Autumn calf rearing

Autumn calf rearing: what to watch

We often think autumn-reared calves will be healthier and the job easier thanks to warm autumn days, and often we can get calves outside earlier to enjoy the sunshine. But for those that are split-calving or rearing all year round, sheds often lack enough ventilation on those warm autumn days. Pen setups may not have the right depth, preventing calves from moving to cooler, shaded areas. Water is the first necessary nutrient that supports feed intake, growth and absorption of all necessary vitamins, and essential minerals. Check all water troughs are working, reachable, palatable, and clean for optimum outcomes. The times when we can empty bedding from the previous seasons sheds soon slip away, and we can often be tempted to reuse bedding from spring rearing as it 'looks' dry, however, this is not ideal. Compacted bedding combined with heat and moisture can trigger outbreaks of parasites and protozoa like Cryptosporidium and Coccidia. Poor airflow also allows bacteria and viruses to thrive. Colostrum, stored transition milk, pre-made calf milk replacers and improperly cleaned feeders and equipment are most at risk for bad bacteria over-growth during the warmer autumn days causing a higher chance for calf scours to begin.

Thermoneutral zone and heat stress

Heat exposure above 25°C combined with 80 percent humidity poses a huge risk of heat stress to calves. Humid, moist calf sheds with poor airflow create perfect conditions for bacterial growth, increasing sickness and disease risk. Keeping sheds dry in the early weeks and getting calves outside into fresh air sooner significantly improves health. Healthy calves spend less energy fighting bugs and more energy growing. The normal core body temperature of a young calf is 38.5–39.5°C. Calves tolerate higher ambient temperatures better than adult cows due to their larger body surface-to-liveweight ratio. The thermoneutral zone for a newborn calf is 10–25°C, so as long as we provide shade, ventilation and clean water, autumn calves generally grow quicker than spring calves because they don't need extra energy for warmth. However, as they approach weaning and the weather shifts to being colder, studies show calves need to increase energy requirements by 27 percent just to stay warm.

The Calf Experts rearing must haves

• Digital small animal thermometer
• New calf teats to avoid any hidden nasties
• Reliance Blue Boost Electrolyte for faster recovery, rehydration and stimulating appetite
• 2 x Calf tubers (one for feeding newborns and one specifically for the sick pen)
• Pain relief/anti-inflammatory (organise with your vet BEFORE season starts)
• Cleaning detergent and scrubbing brush to clean feeders
• Disinfectants like VirkonS and Detonate
• AHD 8% tincture Iodine navel spray for newborn calves
• Flystrike prevention/treatment (particularly important for autumn calving herds, R1's and calf sheds!)
• Gloves for human health
• Absorbent bedding powders like MS DryCare Des and StalosanF to help keep calf bedding dryer and healthier
• Stallion Scour Test kits and pottles for collecting scour faeces to help make the right treatment choices
• FECPAK Test Kits, test faeces for fecal egg counts BEFORE administering any parasite drenches to young calves.

Post-weaning nutrition

A potential downside to autumn calf rearing is feed quality and availability post-weaning as winter kicks in. As calves are slowly weaned off milk and become more dependent on hard feed and grass, they still need to develop their rumens and physically grow. Therefore, their diet must remain energy-dense and highly digestible. By the time weaning starts, there is often still lush autumn pasture and hopefully a steady amount of winter sunshine, but this is not necessarily always the case. Every day needs to be a growing day for young stock. To maintain growth rates and hit liveweight targets post-weaning, protein and energy intake is critical. Feeding a good-quality, high-protein-high starch calf meal from day two and well beyond weaning provides essential protein for growth, starch for continued rumen development, and all the trace, mineral and vitamins required to support lean muscle and skeletal growth, well into the colder winter months ahead. We recommend the premium ranges of the Reliance, NRM and SealesWinslow calf feeds as we trust the science behind the recipes.