Published on Thu, 01/12/2017 - 12:27pm
By Marcia Endres - University of Minnesta
I recently attended and presented at the University of Wisconsin-Extension 2016 Calf Management Seminar event in Altoona and Kimberly. This cold weather we are having lately makes me think about wet calves and the need to keep them warm with lots of straw bedding and appropriate amounts of milk.
Tom Earleywine from Land O’Lakes Milk Products discussed nutritional impacts on calf health and helped the audience understand some myths and truths about calf management. One of the myths is that reducing failure of passive transfer will stop all calf health problems. Although excellent colostrum management is critical, just doing this would not be sufficient to improve calf health. High plane of nutrition with consistent milk or milk replacer at the right temperature is also essential (among many other factors). Some operations are now feeding 3 quarts 3 times a day. The amount of energy that a calf consumes needs to be calculated correctly and it is a combination of volume and concentration of nutrients. Equations used to convert brix% to solids are not correct because brix does not measure fat well. Each milk replacer will have different concentration of fat and level of fat encapsulation which makes the measurement difficult.
One aspect that hit home with me and that Tom emphasized during his talk was water quality. Calves can’t tolerate high levels of sodium, for example, and many farms use water softeners which add sodium to the water. Something to pay attention to along with other minerals that might be present in the water and cause problems. In addition, bacterial contamination of the water can be something causing a lot of health problems but water bacterial analysis is not routinely done on farms. Tom gave an example of a farm in California having many sick calves and not being able to identify the problem as he was doing his best to clean equipment, give calves electrolytes, etc. It turns out that their water source was contaminated with Cryptosporidium – this water was being used to prepare the milk replacer, mixed with the electrolytes, mixed with the disinfectants, and fed to the calves. Crypto was being fed to the calves in many forms! Testing the water for standard plate and coliform counts would be a good practice to make sure the best quality water is being used on the farm for your most susceptible cattle age group. Some of the other factors he mentioned that are necessary for optimum calf performance included excellent cleaning and sanitation, adequate housing and good ventilation.
David Kammel (Extension Dairy Engineer Specialist, UW-Madison) discussed key aspects of designing or remodeling group housing facilities for preweaned calves. There are many details to consider such as group size, pen design, ventilation, bedding management, resting space, etc. David indicated that a group system reduces isolation and weaning stress for the calves, allows for automated feeding, protects workers from weather and improves labor flexibility, individual calf computer records can be available, and a good environment can be provided to the calves most times of the year. Some of the limitations of group housing include increased risk of disease transmission; ventilation could be potentially compromised with feeding room in the way; age range of calves in the group; and the need for large amounts of bedding.
Some of the keys for success in group housing include excellent ventilation design; bedding management to maintain a clean and dry pen; adequate resting, milk, starter and water access; small groups (12 to 15 calves appear to be manageable); limited age range within groups (ideally no more than 21 days); if possible manage as all-in all-out system to break disease cycle (harder to do in smaller herds); identify and treat sick calves quickly. He prefers natural ventilation, but well-designed mechanical systems can work. Positive pressure ventilation tubes are supplemental and help especially when there is less natural air movement.
The barn should be designed for 130% of the average calving rate in order to prevent overcrowding of calf groups. David suggests 35 to 50 square feet of resting area per calf (this does not include feeding and watering areas) depending on bedding management. Calves lie down 17 hours per day, so the area where they rest should be kept as clean and dry as possible. Drainage in resting and feeding areas is very important.
Feeding calves in groups can be done with gang feeders milk bars (mob feeders), ad lib acidified milk feeders, or automated feeders. The milk feeder station space is a wet area; David recommends a 6 to 8 foot elevated and/or drained platform made of concrete that provides confident footing. The water space should be separate from the milk and starter grain feeder area and provide 2 inches per calf perimeter; water should be free choice and a frost proof, easy to clean waterer should be used. Starter grain feeder space should be 12 inches per calf.
On the specific topic of automated calf feeders, I summarized some of our research and reiterated that keys to success include excellent colostrum management; clean, dry, comfortable bedding; adequate resting space per calf; excellent ventilation; quality and quantity of milk; small group sizes; clean and calibrated feeder equipment; and clean nipples and feeder hoses.