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Early Winter Blues

September 12 2005

by Peter Lester

Cropping for winter feed means growing crops that will supply nutrients to sustain the animal in both protein and energy, while at the same time, not neglecting its requirements for vitamins and minerals. While proteins supply the animal with tissue-building compounds, carbohydrates provide the energy. Both of these will be required in abundance over the winter period. Most feeds grown during winter are low in potential of available energy. With the onset of cold wet days, the demand for energy is increased, while usually it's supply decreases.

Crops which supply both of these commodities are not that plentiful. Ryegrass and clover, both of which will grow through our mild winters, are high in protein and low in energy. Animals consuming these will show varying degrees of stress symptoms, ranging from loss of weight, to re-absorption of foetus and even death. 

In the event that an animal falls short in energy, it may call on the supply of proteins to meet its daily demands. When this happens, the animal can become desperate enough to sacrifice the offspring in its womb. Nature cannot sustain foetal growth while the dam starves to death. 

There are signs that you can look for, and these may include any of the following or combinations thereof:
Rough hair coat
Weeping from the eyes
Pink eye
Night blindness
Retained placentas
Silent heat
Persistent foot problems
Enlarged Brisket
Dry scaly skin
One of our major problems here in New Zealand, is our obsession with protein-rich pastures. This, coupled with frequent applications of nitrogen containing fertilisers, leaves our livestock open to nitrate problems and all of those problems associated with low energy availability.

We should be aware that our animals will have used up almost all of their stored fat soluble vitamins, including Vitamins A, D, and E. Many symptoms of deficiency of vitamin A are misread, these include, photosensitization, (often mis-interpreted as facial eczema), pink eye, swollen briskets, and stiff joints. Retained placentas, poor conception rates and high SCC counts in dairy cattle can often be traced to poor feeding, and especially the conversion of carotene to true vitamin A. 
It is advisable to have your Veterinarian inject your animals with Vitamins A, D, and E, going into winter, so that they are better able to cope with the added stresses that inclement weather brings with it. Vitamins A.D and E, and the element selenium are co-functioning and are termed synergistic, that is, each substance complements and enhances the functions of the others. 

Vitamin D. This vitamin is produced by the absorption of ultra violet light acting on oils of the skin. The application of mineral oils to animals depletes vitamin D. It has been suggested that darker coloured animals may need supplementation. One caution here, do not administer this vitamin to dogs or cats without your vets approval.