The Effects of Sex-Sorted Semen on Southern Dairy Farms

This paper examines the impact of sex-sorted semen adoption on dairy farm level economics. Representative dairies are used to simulate the financial impacts of moving to this new technology. Key economic, financial and herd dynamics will be compared among dairies to show how the uses of sex-sorted semen will affect dairy farms. All seven of the representative dairies that were analyzed sold surplus replacement heifers using sex-sorted semen. The increase use of sex-sorted semen can have very positive impacts on dairies throughout the Southern United States.Dairy production, sex sorted semen, production economics, scenario analysis, Agribusiness, Farm Management, Livestock Production/Industries, Production Economics,

Economic Outlook for Representative Dairies Given the August 2006 FAPRI/AFPC Baseline

While projected milk prices are a primary determinant of the financial viability of the representative dairies, the prices of feed crops and cattle prices can also have an impact. Most of the dairies produce hay, silage, and other crops and are often net buyers. Commodity prices have a major impact on dairy returns because feed represents the number one cost for dairies. With the recent increase in demand for corn, prices are projected to increase, potentially affecting rations and feed costs.Agribusiness, Agricultural and Food Policy, Livestock Production/Industries,

MILK SUPPLY RESPONSE IN CALIFORNIA: EFFECTS OF PROFITABILITY VARIABLES AND REGIONAL CHARACTERISTICS

This article discusses supply response for milk in California with the emphasis on the impact of profitability of milk production. Profitability variables are specified as profit margin per cow due to the availability of cost of production data. California production is disaggregated into five regional response equations for market (Grade A) milk and an equation for manufacturing milk (Grade B). Econometric results for larger, more specialized dairies indicate very inelastic responses and long production lags. Results for smaller, less specialized dairies indicate elastic responses and somewhat shorter lags.Livestock Production/Industries,

Management factors associated with bovine respiratory disease in preweaned calves on California dairies: The BRD 100 study.

The objective of this cross-sectional study was to determine how management practices on California dairies may be associated with bovine respiratory disease (BRD) in preweaned calves. A convenience sample of 100 dairies throughout California, providing a study population of 4,636 calves, were visited between May 2014 and April 2016. During each farm visit, in-person interviews with the herd manager or calf caretaker were conducted to collect information about herd demographics, maternity pen, colostrum and calf management, herd vaccinations, and dust abatement. A random sample of preweaned calves was identified and evaluated for the presence of BRD using a standardized tool. A survey-adjusted generalized linear mixed model with a logit link function was fitted with calf as the unit of analysis and dairy as the random effect. Mean study herd size (±SE) was 1,718 (±189.9) cows. Survey-adjusted estimates of breed types in the sample were 81.6% (±0.6) Holstein, 13.1% (±0.4) Jersey, and 5.3% (±0.5) crossbred or other purebred breeds, and calf sex proportions were 73.8% (±1.0) female and 26.2% (±1.0) male. Overall survey-adjusted BRD prevalence in the study herds was 6.91% (±0.69). Housing factors positively associated with BRD were metal hutches compared with wood hutches [odds ratio (OR) = 11.19; 95% confidence interval (CI) = 2.80-44.78], calf-to-calf contact in calves >75 d of age (OR = 9.95, 95% CI = 1.50-65.86), feeding Holstein calves <2.84 L of milk or replacer per day (OR = 7.16, 95% CI = 1.23-41.68), and lagoon water used for flushing manure under hutches compared with no flush (OR = 12.06, 95% CI = 1.93-75.47). Providing extra shade over hutches (OR = 0.08; 95% CI = 0.02-0.37), feeding calves at least 90% saleable milk (OR = 0.27, 95% CI = 0.13-0.54) or pasteurized milk (OR = 0.10; 95% CI = 0.03-0.36), and feeding >5.68 L of milk or replacer per day to Jersey calves (OR = 0.04; 95% CI = 0.01-0.28) were negatively associated with BRD. Our study identified management practices on California dairies with variability and that may contribute to differences in BRD prevalence, which will be incorporated into a risk-assessment tool to control and prevent BRD in preweaned dairy calves

Experiences of Organic Dairy Farmers with Ailing Milk Markets - A Sociological Study in Northern Germany -

The case refers to organic milk production and the marketing of organic milk produce. We describe the situation of two groups of organic dairy farmers working in northern Germany. The two groups are confronted with an extremely difficult choice. They have to choose whether they will continue to follow a quality oriented strategy of organic farming or whether they will favour mass production concepts – based on the principles for organic production of course. Against this background several general results can be drawn from our study. The process which we characterize as “transforming rural communication” is actually underway in rural areas. The consciousness of problems and tasks related to the development of rural areas has become stronger. More off, actors who want to dedicate themselves to these tasks are joining together. In Germany, significantly more regional initiatives can be found today than several years ago, whereby certain political promotion programs play a large role

Environmental sampling to assess the bioburden of Mycobacterium avium subspecies paratuberculosis in drylot pens on California dairies.

Mycobacterium avium subspecies paratuberculosis (MAP) is a bacterium that can cause substantial economic losses in infected dairy herds due to reduced milk production and increased cow-replacement costs. In order to control MAP in dairies with drylot pens, a standardized environmental sampling protocol to quantify MAP in fecal slurry was developed based on an existing protocol for freestall pens. Specifically, following a 24 h hold of the flush, a grab sample of approximately 10 ml of fecal slurry was collected every 1 m along the flush lane of the drylot pens, avoiding individual cow fecal pats. To determine the reliability and repatability of the new environmental sampling protocol for estimation of MAP bioburden at the pen level, two collectors simultaneously collected fecal slurry samples every day for 3 days from six drylot cow pens on two Central California dairies. During the study period no cow movement between pens was allowed with the exception of sick cows. The study herds had MAP seroprevalence of 5.8% and 3.2%, respectively, based on whole pen serum ELISA results. Variance components models for quantitative real-time PCR (qPCR) results showed samples collected from different pens on different dairies accounted for greater variablitiy in MAP concentration (65%), while samples collected by different collectors had the least variability (0.1%). In contrast, variability in MAP concentration in environmental samples collected on different days had 25% variability. The intraclass correlation coefficient showed high reliability (93%) of environmental sampling simultaneously by different collectors. In contrast, the reliability of environmental sampling at different days was 65%, which was similar to the reliability for sampling by different collectors on different days. Investigators can expect high reliability when employing the new environmental sampling protocol along with qPCR testing of environmental samples from drylot pens

Bayesian estimation of diagnostic accuracy of fecal culture and PCR-based tests for the detection of Salmonella enterica in California cull dairy cattle.

Epidemiological studies of low prevalence disease problems are often hindered by the high cost of diagnostic testing. The objective of this study was to evaluate PCR screening of both individual and pooled fecal samples from culled dairy cows for the invA gene of Salmonella followed by culture to determine if the sensitivity and specificity were comparable to the results from traditional culture methods applied to individual samples. Cows from six different dairies were sampled in all four seasons. A total of 240 individual cow fecal samples, 24 fecal pools and 24 pools of 24-hour tetrathionate enrichment broth were tested. Diagnostic sensitivity of PCR screening followed by culture of PCR positive or indeterminate samples (i.e PCR-CUL method) was lower than that of culture (CUL) when applied to individual fecal samples (94.8%, 99.5%), however the specificity was comparable (99.6% and 97.7% respectively). For pools of five fecal samples and pools of five, 24 h tetrathionate broth samples, the specificity of both tests were comparable (∼98%); however, their sensitivity was only comparable in pooled fecal samples (∼93%) but greater for culture compared to PCR-CUL in pooled broth samples (∼99% versus ∼93%). Compared to culture results from testing of individual fecal samples, testing pooled fecal samples by culture had a relative sensitivity of 74% and relative specificity of 96%, testing pooled fecal samples by PCR-CUL resulted in relative sensitivity of 90% and relative specificity of 96%. Testing of pooled 24-hour enrichment broth by PCR-CUL increased the relative sensitivity and specificity to 100%. PCR testing followed by culture of positive or indeterminate samples is a time saving alternative to traditional methods. In addition, pooling of samples may be a useful method for decreasing cost if study aims can accommodate a moderate loss of relative sensitivity

Reducing use of antimicrobials — Experiences from an intervention study in organic dairy herds in Denmark

With the aim of phasing out the use of antimicrobials 23 Danish organic dairy producers from the same organic dairy company participated in Stable School farmer groups from February 2004 to March 2005 in order to go through a common learning and development process towards their common goal. Data on production and herd health were evaluated from two years before to three years after the start of the Stable Schools. For comparison, data was collected from the remaining 35 herds delivering to the same dairy company, 118 organic dairy herds delivering to other dairies and 115 conventional herds. On average, the project herds were smaller with lower production and had half the incidence rate of mastitis treatment than the organic herds from other dairies before the start of the project. The incidence rate of mastitis treatments was reduced considerably from 20 treatments per 100 cow years to 10 treatments per 100 cow years after the project period. Somatic cell count (SCC) and scores for acute and chronic intramammary infections did not change significantly during the study period, and milk production increased at the same rate as in the other herd groups. The incidence rate of mastitis treatments or the reduction of the incidence rate could be related to the herd SCC or the prevalence of blind quarters. The incidence rates of locomotive disorders and reproductive disorders were lower in the project herds compared with herds from other dairies before the project start, and the differences increased during the project period though the reduction of the incidence rates in the project herds was not statistically significant. It is concluded that the farmers participating in the Stable Schools managed to reduce the use of antimicrobials in their herds also after the project period without apparent negative effects on production and udder and herd health