There are many factors which can cause lameness such as an infection, a low fibre diet or nerve damage at calving time. Lame cows that do not respond to treatment will spend increasingly long periods of time lying down. Their milk production will decline through reduced food and water intake. Often these cows require prolonged nursing and treatment. If sent for processing, these cows may also require lengthy withdrawal periods first to avoid drug residues. Some cows may become unable to stand up during treatment or withdrawal time. The best way to prevent a totally incapacitated cow is with careful herd observation, early diagnosis and prompt treatment. Early identification of potential problem cows followed by appropriate action, can prevent severe lameness, improve mobility in a moderately lame cow and increase her productive lifetime. You should always consider whether or not a lame cow can be cured. If not, culling the cow is the only option because her suffering will increase as time goes by without treatment.
Lameness may be prevented by the following means:
- Select breeding stock for good hooves and legs.
- Feed cows rations that contain adequate fibre and minerals.
- Divide the grain ration into three or more feedings per day to prevent laminitis.
- Keep yards, laneways and pastures free of areas that are wet and muddy so that you can prevent the spread of infection.
- Trim hooves at least once per year; two times per year is recommended.
- Prevent lameness due to nerve damage at calving time through good judgment, proper and careful use of calf pullers and early consideration of caesarean section.
- Increase resting time.
- Use a footbath frequently. (See Walking).
Mastitis is the most expensive disease in the dairy industry today. Losses are estimated to be as much as Euro184 per cow annually. It is obvious that dairy farmers must control this disease to achieve maximum profit from their enterprise.
Cost of mastitis based on Euro 200 cow/year:
Source: W.D. Gilson; Percentage of loss for various categories.
About 95 percent of all infections are caused by Streptococcus agalactiae, Staphylococcus aureus, Streptococcus dysgalactiae, Streptococcus uberis and and Escherichia coli. The remaining five percent are caused by other organisms.
Contagious organisms are spread by hands, milking units, etc. They include Strep. agalactiae, Staph. aureus and Strep. dysgalactiae. Strep. agalactiae lives in the udder and cannot exist outside it. It is susceptible to penicillin and once eliminated, usually does not return to the herd unless infected cows are purchased. Staph. aureus lives in the udder and on the skin surfaces of an infected cow. It can be controlled effectively with good management and is moderately susceptible to antibiotics when the infection first involves the gland. Older infections usually do not respond to treatment. Severe cases may cause death. Strep. dysgalactiae lives almost anywhere, from the udder and rumen to faeces and the barn. It can be controlled with proper sanitation and is moderately susceptible to antibiotics.
Environmental organisms live in the cows’ environment and are always present. E. coli bacteria are environmental pollution organisms which live in faeces, polluted water and bedding material. Excellent environmental and premilking teat hygiene is needed for their control. They are not susceptible to antibiotics. Strep. uberis live almost everywhere, from the rumen and faeces to the udder. They can be controlled by proper sanitation and milking clean, dry udders.
It has long been known that the rate of new infections increases with the number of bacteria at the teat end. Previous associations have been made between clean housing, clean cows and lower bulk tank somatic cell counts. An index of environmental sanitation based on the amount of manure present on the cow and in her environment was a predictor for the occurrence of coliform mastitis in one study. A recent tail-docking study completed at the University of Wisconsin-Madison demonstrated a significant increase in the prevalence of environmental mastitis pathogens as poor udder hygiene scores increased. A good milking routine is essential for good udder health. See Milking.
The physical condition of cow teats is an indicator of the quality of the environment, milking management and milking system used. It can also be used as an indicator for the risk of intra-mammary infections. Mastitis risk is a numbers game. Greater numbers of bacteria near the teat-end, increase the risk of infections occurring. Teat sores and cracks provide sites where bacteria can multiply. They can be painful to the cow, causing her to kick, defecate more frequently during milking and decrease milk let-down. Healthy skin is easier to keep clean.
A scoring system for teat-end condition
The teat evaluation procedure should be standardised – always conducted either before or after milking, by the same person, on the same group of cows. Teat-end condition should be reevaluated after any changes (altering teat dip, pre-milking procedure, liners, milking machine, pulsation or vacuum) are made that may impact teat health. Cow teat condition provides important information about the herd’s udder health status.
The teat end is smooth with a small, even orifice. This is a typical status for many teats soon after the start of lactation.
A raised, roughened ring with isolated fronds or mounds of old keratin extending one to three millimetres from the orifice.
Smooth or slightly rough ring
A raised ring encircles the orifice. The surface of the ring is smooth or it may feel slightly rough, but no fronds of old keratin are evident.
Very rough ring
A raised ring with rough fronds or mounds of old keratin extending four millimetres or more from the orifice. The ring’s rim is rough and cracked, often giving the teat end a ‘flowered’ appearance.
Teat-end condition scores may reveal the quality of herd management, the correctness of the milking system and milking process, the existence of unacceptable environmental conditions and existing infectious diseases. Good herd management might aim to keep or reduce roughness scores of R or VR to below 20 percent of teats scored.
Source (adapted from): Animal Sciences Group at Wageningen University, Lelystad.
Keeping cows clean is an essential part of environmental mastitis control. This applies to dry cows, heifers and lactating cows. The amount of dirt on cows indicates the degree of farm hygiene. The incidence of udder and skin infections increases rapidly as the cows become dirtier. It is a group score, and a onepoint rise in it can increase bulk tank’s somatic cell count by 50 000 millilitres.
Hygiene score cows on a scale of one to five on the udder (fore and rear udders, udder floor and teats) and the lower rear legs (from hock to floor, including hoof). If there are cows scoring three to five on hygiene, please try to find out why they are so dirty and make appropriate changes. Dirtiness may be related to the health of the cow, nutrition, the space in which the cow is kept or environmental issues such as bedding or manure scraping.
Hygiene score chart:
|Score 1: target
||Score 2: acceptable
||Score 3: danger zone
||Score 4: too dirty
||Score 5: unacceptable
Source (adapted from): Chiappini et al. J.K Reneau, Univ. of Minnesota, in J Hulsen, Cow Signals.