Ability of low profile cross-ventilated freestall barns to improve environmental conditions for dairy cattle

Recently, there has been interest in constructing mechanical ventilation with evaporative pads to improve the environmental conditions for cows during periods of heat stress. Low profile cross-ventilated freestalls with evaporative pads (LPCV) have become a popular system. The purpose of this study was to evaluate how well these LPCV systems improve the temperature-humidity index (THI) under different ambient conditions. As ambient humidity increases, ability of the LPCV to reduce THI is decreased. Producers wishing to construct LPCV barns should carefully evaluate the climate in which they want to construct LPCV structures.; Dairy Day, 2007, Kansas State University, Manhattan, KS, 2007; Dairy Research, 2007 is known as Dairy Day, 200

Development of a Berry Processing Score for Sorghum Silage

This study was done in an effort to develop a berry processing score (BPS) for sorghum silage, similar to the kernel processing score (KPS) currently used for corn silage. Sorghum silage samples were collected from 3 dairies in Kansas and processed in the Grain Science & Industry grain processing laboratory at Kansas State University using one of four different roll gap settings to give four differently processed samples: unprocessed, 1.5, 1.0, or 0.5 mm. After drying, samples were placed into a Ro-Tap particle separation machine for 10 minutes until the whole sample was separated. Whole samples, as well as separated fiber and whole berry portions were analyzed for percent starch retained on each screen. As the roll gap was reduced, mean particle size (MPS) was also reduced. Percent starch passing through the 1.7 mm screen was greater at the 0.5 mm roll gap for both the whole sample and the whole berry samples, indicating successful processing of the samples. Using these data, we have determined that the appropriate screen to use in determining a BPS for sorghum silage is the 1.7 mm screen. A BPS for any sorghum silage sample can be calculated by analyzing the whole sample for the percent starch that passes through the 1.7 mm screen. This study is still ongoing and more research is needed to determine the recommended BPS in sorghum silage

Influence of freestall building orientation on comfort of lactating dairy cattle during summer heat stress

A trial was conducted during the summer of 2000 to evaluate the effect of freestall building orientation ”east-west vs. northsouth ” on respiration rates of lactating dairy cows, temperature-humidity index (THI) in the barns, barn temperature, and barn humidity. Differences between ambient and barn temperature and THI were higher in east-west vs. north-south orientated barns. Respiration rates were higher in north-south than in east-west orientated structures. The magnitude of differences between barn and ambient temperatures and THI did not fully explain differences in respiration rates between north-south and east-west orientated barns. Other factors such as solar radiation, airflow, and animal stress may have contributed to the differences in respiration rates.; Dairy Day, 2001, Kansas State University, Manhattan, KS, 2001

Keeping cows cool

Heat stress occurs when a dairy cow’s internal heat load is greater than her capacity to lose unwanted heat to the environment. Effects of heat stress include: increased respiration rate, increased water intake, increased sweating, decreased dry matter intake, slower rate of feed passage, decreased blood flow to internal organs, decreased milk production, and poor reproductive performance. Lower milk production and reproductive performance cause economic losses to dairy producers. The ordered priorities for reducing heat are: increasing water availability; providing shade in the housing areas (both dry and lactating cows) and holding pen; reducing walking distance to the parlor; reducing time in the holding pen; improving holding pen ventilation and freestall ventilation; adding cooling for the holding pen and exit lane; cooling close-up cows (3 wk before calving); cooling housing for fresh and earlylactation cows; and cooling housing for midand late-lactation cows

Use of Evaporative Cooling Systems and Their Effects on Core Body Temperature and Lying Times in Lactating Dairy Cattle

A study was performed to assess the effect of an evaporative cooling system on respiration rates, rear udder temperature (Tu), core body temperature (CBT), and resting time in lactating dairy cows. Cows were divided into two treatment groups and rotated between two facilities. Cows were either housed in a bedded pack barn (PACK) equipped with an evaporative cooling system (Cyclone fans, Chippewa Falls, WI) or a tie-stall barn (TIE) equipped with cooling cells. Cows housed in PACK had two cooling treatments: FAN (Cyclone fans only, no fog); and FANFOG (Cyclone fans and fog on). Groups of cows rotated between TIE and PACK every 8 hours, and effects of housing as well as cooling treatment within PACK were analyzed. During FANFOG, PACK cows had a reduction (P \u3c 0.05) in respiration rate (breaths per minute) in comparison to TIE (69 vs 76 ± 2.4 BPM). Breaths per minute also increased significantly throughout the day for TIE but this was not the case for PACK. No differences were found in Tu between treatments. While exposed to the FANFOG environment, cows spent decreased time above 102.2°F CBT when compared to FAN. Cows housed in PACK during FAN and FANFOG also spent fewer hours/ day above 102.2°F CBT vs TIE. Cows housed in TIE showed numerically greater total daily lying times during FAN and FANFOG compared to cows housed in PACK, although these results were not significant. These results confirm that evaporative cooling systems (Cyclone fans and fog) are effective at decreasing respiration rates and CBT, while having no effect on Tu and lying times in lactating dairy cows

Drinking water requirements for lactating dairy cows

A study to determine the amount and location of water consumption in dairy freestall barns located in northeastern Kansas was conducted during the summer of 2000. Three farms, two Holstein farms with either 2-row or 4-row freestall barns and one Jersey farm with 4-row freestall buildings, were used. Summer water usage averaged 30 to 40 gallons per Holstein cow/day and 20 to 40 gallons/cow/day for Jersey cows depending on age and stage of lactation. The farms with Holstein cows had a water usage ratio of 4 to 4.5 lb of water per lb of milk produced and Jersey cows required 3.1 lb of water per lb of milk production. However, at the Holstein dairies, only about 85% of this water was consumed and the other 15% was utilized to refill the tanks after tipping twice daily to clean cross-overs and water troughs. In addition, 35 to 45% of the water consumed is from a water station in the center crossover of each pen. Cattle also drank the least amount of water from the trough located in the crossover furthest from the pen entrance. When given access to a water trough on the milking parlor exit, cattle consumed 10% (3.5 gallons/cow/day) of the daily water intake at this location. Water usage for drinking increased as milk production increased. Adequate water system capacity and water rights are needed to make allowances for future increases in milk production. Water consumption was greater at the center alleys. Therefore, engineers should consider additional space and/or water troughs at these watering stations.; Dairy Day, 2001, Kansas State University, Manhattan, KS, 2001

Effect of headlocks on milk production and feed intake of dairy cattle

Cows previously trained with headlocks did not increase milk production or feed intake when headlocks were removed. Twoyear- old and older cows did not differ in response to headlocks and neckrails. Prudent use of headlocks increases labor efficiency of a commercial dairy. Managing a dairy without headlocks is a challenge because cows must be sorted and worked off the milking parlor flow. In the case of large milking parlors, it may be necessary to process 50-200 cows per hour. Depending upon the treatment facilities, this number of cows may create a bottleneck in the dairy. For many routine procedures, headlocks offer the simplest and most cost-effective alternative. It is important to note that headlocks can be mismanaged. This is especially true during summer months. Locking up cows for extended periods without access to water or shade may have adverse effects during summer heat stress. It is important to minimize lock-up time. Consideration should also be given to training heifers to headlocks prior to calving. It is very likely that untrained heifers may be reluctant to be placed in headlocks. If this occurs, intake could be limited during their first exposure to headlocks. If heifers are not trained to headlocks prior to calving, one should determine if they should be locked-up each day during the first week of lactation. Headlocks can be successfully used on a dairy. The critical question is how will they be managed. Successful managers of headlocks minimize restraint time, push-up or feed pens often (6- 8 times per day), and avoid use of headlocks during late morning and afternoon hours during the summer months

Consumptive water usage of evaporative pads

Dairy Research, 2006 is known as Dairy Day, 2006Consumptive water usage by evaporative pads was measured during 7 days of a 3-week period at a Kansas (KS) dairy and a 2-day pe-riod at a North Dakota (ND) dairy. Water me-ters were installed between the water hydrants, and evaporative pads at each dairy, and were monitored. Data were recorded every 30 min-utes during 5 hr at the KS site and every 15 minutes during 1 to 2.5 hr at the ND site. Ra-tio of pad area to cow equaled 4.8 and 4.5 ft2 per cow at the KS and ND sites, respectively. Airflow rates through the pads were 1.2, 2.1, and 3.2 mph at the ND dairy and 3.3 mph at the KS dairy. During the study period in KS, the temperature humidity index ranged from 78 to 86 and water usage varied from 0.7 to 4.7 gallon per minute. Average pad efficiency equaled 62%. Water usage averaged 0.3 gal-lons per hr per ft2 of pad when airflow rate was 3.3 to 3.6 mph. At the ND dairy, the wa-ter usage averaged 0.1, 0.3, and 0.38 gallon per hr per ft2 of pad for the low, medium, and high airflow rates, respectively. The tempera-ture humidity index equaled 65, 72.5, and 71 for the low, medium, and high airflow study periods. Pad efficiency averaged 93, 86, and 81% from the low to high airflow rates. Simi-lar to pad efficiencies at the KS site, efficiency increased as the outdoor air temperature de-creased. (Key Words: Coolin

The Effects of an Evaporative Cooling System on Reducing Heat Load in Lactating Dairy Cows

This study was conducted to evaluate the effect of 2 cooling systems on barn temperature, core body temperature (CBT), respiration rate, rear udder temperature, and lying time in lactating Holstein dairy cows. Twenty lactating Holstein dairy cows were randomly assigned to 1 of 2 treatment groups: CONV, where cows were housed in a conventional, open-sidewall freestall barn equipped with feedline soakers and fans located over the feedline and stalls; and TUNNEL, where cows were housed in a tunnel-ventilated freestall barn utilizing an evaporative cooling system. TUNNEL was effective at reducing barn temperature humidity index (THI) compared to CONV, but failed to alter CBT (101.5 ± 0.04°F). TUNNEL cows had reduced respiration rates (52.0 vs. 57.9 ± 2.2 breaths per minute) and skin temperatures (91.8 vs. 94.1 ± 0.6°F) compared to CONV, while TUNNEL cows had increased lying time by 1 hour per day (11.8 vs. 10.8 ± 0.3 hours per day). Overall, the evaporative cooling system (TUNNEL) was effective in reducing barn THI leading to reduced respiration rates and rear udder temperatures and increased daily lying time. No treatment differences were detected for CBT, however, likely a result of the cooler ambient conditions under which the study took place

Development of a Berry Processing Score for Sorghum Silage and Assessment of Processing Effects on Sorghum Silage Starch Digestibility

The objectives of this study were to develop a berry processing score (BPS) for sorghum silage, similar to the kernel processing score currently used for corn silage, and to evaluate the effects of processing on starch digestibility. Sorghum silage samples were collected from commercial farms in Kansas and randomly assigned to 1 of 4 processing levels differing in roll gap spacing: unprocessed (UNP), 1.5 (1.5P), 1.0 (1.0P), or 0.5 (0.5P) mm. Differences in BPS and starch digestibility were found–as the roll gap decreased, both BPS and starch digestibility increased. Thus, by processing sorghum silage during harvest and measuring the extent of processing, sorghum silage starch digestibility can be greatly enhanced. Sorghum silage may serve as a viable alternative to corn silage in the diets of lactating dairy cows in areas of the country where corn silage is a high-risk forage crop due to lack of water