1 FAST & DEADLY KILLER IN YOUR AUTUMN PASTURE
IT’S RAINING AGAIN, and you can feel the relief as dry, dusty paddocks begin to take on a green hue of fresh grass.
But that pasture may be hiding a deadly secret that can kill your livestock, especially cattle, within a couple of hours, which is why it’s important to not let hungry livestock loose on fresh, lush autumn feed.
During a drought, nitrogen levels naturally rise in the soil. Once it begins raining more often in autumn, the pasture comes away, enjoying the moisture, the cooler, cloudy weather, the extra nitrogen in the soil, and possibly the nitrogen fertiliser you may choose to apply to give it a boost.
But any or all of these factors can cause the plant to hold excess nitrogen in its leaves at a level toxic to livestock, causing nitrate/nitrite poisoning. Cattle are the most susceptible, but deer, goats and sheep are also at risk. The nitrates are absorbed very quickly, directly into the bloodstream, affecting the blood’s ability to carry oxygen. Animals begin breathing quickly, trying to absorb more oxygen, causing them to become unsteady on their feet, stagger, then fall down. They may froth at the mouth or produce excess saliva, and gasp for air, before dying quickly.
Different animals have different needs, depending on their physiology and habits.
For example, goats have little subcutaneous fat cover and always require shelter from rain and cold weather. Sheep, on the other hand, with a good coat of wool and different fat distribution, can withstand more cold, except when they're babies; we all know from news reports (and unfortunate experience), how quickly cold will kill newborn lambs. Shelter from rain, wind or snow is vital if lambing and storms coincide.
Poultry need places to hide from overhead predators. Pigs require housing, for shade and protection from wind and rain.
Cattle are the most self-sufficient, with less need for shelter, but one thing all animals require is shade in the heat of summer.
Heat and cold both cause stress in animals. Those farmers who think they will cut down all the trees on their farms so they can grow a little more grass will need every blade of it for their animals to eat to enable them to keep as warm as they would have been under the trees' shelter in winter. In the summer their animals will become too hot and won't eat anyway.
Heat stress is a serious problem for many animals. If you've ever suffered heat exhaustion or heatstroke yourself, you'll know how utterly awful it makes you feel. Animals jave larger bodies than ours and without the freedom to get out of the heat, can become life-threateningly ill.
The upper North Island in particular is a risky area in summer when the humidity is high. Ruminants lose heat primarily by breathing, but if the outside air temperature and humidity is high, they can't cool down.
If you're lucky there will be mature trees present on your land, but if you've ended up on a subdivided bare block, you may have to start from scratch. There are different qualities of shade, from the protection from direct sunlight afforded by a single layer of cloth or roofing to the deep coolness beneath a stand of large, thickly-leafed trees.
Good tree shelter is not usually something one can create quickly. Most of the fast-growing leafy trees tend to be unwanted weed species, but there are many natives and many 'safe' exotics which will serve the purpose. Seek local advice on species which will do well in the areas in which you wish to plant them, provide the sort of shelter you require and are non-toxic to your animals.
A cabbage tree I planted a few years ago first provided enough shade for an elderly bull to keep his head and neck cool, then gradually more of his body and now that patch of shade can be shared by two animals. In another paddock, trees which had inconveniently come up along fence lines and been left for too long, are now pruned so they don't grow through the wires. They are becoming big enough to provide some shade for single animals, but before long we'll have a north-side shade belt
Autumn is just the best time of year. The weather is still warm but the sting has gone out of the sun. The paddocks are dry. Stock don’t seem to need to eat much to hold condition when they aren’t fighting storms and cold weather. The poplar leaves are going a bright duckling yellow and farm work has dwindled to a list of things to do when I feel like it, like a new fence to put in on a hill paddock or sedge to grub over the back, firewood to collect for winter, and clearing electric fences.
But mostly it is a time of warmth and no pressure, and on the veterinary side of our life, calls dwindle to the routine rather than the dramatic.
But the farmers still have to keep stock moving around. Regular stock shifts stop any one area getting grazed too hard, and even if the grass isn’t growing much in the dry, the cattle still like a change of scenery every few days.
But if there is one thing about autumn I don’t like, it’s wasps. Paper wasps nest up under the eaves of the house, under the deck and throughout the garden, and hide in the blackberry patches along the back roads. It makes gardening and blackberrying a bit hazardous when one might suddenly be dive bombed by a million angry little hornets with needlelike stingers, jabbing one into a hasty retreat.
Most country folk are used to them and keep a good lookout for their mushroomshaped houses of chewed wood fibre. But clients Phil and Maureen hadn’t allowed for German wasps. These yellow and black-striped buggers like to find a hole in the ground and eat away at it until it is a whole lot bigger, a city.
Phil and Maureen were shifting a mob of heifers, Phil calling the girls to follow to the next gate, Maureen and Mitzi the dog, a big chested, woolly-coated beardie, bringing them up behind.
Heifers behave like silly teenagers at the best of times, but Phil said they had the mob moving along nicely, about 50 head in the mid-afternoon. The heat had gone out of the sun but it was still quite warm as they waited for the cool of the evening ahead. The cattle had to cross a drain to get to the end of the paddock and the gateway leading to fresh grazing, but that was no big deal as the drain was dry at this end of a long summer. It was a wide open drain they could easily walk down into and up the other side. No problem. That was until half the mob was across the other side. That was when the wasps woke up, a great black angry swarm that came buzzing out of the ground. “Well, then we had heifers going in all directions,” said Phil. “It was a stampede in 360 degrees. I still hadn’t twigged as to what caused it and just thought they were being stupid.
“Mum and the dog were trying to control the situation.”
“The dog raced off down one side in a valiant attempt to pull the cattle back into a group and mum runs off down the