control: 6 litters, 35 pups, mean litter size 5.8, mean of litter means 10.66 g
treated: 6 litters, 40 pups, mean litter size 6.7, mean of litter means 9.85 g
A. Pups as n (40 vs 35), Welch t-test: difference -0.76 g, p = 0.00025
B. Litters as n (6 vs 6), Welch t-test on litter means: difference -0.82 g (95% CI -1.62 to -0.02), p = 0.047
C. Litters as n, litter means adjusted for litter size (linear model): difference -0.76 g (95% CI -1.60 to 0.08), p = 0.071