1. Effect of sexed semen on conception rate, calf sex, dystocia, and stillbirth

2. Data Holstein breedings from 2006 through 2008 Total breedings
1,105,913 heifer matings
9,778,629 cow matings
Marketing code 514 was not included 2

3. Extent of sexed-semen usage
Year of Breeding
Conventional Semen
Sexed-Semen
Number %
Heifer Breedings
2006
369,213 98
5,559 2
2007
368,406 90
41,236 10
2008
241,727 82
53,905 18
Cow Breedings
2,476,780
100
2,015
0.1
4,097,359
7,974
0.2
3,182,479
12,016
0.4

4. Heifer breedings by service number
% of Total Breedings
% Sexed Semen Breedings
Conventional
Sexed 1 56 8 82 2 21 14 3 4 5 6 7

5. Heifer breedings by service number
Conception Rate (%)
Conventional
Sexed 1 60 44 2 56 37 3 51 33 4 47 30 5 42 27 6 36 23 7 28 14
Overall mean CR of 42% for sexed-semen

6. Cow breedings using sexed-semen
% Sexed-Semen Breedings
Service Number
Lactation Number 1 2 3 4 5 43 14 7 11
When comparing to the number of total matings, there is <1% sexed-semen breedings for every service number in each lactation

7. Cow breedings using sexed-semen
Conception Rate (%)
Service Number
Lactation Number 1 2 3 4 5
Conventional Semen 35 31 30 28 26 33 29
Sexed-Semen 25 21 24 22 20 11 23
Overall mean CR of 25% for sexed-semen

8. Calf sex Calf Sex Heifer Breedings (%) Cow Breedings (%) Conventional
Sexed
Single Females 50 90 45 85
Single Males 49 9 11
Twins 1 5

9. Incidence of Dystocia Calf Sex Heifer (%) Cow (%) Conventional Sexed
Single Females 4 2 1
Single Males 8 9 3
Twins 5

10. Incidence of Stillbirth
Calf Sex
Heifer (%)
Cow (%)
Conventional
Sexed
Single Females 9 10 4 3
Single Males 11 15
Twins 13 8
Significant difference in heifers when single males were born when comparing conventional to sexed semen

11. Conclusion
Trends show increasing usage since 2006, when sexed semen became commercially available
Farmers are using sexed semen in heifers and first service inseminations for cows, when conception rates are traditionally higher
90% heifer calves when using sexed semen
No increase incidence of dystocia
Some significance when males calves are born with sexed semen 11