Civil Rights Information

Location: Thomas Farms, Marydel , DE

Gordon Johnson, Extension Ag. Agent, Kent Co.
Joanne Whalen, Extension IPM Specialist
Marty Spellman, Extension IPM Associate

I. Introduction

One of the key findings over several years of work on fly control in dairies has been that calf pens are a major breeding area for flies. This summer we did a small trial comparing several bedding materials for use in calf pens. These materials were evaluated for bedding characteristics and attractiveness to flies as a breeding area. The four bedding materials evaluated were straw, peanut hulls, coconut Fiber (Coir), and composted pine bark fines. 

Straw is most commonly used for bedding calves and served as the control. Peanut hulls have shown some ability to limit fly development in past work. Coconut fiber is a byproduct of the coconut industry overseas and is being imported in quantities to use in the greenhouse, nursery and bioremediation industries. It is very absorbent and has the positive characteristic of drying rapidly on the surface. Composted pine bark fines are a byproduct of the forestry industry and is readily available. It is used extensively in the nursery industry and has been shown to have some insecticidal properties.

II. Procedures

Each treatment was applied to a separate pen and this was repeated three times (a total of 12 pens). Bedding was maintained from the time calves were placed in the pens until the time they were removed (60 days). Pens were bedded initially and additional bedding was added as needed. Some manure and bedding material was removed in several treatments during this period when excess built up in the pens.

During the period the calves were housed, the pens were evaluated for the following: (1) Calf comfort, (2) Calf cleanliness, (3) Seepage from pens, and (4) Fly levels (see charts for rating scales). After calves were removed, pens were cleaned in layers, the manure/bedding material was sorted through, and levels and locations of fly maggots and pupae were recorded.

III. Results

Results from this small trial were very interesting. For the first month of this study, seepage from pens was highest in the straw treatment followed by peanut hulls and pine bark. During the second month of the study, seepage was similar for all three treatments. The coconut fiber treatment had little or no seepage during most of the test (Chart#2).

Calf comfort and cleanliness were acceptable in all treatments, although calves on the pine bark tended to be less clean (Chart #1 and 3). Adult fly levels were variable and no conclusions can be made from the numbers recorded in the different pens (Chart# 4). 

On the final evaluation date, there were dramatic differences in maggot and pupae levels with treatments. The highest levels of maggots were found in the straw treatment. Maggots were found at all levels in the straw bedded pens. Maggot levels in the peanut hull treatments were also high but located more at the top of the manure pack. In the coconut fiber treatments, there were much lower maggot levels in the pens and they were located in a small hot spot in the middle of the pen. The pine bark treatments had virtually no maggots, suggesting the pine bark indeed has pesticidal properties. Overall, pupal levels were low in all treatments except the straw. (Table 1.)

IV. Conclusions

Although this is one small test, it does strongly suggest that flies in calf pens can be managed through bedding choices. Since pupal levels are directly related to potential adult fly populations, all treatments show promise as an alternative bedding material. Of particular interest is the possibility of layering pine bark fines with other bedding. The coconut fiber also looked promising as a bedding alternative.

Click on images below to view full size images.

Table 1. Final Evaluation - Bedding Study

Date: September 12, 2002
Location : Thomas Farms