Loren W. Tauer

The Cost of Generic Clinical Mastitis in Dairy Cows as Estimated by Using Dynamic Programming

The objective of this study was to estimate the cost of generic clinical mastitis (CM) in high-yielding dairy cows given optimal decisions concerning handling of CM cases. A specially structured optimization and simulation model that included a detailed representation of repeated episodes of CM was used to study the effects of various factors on the cost of CM. The basic scenario was based on data from 5 large herds in New York State. In the basic scenario, 92% of the CM cases were recommended to be treated. The average cost of CM per cow and year in these herds was

Effects of clinical mastitis caused by gram-positive and gram-negative bacteria and other organisms on the probability of conception in New York State Holstein dairy cows

71. The average cost of a CM case was

SHORT-RUN AND LONG-RUN EFFICIENCIES OF NEW YORK DAIRY FARMS

179. It was composed of

Effects of repeated gram-positive and gram-negative clinical mastitis episodes on milk yield loss in Holstein dairy cows.

115 because of milk yield losses,

The cost and management of different types of clinical mastitis in dairy cows estimated by dynamic programming

14 because of increased mortality, and

The Cost and Benefit of Listeria Monocytogenes Food Safety Measures

50 because of treatment-associated costs. The estimated cost of CM was highly dependent on cow traits: it was highest (

The Empirical Impact of Bovine Somatotropin on a Group of New York Dairy Farms

403) in cows with high expected future net returns (e.g., young, high-milk-yielding cows), and was lowest (

Effects of repeated episodes of generic clinical mastitis on mortality and culling in dairy cows.

3) in cows that were recommended to be culled for reasons other than mastitis. The cost per case of CM was 18% higher with a 20% increase in milk price and 17% lower with a 20% decrease in milk price. The cost per case of CM was affected little by a 20% change in replacement cost or pregnancy rate. Changes in CM incidence, however, resulted from changes in these factors, thus affecting whole-farm profitability. The detailed results obtained from this insemination and replacement optimization model can assist farmers in making CM treatment decisions.

Age and Farmer Productivity

The objective of this study was to estimate the effects of different types of clinical mastitis (CM) on the probability of conception in New York State Holstein cows. Data were available on 55,372 artificial inseminations (AI) in 23,695 lactations from 14,148 cows in 7 herds. We used generalized linear mixed models to model whether or not a cow conceived after a particular AI. Independent variables included AI number (first, second, third, fourth), parity, season when AI occurred, farm, type of CM (due to gram-positive bacteria, gram-negative bacteria, or other organisms) in the 6 wk before and after an AI, and occurrence of other diseases. Older cows were less likely to conceive. Inseminations occurring in the summer were least likely to be successful. Retained placenta decreased the probability of conception. Conception was also less likely with each successive AI. The probability of conception associated with the first AI was 0.29. The probability of conception decreased to 0.26, 0.25, and 0.24 for the second, third, and fourth AI, respectively. Clinical mastitis occurring any time between 14 d before until 35 d after an AI was associated with a lower probability of conception; the greatest effect was an 80% reduction associated with gram-negative CM occurring in the week after AI. In general, CM due to gram-negative bacteria had a more detrimental effect on probability of conception than did CM caused by gram-positive bacteria or other organisms. Furthermore, CM had more effect on probability of conception immediately around the time of AI. Additional information about CM (i.e., its timing with respect to AI, and whether the causative agent is gram-positive or gram-negative bacteria, or other organisms) is valuable to dairy personnel in determining why some cows are unable to conceive in a timely manner. These findings are also beneficial for the management of mastitic cows (especially those with gram-negative CM) when mastitis occurs close to AI.

Comparing technical efficiency of farms with an automatic milking system and a conventional milking system

Short-run and long-run technical and allocative efficiencies were computed for 395 New York dairy farms using data envelopment or nonparametric procedures on 1990 Dairy Farm Business Summary data. The farms were, on average, more allocatively efficient in the short run than in the long run, but were more technically efficient in the long run than in the short run. Stanchion barns were as efficient as milking parlors, and milking more than two times per day did not increase efficiency.