Defining and Managing Special Cows
| Title | : | Defining and Managing Special Cows |
| Source | : | Cornell University |
| Author | : | Bill Stone, DVM |
| Date | : | 1997 |
| Content | : |
Defining and Managing Special Cows
By Bill Stone, D.V.M., Ph.D., Senior Extension Associate, PRO-DAIRY Program, Cornell University
Introduction
“Special cows” will be defined here as any animal needing individual attention or requiring unique considerations. Special cows include the following types of animals:
Management considerations for each of these categories of animals will be discussed, with an emphasis on prefresh and fresh cows.
Dry and close-up cows
Cows should be in the dry group from dry-off until three weeks prefreshening. Dry cows should be housed in free-stall barns. They should be observed twice daily. Herdsmen are evaluating cows for any signs of general depression, mastitis, or impending calving. Some dairymen teatdip all dry cows daily for 7-10 days post-dryoff, since this is a time when many new udder infections occur. Restraint facilities would be needed for this and to administer vaccines as dry cows are moved to the close-up group.
Dry cows should be moved to the close-up group from 18-24 days (weekly moves) or 20-23 days (semiweekly moves) pre-calving date. Heifers should be moved one week earlier than cows. Vaccines are often administered at this time. Close-up cows and heifers should be housed in freestalls. The additional square footage and bedding required for a bedded pack is usually not economical.
Animals should be moved to a bedded pack immediately prior (hours to 2-3 days) to calving. The pack should have from 80-100 ft2 (1) of resting space per cow. Many producers will teatdip and check these cows for mastitis daily. A headchute and gate located in one corner of the pack is very useful for restraining cows in need of calving assistance. Since most people are right-handed, locating the chute so that the right side of the animal is closer to the wall will make it easier to assist during calving.
Cows could be moved into boxstalls immediately prior to calving. The main concern with this calving procedure is the additional labor required to clean and bed individual pens. Additionally, management must ensure that these animals have access to fresh feed and water if they are going to be kept in the pen longer than an hour or two.
Bedded packs must always be kept clean and dry for the prevention of disease in both the cow (mastitis, metritis), and the calf (Johnes, cryptosporidiosis). Herds with Johnes disease should consider having two freshening areas – a “clean” area where cows with a low probability of having Johnes disease would calve, and an “infected” area where Johnes confirmed or suspected animals would valve. Dairies have accomplished this dual freshening pack approach in various economical manners. One approach is to use the calving facility in the old barn for the infected cows, and that in the new barn for
the non-infected cows. Another is to move Johnes cows directly from freestalls to a boxstall before freshening, not allowing them to contaminate the main freshening pack.
Calves should be removed from their dams before they begin stumbling around the pack or boxstall. Moving them to a drying box (a plywood box with a heat lamp) is a good practice in cold climates. A small holding pen should be located close to the calving pack to facilitate transfer off of the calving pack.
Floppy disc and a request for a backup were mailed to 280 northeast herds with DairyComp 305 (2). More than 170 herds returned discs; six could not be used due to damage to the disc, while seven more were eliminated because archive files were not included and dead cows were removed from the cowfile in less than 365 days. The final data set contained 86,523 cows in 160 herds (540 cows/herd) where 88,594 freshenings had occurred during the past year. The total number of freshenings that had occurred in each herd over the preceding 365 days was tabulated and compared to the total number of lactating and dry cows on the day the backup was made (Figure 1). Both the mean and median annual number of freshenings exceeded cow numbers by approximately 2%. As Figure 1 indicated, there was considerable variation among herds.
Approximately 26% of herds freshened at least 5% more than their total number of cows, while approximately 17% of herds freshened at least 5% fewer cows than total cow numbers.
The total number of calvings per month for each herd was also tabulated. This was compared to an exactly uniform monthly distribution of freshenings (total number of freshenings/12). It was then assumed that the dairy had designed its prefresh facility using the uniform calving distribution approach. The percent of herds that exceeded the uniform calving distribution by 25, 35, and 50% and the number of months that this occurred were also calculated (Figure 2). Uniform distributions of calvings rarely occur: only 10% of herds had no months when the prefresh group would not have been over-crowded. Spikes in freshenings probably occur primarily due to either the purchase of a relatively large number of animals due to freshen around the same time, or a surge in conceptions following a dip in the reproductive program.
As Figure 2 indicates, using the uniform calving distribution of prefresh facility design would have resulted in 65% of the herds being 25% over-crowded during at least 2 months of the year, while 40% of the herds would have been 35% over-crowded during at least 2 months of the year. Over forty percent of the herds would have had at least one month when the prefresh group was at least 50% over-crowded.
The exact cost of over-crowding the prefresh group is of course not known, and certainly will vary with management’s ability to arise to varying conditions. However, it is known that stress increases the incidence of freshening health disorders. Guard (3) estimated that each retained placenta cost a dairy an estimated $206 while and LDA cost more than $300. Table 1 contains estimated for the number of cows in various special groups. “Perfect uniformity” assumes an even distribution of freshenings throughout the year. “Reality” recognizes that there will be surges in the number of freshenings. Both scenarios assume that there will be five percent more freshenings per year than there are cows (milking and dry) in the herd. “Reality” has tried to take into account surges in calvings that Figure 2 indicates happen quite frequently. Increased use of programs like OvSynch will group freshening s even more, making it even more important to have a large enough pack to freshen cows on. Expanding the freshening pack to be able to handle “reality” as compared to “perfect uniformity” is worth the investment. Space on a bedded pack for each additional animal will cost approximately $1650 per head (4 row barn, 90 ft2 of bedded pack per head, $10/ft2 construction costs). A four percentage point decrease in the incidence of retained placentas and a 1.5
percentage point decrease in the incidence of left displace abomasums would pay for the additional four cows of pack space per 100 cows in a five year time period (Table 1).
Ideally, facilities can be designed with flexibility in mind. Moveable gates to adjust for varying numbers of animals in the dry and prefresh group can be very helpful.
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Table 1. Estimated group sizes for two calving scenarios, and the cost/benefit of additional freshening space.
| Perfect Uniformity1 |
Reality1 | |
| Total cows |
100 |
100 |
| Annual freshenings |
105 |
105 |
| Milking cows |
87 |
82-90 |
| Dry-far cows |
9 |
9-15 |
| Prefresh cows & heifers |
7 |
6-12 |
| Freshening pack |
1 |
5 |
| Fresh pack (1-3 DIM2) |
3 |
3-8 |
| Treated/sick cows(freestalls) |
1 |
1.5-2.5 |
| Spending for “Reality” 4 animals worth of freshenings pack space |
$6600 |
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| Annual savings from a 4 percentage unit Decrease in retained placentas |
$865 |
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| Annual savings from a 1.5 percentage unit Decrease in LDAs |
$490 |
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1”Perfect uniformity” assumes an even distribution of freshenings throughout the year, while reality adjusts for the variability typically seen in dairy herds.
2Fresh (1-3 DIM) cows and injured/lame cows would be kept on this pack.
Fresh cows
It is my opinion that fresh cows should be kept on a bedded pack for a short time period (1-3 days) following calving. This allows them to at least somewhat recover from calving in a more spacious environment. These cows can be crowded slightly more than prefresh cows; 50-70 ft2 per cow is sufficient. Additional time on a pack is not necessary for healthy fresh cows that are being moved to comfortable freestalls.
There are advantages to having a fresh group for both the cow and the herdsman. The group can be managed to prevent over-crowding. They can be fed a ration that may be more appropriate for fresh cows. Also, additives that may be more likely to benefit the fresh cow can be targeted to only them, sparing the expense of feeding them to later lactation cows. The main benefit for the herdsman is one of labor efficiency – cows that need the most attention are grouped together. The general appearance, attitude, and degree of rumination of fresh cows should be evaluated twice daily for the first 7 to 10 days. Additionally, these cows should be evaluated daily for the following: body temperature, rumen fill, uterine discharge, ketosis, and milk production. Cows should stay in the fresh group for a minimum of 7-10 days before being moved to a high group. Longer time periods (40-60 days) may be needed to achieve the benefits of certain feed additives (protected amino acids).
Sick and treated cows
This group can be a real problem – they take longer to milk, milking equipment requires cleaning after milking them, and they are more likely to harbor and break with infectious diseases. Some cows (lame, injured, toxic mastitis) would benefit from being on a bedded pack. Freestalls are fully adequate for others (uncomplicated cases of mastitis, metritis, and respiratory infections). Probably the best compromise between labor efficiency and economics is to put lame or injured animals on the fresh pack, and keep sick cows in their own group on freestalls. Two important principles to keep in mind are fresh cows and sick cows should not share the same pack, and generally and injured animal requiring a protracted recovery period should be culled.
Cows with Salmonella should be immediately isolated from other animals. It is in the best long-term interest of our industry to humanely euthanize any animal that can’t walk onto the cull truck.
Routine task
Facilities should be designed so those cows requiring routine procedures (breeding, vaccinating, bST, etc.) can be handled efficiently and effectively. Various approaches will be discussed elsewhere in these proceedings. It should be considered, however, that conception rate decreases as the time from semen thaw to placement increases, that modified live vaccines can easily become killed, and that improperly injected bST results in suboptimal performance.
Purchased and re-entering cattle
Newly purchased cattle and those re-entering the premises after being in contact with other cattle should be isolated from the home herd for at least two weeks (4). The isolation facility should be clean, dry, comfortable, and well-ventilated. Depending on the weather, an outdoor lot with access to a windbreak can be completely acceptable. It is generally better to mix newly purchased cattle with the home herd if the facility where they would be isolated is an uncomfortable, poorly ventilated old dairy structure.
Conclusions
The handling of special cows is one of the main areas separating top dairies from mediocre dairies. Facility design should consider cow comfort, labor efficiencies, economics, and calving distributions.
References
- Dairy Freestall Housing and Equipment, 1997, 6th edition. Midwest Plan Service, Iowa State university, Ames, IA.
- Valley Agricultural Software, Dairy COMP 305. Tulare, CA.
- Guard, C. Feeding High Producing Cows, Hoards’ Dairyman Supplement. September, 1999.
- New York State Cattle Health Assurance Program, Core Disease Module. 1999. New York State Department of Agriculture and Markets, Albany, NY.
Source: Cornell University
Author: Bill Stone, DVM