The oldest lamb was born on January 26. The youngest lamb was born on March 22. Upon arrival, the lambs ranged in age from 31 to 86 days and averaged 65.1 ± 17.4 days of age. The median age was 70 days. The median date of birth was February 11. Less than 2 days separated the average age of the rams, SC, and wethers.
As it was a dairy farm, the lambs were weaned at an early age, ~30 days. After weaning, they remained in the barn/dry lot until they were transported to the University of Maryland's Western Maryland Research & Education Center on April 22.
Birth weights ranged from 5.5 to 16.0 lbs. and averaged 11.5 ± 2.2 lbs. Birth weights were similar for ram, SC, and wether lambs. Birth type ranged from 1 to 3 and averaged 1.95 ± 0.55. The median birth type was 2 (twin). Birth type was similar across treatment groups. Most of the lambs (87.5%) had the same sire.
The lambs were weighed upon arrival. Starting weights ranged from 28.0 to 71.0 pounds and averaged 44.5 ± 10.6 lbs. The ram lambs were a little heavier than the wether lambs: 45.1
± 10.5 vs. 43.5 ± 10.9 lbs. The SC were intermediate: 45.1 ± 10.9 lbs.
Castrations were performed by 10 days of age. Every third lamb was left a ram, castrated, or made a short-scrotum.
|Sex||No.||Start age, d||Birth type||Birth wt, lbs.||Start wt, lbs.||Same sire, #|
Compared to last year, this year's lambs were younger (11 days) and lighter (11 pounds).
All of these factors will be put into the statistical model to determine if they affected the outcome of the experiment. Last year, they did not.