Feed Flow for Animal Requirements for Maintenance and Production

Determining the Nutrient Requirements of the Production Herd

When planning the feed flow for an operation it is first necessary to determine the production cycle of the animal. In this way, it becomes possible to ascertain the general requirements of the herd over time. This can then be matched to the provision of nutrients from the natural pasture at that same period and shortfalls can be determined.

There are five important periods that need special attention during the production cycle of a female small stock animal (sheep and goats):

Dry

This is the period between weaning the offspring and being bred. During this period, the female is regaining the weight lost while nursing the offspring. She must reach a satisfactory condition score before being bred again. However, the nutrient demand here is the lowest.

Mating

Flushing can be used to increase the ovulation rate. Flushing involves providing supplementary feeding 3 weeks before the male is introduced, and 3 weeks after they were introduced. If the herd is on the veldt, flushing can be accomplished by putting the females onto lush pasture, or by feeding pellets or grain.

Early Gestation

(1st 100 days): foetus growth is slow during this period. A maintenance diet is enough and no ill effects will be found if the females are grazing veldt.

Late Gestation

(Last trimester): foetal growth is very rapid and the foetuses gain 70% of their birth weight in this 50-day period. Protein and energy requirements increase dramatically. In adverse weather conditions, the farmer should provide adequate feed for the pregnant females, to avoid losing offspring or having offspring born in poor conditions. During the 5th month of the gestation period, the daily gains of the female should range from 0.1 to 1.2 kg.

Lactation

This is the most critical period. It is vital that the female’s requirements are met, as the production of sufficient milk of good quality ensures that the offspring are healthy, grow fast, and at the end of the day they produce more meat, which means more money for the farmer’s pocket.

Active Growth Stage of the Young Animal

A high-quality feed should be fed to young animals because the requirements for growth are high and the rumen capacity at this stage is still a limiting factor. Poor nutrition during this stage can lead to permanent stunting of the animal. Differences of nearly 20 percent in mature body mass were obtained as a result of differences in nutritional treatment prior to four months of age. Also, the influence of pre-and postnatal treatments was additive. This means that if the mother is fed well in the last few weeks of pregnancy, and the young that are born are strong, then, if the young are also fed well up to weaning, the final result will be even stronger and healthier offspring.

Determining the Nutrient Provision of the Pasture

It is now necessary to match these to the nutritive value of the natural pasture and see if any gaps occur.

If we assume that the small stock herd mentioned above is being produced in a summer rainfall area such as the Northern parts of South Africa, the following pattern emerges:

Determining the Nutrient Provision of the Pasture

The nutrient requirements of the herd and the nutrient provision of the natural pasture are now superimposed on each other. Where a shortfall of nutrients occurs, the pasture can be supplemented with either energy-rich licks or protein-rich licks as required. As a general rule, a salt lick containing minerals should be provided all year round.

Keep in mind that with ruminants the farmer is actually feeding the micro-organisms in the rumen and not the ruminant animal itself. Therefore all feed management decisions should keep the livelihood of the micro-organisms in mind. For example, any changes in feed should be done slowly over at least a seven day period. Furthermore, inexpensive Non-protein Nitrogen sources such as urea (or sterilised chicken litter) can be used instead of expensive protein resources such as lucerne, fish meal etc. This is because the micro-organisms are capable of using these Non-Protein Nitrogen resources in the synthesis of amino acids and proteins.