Dear daktari, I keep six cows under zero grazing system. Every day, I keenly check the amount of feeds my cows eat. I have noted that sometimes they eat less even when the cow is healthy. What could be the cause of this? [Amos Sikolia, Likuyani, Kakamega County]
Thanks Sikolia for your good question. First, let me laud you for your good animal husbandry practice of keenly observing the eating behaviour of your livestock. It is a good practice that will not only help you arrest a problem in good time but also improve their productivity. Back to your question.
Overfeeding and underfeeding
Many farmers overfeed their animals, thinking that this is beneficial. It is not. Overfed animals will show signings of bloat (extended stomach), impaction and indigestion. This can easily predispose the animal to other diseases due to production of toxins by bacteria that thrive in such conditions or result in ketosis. This will result in reduced production of milk. Underfeeding will result in nutritional diseases and prolonged underfeeding lowers productivity. How much feeds an animal eats is dependent on management, environmental or animal factors. I will discuss the major factors.
Feed availability and frequency of feeding
Feed availability will influence how much an animal eats. Cattle are avid feeders and it is always advisable that feed is made available to them ad lib (at all the times – the right feeds). Excessive exposure to some feeds may be dangerous for example abrupt availability of lush pastures or cereals like maize can come with deadly digestive conditions. Access to good quality feeds is always a safe and will increase production as the cattle will eat to their fill. But because dairy production is a commercial venture it is good enough to give the cow feed that is sufficient to satisfy their appetite and meet production targets. In systems where feeding is done on a frequency basis, research shows that when animal are feed more frequently – over five times a day – they produce more. This is based on the stability of rumen Ph which is stable with frequent feeding, a condition that improves milk production.
The quality of feed
Feed quality affect palatability. This simply means that good quality feed will encourage the animal to take more and subsequently produce more. The quality is determined by freshness and taste. Mouldy is an indicator of spoilage and may produce a bad taste hence little of such feeds will be ingested and rightfully so to protect the animal’s biological system from harm.
Level of processing
Processed feed is more palatable than unprocessed mix, a reason concentrates are like hot cakes to cattle. Processing takes many forms from simple chopping to reduce Napier grass length to complicated factory processes. Grinding often improves feed intake. During grinding mineral supplements can be added or mixed which will further increase intake. However very fine grinding might negatively affect digestibility. Research shows that coarsely-ground hay is not only more digestible but also more palatable. Heat treatment of some feeds like cottonseed or soybean increases palatability. Several environmental factors like heat, rain and noise lower feed intake. Age, disease and pregnancy status and level of activity are animal factors that affect feed intake.
[Dr Othieno is a veterinary surgeon and the head of communications at the Food and Agriculture Organisation of the United Nations (FAO) Kenya. The views expressed here are not necessarily those of FAO]