Thorough planning is the key to success and since a lot of money is invested in the design of production systems, it is important to think it through properly. Look before you leap.

This month we start with the design of your sheep farming operation. We thank the ARC Institute for Agricultural Engineering in South Africa who made their manual on sheep production and facilities available to the readers of ProAgri Zambia.

Design of sheep production facilities

An intensive production system consists of the elements as listed below and are mainly determined by the size of the herd:

Handling facilities:

These elements must make provision for the reception, handling, treatment and dispatch of the sheep. The handling area can include the following:

• loading platform
• dip
• scales
• crush
• sorting pens
• holding pens (reception and dispatch)
• adaptation pens
• pre-herding corral that allow sheep into the working area in groups.

Housing area:

• lambing pens
• ram pens
• lam pens
• ewe pens
• pens for ewes with lambs

Feed processing complex:

• Feed store
• feed mixers, hammer mill, feed carts, et cetera

Hospital

Office

Shearing sheds

The above elements will be discussed according to the following points:

• Planning procedure
• Climatic requirements
• Choice of a site and zoning
• Design norms and space requirements
• Ventilation requirements
• Waste handling

Planning procedure

Before detailed designs can be done, certain factors must be quantified and certain decisions must be made. The following procedure can be of assistance with the planning of an intensive production system.

• Determine the type of production system and the number of animals or groups involved.
• Decide on the type of facilities to be incorporated in the production system with regard to the type of system, number of animals, climate, infrastructure and capital.
• Calculate the size of each facility and make a scale sketch of each building and camp. If existing facilities will be used, make absolutely sure that it will suit the requirements and possible future expansion.
• Identify possible sites. The choice of a site will be discussed, but important factors will include the total size, accessibility, future expansion and natural factors such as topography gradient and wind directions. If existing buildings will be used, the choice of a site is therefore limited.
• Sketch a preliminary lay-out for every possible site.
• Discuss the lay-outs with the client and make a combined decision on the best” choice, taking into consideration other factors, such as construction costs, availability of materials and effectiveness of the lay-out.
• Begin with the detailed planning and design and consider the client’s specific requirements, preferences and reservations, as well as the available budget.

Flexibility of the final lay-out is very important and ensures effectiveness by making various activities possible at the same time. The importance of client involvement cannot be over-emphasised. The system will be used by the client and the client must be satisfied with it. Expensive features, which are never used, are sometimes built into productions  systems. This practice should be avoided.

Climatic requirements

Although sheep are well adapted to the climatic conditions in Southern Africa, it is important to realise that housing facilities can change these conditions  dramatically. These changes can have a significant influence on the feed intake and the occurrence of disease.

“Enterotoxaemia (pulpy kidney) usually occurs during a change in the season or grazing”.

The above hypothesis is a free translation from “Intensive fat lamb production in Natal”, Grobbelaar and Botha, and associates the occurrence of a disease to the change in season or environment. This association of environmental conditions to diseases is a common occurrence. Just think of all the causes allotted to the common cold. The physiological processes responsible for the correlation between stress and disease are still not fully understood. It is, however, common knowledge that anxiety, as a result of a change in temperature or environment, can break down the resistance of a person or animal. In such a situation, the relevant person or animal is more susceptible to diseases.

Keeping this hypothesis in mind, it can be accepted that cold and hot weather will in turn have an influence on the immunity system of a sheep. The meteorological conditions or parameters with regard to animal diseases can, according to Kelly (1982), be divided into five groups:

Direct causes:

These include non-contagious diseases or conditions such as sunburn, heat exhaustion or freezing.

Pathogen survival:

It is common knowledge that the growth and reproduction of microbes are largely determined by meteorological conditions. Some researchers even claim that the weather or a combination of temperature, moisture and microbiological growth has the greatest influence on animal health.

Animal behavioural patterns:

The behaviour of animals change as the animals are exposed to lower or higher temperatures. When it is cold, sheep are inclined to huddle together in order to increase or retain body temperature. This huddling together causes environmental moisture, especially as this action restricts ventilation. Diseases are easily transferred from one sheep to another in such an environment.

Feed intake:

At low temperatures, the feed intake of sheep increases involuntarily in order to maintain their body temperature. A limitation of rations during this period can decrease the resistance of the animal, which increases susceptibility for diseases.

• Under warmer conditions, the feed intake decreases because the metabolism is slower, with the same effect as a limitation in the ration during low temperatures.
• According to Boshoff (1983), only about 50% of the daily dry material intake is utilised for production.

Stress as a result of temperature can be easily underestimated if this fact is not taken into consideration.

Immunity or resistance:

Experiments proved that temperature has a definite influence on the resistance of the animal against for example streptococci, staphylococci and pasteurelosis. The temperature comfort zone of sheep lies between 5°C and 21°C. Therefore, it can be expected that productivity will be negatively influenced outside these perimeters. The choice of a site can have a great influence on temperature and temperature variations. Factors which influence temperature must therefore be carefully considered when a site is chosen.

Choice of a site and zoning

The choice of a suitable site is not only important from the perspective of the sheep unit or the specific needs of the sheep. It is also important that a site is chosen in such a way that it complements the entire farm lay-out and takes other operational activities into account.

Next month we shall look at the factors that may influence the choice of a site, design norms and space requirements, ventilation requirements and waste handling.

Published with acknowledgement to the ARC Institute for Agricultural Engineering for the use of their Sheep Facilities Manual. Visit www.arc.agric.za for more information.