Tuesday, August 3, 2010

Hogget lambing articles in Rural News and local High Country herald

I have recently read a coupler articles in Rural News and our local High Country Herald re hogget lambing regarding a professor  from and a study from Massey University. 

I was somewhat concerned about some of the claims in there, including interalia a claim for example that a hogget lambed as opposed to one that has not, has only a 5kg difference in body weight as a 2th, no affect on long term longevity etc. 

I am concerned about the claims being made, because if it is based on a Massey study that started around 5 years ago, then it is my understanding that this trial mated a mob of ewe hoggets to rams, and those that got in lamb became one trial mob, and those that did not get in lamb became the control mob as a comparison.

For those of us who do mate ewe hoggets, I think we are fully aware that 80 to 90% of our bigger and better ewe hoggets, or something around that figure, get in lamb, while the majority of the balance who don't get in lamb are the smaller and often poorer quality hoggets.

So what is the significance of this, well quite clearly if you compare those that got in lamb with those that didn't, over their life time, then its a totally meaningless comparison: as you are comparing on average bigger better quality hoggets with inferior poorer quality hoggets.  

To ensure such a trial was of value and produced results of merit, a mob of hoggets would need to be randomly drafted in half, with one mob being mated and one not mated or covered with teasers, then those in lamb  are then compared with a random mob of the not mated, or better still with those who were covered by teasers with the other mob.  Just a basic premise one must adhere to end up with reliable statistics. 

Accordingly for example any claim that ewe hogget mated is only 5kg lighter as a 2th than had she not been mated based on a flawed trial, if it is based on the trial as I understand that it is, then  quite simply  any conclusions drawn from it are probably crap!

1 comment:

  1. please note that the last line should say "if it is as I understand it, then the claims are quite simply crap."