Generally, the author tried to draw broad conclusions about the superiority of the Kiko breed as a meat goat from a sample of only three bucks. No statistically valid conclusions can be reached either way about the characteristics and suitability of an entire breed from such a small sample.
Specifically, it was stated that the Kiko demonstrates superior parasite resistance compared to the Boer. The data does not support this conclusion. The test goats were divided into three 0.6 acre paddocks during the test. The three Kiko goats were placed in one paddock, resulting in a stocking rate of 0.2 acres per goat. Three of the Boers were also placed in one paddock resulting in an identical stocking rate of 0.2 acres per goat. Of these six goats only one required treatment during the test for internal parasites, and that animal had a problem from the very beginning of the test. The remaining six Boers were placed into one 0.6 acre paddock resulting in a stocking rate twice as high as the other animals were exposed to. Not surprisingly every buck in that paddock had to be treated at least once for worms. All this proves is what every commercial meat goat operator has known for years, that if you increase the stocking rate you will need to worm more frequently.
To conduct a valid comparison between breeds of parasite resistance the animals would have to be kept under identical conditions, preferably in a common paddock.
Next the author points out that the Kikos averaged 0.38 lbs/day of weight gain versus 0.37 lbs/day of weight gain for the Boers. The actual numbers were 0.3783 lbs/day for the Kikos versus 0.3711 lbs/day for the Boers. This is a statistically insignificant difference given the small sample sizes (3 Kikos and 9 Boers). The article did not include complete weight gain data, so the reader could not see that the average weight gain since birth for the Boers was 0.4374 lbs/day while the Kikos averaged only 0.3488 lbs/day of weight gain since birth. The average age for the Boers was 221 days at the end of the test, and the Kikos were almost exactly the same average age, 220.67 days. The weight difference between the Kikos and Boers was significant at the end of the test with the Boers averaging 96.45 lbs each and the Kikos weighing only 76.97 lbs each.
Which brings me to the last conclusion made, that the Kikos demonstrate better feed efficiency than the Boers. It is important when evaluating performance test data to understand that several types of data presented cannot be compared, even between animals at the same test, because the results are highly dependent on and effected by the size of the animal being measured. This probably explains why the article conveniently left out comparisons of average scrotal circumference between the Kikos (24.23 cm) and the Boers (27.46 cm), and average ribeye area of the Kikos (2.67 sq. in.) versus the Boers( 3.05 sq. in.). I don't offer those statistics to degrade the Kiko, but merely to demonstrate the obvious, that larger goats are going to generally have larger body parts. To make a valid comparison between breeds you would have to compare large samples of similar sized animals measured using the same techniques at the same locations on the goat's anatomy.
Feed efficiency is another area where it is difficult to make comparisons between different sized animals. The data I have seen from other tests where feed efficiencies for individual animals have been measured, has shown a strong inverse relationship between animal size and feed efficiency. In other words, as animal size increases, feed efficiency decreases. This makes sense since the larger animal must consume more feed just to maintain its weight. In this case the smaller average size of the Kikos coming off test favored them in a comparison of feed efficiencies, but that comparison is no more valid than the comparisons of scrotal circumference and ribeye area.
Additionally, in this test feed efficiency was measured based on the amount of concentrate consumed. The bucks were in 0.6 acre paddocks where they could browse in addition to eating concentrate, but the amount of browse consumed was not measured or included in the feed efficiency calculation. This is important because the group of goats that demonstrated the lowest feed efficiency, was also the group of goats that had access to half the browse per buck. It stands to reason that these bucks had to consume more of the concentrate because they had less browse available. The higher stocking rate also contributed to higher numbers of internal parasites in those bucks, which would further decrease feed efficiency.
A valid comparison of the feed efficiency of different breeds of bucks would require measuring the feed efficiency of similar sized animals kept under identical conditions.
I feel that performance tests are very important to the improvement of meat goats of all breeds. The selective and/or inaccurate use of the results can cause long lasting damage to the industry as a whole by leading producers to make poor choices in the selection of breeding stock and discouraging breeders from testing their animals. Thank you for giving me the opportunity to address these issues.
This page updated 07/20/02
Get your own Free Home Page
This page hosted by