WINTER OPTIONS FOR CATTLE IN THE HIGHVELD OF ZIMBABWE

Eddington Gororo

WHY WINTER?

Dry season (no rainfall)May to November

Worst period is September – November (spring)

High temperatures

CHARACTERISED BY

#1 Loss in veld quality Due to

frost, bleaching by the sun accumulation of structural carbohydrates

which are less digestible translocation of nutrients to root reserves in

preparation for the winter months, from which next season re-growth is derived

CP levels fall from 8 – 11% during summer to 1 – 3% in winter;

TDN falls from about 80% to <50%

#2 Depletion in quantity of veld resource veld fires continued grazing with no re-growth there is no grazing for animals

#3 Increased risk of plant poisoning poisonous forbs are first to appear in

spring or following a winter burn.

#4 Depletion of water supplies Less water to drink Water quality goes down – becomes

warm, stale and fetid Cattle travel long distances to water Frequency of watering goes down

IMPLICATIONS FOR CATTLE

Loss of live weights and body condition thus reversing weight gains (LWG) made in summer.

Delayed onset of puberty in heifers, thus increasing age at first calving (AFC)

Cows take long to cycle again following calving, resulting in reduced pregnancy rates and long calving intervals (CI)

Reduced fertility in the breeding herd - If cows lose up to 16% of their body weight, they are unlikely to re-conceive during the next bulling season.

Lower birth and weaning weights for calves resulting in low cow productivity (i.e., weight of weaned calf per cow in the herd)

Starvation and death of animals due to nutritional imbalances e.g., pregnancy toxaemia.

Plant poisoning and deaths Longer production period, thus higher

cost of keeping stock on the farm Ultimately, loss of business profitability.

OPTIONS FOR WINTER SURVIVAL

OPTIONS FOR WINTER SURVIVAL1. Winter supplements

blocks, cubes, licks, meals and cakes (home-made or bought-in)

2. Conserved forage hay, silage, foggage, leaf meal

3. Crop residues stover, straw, etc.

4. Multi-purpose forage trees Leaucaena, Callyandra, Acacia, Sesbania, etc.

5. Grazing management Deffered grazing, vlei grazing, firebreaks, etc.

Aim is not to fatten but to maintain (or reduce loss in) liveweight and BCS, unless one is finishing for the market

GRAZING MANAGEMENT Ensure that bulky grazing is available throughout the year. It is

cheaper and feasible to supplement quality rather than quantity.

Seasonal rotational resting the year is divided into three main grazing seasons: dry season, early

summer and late summer, and paddocks are rested for an entire season in rotation.

Deferred grazing Involves putting up a pasture in late summer so that the grass can be

utilized in the dry season (foggage). Vlei grazing

Vlei areas are best utilized in winter compared to top land grazing as they are marshy and may pose serious liver fluke problems in summer.

Areas with failing water sources and those most susceptible to veld fire should be utilized early.

Firebreaks Should be made early to save as much graze as possible.

CONSERVED FODDER Hay

‘Make hay while the sun shines’ (Proverb) Quality depends on stage of harvesting, botanical

composition and level of field and storage losses E.g., veld grass cut and conserved at the early

flowering stage may contain a good 6 –9% crude protein content with 50% TDN.

Nutritive value (CP, TDN, ME) can be improved through urea treatment or ammoniation for better animal performance. The CP content can be raised from 1-3% to 10-12% in treated hay.

Grass hay, grass-legume hay, pure legume hay (e.g., velvet bean, lablab, lucerne, etc.)

CROP RESIDUES Traditionally been used for winter survival of

cattle in the Highveld. Includes

maize stover, wheat and barley straw, soyabean straw, etc

Grazed in situ, maize stover is a low quality roughage (about 3% CP and 5.9 MJ/kg air dry), animal performance on stover being initially enhanced by grain gleanings of about 100-200kg/ha.

Ammoniation or urea treatment to improve nutritive value and animal performance

Salt treatment for enhanced VFI

MULTIPURPOSE (FORAGE) TREES

Cut and carry Dried leaf meal

WINTER SUPPLEMENTS

Protein supplementation of cattle in winter can convert body mass losses to gains and increase calving rates by 4 – 5% and weaning weights by 18 – 45kg/head.

Supplementary feeding should start as soon as animals start losing weight (May/June)

Include blocks, cubes, licks and meals (home-made or bought-in)

FORMS OF WINTER PROTEIN SUPPLEMENTS

1. Licks e.g., urea/molasses licks. usually fed in drums with a rotating tyre.

2. Meals and cakes are expensive to use as winter supplements for range animals. Should be given on a daily basis in feed troughs. Feed troughs tend to favour the strongest animals in the herd,

which may not be the best breeders and there is rapid degradation of the land around them.

However, rubber troughs or half drums can be used so that feeding venue can be changed daily.

3. Cubes should also be given on a daily basis. they must be dribbled from an open sack off the end of a slowly

moving tractor. This allows even the weakest animal in the herd a chance to access your generosity.

Cattle are very good at picking cubes from the ground and therefore feeding venue can be changed daily.

FORMS OF WINTER PROTEIN SUPPLEMENTS

4. Blocks most commonly used form of protein

supplement. Intake of protein in block form is controlled

by the hardness and salt content of the block.

These are fed about three times per week and usually weigh 15kg or 30kg with 30 – 50% CP content.

The higher CP content blocks are more economic because they cost considerably less in transport and per unit of crude protein.

FORMS OF WINTER PROTEIN SUPPLEMENTS

5. Maize grain, molasses and chicken litter Can be used for supplementary feeding of cows or over-

wintering of growing stock, molasses plus chicken litter are cost effective sources

of energy and protein respectively. But they have to be mixed with chopped roughage or a maize grain source for palatability.

However, combination of the non-protein nitrogen and quickly degradable energy benefits the efficiency of utilization of both.

A group of one-year-old steers gained an average of 320g/day in 122 winter-feeding days on chicken litter at ART Farm (Winkfield 1996). However, this product is not so palatable and may need to be mixed with chopped roughage or grain and molasses to mask the offensive smell.

STRATEGIC FEEDING Blanket supplementation of all stock is uneconomic. Animals should

be sorted into categories with different priorities and requirements to reduce feed costs and increases profit margins for the farm.

It usually makes more business sense to supplement breeding stock. The most profitable response to protein supplementary feeding is obtained from pregnant heifers, immature cows, weaners, and pregnant mature cows in that order. Empty mature cows may show no or little response to supplementation.

In the case of in-calf breeding cattle, feeding as early as is economically possible is important. Start at very low levels, gradually increasing until after calving down (October-November) at which time feed can then be increased rapidly. The reasons for this are two-fold: it is necessary to ensure urea microbe build-up in the rumen and two thirds of foetal growth occurs in last trimester of gestation (June to

September period). To supplement energy after the calf is born is too late for next year’s calf crop. First aid management does not work in this situation.

FEEDING LEVELS Feed the right amounts of

supplement to achieve specific targets.

Targets: bring cows just to the critical LW or BCS

necessary for conception and no more to achieve specific live weight gains in

weaners. Regular monitoring of

performance.

REGULARITY OF FEEDING Begin supplementation early (April-May),

before animals start to lose body condition and weight

Feed on a regular basis, not on a stop-start basis.

Try to feed about the same time every day; otherwise cattle will waste a tremendous amount of valuable grazing time waiting for you to turn up.

Ensure there is a ready, plenty, clean source of water always.

CONCLUSION

The ability to maximise the potential of a winter cattle management program is both a science and an art; a fine blending of management tools, of observation and foresight. Good luck with yours!!

CONTACT ME

Eddington Gororo Department of Animal Production and TechnologyChinhoyi University of TechnologyPrivate Bag 7724 Chinhoyi, ZimbabweTel. +263 773 9 16375Email: gororoeddington@yahoo.com