SILVER-FOX FARMING. 
37 
have better chances to develop and grow to maturity than those 
horn at earlier or later dates. Generally the growth of very early 
pups is retarded by cold weather, while extremely late pups are 
handicapped by heat and flies. 
The breeder should make every effort to ascertain the date of 
breeding. By keeping a service record he is able to determine accu- 
rately when to expect the pups. Table 1 shows the breeding and 
whelping dates for service on any day from January 1 to April 30, 
the calculations being based on a 51-day gestation period. 
Table 1. — Dates of breeding and whelping, based on 51-day gestation period. 
The first line of dates in each colunvn indicates the date of breeding and 
directly opposite in the same column is the date on which the vixen may be 
expected to whelp. 
Jan. 
1-Feb. 
20 
Jan. 
2-Feb. 
21 
Jan. 
3-Feb. 
22 
Jan. 
4-Feb. 
23 
Jan. 
5- Feb. 
24 
Jan. 
6- Feb. 
25 
Jan. 
7-Feb. 
26 
Jan. 
8-Feb. 
27 
Jan. 
9-Feb. 
28 
Jan. 
10-Mar. 
1 
Jan. 
] 1-Mar. 
2 
Jan. 
12-Mar. 
3 
Jan. 
13-Mar. 
4 
Jan. 
14-Mar. 
5 
Jan. 
15-Mar. 
6 
Jan. 
16-Mar. 
7 
Jan. 
17-Mar. 
8 
Jan. 
18-Mar. 
9 
Jan. 
19-Mar. 
10 
Jan. 
20-Mar. 
11 
Jan. 
21-Mar. 
12 
Jan. 
22-Mar. 
13 
Jan. 
23-Mar. 
14 
Jan. 
24-Mar. 
15 
Jan. 
25-Mar. 
16 
Jan. 
26-Mar. 
17 
Jan. 
27-Mar. 
18 
Jan. 
28-Mar. 
19 
Jan. 
29-Mar. 
20 
Jan. 
30-Mar. 
21 
Jan. 
31-Mar. 
•22 
Feb. 
Feb. 
Feb. 
Feb. 
Feb. 
Feb. 
Feb. 
1-Mar. 23 
2-Mar. 24 
3-Mar. 25 
4-Mar. 26 
5-Mar. 27 
Feb. 6-Mar. 28 
Feb. 7-Mar. 29 
8-Mar. 30 
9-Mar. 31 
Feb. 10-Apr. 1 
Feb. 11-Apr. 2 
Feb. 12-Apr. 3 
Feb. 13-Apr. 4 
Feb. 14-Apr. 5 
Feb. 15-Apr. 6 
Feb. 16-Apr. 7 
Feb. 17- Apr. 8 
Feb. 18-Apr. 9 
Feb. 19-Apr. 10 
Feb. 20-Apr. 11 
Feb. 21-Apr. 12 
Feb. 22-Apr. 13 
Feb. 23-Apr. 14 
Feb. 24-Apr. 15 
Feb. 25-Apr. 16 
Feb. 26-Apr. 17 
Feb. 27-Apr. 18 
Feb. 28-Apr. 19 
Mar. 1-Apr. 20 
Mar. 2-Apr. 21 
Mar. 
3-Apr. 
22 
Mar. 
4-Apr. 
23 
Mar. 
5-Apr. 
24 
Mar. 
6-Apr. 
25 
Mar. 
7- Apr. 
26 
Mar. 
8-Apr. 
27 
Mar. 
9-Apr. 
28 
Mar. 
10-Apr. 
29 
Mar. 
11-Apr. 
30 
Mar. 
12-May 
1 
Mar. 
13-May 
2 
Mar. 
14-May 
3 
Mar. 
15-May 
4 
Mar. 
16-May 
5 
Mar. 
17-May 
6 
Mar. 
18-May 
7 
Mar. 
19-May 
8 
Mar. 
20-May 
9 
Mar. 
21-May 
10 
Mar. 
22-May 
11 
Mar. 
23-May 
12 
Mar. 
24-May 
13 
Mar. 
25-May 
14 
Mar. 
26-May 
15 
Mar. 
27-May 
16 
Mar. 
28-May 
17 
Mar. 
29-May 
18 
Mar. 
30-May 
19 
Mar. 
31-May 
20 
Apr. 
1-May 
21 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
Apr. 
2-May 22 
3-May 23 
4-May 24 
5-May 25 
6-May 26 
7-May 27 
8-May 28 
9-Mav 29 
10-May 30 
11-Mav 31 
12- June 1 
13-June 2 
14-June 3 
15-Junc 4 
16- J une 5 
17-June 6 
ls-June 7 
19-June 8 
20-June 9 
21- June 10 
Apr. 22-June 11 
Apr. 23-June 12 
Apr. 24-.Iune 13 
Apr. 25-Ji:ne 14 
Apr. 26-June 15 
Apr. 27-June 16 
Apr. 28-June 17 
Apr. 29-June 18 
Apr. 30-June 19 
The average length of the profitable reproductive period in a fox 
is about 10 years. The number of young in a litter varies from 1 to 
10, but the average from adult parents is 4. The average number 
of pups raised at present, however, is about two to the litter. 
MATING. 
Hope for increased profits in fox raising lies almost entirely in 
improving the stock by selective breeding. The better practice has 
been to mate a dark-silver male (25 per cent or less silver) with a 
lighter female (25 per cent or more silver) with the expectation that 
the majority of the pups produced will fall in the dark-silver class. 
This does not always occur, lunvever, for the reason that the ancestors 
of the parents may not have been bred along dark-silver lines. On 
the other hand, if the ancestors as well as the parents have been 
mated with the aim of producing extra-dark and dark-silver pelts, 
then the chances are that the offspring from such matings will con- 
tinue to produce dark silvers. 
