Dairy Farm Guide - Best dairy farming information from trusted resource!
The calf housing facilities should be comfortable for the calf and convenient for the farmer. General requirements include dry, well ventilated pens with ample of bedding, and isolation from older animals.
Weaned calves can be moved to calf grow-out facilities such as outside pens with overhead shelter. The move can be made when the calves are as young as 4 months of age or as old as 6 months of age. The calves can be placed in groups of up to 20 calves each. The age and size spread should not be more than 2 months and 50 kg, respectively. Allow about 3 m2 per calf and 25 cm of feed space.
Depending on where your dairy is located this may be a hot weather season for you. It is always challenging to maintain good gains under these weather conditions.
What is “hot” weather for calves?
Thermoneutral conditions for young calves cannot be expressed as one fixed temperature value. They are a range of environmental temperatures. Within this range the calf’s heat production or metabolism is approximately constant. The width of this “thermoneutral” zone is estimated as about 10°-20° C. Under environmental conditions within the “comfort” zone, calves do not have to use energy to either warm or cool themselves. The bottom and top of this zone are designated as critical temperatures – lower and upper. The upper critical temperature is not fixed. It changes depending on the calf’s age, plane of nutrition, wind velocity and humidity.
What do calves do to increase their rates of heat loss?
Heat losses occur through radiation, convection, conduction and evaporation. Evaporation losses include water vaporization from both skin and mucous membranes. Therefore, we see calves standing rather than lying down. They seek shade rather than full exposure to the sun. Calves also increase their respiration rates and may even be seen panting when severely heat stressed. Although we cannot observe this change, there may also be an increase the rate of blood flow to the skin. In addition calves may decrease their dry matter intake especially from calf starter grain and increase their water consumption.
What can be done to promote good growth in hot weather?
Provide opportunities for calves to find shelter from direct sun. Shelter from the sun (radiant heating) allows calves to radiate heat away. Provide fresh, clean water. Water intake doubles as environmental temperatures go from 20° to 40°C. The essential management decision is to keep water in front of the calves all the time. Once severely dehydrated calves are suddenly allowed access to essentially unlimited water they can suffer water intoxication leading to loss of consciousness.
Night time feeding can be a good option to optimize the dry matter intake. In case of severely depressed Dry matter intake, densification of ration can be practiced.
Identification:
Identification of calves is an important managerial tool that guarantees accuracy of heat dates, breeding dates, calving dates and monthly milk weights. Every calf should be identified at birth with a permanent visible herd number. Permanent identification is also required to register purebred calves. Identification numbers should not be duplicated. Branding is another identification method. Calves are usually branded before its one-month old by either freeze or hot branding.
