cold weather feeding strategies

1. Cold Weather Feeding Strategies

2. What Influences Calf Growth? Nutrition Health Genetics Environment

3. Biology of Cold Stress Maintaining body temperature requires energy Cold stress increases maintenance energy req’t Calves have limited capability to regulate their body temperature Immature metabolism Preruminant – lack of ruminal fermentation Lack of appreciable fat stores Must consume enough calories to generate enough heat

4. Thermoregulation Thermoneutral zone Range where maintenance energy requirements are relatively constant 50-80°F for young calves Lower critical temperature Temperature at which maintenance energy requirements increase More energy required to maintain core body temperature, at the expense of growth and immune function

5. Age Effects on Lower Critical Temperature Calves experience cold stress at moderate temperatures Lower critical temperature decreases with age, greater energy intake, and ruminal development

6. Environmental Effects on Critical Temperature Housing environment impacts degree of cold stress Key Factors Free of drafts Dry Deep bedding allows for: Insulation Nesting behavior Increased lying time Drier hair coat

7. Temperature Effects on Maintenance Energy Requirements

8. Impacts of Cold Stress on Calves Deplete body fat reserves Young calves don’t have much anyway! Can literally starve to death Depressed immune function Energy not available to fight disease Poor response to treatment Decreased growth performance

9. Key Management Practices Calf jackets Straw > wood chips or sand

10. Effect of Bedding Type

11. Key Management Practices Calf jackets Straw > wood chips or sand Air quality As barns get closed up, airborne bacteria may increase – greater respiratory and scours problems Maintain air flow while eliminating draft Water availability Offer warm water for 30 minutes twice daily

12. Cold Weather Calf Management Objectives Exceed maintenance energy requirements and maintain desired growth rates Focus on young calves <3 weeks old Nutritional strategies Increase amount of powder 10 ? 12 oz per 2 quarts Utilize a fat supplement 2 to 4 oz/calf/day Increase liquid feeding rate 2 ? 2.5 to 3 quarts/feeding Add a 3rd feeding 2 quarts/feeding fed 3X

13. Considerations for Strategies Does the farm use bottles or pails? Bottle size limits how much liquid is fed 2 quart bottles are common 3 quart bottles are available Will be a factor in what strategy is recommended Key question: Increase energy density, feed more volume, or both?

14. Strategy #1: Increase Solids Percentage Standard mixing rates 8 oz dissolved in 2 quarts fed twice daily (12% solids) 10 oz dissolved in 2 quarts fed twice daily (15% solids) 12 oz dissolved in 2 quarts fed twice daily (18% solids) 18% solids is maximum recommended! Ability to increase intake is limited w/ this approach Mix rate of 12 oz/2 quarts is upper limit

15. 100 lb Calf – 20-20 MR

16. Strategy #2: Use KCAL (7-60 Fat Supplement) What is KCAL? 7% crude protein, 60% fat supplement How much do we feed? 2 or 4 oz/calf/day How much fat if KCAL is added to a 20-20? 2 oz/calf/day = 24% Fat 4 oz/calf/day = 27% Fat

17. Strategy #2: Areas of Caution, Solids % with KCAL

18. Strategy #2: Use KCAL (7-60 Fat Supplement)

19. Strategy #3:Increase Liquid Feeding Rate

20. 100 lb Calf – 20-20 MR

21. Strategy #4:Add a 3rd Feeding of MR Solution Ideal Approach Spread out feedings Reduce risk of refusals Implementation Issues Labor Inconvenience Feed an extra 1-2 quarts at noon

22. Feeding Program

23. Economics

24. Conclusions Calves need more calories during cold weather for maintenance, growth, and immune function Focus on housing and bedding will decrease maintenance energy requirements Increasing liquid feed intake and fat supplementation are effective strategies Good calf starter management is key Focus efforts on calves = 3 wks old!!!