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- Healthy, well-conditioned animals that can produce cost-effectively are essential for a successful calf crop, with many producers using estimated breeding values to maximize genetic potential.
- Adequate roughage supply is key to livestock success, as cattle need at least 2.5% of their body weight in quality roughage to maintain production.
- Annual vaccination plans for common diseases such as brucellosis, trichomonosis, and three-day stiffsickness are vital to maintaining herd health and production.
- Regular bull testing and physical evaluations before breeding season help ensure bulls are fit and free from sexually transmitted diseases.
- A 65-day breeding period is recommended to concentrate calving and apply selection pressure, identifying heifers and cows with high fertility and functional efficiency.
Healthy animals with a good condition score, coupled with the ability to produce cost-effectively, are a prerequisite for a good calf crop. Many modern-day producers utilise estimated breeding values to successfully harness the genetic potential in their herds. However, superior animals that are sick or have a sub-par condition score will not be able to fulfil their genetic potential come the breeding season, meaning producers will forfeit their return on investment.
According to Johan Mouton, technical manager of research and development at RCL Foods’ Molatek brand, the supply of enough roughage to get livestock through the year is the golden thread that runs through a successful livestock enterprise. Cattle require at least 2,5% of their bodyweight in roughage of relatively good quality to maintain production.
A producer can achieve this target by having his cattle graze in phases, resulting in them having access to enough grass throughout winter. The recipe for utilising grazing is often said to be the key to success; even more important, though, is letting the veld rest for an optimal amount of time during summer.
Use technology correctly
If you want to improve animals’ condition for the breeding period, it is best to manage them in production groups, to supply feed consistently so heifers can gain weight from weaning onwards, pursue reproduction, utilise technology, and understand and master challenges. A grazing specialist can assist in evaluating the veld and setting up a supplementation plan.
Tools such as artificial insemination, estimated breeding values, genomics, and computer programs that simplify management all support the breeding of animals with high functional efficiency that can produce cost-effectively.
Dr Danie Odendaal, director of Veterinarian Network, says this is precisely where the health and nutrition of animals come into play. The production chain is only as strong as its weakest link, and a weak chain makes it impossible to improve meat production.
Systematic management of beef cattle’s annual production cycle is the only way to effectively boost herd health. In addition to being dynamic, good herd health and production are contingent on sound management systems.
Annual vaccination plan
Brucellosis, trichomonosis, vibriosis, and three-day stiffsickness are among the most prevalent diseases affecting herd health and the calf crop.
If one animal in a herd is infected with brucellosis, the entire herd is considered infected. Infected cows and in-calf heifers usually remain permanent carriers of the pathogen and may continue to spread the disease by shedding the bacteria. This leads to production losses, and animals that test positive for brucellosis must be slaughtered.
Trichomonosis is another sexually transmitted disease carried over by bulls. Bulls that underwent a sheath wash and tested positive are usually slaughtered; females can be immunised with a trichomonosis vaccine prior to the breeding season.
Infected bulls are the main transmitters of vibriosis, but infected heifers and cows may also be a source of infection. Cyclic cows are more susceptible to infection; moreover, resorption complicates diagnosis.
Three-day stiffsickness is a highly contagious disease that can affect up to 40% of susceptible animals in a herd (mortalities usually do not exceed 2%). The virus responsible for the disease causes severe damage to cells and organs. Infected bulls may be temporarily infertile, and sore joints will prevent them from covering cows. In a single-sire breeding herd, the loss can amount up to R140 000 if a new bull is not put with the females, says Dr Odendaal.
Cows that contact the disease in late gestation may abort, while cows that contract the disease during the mating season may lose condition and fail to conceive. The biggest loss, however, is often ascribed to the drastic decrease in milk production. In dairy cattle, milk production may come to a standstill, while less milk produced by beef cows can lead to compromised weaner calves and lower weaning weights.
Test all bulls
A veterinarian must test all breeding bulls in October for sexually transmitted diseases by doing a sheath wash. Especially young bulls older than 18 months of age and bought-in bulls must undergo testing.
A veterinarian must also perform a physical examination of bulls to make sure they are fit, and that the testes and internal reproductive organs are healthy. He or she must collect a semen sample and determine the semen’s concentration, mass motility, progressive motility, and morphology.
A condition score between one and five – with one being emaciated and five overly fat – must be assigned to the bull; its teeth must also be examined. If the condition score of the bull is lower than three, additional nutrition should be provided. Bulls’ condition should preferably remain constant, or decrease only slightly, during the breeding period. Any drastic change necessitates individual attention.
Inspect the cow herd shortly before the breeding season commences by following the requirements set out in the breeding goal. Cull the females that don’t make the cut. Part of the assessment is awarding a condition score that ranges from 3 to 3,5. Cows that are too thin or overly fat usually struggle to conceive.
Monitor condition
A sudden and unexplained decline in condition is cause for concern. The varying availability of grazing throughout the year has a direct impact on the condition (fat and muscle reserves) of cattle. In order to judiciously manage grazing and the provision of lick supplements, the condition scores of all breeding cows and bulls must be recorded and analysed four times a year – in August, November/December, March and June.
Good pasture and nutrition management is particularly important for producers who want to follow a 65-day breeding period in a bid to apply selection pressure in terms of fertility and functional efficiency. This is aimed at identifying heifers and cows that calve regularly, recover well, and will conceive in the next breeding season.
Because animals that fail to conceive in such a system are culled, it is essential to identify factors other than sub-par genetic fertility that are also detrimental to the animal. Should mediocre management be a factor, it could mean that superior animals are being culled for the wrong reasons.
The best time for breeding
A short breeding season inevitably leads to a short calving season, whith an accompanying improvement in observation and cow herd management. Take note of the fact that the average heat cycle of cows and heifers is 21 days, and that they will show standing heat for one day in each 21-day cycle. A bull can only cover them when they show standing heat. Hence, there are really only three days in a 65-day breeding period during which females can be bred and conceive.
The aim is for 60% of cows/heifers to conceive during the first 21-day cycle, and 85% of the total cow herd in the 65-day breeding period.
It is therefore crucial to monitor the health status, condition, and functional efficiency of the herd in order to identify issues timeously that can have an impact on conception.
For more information, contact Dr Danie Odendaal on 082 454 0532 or send an email to vnet1@absamail.co.za. – Andries Gouws, Plaas Media
