Too often, dry cows get minimal herdsman attention on many dairies. Drying off cows can be accomplished through routine protocols that minimize risk and maximize results when done correctly. When done poorly, mastitis, lameness, low-quality colostrum and open dry cows can result. I wrote an article for herdsmen in the August Issue 4 of El Lechero to help them understand facts regarding dry cow management. I’d like to summarize that information for you and suggest that you tighten up implementation of your dry cow protocols as necessary.
1. Nutrient diversion from milk production to fetal growth allows rapid development of the fetus during the last trimester. Assure that all dry cow candidates are pregnant prior to antibiotic or vaccine administration.
2. Abrupt stopping of the milking of cows causes rapid udder involution. Intramammary pressure signals secretory cells to cease production.
3. Bacteria can penetrate the udder during the dry period. Despite the formation of a keratin plug and the presence of natural defenses at the teat end, dry cows are susceptible to developing mastitis within the week after dry-off and again within a week prior to calving. Streptococcus species of bacteria account for the most common pathogen responsible for mastitis contracted during the dry period.
4. Cows possess the uncommon ability to concentrate antibodies from blood into their udder during the dry period. This is the principle behind why colostrum is so antibody-rich.
5. The dry cow replenishes tissues that she will need to maximize milk production after calving:
a. Rumen wall papillae regenerate.
b. Milk secretory cells regenerate.
c. Proper foot trimming permits reshaping feet prior to calving.
• If necessary, teach your herdsman to develop a list of cows to dry off with criteria for both “days carried calf” and by milk production. Give him/her criteria by which you want low milk-producing cows dried off early rather than continuing to milk non-profitable cows.
• Teach your herdsman to palpate dry cows. This is a technical skill that can be taught (involve your veterinarian) and learned by competent herdsmen. Teach to detect two of the three signs of pregnancy: fetus, cotyledons and middle uterine artery. Have a backup plan for an experienced person or veterinarian to double-check questionable pregnancies.
• Change the daily routine of groups of cows to dry off one or two days before actually drying them. Upset (don’t molest) cows so they eat less, reduce milk production and “sense” something is different. Do things such as: change feed, group “cows to dry” together but separate from their herdmates, group them together to trim feet and move them to the dry pen with new herdmates. These techniques signal the cow to reduce feed intake and milk production.
• Monitor how dry treatment therapy is administered frequently. Most large herds dry treat weekly and do large numbers of animals at one time. Milkers and others are “enlisted” to instill dry tubes and teat sealants; most have not been trained nor are aware of the complications of unsanitary treatment methods. Write out these treatment protocols.
• Scientific studies demonstrate that teat sealants reduce pathogen entry into udders during the dry period. Not every herd is a candidate to use them; involve your veterinarian and other off-farm consultants to determine if these are cost-effective for you.
• Do not retreat dry cows at any time after the initial dry treatment. This practice is not recommended even for high SCC cows for two reasons: It re-opens the teat end, destroying the keratin plug and, because of udder involution, there is no milk to absorb antibiotic and transport it to the secretory tissue, harboring bacteria.
• Develop a vaccination program (with your veterinarian’s input) that maximizes concentrating specific antibodies in the udder during the dry period. With a good vaccination program and a good colostrum delivery program, you may be able to eliminate the use of oral vaccines in newborns.
• Assure that dry cows are trimmed correctly. Not every foot on every cow needs to be trimmed. Either train your herdsman on proper foot trimming technique or monitor your off-farm foot trimmer so that every foot is examined and when necessary, trimmed properly. Much lameness in high-producing cows can be eliminated with proper trimming; poor trimming technique causes lameness!
Your “management energy” to train and monitor your herdsman can result in maximum outputs from your fresh cows and minimum risk to your dry cows. Just another small step toward maximizing profitability! PD
Tom Fuhrmann, DVM