Choosing For Breeding: Teat Size

This is from our Little Milkers website - it is one of four essays about heritability of traits in goats. Carol researched the genetics and actual heritability of major traits. This is the first of four articles summarizing the parts that are key to our breeding program this year.

The goal of any breeding program should be continuous improvement of traits - we should be seeking out the best possible matches for our does. That means not finding a buck, but picking the best buck to match against each individual doe. Not just rolling one buck into the pen, unless that buck is batting clean-up at the end of the season.

This week we have going back and forth about teat size - how big? Bigger teats are easier to milk because they contain more milk and so speed milking.

Heritability is a genetic term that means "How easy is it to change a trait in the offspring?" This is a double-edged sword because we want to change the less-desirable traits (small udders, teats that point outward, etc) and then keep the more-desirable traits.

• Udder and teat location traits have moderate heritability (> 0.40)

• Teat dimensions have high heritability ( > 0.70)

  
  

Those heritability numbers above tell us that teats are conserved and these are less likely to change, the doe will control that closely. Moms will give their daughters their own teats, but they are less likely to pass on their udder. It could be smaller or larger, meaty or butter smooth, etc.

Tetris' udder - a vast improvement on her mom (teat size!)

So one of our goals this year is to boost teat size for 3 of our senior does - Wiggy will be getting the job to try that out. But like all things, it is not perfect. Wiggy did a great job with improving Mina's udder in our retained daughter Tetris. Same was true for Zelda on teat size.

But we cannot count on him to repeat this exactly with does - this is what makes breeding time exciting.