ASAE Conference Proceeding
This is not a peer-reviewed article.
Observations on Building Design and Youngstock Health
C. E. Gardner, DVM, MBA
Pp. 345-349 in Fifth International Dairy Housing Proceedings of the 29-31 January 2003 Conference, (Fort Worth, Texas, USA), ed. K. A. Janni. ,Pub. date 29 January 2003 . ASAE Pub #701P0203
Agway Feed and Nutrition Company operates four commercial calf and heifer rearing facilities in New York and Pennsylvania, with a total of roughly 11,000 animals under care. This program seeks to maintain tight biosecurity and disease control. Building design has had a pronounced effect on disease incidence and severity, due to differences in ventilation and isolation. Greater isolation reduces spread of disease, as does superior ventilation. However, inadequate protection of young animals can result in increased pneumonia. Building design also impacts injuries and ease of animal movement. This presentation will demonstrate and explain the above factors.KEYWORDS. Disease, Injuries, Pneumonia, Protection, Ventilation
Building design often has an effect on animal health and performance. Ventilation, animal isolation, ease of cleaning, access to feed and water, and susceptibility to injury are some areas that are impacted by design. Ability to move animals easily is another. Once construction is completed, changes are either expensive or impossible to do; therefore it is important for the original design to be correct.
Between 1998 and 2000, Agway Feed and Nutrition Company constructed four commercial calf and heifer raising facilities, designed to accommodate a total of 11,000 animals. The farms are located in Western New York (WNY), northern New York (NNY), Eastern New York (ENY), and Pennsylvania (PA). The range of age is from baby calves to heifers 7 months pregnant. A cornerstone of Agway’s program is to provide biosecurity and to minimize disease. After 3 and a half years of operation, the impact of building design is evident. This paper will discuss some of the things Agway has observed.
All of the New York State facilities have four sided barns, with curtained side walls and an open ridge. Once animals reach 12 weeks of age, free stalls are used, with both four row and six row configurations. In Pennsylvania longer, narrower, buildings, with mono-sloped roofs and open fronts were constructed. Two row and three rows of free stalls exist there. The four and two row configurations were used in the breeding barns, where it is necessary to lock up every animal every day.
It should be noted that the data reported in this paper comes from observation of events that occurred during normal operation of these facilities. No controlled studies were done, as we were trying to get the best health and performance from all calves at all times. Confounding situations sometimes exist that make it difficult to form definite conclusions, but we at Agway have formed some opinions regardless. This paper will review the facts and our opinions.
Baby Calf Housing
The facilities in WNY and ENY house calves from new-born to six weeks in individual pens located within buildings measuring 15m by 18 m (50 ft by 60 ft), with 3 m (10 ft) side walls and a 20 cm (8 inch) ridge opening. The ridge opening is covered by a “cap” placed roughly 20 cm (8 inches) above the ridge. They have a conventional “A” roof with translucent panels to let in sunlight, and a 4:12 slope. Curtains on the side-walls can be positioned to facilitate or restrict air flow. Four rows of pens, with 12 pens in each row are located in each barn. Stalls are filled as calves are admitted, usually taking roughly one week to fill a barn. Pen size is 1 m by 2.2 m (39 inches by 86 inches).
The NNY farm utilizes a “coverall” type of design, which provides more air space above the calves. The barns there are 15 m by 33 m (50 ft by 108 ft, with four rows of 12 pens on both ends, separated in the middle by a 6 m (20 ft) space. Each end is treated as one “barn”.
In contrast to these facilities, the PA site utilizes single rows of 46 pens, with a mono-slope roof, open to the south. Calves in this housing set-up are much more isolated than in the other three facilities. This farm experiences significantly less disease and deaths among pre-weaned calves than do the ones using the other type of housing. While weather conditions and personnel differ between the facilities, the primary factor affecting the disease rate is believed to be facility design. The chart below summarizes mortality rate for the four units, from July 1, 2001 to June 30, 2002. Mortality is defined as # pre-weaning deaths divided by number of calves started. Morbidity data follows a similar pattern.
Pre-Weaned Mortality Rate, July 2001-June 2002
NNY Wet Calf Barn New York Wet Calf Pens
WNY and ENY Wet Calf Barn PA Wet Calf Pens
At all of the farms, calves are moved approximately 4 days after weaning to pens of eight calves each. At the WNY farm, each pen has a 3 m by 3.6 m (10 ft by 12 ft) bedded pack area, with a 1.2 m (4 ft) flush alley between the bedded pack and the feed manger. The ENY farm has a 3 m by 5 m (10 ft by 16 ft) bedded pack, and a 2.4 m (8 ft) scrape alley. The NNY farm has pens 3.6 m by 3.6 m (12 ft by 12 ft) with a 1.5 m (5 ft) walk alley between the pen and the edge of the barn, plus a 2 m (7 ft) flush alley between the pack and the feed alley. This farm also has the “coverall” design, providing more air space over the calves. The WNY farm has the least total square footage of space per animal, and the NNY has the most.
The PA site once again utilizes the “half barn” design, with 5 m by 5m (15 ft by 15 ft) bedded areas and a 2.4 m (8 ft) scrape alley. The barn is 73 m (240 ft) long. Initially there were no solid dividers to block wind currents. During the fall of 2000, a high incidence of respiratory disease was noted. It was our opinion that the building did not provide enough protection from wind, and so floor to ceiling dividers were installed at every other pen. This brought improvement, but the incidence of respiratory problems was still judged to be too high, and growth rates were lower than desired.
In the fall of 2001 “hovers” were installed, consisting of hinged 1.2m by 2.4 m (4 ft by 8 ft) sheets of plywood mounted horizontally 1.8 m (6 ft) feet off the floor along the rear wall of the building. It was noted immediately that calves tended to congregate under the hovers on cold mornings. The incidence of respiratory disease dropped again, and growth rates improved. As in many other on farm situations, the results were confounded to an extent by a concurrent change in calf starter, but we believe the hovers played a significant role in the improvement.
Actual deaths from respiratory disease on our farms is relatively rare. We believe the more important effect is on rate of gain. The chart below shows typical rates of gain for the four units while in the weaning barns. Data for the PA facility is shown before and after the improvements. It should be noted that a wide variation is seen between groups. Weather and personnel also have a huge impact on respiratory disease.
Typical Rate of Gain, Pounds Per Day, Weaning Barns
Weaning Barn, NNY Weaning Barn, WNY
Weaning Barn, Original, PA Weaning Barn, Modified, PA
At approximately 12 weeks of age, calves are moved from bedded packs to free stalls, and a total mixed ration is introduced. As this is the age when calves are adapting to forages, the building used to house them are called “transition” barns. Calves are housed in these barns until roughly 7 months of age. For most of the farms, the incidence of disease in low in these calves, and growth is excellent.
One exception exists at the facility in eastern New York, where the pitch on the roof is judged to be too flat, impinging on ventilation. The quality of the air in this building (Transition Barn) is noticeably poorer than of a very similar, adjacent building (Grower Barn) used for older animals on this farm. The only difference is the pitch of the roof, being 3:12 for the one with poor air quality, and 4:12 for the one with better air quality.
Transition Barn, ENY Grower Barn, ENY
Anytime large numbers of heifers are kept in confinement, injuries are bound to occur. At the Pennsylvania facility, we observed an excessive level of fore-limb fractures between the ankle and knee, for animals in free stalls. Some investigation revealed that construction had departed from the design, replacing a brisket board formed by concrete at the front of the stall with a wooden one mounted on brackets. The latter configuration allowed animals to get a front leg under a mounting support, and then if they tried to rise suddenly led to a facture. Once this fact was known, an additional board was added to the brisket board, making it unlikely for the heifer to get her leg under the support. Fractures stopped, but retrofitting the barns incurred a cost of $12,000.
As animals grow at the farms, they move into barns with larger pens. By three months of age, heifers are grouped in pens of roughly 120 animals each, and are moved every three weeks. Thus roughly 3,000 animals have to be moved every third week. Many of these heifers simply move to an adjacent pen in the same barn, but several hundred will go to a different barn.
To facilitate the moving, fenced “lanes” were constructed between barns. They are 3.3 m (11 ft) wide. However, at one facility the doors leading into the next barn are only 1.2 m (4 ft) wide, and represent a severe bottleneck. While it can be re-built, it would obviously been far better to get it right the first time.
Agway’s T.S.P.F.TM Heifer Program has raised calves and heifers with relatively low mortality and morbidity, while attaining excellent growth rates. In general, building design has served our needs well. As with any animal construction, there are certain features we would do differently in the future. This paper has reviewed some of the areas where we make changes.