In this third article of my series on the mitigation of risk in the farming of sheep, I will illustrate how the inclusion of risk mitigation strategies and innovative solutions, in combination with the traditional value analysis of a defined element of production, can work to add new perspectives to farming operations. The health of the animal’s dentition has a direct bearing on its ability to graze and to prepare the grass and other vegetation for digestion. The objective being the conversion of the majority of its nutrition into either body weight, in the form of meat and fat, or a fleece (vag) of high quality wool. Body weight is the correlating metric used together with number of teeth to approximate age, however these correlations differ from breed to breed. As there are many hundreds of listed breeds of sheep (Ovis aries) each with their own ‘breed standards’ of age/weight, body form, wool type etc., number of teeth is an easier metric to use in determining age, for example ‘breed standard’ for a ‘2 teeth’ Dorper ewe is 70.9kgs, whereas the Afrino standard for an animal of the same age is 52.9kgs
As a key dynamic in the growth of the sheep to a fully contributing production unit, the time/cost ratio for the achievement of the best body weight at the appropriate age is a critical management metric. The development of robust dentition underpins this achievement, with the premature loss of incisor teeth in sheep being an absolute ‘show-stopper’ for a sheep farmer since affected animals are unable to graze on short and/or rough pasture, leading to malnutrition, poor production and weight loss. A further important point worth noting as it is often overlooked, is that all synthetic ‘medicines’ will leach key minerals and other trace elements from the sheep’s body. If these are not replaced, imbalances, deficiencies, impairments and disease will result with a direct impact on dentition and dental health. Consider the relationship between bone density, the development of healthy teeth, and the correct balance of minerals such as calcium and magnesium.
My Risk Mitigation overlay develops the multi-dimensional view of the risk by considering four aspects:
1. Description of the risk
2. Possible Cause of risk issue
3. Risk Mitigation
4. Innovation and/or resolution
1. Description of the risk
Dental impairment resulting in the poor physical development of the animal and increased costs of rearing to maturity due to veterinary and associated costs. Higher management costs and loss of time and opportunity, lead to greatly reduced profitability for the affected animal within the value chain of operations, production and time.
2. Possible causes of the risk to ovine dentition
Environmental damage - while being loaded onto or unloaded from livestock transporters, or in transit, damage on farm structures, damage caused by flock members or other farm animals, damage when grazing if coarse sand or small stones are taken in with grass, damage caused by objects in camps e.g. salt licks.
Mineral and trace element deficiencies – if the milk of lactating ewes is deficient in key minerals, electrolytes, vitamins and trace elements, it is guaranteed that the lamb will suffer the consequences, if the lamb is weaned too early or too late, imbalances in nutrition levels and development will occur. Organic and systemic pathologies are one of the more serious consequences of this range of deficiencies, for example, poor gut absorption among lambs and yearlings, and challenges to the healthy eruption and development of teeth in juvenile animals.
Toxins in water and/or grazing, for example fluoride, chlorine and other pollutants in drinking water, together with pesticides, herbicides, and synthetic fertilizers in grazing. These will all have adverse effects on the development of robust dentition, as well as negative effects on overall animal health.
Poor genetic lines and/or lack of genetic diversity – dental health might not have been verified during ram selection, or poor dentition and other dental-related challenges could be evidence of the sustained lack of genetic diversity in the breeding flock.
The Mitigation of Risk ( Part 2) The Mitigation of Risk
Infection and disease – overall dental health and development can be caused by poor hygiene standards on the farm, for example bacterial infections. More challenging is if unidentified carriers of disease are a root cause. Patience and repeated observations and testing of potential carriers needs to be carried out. If causative factors have been identified, yet problems persist, it is worthwhile checking the diagnoses, prescription and administration of veterinary interventions. Most often, compromised immunity together with poor diet and/or insufficient nutrition will be found as the root cause of most health challenges, and consequently it would be worthwhile to check the quality and value of your grazing.
Stress – there are cases where poor dental development and/or loss of teeth has been caused by physical and environmental stress, for example the late rejection of the lamb by the ewe, aggressive behaviours within the flock between members, stress caused by predators, dramatic changes in weather conditions, stress and careless or rough handling while in transit, and even noise levels.
3. Risk Mitigation
Management-by-walking-about, where the farmer’s physical and cognitive presence among the sheep, promotes and reinforces appropriate action.
Further study and reading on ovine dentition and common problems.
Improving an understanding of the role played by minerals and vitamins in ovine dental health and supplements needed, and the damage caused by synthetics.
Analysis of current grazing vegetation, soil and water to establish mineral deficiencies in the farm’s production value chain. It might be a good idea to drink the water yourself.
Blood analyses of a statistical sample of the current flock to establish prevalent levels of critical trace elements and vitamins etc.
Verification of quality of dental development and health of sire rams.
Over an extended period of time, observe the behavior and interactions of flock members. Understand what to look for in terms of deviant and disruptive, aggressive or abnormal behaviour.
Ensuring that current dosages and quality of supplements and supplemental feeds given to the sheep, are in fact accurate for the breed and age of the sheep, season (time) of the year, condition of the veld, and other stress factors. Also check the expiry dates of supplements being administered and verify the quality of supplemental feed being given to the animals.
Inspect grazing camps for the intrusion of competitor, wild herbivores, e.g. antelope species, as these will be reducing the volume and quality of grazing and water available for the sheep, and objects on which the sheep might damage or break its teeth. Check and maintain fencing in grazing areas.
4. Innovation and/or resolution
In the case of ovine dentition, prevention is better than cure.
It has most often proven to be strategically worthwhile in the long term, to remove and cull sheep showing evidence of genetically-linked challenges with dentition development and/or health.
When it comes to cases of damage to teeth caused by environmental factors, resolution of the risks must be based on a return to basics, and greater management and attention, especially management-by-walking-about, i.e. daily, physical observation of the flock(s), their behavior and the grazing camp.
Harnessing the power of science and technology will offer a greater degree of confidence when implementing corrective nutrition protocols, specifically when dealing with minerals, salts, vitamins and trace elements. Analysis of grazing vegetation, water and even blood samples, will go a long way to pinpointing an accurate starting point of risk mitigation interventions. The value of Database Management will be addressed in a later article in this series.
There is no silver bullet or short-cut to the resolution of risks related to ovine dentition.
Conclusion
As with us humans, so it is with sheep: “We are what we eat and drink.” Clearly if the sheep cannot eat, chew and digest efficiently, it will never amount to much. An understanding of ovine dentition and development is a key issue for a sheep farmer, considering that so much of what he is working towards achieving depends heavily on the animal’s ability to convert grazing into body weight and/or a high quality fleece. As evidence of the value of knowledge about ovine dentition, I would encourage you to review the correlation between a sheep’s dentition and the grading of its carcass. A basic, working knowledge of ovine dental physics and the role played by the chemistry of key minerals, salts, vitamins and trace elements cannot be considered as peripheral or optional.
If you would like to communicate directly with the author, you are invited to contact PJ at the following email address: This email address is being protected from spambots. You need JavaScript enabled to view it.
