Preventing calving difficulties in your heifers and cows.
It’s the time of year where all we have on our mind is preventing calving difficulties in your heifers and cows. Good nutritional management and proper bull selection will be the best approach for calving out heifers (and cows). The drought has caused a whole raft of problems for some who had to restock with unknown and unfamiliar genetics and in some cases undernourished and undergrown heifers.
Due to the herd building that is in progress post drought we don’t always have the luxury of purchasing good quality females and if you have bought PTIC females you just may have bought yourself a problem. It’s quite topical in our area at the moment as herds are calving and we are hearing of quite a few troubles.
Calving difficulty (dystocia) is a major cause of calf deaths and is second only to rebreeding failures in reducing calf crop percentages. Cows that have difficulty during calving have significantly lower fertility at rebreeding.
Nutrition in the last trimester of pregnancy is critical….
Don’t drop the ball on your cows….Composition and availability of nutrients in pastures and crops can affect the supply of key minerals to your pregnant females so it’s important to keep a good eye out, in the last trimester especially.
Intake of energy and protein can vary considerably due to changes in the weather also.
Female deaths which occur in the last trimester of pregnancy are often due to one of three problems and can be managed through some nutrition based strategies.
Many attempt to correct problems that they have neither the instruments nor the knowledge to handle, while others refuse to intervene in even the simplest dystocia problems. Neither approach is good. The breeder and veterinarian should cooperate to deal with problems. All cattlemen should be able to recognise early signs of dystocia and determine when or if professional help is needed.
Understanding & Prevention
It will give some piece of mind to go into calving with the cow’s nutrition sorted. We are not just managers of cattle after all…
We are managers of soils and pastures and if we fail to recognise and manage these critical elements our cattle will pay the price which in turn is US paying the price.
Understand your feed bank
Dry matter intake of grazed pastures can also vary quite considerably due to changes in weather conditions. Not only will this affect the supply of energy and protein to the animals, but the mineral supply will also be reduced.
This can lead to a number of metabolic disorders i.e. grass tetany and milk fever, which fortunately can be managed through some nutrition-based strategies.
Cow deaths which occur in the last trimester are often due to one of three nutritional problems; milk fever, grass tetany and pregnancy toxaemia. There is a significant increase in demand for essential nutrients leading up to calving to prevent calving difficulties in your heifers and cows, calcium is one of the more critical.
CRUTIAL METABOLIC DISORDERS TO PREVENT
Hypocalcaemia or milk fever – Calcium deficiency.
Calcium is the most abundant mineral in the body and generally there are good levels in forage, however when cows are lactating their requirements are often unable to be met.
This condition can cause the cow to go down at the point of calving and muscle function is compromised which affects her ability to regulate muscle contractions and they are often weak. Also known as ‘lazy calving’
Cause: Lush green feed, particularly green cereal crops as these are known to be low in sodium, calcium and magnesium. They are high in potassium which further exacerbates low calcium and magnesium uptake.
Legumes such as lucerne, peanut, clover and soybean hay are good sources of calcium, but corn and sorghum silage are poor sources. In general, most concentrates are relatively poor calcium sources.
Prevention: If you have to calve on a cereal crop offer roughage in the form of hay or straw.
Signs: lack of muscle co-ordination and twitching, slow calving, dry muzzle, depression, altered rectal temperature, bloat, lay down, weak pulse, flaccid muscles and death.
MORE INFO: MLA – Hypocalcaemia/Milk Fever
Hypomagnesaemia or grass tetany – Magnesium deficiency.
Magnesium has a positive impact on muscle function and helps with the ease of calving.
A cow constantly loses magnesium in urine, faeces and milk so it needs magnesium daily to meet requirements.
Causes: Magnesium is lower in cool season grasses and cereals or when potash and nitrogen fertilisers are used. Moisture content in grass is high and vigorous growth can also be problematic. Sudden changes in feed and bad weather, especially winter storms. Stress such as transport or yarding.
Prevention: Increase energy and roughage intake and offer a magnesium supplement in the form of lick blocks, slow release capsules or magnesium in the form of powder onto hay or in a lick. Provide salt, move lactating cows to a high legume pasture with high dry matter if possible and provide shelter.
Longer term solutions include correcting soil acidity with lime or dolomite, plant clovers, limit nitrogen and potash applications until soil is corrected.
*immediate* Provide magnesium supplement.
Signs: The problem with animals suffering from grass tetany… they are often found dead. They are usually found lying on their side with outstretched legs and signs that thrashing has occured. Early signs will include excitability, stiff gait, aggressiveness and staggering.
Treatment in critical cases: a veterinary can restore blood magnesium levels with an intravenous calcium and mag solution and this produces best results.
Cows cannot physically eat enough calcium or magnesium to meet their needs during and after calving from green feed alone.
MORE INFO: MLA – Grass Tetany
Pregnancy toxaemia or Preg Tox – is a form of ketosis.
This occurs when the breakdown products of fat, called ketones, build up in the brain and become toxic. It is commonest in fat pregnant cows. In times of falling feed quality or limited feed quantity. Many find it hard to believe that fat cows can die from insufficient feed. This condition is extremely dangerous and cows that suffer may never recover.
Causes: Overly fat cows in their last trimester of pregnancy and cows bearing twins being allowed to lose a lot of weight due to declining feed and feed quality.
Onset of the disease can also be triggered by inclement weather.
Prevention: Don’t allow your cows to get overfat. If they do enter the last trimester overfat don’t allow their feed intake and nutrition to drop so as to not sustain their healthy pregnancy requirements. Late pregnancy is very taxing on a cows resources.
Offer the whole herd supplemental feed or good quality hay.
Signs: Cows may become excitable and have an unco-ordinated, high-stepping gait. The typical symptoms then develop – they become depressed, recumbent and are unable to rise Separation from the herd faster breathing, mucous covered manure which can contain blood are also markers. If you have a good nose you may able to detect the sweet odour of acetone (a ketone) on her breath which is caused by the breaking down of her own fat stores.
As soon as a single case of pregnancy toxemia has been confirmed, the nutrition of the entire herd must be boosted by offering supplemental feed or good quality hay. Cows that seem to be at immediate risk because they aren’t eating can be given propylene glycol as a preventive measure.
MORE INFO: MLA – Ketosis/Pregnancy Toxaemia
Healthy females = live calves
It is important to look at all of these factors to help protect our breeding herd and also improve the percentage of live calves that hit the ground.
Failure to supplement with these critical elements can result in poor conception rates, failure to cycle, risk of metabolic disorders and a decline in growth rates, consequently resulting in an economic loss.
**It’s important to realise that supplementation will vary with your plant species, soil type, plant stage, season and environment.
For any questions about preventing calving difficulties in your heifers and cows, or anything else discussed in this blog post, please feel free to CONTACT US.