How feeding improves breeding

Toby Doak: How feeding improves breeding

Beef
BETTER BEEF: Cows need to have the energy reserves to feed a calf, and enough left over to again cycle and conceive.

BETTER BEEF: Cows need to have the energy reserves to feed a calf, and enough left over to again cycle and conceive.

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Cows need to have the energy reserves to feed a calf, and enough left over to again cycle and conceive.

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A COW in good condition when she calves, has both the energy reserves to feed the calf and then enough left over to again cycle and conceive.

The question is how good is good when it comes to body condition.

Basically it depends on where you live.

The closer the to equator, the better the condition of the cows needs to be.

There is a tactical measure which can be taken to ensure the cows are in adequate body condition at calving. That is to wean the calf before the cow gets too thin.

For northern Australia, body score 3 is too thin. Ideally cows need to be a minimum of score 4.

Since the desired body score condition (BCS) at calving is obvious to experienced cattle producers, it is a simple procedure to know when the calf must be removed to ensure the cow's ongoing body condition.

There are other critical factors to ensure improved calf weaning percentages, including bull fertility, short 60 day calving seasons, flushing for five weeks starting two weeks before mating, and well grown replacement heifers.

A uniform calf crop aids in marketing and cows in the same physiological state means supplementation can be standardised and grazing management simplified.

It is much easier to deal with a physiological uniform group of animals than ones that reproduce at all times of year.

Profitability of calf production can be greatly increased by improvements in reproductive efficiency.

Losses in income are associated with non-pregnant cows, calves that are born late in the calving season and death of calves at birth.

Too many heifers and cows exposed to bulls during a breeding season do not become pregnant and wean a calf the next year.

Too many heifers and cows exposed to bulls during a breeding season do not become pregnant and wean a calf the next year. - Toby Doak, Alltech Lienert Australia

A major reason for the inefficiency is that cows are not pregnant at the end of the joining period, because many have not been in estrus as a direct result of poor condition.

In addition, some cows do not start estrous cycles until late in the breeding season when feed picks up, so if they become pregnant calves will be born late the next year.

Calves lost at birth are usually associated with difficult or delayed parturition, again linked to body condition.

Two major factors that regulate reproductive performance of beef cows are nutrition and suckling.

Nutrient intake influences body energy stores. Body energy stores can be mobilised when a cow receives less than the required amounts of nutrients during pregnancy or lactation.

Body fat stores regulate the secretion of hypothalamic (brain) and pituitary hormones to control the functions of the ovary.

If cows are too thin at calving, the hormonal signals necessary to stimulate the ovary and start estrous cycles are not released. Cows won't exhibit heat until late in the breeding season, or not at all.

The suckling stimulus also delays the release of hormones necessary for the reinitiating of estrous cycles after calving.

It is well understood that cows that lose their calves at birth usually come into heat sooner than cows with suckling calves.

Under grazing conditions we need to utilise cows to convert forage to milk for growth of calves.

There are few management options that can be used to increase reproductive performance by altering suckling.

The practical approach to increase pregnancy rate, and time during the breeding season that cows become pregnant, is by strategic use of supplemental feeding during pregnancy.

During late pregnancy, in order to maintain BCS, a mature cow requires 9 per cent protein minimum in the total diet. A heifer entering her first calf needs 11pc protein minimum.

Protein nutrition is integral to colostrum quality in cows.

Reducing colostrum levels in calves predispose them to sickness and poor growth rates.

After calving and prior to joining, protein needs vary according to milking ability and weather.

Cows calving at BCS of 4-5 will resume cycling 55 days post-calving, However, cows with a body condition score of less than 4 will require as many as 80 days to resume cycling .

Feeding greater amounts of energy after calving can improve the pregnancy rate or shorten the interval from calving to conception in thin heifers, but it will not compensate entirely for the poor condition of heifers at calving.

In other words, increasing the plane of nutrition for heifers with BCS of 3 after calving will not allow them to rebreed as well as heifers that calve with a BCS of 4.

It is a good practice to have heifers calve earlier than the cow herd so that they will breed back and calve at similar times the next year.

Many factors influence the birth weight and survival of calves.

Reduced nutrient intake during the last third of pregnancy may cause reduced birth weights as well as calf mortality, reduced milk production and decreased postnatal calf growth.

Studies indicate that beef cows that have been fed restricted diets during late gestation often have calves with lighter birth weights compared to cows with adequate nutrition.

Alltech Energy BC

Alltech Energy BC (Body Condition) is an energy dense vegetable product specifically designed for beef cattle. Each kilogram contains 37 megajoules of metabolisable energy.

It is bypass fat, which remains solid in the rumen without impacting the microbial population. It is broken down later in the digestion process.

The nutritional profile of Alltech Energy BC contains a range of fatty acids including, steric, oleic and palmitic acid that can be included in grain or mineral mixes, total mixed rations or top-dressed onto feed commodities.

Importantly the use of Alltech Energy BC will not suppress dry matter intake therefore overall calorie intake is improved.

Long-chain saturated fatty acids, particularly C16:0 palmitic acid, are not just a good source of energy, but they also have been found to be easily digestible and support increased body condition and live weight gain.

In the lactating cow milk solids and milk volume will also be supported by using Alltech Energy BC.

What's the cost 

Intakes can vary from 50 grams/head to day to 200 grams per head per day at a cost of 15-60c/head/day.

Feeding a breeding cow 100g of Alltech Energy BC for the last trimester will cost $28/head.

MORE READING: 'How to get fat on young cattle'.

The story How feeding improves breeding first appeared on Queensland Country Life.

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