D.V. Armstrong

Pregnancy outcomes in two commercial dairy herds following hormonal scheduling programs

There are a number of options for hormonal management of post partum dairy cows; however, only a few studies have made direct comparisons of these programs in commercial herd settings. We compared reproductive management programs of 2 commercial dairy herds to evaluate the efficacy of prostaglandin-based treatment regimens on reproductive outcomes. Cows in Herd A were left untreated and served as the negative controls. Cows in Herd B were given PGF2alpha every 14 d until first insemination beginning 45 d post partum and served as the positive controls. Treatment 1 (Ovsynch), initiated randomly during the estrous cycle, consisted of sequential injections of GnRH, PGF2alpha, GnRH again and insemination 16 to 20 h later. Treatment 2 consisted of an Ovsynch protocol, as described above, which was begun 7 d post estrus (Ovsynch + 7). In Herd A, the number of days from parturition to conception (days open) for controls, for Ovsynch and for Ovsynch + 7 were 126, 112 and 102, respectively. In Herd B, respective days open were 102, 100 and 93 for controls, Ovsynch and Ovsynch + 7. Hormonal intervention reduced the number of days open in both herds.

“Perceptions as Reality” on Large-Scale Dairy Farms

Recent psychological research supports the claim that decision-makers respond to their perceptions of uncertainty in their businesses. Using large-scale Arizona dairy operations as a case study, this analysis indicates that operators of large industrialized farms perceive their business environments in a unique manner. Farm size, age, and ownership variables were particularly significant in explaining perception and management response rankings. Efforts to correlate perceptions to management responses produced mixed results.

Relocation and expansion planning for dairy producers

Relocating or expanding a dairy facility requires a tremendous amount of time and planning. Owners or managers of dairies will go through a number of steps including: 1) developing a business plan; 2) choosing a design process; 3) developing specifications; 4) selecting location/site; 5) obtaining permits/legal; 6) obtaining bids; 7) selecting contractors; 8) buying cattle; 9) purchasing feeds; 10) financing; 11) managing construction; 12) hiring and training employees; 13) developing management protocols for the dairy; and 14) managing information flow. The dairy can be divided into these components: 1) milking parlor; 2) cow housing; 3) special needs facility (e.g., hospital, closeups); 4) replacement heifer housing; 5) manure management system; and 6) feed center. This article will focus on milking parlors, cow housing, grouping strategies, and site selection.

Influence of season and microclimate on fertility of dairy cows in a hot-arid environment

Records were obtained over a 3 year period from six Holstein dairy farms of 300 to 500 cows each in the Phoenix, Ariz. area. Dairies were selected on the basis of similar management practices, herd size, milk production and facilities (with the exception of cooling systems). Microclimatic modifications (two dairies each) were shade only (approximately 3.7 m2/cow), evaporative-cooled shades and low-pressure water foggers under the shades. Data were categorized by season of calving (spring, Feb.–May; summer, June–Sept.; and fall, Oct.–Jan.). Traits evaluated were calving interval, days open and services/conception. Calving interval was shortest for cows calving in the spring (378 days), intermediate in fall (382 days) and longest in summer (396 days). Similar seasonal trends were observed for days open (103, 103 and 119 days, respectively) and services/conception (1.54, 1.81 and 1.93, respectively). All differences between spring and summer were significant (P < 0.05). Calving interval and days open were less for evaporative-cooled groups (374 and 98 days, respectively), with no difference between shade only and foggers (391 and 392 days, 112 and 116 days, respectively). Services/conception were similar for all groups (1.72 to 1.79). A significant interaction between microclimate and season for services/conception could be interpreted as (i) smaller season differences for evaporative-cooled groups than for shade or foggers, or (ii) a change in the ranking of control and fogger groups during summer versus fall. Evaporative cooling was more effective than fogging for reducing the detrimental effects of seasonal high temperatures on fertility.

Impact of frequency of feedline soaking combined with evaporative air cooling in a humid environment

Heat stress in hot and humid environments reduces milk production, decreases reproduction, and increases health-related problems. The summertime environment in north-central Florida is especially difficult because the combination of high relative humidity and high temperature results in a temperaturehumidity index (THI) above the critical value of 72 for significant portions of the day. Previous work at Kansas State University had shown that the combination of soaking and evaporative air cooling could effectively cool heat-stressed cattle. Effectiveness of this feedline soaking, either in the afternoon and at night, or only at night, in combination with evaporative cooling was evaluated on a commercial dairy located in north-central Florida. A high-pressure fogging system and feedline soakers were installed in a typical 4-row freestall barn equipped with tunnel ventilation creating a north to south airflow of 6 to 8 mph at the cow level. Eight lactating Holstein cows in each of two, 292-stall pens were selected and fitted with vaginal temperature probes. Data on vaginal temperature and respiration rate were used to evaluate two cooling treatments. Barn temperature averaged 74.8 ± 5.4oF, relative humidity was 84.6 ± 15.4 %, and THI was 74.7 ± 5.3 during the study. The evaporative cooling system reduced average barn temperature by 0.9oF and reduced afternoon temperatures by a maximum of 9.2oF. Average respiration rates were less (58.5 vs. 66.9 breaths/min) in the afternoon and night soaking treatment, compared with the respiration rate of cattle in the night soaking treatment. Differences were greatest at the 10:00 p.m. observation (55.0 vs. 73.3 breaths/min). Average vaginal temperature was also less (102.0 vs. 102.6°F) in the afternoon and night soaking treatment. Our results indicate that the combination of cooling the air via a highpressure fogging system and feedline soaking reduced heat stress experienced by dairy cattle. Using feedline soaking during the afternoon and night was more effective than soaking only at night.

Impact of soaking cows housed in a tunnel-ventilated, evaporative-cooled barn in Thailand

Ten multiparous lactating Holstein cows were arranged in a replicated 5 × 5 Latin Square design to evaluate the effect of soaking frequency and volume of water per soaking on lactating cows housed in a tunnel-ventilated and evaporative-cooled freestall barn. Rectal temperature, respiration rate, and body surface temperatures were measured every 5 minutes. Treatments were: control (C); soaking every 5 minutes with 0.26 gallons (5L); soaking every 5 minutes with 0.53 gallons (5H); soaking every 10 minutes with 0.26 gallons (10L); or soaking every 10 minutes with 0.53 gallons (10H). Average ambient temperature and humidity were 86.5oF and 68% outside the barn, and 80.4oF at 86% inside the barn, respectively. Water having a temperature of 80.6oF was applied manually from the shoulder to the tail. Treatments were applied after three initial measurements were assessed. Seventeen measurements were made during treatment application and five measurements after the treatments were stopped. Air velocity over the shoulder of the cows was 4 mph. Respiration rate and body surface temperature for all treatments were less than those of the control, except for rear udder surface temperature in the 10L treatment. Rectal temperature for 5L, 5H, and 10H were less than those of the control. Respiration rate for 5L and 5H were less than that of 10L. These data indicate that soaking can be used in combination with tunnel ventilation and evaporative pads to reduce heat stress.