Hierarchy of nutrient use in your animal
ONE of the most important aspects for a livestock farmer to understand is the nutrient requirement of animals, its management and impact on the performance of his herd. Livestock nutrition is a course on its own with a range of subjects within it but the intention of this instalment is to provide a simplified understanding of the prioritisation of nutrient use in the body of your animals. This means the nutrients which are found in the feed that your animals take are not used for everything that the animal needs to do but there is a hierarchy of use of nutrients such that if the feed is not enough only those uses on the top of the list get preference. The priority of use of nutrients in the animal body follows this order; maintenance, development, growth, lactation, reproduction and fattening. This means maintenance is the top priority while fattening is the least priority. Therefore, when you feed your animals whether from commercial feed or from the rangeland it is important to ensure that your animals are getting enough feed so that they can be able to apportion nutrient use across this spectrum of use. In a diminished veld with very little grass and probably grass which has lost its nutritive value, animals are looking just to maintain their body condition so that it can continue performing other functions such as lactating its calf. When the veld deteriorates further the animal will get to a point where it is barely getting enough to keep it alive and none of the other functions are performed.
Growth and development are other important functions that receive nutrient allocation from what the animal is feeding. This is more pronounced in younger stock such as your steers and heifers. In a good plane of nutrition this category of animals will allocate a good proportion of nutrients for growth and development. This is a process of bone and muscle development as well as organ development. It is imperative therefore that if you want to realise fast growth from your heifers and steers you need to keep them on a high plane of nutrition which will satisfy first their maintenance and then growth and development. Lactation is another important function performed by nutrients in the body of your animals. Lactation refers to production of milk by your cows. It is not rocket science that cows need good nutrition to produce milk and this is why in most rural homes smallholder farmers take their cows to the
veld to feed for an hour or two before they bring them back for milking. This ensures that your cow gives you more milk per milking. However, this is a function which your cow will easily sacrifice if there is not enough feed in the veld to answer to the needs of the top three requirements that we discussed above.
The consequence is obviously not pleasant to a farmer as you will either lose your calf if it was still highly dependent on milk or you will have a stunted calf. Reproduction is another important function of nutrition and you can see from the order of priority that it is on fifth position. This means that reproduction is almost the last thing in the mind of your animals be they bulls or cows!
The animals will firstly satisfy the other requirements before they can allocate nutrients towards reproduction. However, I would like to believe that if it was a voting matter farmers would vote for reproduction to be at the top because they want that calf. As a general rule, animals in a poor plane of nutrition will not reproduce as it requires more feed to sustain a pregnancy and even to lactate a calf. Farmers, you need to understand therefore that your plane of nutrition has to be good for you to manage reproduction in your herd.
The post-calving period is the most important one as you would want your cow to breed within the first three months after calving if you are to have a calf every year. This means if your nutrition is not in order your cow will not recover quickly from the calving process and it will take time to start circling again.
Also your cow will not be producing enough milk for the calf. This is a period that farmers need to manage with serious interest as it affects your herd growth. So you have to provide enough feed whether from the veld or commercially such that you manage the post calving period effectively. Fattening is the last on the hierarchy of nutrient use which means your animal will first fulfil all the other roles before it starts depositing fat. In order for cattle to deposit external fat as well as internal fat (marbling), the animal must be on a high enough plane of nutrition. Farmers are therefore advised to provide adequate nutrition to cover the entire nutrient distribution hierarchy so as to have a productive herd.
Uyabonga umntakaMaKhumalo.