Beef genetic strategies for Zimbabwe
Have you ever really thought about your genetic strategy for your cattle, and planned how, when and what you are going to breed, where your market is, what breeds are most suitable to your environment?
We have broken this article into 6 parts where we will consider production and markets, types of cattle, breeding systems, breeds, selection, genetics and economics.
1. Production and Markets
Firstly we need to consider factors that are not genetic. What are the conditions on your farm or ranch. These will include the following factors:
- CLIMATE – While Zimbabwe generally has a sub-tropical environment, the country varies from the higher rainfall areas of Mashonaland East to the lower altitude lowveld which can be very hot and dry. The Midlands can be a combination of both. Climate affects the forage quality. We have Sourveld in the higher rainfall areas and sweetveld in the lower rainfall areas. Understanding the climate where you farm is important in formulating a genetic strategy that will suit your climatic conditions.
- MARKETS – are you going to sell your ‘crop’ at weaning, background the cattle yourself, or ‘finish’ the cattle and sell them for slaughter. For calves and backgrounded cattle the producer is paid for weight and for price per kilogram for the buyer’s estimate of the value beyond weaning. If you keep the animals to slaughter the returns are influenced by the animals performance post weaning.
- QUALITY – what quality standards does your market demand. In Zimbabwe currently there is no measure of marbling or carcass quality. Currently weight, fat cover and age (dentition) is what our grading system is based on. If we do export in the future will there be a demand for carcass quality? Different markets call for different strategies.
Unlike most other livestock enterprises production conditions cannot readily be controlled easily or economically. In cow/calf operations it is more efficient and economical to adapt the the operation to the production environment.
2. Types of Cattle
The next step in developing a genetic strategy is to understand what types of cattle fit into your production conditions and markets. When cattle do not match the production conditions and markets either performance is reduced or the market does not pay for what you have produced. Either way Income drops.
When choosing a cattle type we should consider cattle that originate in environments of similar characteristics. Analyse what forage you have available and determine what cattle may suit your conditions.
Some examples of different forage types in Zimbabwe are:
- Highveld (Sourveld) – generally the grass is abundant but the quality declines rapidly. Cattle with lower milk and lower energy demand for maintenance are best suited to this environment. Large cattle with high milk can lose body condition rapidly and reproduction rates will drop. Easy fleshing cattle with low to moderate milk usually do best in this environment.
- Lowveld (Sweetveld) – Grass is sparse but it retains it quality much better than sourveld grasses. This environment is usually very hot and dry. Generally medium - larger framed cattle can do well in this environment as long as they are adapted.
What are ‘Adapted Cattle’? Adapted cattle are primarily of a type that physically suit the environment in which they are being farmed.
Physical characteristics are size, coat quality (smooth or hairy), pigment and feet and legs (walking ability). Other adaptation qualities come from being exposed to diseases that are prevalent in the environment and developing antibodies to the disease challenges in that particular environment. The best immunity comes from being born in an environment and the calf receiving antibodies from the mothers colostrum. Immunity also is developed by being continually exposed to the diseases in a particular environment and therefore developing antibodies to those diseases.
Forage deficiencies can be offset with supplemented feed but the cost of producing that feed should be weighed up against return.
When selling at weaning the paramount factors in choice of types are production efficiency and calf value at that point. For retained ownership efficiency and returns are directly influenced by post weaning efficiency and carcass merit.
3. Breeding Systems
We know need to plan a breeding system before even considering breeds or selecting breeding stock. There are basically 2 types of breeding systems called continuous and terminal. The difference in these systems is the source of replacement females.
In continuous systems heifers are retained to return to the breeding herd. So in addition to traits important to market progeny you should also consider what traits you desire in your replacement heifers.
In a terminal system no emphasis is made on replacement females terminal systems can focus on what traits are important to the market. Typically the heifers produced in this type of system would be treated as ‘steers’ and these heifers would not be used for breeding. The challenge is buying in replacement heifers of good enough quality or producing them in another herd.
While straight breeding (using cattle of a single breed) can be used in commercial production it lacks the advantages of a well planned cross-breeding program and the benefits of heterosis or hybrid vigour. Cross-breeding is more difficult in smaller herds and so in this situation breeders may want to consider using composite breeds.
The fourth step is to choose breeds. In Zimbabwe we have 15 registered stud breeds of cattle. While many of these breeds originate in other countries most of these breeds have been selected and bred under Zimbabwe conditions. Broadly speaking we can classify the breeds into:
- Bos Indicus
- African Bos Indicus (Boran)
- American Bos Indicus (Brahman)
- Bos Taurus
- Continental (Simmental, Limousin)
- European (Angus, Hereford, Sussex)
- Sanga (Tuli, Mashona, Nguni)
- Composite (Beefmaster, Bonsmara, Brangus, Charbray, Droughtmaster, Santa Gertrudis)
- Hybrid Bulls (2 – 4 breed composites of the above)
Although breeds should be chosen primarily on their adaptability to climatic and other production conditions, producers should also take into about performance and marketing. If you are cross-breeding it will make sense for the female herd to be the most adaptable and use a performance breed as the male line. If you are breeding a composite start with a base of adaptable females.
5. Individual Selection
The next step is individual selection. Selection of females does have an influence in the genetics of a herd, however even in a terminal cross a sire has much more influence than any female. This is because a sire will be the parent of 20-25 calves a year or, if using artificial insemination, could be many more. The genetic composition of any cow herd is determined largely by the the sires used in the last 3 generations. Regardless of breeding system sires are the most crucial element in genetic selection.
Sires should be firstly able to do the job. They must be structurally sound, have good feet and legs so they can walk long distances and be fertile. Ease of calving is also important especially for bulls used in heifers. Ease of calving is correlated to birth weight of the bulls but EBV’s for calving ease are more accurate. Limit the selection criteria to traits that are economically important. These could be traits such as reproduction, weight and body composition and actual carcass measurement. Too often we select bulls on size. Remember the biggest bull will have big daughters and these will not be the most adaptable. Breeders should give as much information as possible. We use Breedplan for genetic evaluation but currently only the Tuli breed have EBV’s available.
6. Genetics and Genomics
Net income from a beef cattle herd os calculated using the formula
Net income = (Number of head sold x sale weight per head x price per kg) – Total cost
The main influence on number of head is reproduction efficiency and survivability. However different breeds vary on growth and management systems. On fixed systems producers can maintain more smaller cows resulting in more calves to sell but the average weight is likely to be reduced. If weaned calves are retained for grazing fewer breeding cows can be maintained, sale numbers and price / kg will be lower and average sale weights will be higher.
Factors that influence weight are genetics, nutrition, climate, disease, adaptability and management.
Price per kg is determined by the perceived value to a buyer at whatever stage the producer sends the cattle to market
Cost of production should include all costs and not just out of pocket expenses.
The most profit does not come from the most numbers, the heaviest weights, the highest price or the lowest cost. The most successful producers develop adapted genetic strategies that optimise and balance these factors to optimise resources.