farming for hypertension (OR=0.83, P=0.0105) and hypercholesterolemia (OR=0.853, P=0.0522). Non-significant results were seen for heart disease (OR=0.67, P=0.128) and diabetes (OR=0.856, P=0.1358). The model for 1999 asthma prevalence showed a significantly elevated risk for farming (OR=1.542, P=0.0004). Logistic models created for the 10-year incidence of hypertension, hypercholesterolemia, diabetes, and heart disease did not show a significant effect for farming. The protective effect of farming observed for the 1999 prevalence of hypertension and hypercholesterolemia was not seen for the 10-year incidence of these diseases.

Financial management practices and farm profitability

The adoption of several basic financial management practices is examined for a group of New York dairy farms. The study provides estimates of the extent to which various business analysis and control, investment analysis and decision making, and capital acquisition practices have been adopted. Many practices, such as net present value analysis, are not widely adopted by farmers. The relationship between the adoption of financial management practices and farm profitability is also examined. Results suggest that the adoption of financial management practices, such as using investment analysis techniques, significantly impacts farm financial performance.

Optimization of Phosphorus Index and Costs of Manure Management on a New York Dairy Farm

Manure allocation on large‐scale confinement animal feeding operations is a complex management decision. This study assesses the cost effectiveness and the risk of P loss associated with various combinations of manure management options for a typical midsized dairy farm in New York State. The farm has 587 adult dairy cows (Bos taurus) and 430 young animals (1202 animal units). Fifty‐three fields (26 cornfields and 27 pastures) ranging in size from 1 to 15 ha are available to receive livestock manure. Morgan's Soil Test P values range from 1.1 to 87.3 kg ha−1 (mean of 20.1 kg ha−1). Options included optimal allocation of manure in time and space, surface application, incorporation, and manure storage facilities of three‐, six‐, and eight‐month storage capacities. The decision process considered nutrient management costs (manure handling and fertilization) and the New York State P Site Index (P Index) as an indicator of one of the environmental impacts of manure management. Mathematical programming techniques and utility functions are used to select the best combination of manure management practices. The results show a convergence indicating that the best management decision would be to follow a manure allocation scheme optimized in time and space, to have three months of manure storage capacity, and to surface‐apply manure. Compared with current practices, the recommended combination of practices results in an approximate 45% reduction in the mean area‐weighted P Index (64.2 vs. 36.1) for a cost increase of less than 2% ($146 573 vs. $148 821).

High-temperature, air-blown gasification of dairy-farm wastes for energy production

A study was carried out to investigate the feasibility of integrating an advanced gasifier into the operation of a dairy farm for converting biomass wastes into fuel gas that can be used for power production. The disposal/utilization of excess animal wastes is a serious problem facing the dairy industry. Implementation of a gasification system on the dairy farm may provide an economical means of disposing of this waste. In our scheme, an advanced, high-temperature air-blown gasification system is used to convert the waste into synthetic fuel gas. A ceramic regenerative heater supplies the high-temperature air. Results of performance calculations indicated gasification conversion efficiencies of 65–85 % are possible, depending on the gasifier operating configuration. The syngas produced by the gasifier can be used on the farm for generating electricity and heat, or for other energy needs, thus helping to reduce the operating cost of the farm. In a case study, using information collected from an Upstate New York dairy farm, the results showed that gasification of dairy wastes would allow this particular farm to produce more than two times the amount of energy required for self-sufficiency.

Using Voluntary Approaches to Reduce Environmental Damages: Evidence from a Survey of New York Dairy Farms

This paper presents the results from a survey of New York dairy farms that links manure management practices and farmer willingness to participate in voluntary environmental programs, focusing on those operations that are not automatically designated as Concentrated Animal Feeding Operations. A wide divergence is found between actual and recommended manure management practices on individual dairy farms, the apparent ability of farms to divert financial resources to environmental practices, and the willingness to participate in voluntary programs at various annual costs per cow. These findings have policy implications for the USDA-USEPA [30] National Strategy for Animal Feeding Operations. The findings also may help foster comparisons and enhance understanding of environmental management issues in Japan and the United States.

Optimization of Phosphorus Index and Costs of Manure Management on a New York Dairy Farm

Manure allocation on large-scale confinement animal feeding operations is a complex management decision. This study assesses the cost effectiveness and the risk of P loss associated with various combinations of manure management options for a typical midsized dairy farm in New York State. The farm has 587 adult dairy cows (Bos taurus) and 430 young animals (1202 animal units). Fifty-three fields (26 cornfields and 27 pastures) ranging in size from 1 to 15 ha are available to receive livestock manure. Morgan's Soil Test P values range from 1.1 to 87.3 kg ha−1 (mean of 20.1 kg ha−1). Options included optimal allocation of manure in time and space, surface application, incorporation, and manure storage facilities of three-, six-, and eight-month storage capacities. The decision process considered nutrient management costs (manure handling and fertilization) and the New York State P Site Index (P Index) as an indicator of one of the environmental impacts of manure management. Mathematical programming techniques and utility functions are used to select the best combination of manure management practices. The results show a convergence indicating that the best management decision would be to follow a manure allocation scheme optimized in time and space, to have three months of manure storage capacity, and to surface-apply manure. Compared with current practices, the recommended combination of practices results in an approximate 45% reduction in the mean area-weighted P Index (64.2 vs. 36.1) for a cost increase of less than 2% ($146 573 vs. $148 821).

Effect of previous antimicrobial treatment on fecal shedding of Salmonella enterica subsp. enterica serogroup B in New York dairy herds with recent clinical salmonellosis

The association of herd- and sample-level factors with the isolation of Salmonella group B from cattle fecal samples was analyzed. Study farms were 65 dairy herds with a recent history of laboratory-confirmed clinical salmonella infections. Herds were visited once per month for three months to collect data and samples for bacteriological culture. Herd size varied widely from 34 to 3700 total cattle on the farm (median=370). Salmonella serogroup B was isolated from 270 of 2726 samples tested. The predominant serotypes identified were S. Typhimurium and S. Typhimurium var. Copenhagen. Logistic regression was used to analyze the relationship between potential risk factors and isolating Salmonella serogroup B. The only herd-level factor which was significantly associated with fecal shedding was total herd size (hundreds of cattle OR=1.09; 95% confidence interval (CI): 1.05, 1.14). The probability of a positive sample decreased substantially for longer intervals between the initial clinical case and sampling (interval in months OR=0.5; 95% CI: 0.3, 0.6). The presence of diarrhea increased the risk of shedding (OR=2.1; 95% CI: 1.4, 3.0). The effect of recent treatment with antimicrobial agents depended on age group. For heifers and cows, recent antimicrobial treatment increased the probability of isolating Salmonella (heifers OR=11.8; 95% CI: 2.9, 48.8; cows OR=4.1; 95% CI: 2.0, 8.4), but this effect was not statistically significant for calves before weaning. Among animals without recent antimicrobial treatment, preweaned calves were more likely to have positive samples than cows (OR=3.5; 95% CI: 1.8, 6.9; heifers OR=4.7; 95% CI: 2.3, 9.6).

Dairy Farm Management and Long-Term Farm Financial Performance

The financial performance and relationships between several management factors and financial performance are examined in a panel of 107 New York dairy farms. A panel regression model with fixed effects is estimated in an effort to identify management factors that influence profitability. The model is estimated with two-stage least squares to account for endogenous farm size and debt use variables. Production management factors such as farm size, rate of milk production, and milking system had a positive impact on farm profitability. Financial management variables for the type of accounting system used and the debt use were also significantly related to profitability. Unlike the findings of many other studies, measures of human capital did not have a statistically significant impact on profitability.

Profitability of Grazing Versus Mechanical Forage Harvesting on New York Dairy Farms

The profitability of rotational grazing versus mechanical harvesting of forages was estimated using data from 237 nongrazing and 57 grazing farms participating in the New York farm business summary program in the year 2000. The objective was to perform an empirical comparison of the profitability of grazing versus mechanical forage harvesting systems. A regression analysis technique that controls for treatment selection bias is used to determine the impact of grazing on the rate of return on assets. This is accomplished by joint maximum likelihood estimation of a probit adoption function and a profit function. The results indicate that treatment selection does not have an important impact on the estimate of the profitability of grazing. There were wide ranges and overlap of profitability among herds using the two systems. However, other things equal, farmers utilizing grazing systems were at least if not more profitable than farmers not using grazing systems. After controlling for the factors influencing the decision to graze, we found that herd size, rate of milk production per cow, and prices received for milk have a strong positive impact on profitability. Farmers who perceive potential lifestyle benefits that might be obtained by implementing a grazing system likely do not have to pay an income penalty for adopting a grazing system.

Estimating risk‐adjusted interest rates for dairy farms

The Capital Asset Pricing Model (CAPM) is used to estimate the cost of equity for each of 62 New York dairy farms that participated in a business analysis program from 1988 through 1997. The estimated betas were statistically less than one for all farms. Risk‐adjusted interest rates ranged from a high of 9.46 per cent to a low of 0.72 per cent, reflecting these low estimated betas.