Saturday, August 29, 2015

FECs Increase Slightly

For the individual samples collected on August 20 (d-42), fecal egg counts ranged from 25 to 12475 and averaged 1872 + 2142 epg. The standard deviation was larger than the mean, indicating a wide distribution of fecal egg counts. The median fecal egg count was 1225 epg.

Nineteen goats had fecal egg counts below 500 epg. Thirty-three goats had egg counts below 1000 epg.  Forty-five had egg counts between 2000 and 5000. Only five goats had egg counts above 5000 epg.

The dispersion of egg counts was similar to two weeks ago. The 24 goats with the highest egg counts (30% of the goats) accounted for 67 percent of the total egg output (per gram of feces).

Despite many goats having high egg counts (over 2000), evidence of clinical parasitism was minimal on August 20. Only two goats were dewormed.

Goats with consistently low fecal egg counts are considered to be resistant. Goats with high fecal egg counts that have good FAMACHA© and body condition scores (and do not require deworming) are resilient to parasites.  Resilience is the ability to maintain health and performance despite carrying a parasite burden.

Resistance and resilience are both important production traits. You don't want to have to deworm a buck, but you don't want him infecting the pastures either. Nor do you want him to pass those genetics onto his many offspring.

So far, many of the bucks are proving to be
both resistant and resilient to parasites

Resistance tends to be more heritable than resilience.  Both traits are also heavily influenced by environmental conditions. Regardless of genetics, goats will have low egg counts if the level of challenge is low. Similarly, they will have higher egg counts if the level of challenge is high. Good nutrition can improve resilience.

Bucks that remain on the farm that have lower egg counts are not more resistant than the bucks in the test. The environmental conditions (challenge) is different. Only the 84 bucks in the test can be compared with this data.

Download April 20 (d-42) fecal egg count report