Table 3.
Reproductive Indices and Offspring Endpoints from the Two-Generation Reproduction Study on ATR (ATR2)
| ATR feeding level (ppm [mg/kg/day]) | ||||||||
|---|---|---|---|---|---|---|---|---|
| 0 | 10 (0.73) | 50 (3.64) | 500 (38.7) | 0 | 10 (0.73) | 50 (3.64) | 500 (38.7) | |
| Parental generation | F0 generation | F1 generation | ||||||
| Number of mated females | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 |
| Number of pregnant females | 29 | 28 | 26 | 26 | 24 | 18 | 28 | 26 |
| Fertility index (%)a | 96.7 | 93.3 | 86.7 | 86.7 | 85.7 | 69.2 | 93.3 | 89.7 |
| Mating index (%)b | 100 | 100 | 100 | 100 | 93.3 | 86.7 | 100 | 96.7 |
| Gestation index (%)c | 96.6 | 100 | 100 | 96.2 | 95.8 | 100 | 100 | 96.2 |
| Number of viable litters | 28 | 28 | 26 | 25 | 23 | 18 | 28 | 25 |
| Mean number of viable newborn ± SD, day 0 | 13.2±3.6d | 15.0±2.1 | 15.0±2.1 | 13.7±4.6 | 11.0±5.0 | 13.3±2.8 | 13.4±3.3 | 12.4±4.1 |
| Mean number of of still birth ± SD, day 0 | 0.26±0.53d | 0.25±0.44 | 0.23±0.51 | 0.35±0.69 | 0.50±0.83 | 0.17±0.51 | 0.07±0.26 | 0.31±0.74 |
| Offspring generation | F1 generation | F2 generation | ||||||
| Number of viable males, day 0 | 166 | 218 | 206 | 171 | 131 | 114 | 182 | 150 |
| Number of viable females, day 0 | 190 | 203 | 183 | 184 | 133 | 126 | 194 | 171 |
| Sex ratio (% males) day 0 | 46.6 | 51.8 | 53.0 | 48.2 | 49.6 | 47.5 | 48.4 | 46.7 |
| Percentage of pups alive on PND4 | 96.6 | 96.9 | 97.7 | 95.7 | 89.6 | 98.7 | 97.1 | 99.5 |
| Percentage of pups alive from PND 4 to PND 21 | 97.6 | 91.1 | 96.2 | 98.0 | 96.6 | 98.6 | 99.6 | 98.4 |
| Mean pup weight (g), PND 0, males ± SD | 6.4±0.1 | 6.0±0.1 | 6.2±0.1 | 6.3±0.1 | 6.4±0.1 | 6.0±0.1* | 6.2±0.1 | 6.2±0.1 |
| Females ± SD | 6.0±0.1 | 5.7±0.1 | 5.7±0.1 | 6.0±0.1 | 6.0±0.1 | 5.8±0.1 | 5.8±0.1 | 5.9±0.1 |
| Mean pup weight (g), PND 4, males ± SD | 9.1±0.2 | 8.1±0.2* | 8.6±0.2 | 8.7±0.2 | 9.3±0.3 | 8.8±0.3 | 9.0±0.2 | 9.0±0.2 |
| Females ± SD | 8.6±0.2 | 7.7±0.2* | 7.9±0.2* | 8.4±0.2 | 8.9±0.2 | 8.4±0.2 | 8.5±0.2 | 8.6±0.2 |
| Mean pup weight (g), PND 7, males ± SD | 14.4±0.4 | 13.0±0.4 | 13.5±0.4 | 13.4±0.4 | 14.0±0.5 | 13.4±0.5 | 13.7±0.4 | 13.3±0.4 |
| Females ± SD | 13.4±0.4 | 12.2±0.4 | 12.4±0.4 | 12.7±0.4 | 13.4±0.4 | 12.7±0.4 | 12.8±0.3 | 12.9±0.4 |
| Mean pup weight (g), PND 21, males ± SD | 49.9±1.1 | 45.1±1.1 | 47.2±1.1 | 46.2±1.2 | 47.8±1.3 | 44.6±1.4 | 43.8±1.1 | 43.0±1.2 |
| Females ± SD | 46.8±1.0 | 43.4±1.0 | 44.0±1.0 | 44.4±1.0 | 44.2±1.4 | 42.5±1.4 | 41.3±1.2 | 42.3±1.3 |
a
Fertility index = (number of pregnant females/number of females cohabited with males) × 100.
b
Mating index = (number of sperm-positive females/number of females cohabited with males) × 100.
c
Gestation index = (number of females with live-born/number of sperm-positive females) × 100.
d
Two pregnant females were excluded from the evaluation because the day of insemination (day 0) could not be ascertained.
*
Statistically different from controls at p ≤ 0.05, covariate analysis (litter size as covariate).