A demonstration project of interdisciplinary dairy herd extension advising funded by industry and users. 1. Implementation and evaluation.

An interdisciplinary team of extension workers conducted a 2-yr demonstration project using 30 herds with the objectives of increasing production efficiency and profitability and gaining experience in integrated problem solving. After 1 yr, 88% of the participants thought that the monthly fee paid to extension was a profitable investment. At the end of the project, 70% of the participants thought that increases in milk yield per cow were due to a combination of improvements in two to four management areas rather than to changes in any single management discipline. Additional labor was necessary to implement recommendations. Two issues were key in successfully convincing dairy operators and families to accept management recommendations: 1) a coordinated team effort aimed at integrated problem solving, followed by written recommendations and regular dialogue with the producer, and 2) possession of effective social decision-making skill by the participant family. Most farms in the project depended primarily on family labor and social decision making to implement management changes. Only those families that could jointly agree to implement a new management decision fully benefited from professional advice. A demonstration project of interdisciplinary dairy advising was an effective method to gain problem-solving expertise and to build credibility for extension services.

A demonstration project of interdisciplinary dairy herd extension advising funded by industry and users. 2. Impact on herd performance.

The objectives of this 24-herd, demonstration project of extension advising were to measure the impact of integrated problem solving on measures of DHI performance for 2 yr during and 2 yr after the project. During project advising, increases in rolling herd average milk and fat yields and 3.5% FCM were similar for project and state herds. When rolling herd average for milk yield for state herds was adjusted for two USDA milk reduction programs, milk yield of project herds was estimated to have increased 434 lb more per cow than that of DHI state herds. Compared with state DHI trends, project producers significantly improved in percentage of low SCC, days open, and age at first calving. Two years postproject, DHI milk yield declined for project and state herds, probably because of drought. Demonstration herds did not outperform state DHI herd average in milk yield or in other efficiency parameters during the 2-yr postproject. The extension advising in the demonstration project had the most positive impact on management of low ranking herds. Only low ranking herds had an advantage in rate of improvement, compared with high ranking herds, in rolling herd average for milk yield during and after the project and in SCC and days open during the project. Gains by managers of herds ranking low and in the middle in DHI parameters were generally lost or declining postproject.

A demonstration project of interdisciplinary dairy herd extension advising funded by industry and users. 3. Impact on management practices.

The objectives of this 24-herd, demonstration project of integrated problem solving and extension advising were 1) to evaluate dairy production management practices, 2) to formulate recommendations for guiding producers to correct management deficiencies, and 3) to measure the rate of practice adoption. Management evaluations focused on herd nutrition and forage crops, mastitis control and milking equipment, reproduction, and herd health. Sixty-eight management practices or milking equipment components were evaluated on each farm. A total of 216 recommendations were made in nutrition and forage crops as follows: calf and heifer management, 89; forage crops, 73; dry cows, 26; lactating cows, 19; and general, 9. The least adopted suggestions for nutrition and crops were for forage crop management. A total of 283 recommendations were made in mastitis management or milking equipment as follows: milking practices, 90; milking equipment, 90; general mastitis control, 61; environment, 32; calf management, 9; and stray voltage, 1. Producers most resisted updating and maintaining milking equipment within the milking management area. Detection of estrus was the focus of reproductive management advising. A total of 80 practices were recommended as follows: one person responsible, 24; specific location, 24; specific time, 24; and regular veterinary visits, 10. Designation of a specific site was the least adopted of these recommendations. Overall, 419 of 581, or 72%, of all recommendations were adopted.

Addition of buffers to high quality alfalfa hay-based diets for dairy cows in early lactation.

Beginning 4 wk postpartum, 14 Holstein cows were paired according to expected calving date and lactation number and assigned randomly to one of two treatments in a single reversal experiment designed to study the effects of added buffers to high quality alfalfa hay-based diets. Cows were offered daily 14.5 kg of concentrate containing 0 or 2% sodium bicarbonate and .5% magnesium oxide (as fed), plus free choice high quality alfalfa hay in a ratio of forage:grain approaching 50:50 (dry matter). No differences were in milk production, milk fat percentage, fat-corrected milk, or dry matter intake. Dry matter intake of grain was decreased with addition of buffers. Kilograms fat-corrected milk per kilogram of dry matter intake were 1.41 and 1.45 for control and buffered diets. No differences were significant for rumen pH, ammonia concentration, molar proportions of acetate and propionate, or ratio of acetate: propionate. Concentrations of total volatile fatty acids were higher for cows fed the buffered diet. No differences were in blood acid-base status or in various serum metabolites. Urine pH was 8.11 and 8.20 for control and buffered diets. Fractional urinary excretion of magnesium and sodium was greater when cows consumed the buffered diet. Diet digestibilities and rate of passage were not affected by dietary buffers. Addition of sodium bicarbonate plus magnesium oxide did not improve performance of early lactation cows fed high quality alfalfa hay as the sole forage.