Table 5. Summary of enrichment effects on male reproduction and other productivity-related variables in Black mink in Experiment 2.
| Effect direction | Effect size | Statistics | |
| Male reproductive measures | |||
| Number of successful matings (all farms) | NSD | 10 (7–14) vs, 19 (6–14)1 | Z = −0.03, p>0.10 |
| Farm A only: Percent of mating attempts successful | NSD | 61.0±0.1 vs. 57.0±0.1 | p>0.10 |
| Time to “catch” female to copulate: all successful males (min) | NSD | 16.1±0.8 vs. 16.0±0.8 | p>0.10 |
| Latency to copulate: all successful males (min) | NSD | 28.4±1.5 vs. 29.0±2.7 | p>0.10 |
| Duration of copulation: all successful males (min) | Increased | 47.8±3.7 vs. 40.2±2.1 | Welch's t1,41 = 1.76, p = 0.085 |
| Brother pairs2 | Increased | Sign test M = −3.50, N = 9, p = 0.039 | |
| Testosterone (ng/g) | Decreased | 26 (23–41.5) vs. 39 (27.5–50.5)1 | z = 2.45, N = 70, p = 0.014 |
| Epiandrosterone (ng/g) | Decreased | 6.7 (5.3–9.3) vs. 9.0 (6.2–12.5)1 | z = 1.96, N = 70, p = 0.049 |
| Other practical consequences (both sexes) | |||
| Feed left uneaten (g) | NSD | 18.0±2.4 vs. 18.4±2.3 | p>0.10 |
| Pelt prices (USD) | NSD | Females: 80.4±0.8 vs. 80.5±0.9; Males: 118.2±0.8 vs. 117.1±0.9 | p>0.10 |
| Cage cleanliness | Increased | 42.9% vs. 35.2% clean | ?2 = 4.80, N = 799, p = 0.0284 |
Italics indicate a statistical trend 0.05<P<0.10. Only female reproductive measures include the late E group.
1
Medians with interquartile ranges in parentheses. These analyses do not control for cortisol metabolites levels, but doing so did not influence the outcomes.
2
Paired analyses were conducted for siblings on all measures of reproductive success; however, results are only presented if significant effects were detected that were not apparent in the larger group.