Cow's Diseases 101
As dairy farmers we need to know basic common diseases to keep us informed and be conscious of the health status of our dairy cows. This is also one way of getting to know how to care for them and be aware on how to treat and abate these problems should they arise.
A large number of health problems can be attributed to nutritional imbalances, deficiencies and erratic management deficiencies. Adding up to these problems are the ever changing nutritional needs of the cows, her lactation /dry period needs, feed quality changes and the farmer's management practices.
Decrease cow's resistance and compromised immune system may result from stress from metabolic problems. Thus the need for prevention.
Let's get to know these nutritionally related herd diseases.
Energy Metabolism Associated Diseases
- Fat Cow Syndrome - obese cows or "too fat" caused by excess energy foods like concentrates, corn silage and hay . These cows are susceptible to milk fever, ketosis, displaced abomasum, retained placenta, metritis
- Ketosis - is a metabolic state where most of the body's energy supply comes fromketone bodiesin the blood, It is characterised by serum concentrations of ketone bodies over 0.5 millimolar with low and stable levels of insulin and blood glucose. Signs of ketosis include "off -feed", weight loss, decreased milk production, listlessness and other unusual signs.
- Retained placenta- is the retention of the afterbirth in dairy cows. The effects of retained placenta is infertility due to delayed involution of the uterus and chronic metritis, delayed conception and associated loss of milk production
- Infertility - caused by poor body condition: extremely thin or too-fat cows reduces reproductive efficiency. Too fat cows have more post calving problems like retained placentas, metritis and cystic ovaries while too thin cows have breeding problems like prolonged time lapse before resuming normal heat cycles.(30-40 days post calving) Body score 1 is too thin and 5 as too fat.
Acidosis or Diseases associated with Low Fiber
- Bloat - happens when forage to concentrate dry matter ratio is too low. When feeding corn silage diets, do not go below 55% of the ration dry matter. When feeding haylage, do not go below 40-45% of ration dry matter. When the rumen pH is too low (too acidic) normal digestion is affected due to minimal feed intake. A frothy form of bloat can occur when cows consume large amount of as fresh grasses
- Laminitis - foot problems is a disease that affects the feet of hooved animals (ungulates) and it is found mostly inhorsesandcattle. Clinical signs include foot tenderness progressing to inability to walk, increased digital pulses, and increased temperature in the hooves. Severe cases with outwardly visible clinical signs are known by the colloquial termfounder, disease may lead to perforation of the coffin bone through the sole of the hoof, requiring aggressive treatment or euthanasia.
- Indigestion/Off-feed -
- Liver abcesses - excess acid brought about by prolonged low forage to-concentrate ratio and ruminal acidity causing rumen erosion/ulcers from which various bacteria may enter the bloodstream. These bacteria are filtered by the liver, resulting in liver infection and creating abcesses
- Displaced Abomasum -
- Low Milk Fat Content - can occur by feeding low forage-to-concentrate rations, that are high in fat, in which the forage has been finely ground. This can also lead to acidosis, off-feed problems and sore feet.
Calcium/Phosporous Metabolism Diseases and Complications
- Hypocalcemia (Milk Fever) - is caused by a large calcium demand at the onset of milk production. When the cow is unable to meet calcium demand to ration imbalance, Vitamin D influence or paratyhroid gland activity regulates metabolites during this period.
Signs of milk fever includes staggering, inability to rise, muscular weakness, recumbency (Lying down) and sub-normal temperature. The following may also occur due to milk fever:
- difficult calving due to muscular weakness preventing proper labor
- increased chance of uterine prolapse
- tendencies to increase retained placentas
- Uterine infection or metritis
- Bloat due to rumen muscle loss or atony
- Abomasal displacements
- Risks of ketosis
- decreased milk production
- reduced total productive life in the herd
- Disease Control of Calcium/Phosphorous Imbalance
The month prior to calving is the most critical and important time to adjust imbalances causing metabolic problems.
- Limit precalving calcium intake. Excess calcium intake tends to inhibit normal calcium mobilization from the bones
- Total calcium requirement for a 600 kg dry cow is 40 gm/day or.04% calcium to dry cows
- If milk fever persists. limit total calcium to less than 60 gm/head /day if hypocalcemia still continues, reduce the precalving ration to 20-25gm/day
- Avoid feeding high phosphorous levels. It should be maintained at 28-30gm/day or 0,24 % of ration to dry matter
- Keep pre-calving potassium levels as low as possible because high forage potassium levels may cause milk fever in cows regardless of calcium intake. Forages low in potassium are usually low in calcium. If this is not practical, consult a nutritionist about feeding anionic salts to dry cows.
Other feeding management-related disorders:
- Hardware Disease - ingestion of metallic particles, wire, or nails in feed causing internal damage, chronic disease poor performance and possible death
- Indigestion- poor performance due to poor feed quality, poor clean -out bunks and feeders, improper shelter
- Acidosis - wrong forage to feed ration, crowding at the feeding areas, poor timing and adaptation to feeds and other negligent practices
- Udder edema - nutritional imbalance due to excess energy, protein, salt and magnesium deficiency
Good Nutritional Management Guidelines:
- Feed a ration balanced for protein, energy, fiber, vitamins and minerals
- Group cows according to production and adjust body conditions accordingly during lactation
- Dry cows off at 3.5 body condition score, the desired body condition score for the dry period and calving
- Provide exercise for dry cows
- Maintain a balance of forage-t-concentrate in the total ration after calving during adaptation to peak lactation
- Feed grass, haylage or pasture to dry cows to minimize calcium intake to prevent milk fever
- Limit corn silage fed to dry cows at approx 15 kg /day and approx 5 kg grass or equivalent forage
- Limit concentrate feeding after peak lactation and conception have occurred
- Maintain a 12-13 month calving interval to avid long dry periods by providing good health and nutrition measures and expert reproductive practices.
Provide the cows with clean, dry comfortable environment, good water source to maximize intake of palatable , well balanced ration to meet their production needs. Consult and work with your local veterinarian, diagnostic laboratory, nutritionist and extension personnel to avoid costly metabolic diseases.
Ref: NebGuide: Duane Rice and RIck Grant