Impact of bedding source on calf performance during summer
As we draw nearer to the summer season, the importance of keeping calves clean and comfortable is magnified. Besides protecting calves from normal health incidences, we must also deal with the discomfort caused from flies. Calves reared in a comfortable and dry environment are more likely to eat more and be healthier than those not kept dry and comfortable. Bedding source not only has an impact on keeping calves comfortable, but may also impact the number of flies produced as well. This article will highlight both issues as we look at bedding source and calf performance. The first is a research study looking at the effect of bedding source on calf performance conducted by researchers at Purdue University and the second is a research study evaluating bedding source and production of flies conducted at the University of Minnesota.
- Effect of bedding material on performance, health and hide contamination of calves reared in hutches (presented at the 43rd American Dairy Science Association and American Society of Animal Science Midwestern meeting in Des Moines, IA, in March).
This study compared the effect of bedding source on growth and health of calves and the presence of microbes on their hides during the summer. Twenty-eight heifer calves were assigned sequentially by birth date to the next available hutch containing one of three bedding materials: straw, sand or wood shavings. Calves were observed twice weekly from birth to weaning at approximately 60 days of age for general appearance, respiratory health and fecal score. Weekly measurements of body weight, hip height, wither height and heart girth were taken. At 4 and 8 weeks of age, bacteria swabs were obtained from the right mid-abdomen and used for analysis of total aerobic and coliform populations.
The results of this study indicate that straw, sand or wood shavings as bedding sources perform similarly with respect to calf growth, general health and hide contamination during summer conditions. Bedding source affected hip height at weaning as calves bedded with straw (36.9 inches) and sand (36.4 inches) grew taller than those bedded in wood shavings (35.6 inches). Respiratory health, fecal health, appearance or total aerobic and coliform counts were not affected by bedding source. Body weight, wither height and heart girth were also unaffected by source of bedding material.
- Choice of bedding material on production of pestiferous stable flies and house flies in replacement heifer housing (presented at the 21st Annual MOSES Organic Farming Conference, LaCrosse, WI, in February).
Two kinds of flies harm dairy cattle, annoy farmers, and reduce profitability. Blood feeding stable flies slow calf growth while non-biting house flies spread pathogenic bacteria. Both flies develop as maggots in moist organic debris and are readily found in calf bedding. The objective of the study was to determine if bedding source affects production of filth flies and abundance of beneficial fly killing wasps in bedded-pack pens. Nine pens (7 heifers per pen) were first cleaned and then bedded with straw, pine shavings or hardwood sawdust for 12 weeks. Additional bedding was added as needed to maintain a dry pack surface.
Bedding use averaged 317 pounds straw, 268 pounds shavings and 291 pounds sawdust per pen per week. Heifer growth and cleanliness were not affected by bedding source and heifers gained an average of 2 pounds per day. Bedding pack temperatures did not vary among bedding sources. Pack depths were different with straw being deepest (10 inches), shavings intermediate (9 inches) and sawdust being shallowest (8 inches).
Samples from the bedding packs indicated pens bedded with pine shavings and hardwood sawdust contained fewer developing house flies and stable flies than pens bedded with straw. Surplus from straw would have been much greater were it not for naturally occurring beneficial fly-killing wasps, which were more active in straw. Differences in fly abundance may have been due to porosity and compaction. If this is indeed the reason, then corn stalks are likely to be as bad, if not worse than straw.
Further research is needed to understand why straw produced more flies, why beneficial wasps were more active in straw, and whether dairy producers can depend on naturally occurring wasps being present at their calf production facilities. At this time, results indicate that if costs are not prohibitive, fly production from calf pens in summer will be lower if pens are bedded with shavings or sawdust, rather than straw, corn or bean stalks.
Managing calf facilities in summer can be challenging. These studies showed that although health and performance of calves were not affected by bedding source, consideration should be given to bedding source for fly population. And remember, keeping calves clean, comfortable and dry must always be part of good calf raising practices, whatever the bedding source and season of the year.
Published in Dairy Star April 15, 2010