Soay lamb weights: a brief dataset

Over the last few days we have been talking with a potential customer about the feasibility of shipping several lambs by air to her next summer.  In the course of those conversations she wanted to know how much our lambs weigh when they are sufficiently past weaning to be ready to ship by land or air.  The airlines have pretty strict rules about how small “pets” must be in order to ship two animals per crate so as to keep the cost at a tolerable level.

As luck would have it, we were able to quickly give her average weights for 33 lambs weaned at 12 weeks who we happened to weigh after they had been acclimated to grass-only meals for about a month and were physically ready to leave our farm.  Here’s a quick summary of the weight data, which we hope will be useful to other breeders and potential buyers who also are considering air freight or just plain wondering at what rate Soay lambs grow.

These 33 British Soay lambs were born between April 3 and April 12, 2011, and all were weighed on August 5, 2011, when they were within a few days either way of 4 months old.  The data includes lots of twins, whose weights not surprisingly tend to be somewhat lower than single lambs, although not universally so.  The data also includes Peanut, our ram born at 1 pound 15 ounces.  If we had excluded him from the data, the average ram weight would go up about a pound.

The 13 ewe lambs ranged from 22 to 34 pounds, with a mean weight of 26.5 pounds, median weight 26 pounds.

The 14 ram lambs ranged from 20 to 40 pounds, with a mean weight of 32.4 pounds and a median weight of 33.5 pounds (the Peanut effect)

The 6 wether lambs ranged from 22 to 34 pounds, with both mean and median weights of 28 pounds.

For now …