Immunization against inhibin enhances both embryo quantity and quality in Holstein heifers after superovulation and insemination with sex-sorted semen.
The objective was to investigate the feasibility of improving embryo yield in superovulated cows following insemination with sex-sorted semen by prior immunization against inhibin. Twenty-eight heifers were allocated into three groups: High (n=10), Low (n=10), and Control (n=8). The High group received one primary (1mg) and two booster (0.5mg) vaccinations (28-d intervals) with a recombinant inhibin alpha-subunit in 1 mL of white oil adjuvant, whereas the Low group received half that dose, and the Control group received only adjuvant. After the last immunization, all heifers underwent a standard superovulation treatment (decreasing doses of pFSH for 4d), followed by two AI with 2 x 10(6) sex-sorted semen after the onset of estrus. Inhibin-immunized heifers had higher (P<0.01) plasma antibody titres, and an earlier onset of estrus (P<0.05) than Control heifers. The total number of embryo/ova, transferable, and grade 1 embryos in the High group (15.4+/-1.9, 5.7+/-0.7, and 3.8+/-1.0, respectively) was significantly greater than that of the Control group (9.1+/-1.2, 3.1+/-0.5, and 0.6+/-0.2), but was intermediate (P>0.05) in the Low group (13.0+/-2.3, 4.4+/-0.7, and 1.2+/-0.3). There were no significant differences among groups in number of unfertilized ova and degenerated embryos. The High group also had higher (P>0.05) plasma progesterone concentrations on the day of embryo collection. In conclusion, immunization against inhibin improved both embryo quantity and quality following superovulation and insemination with sex-sorted semen.
Li
C
C
Department of Animal Science, South China Agricultural University, Guangzhou 510642, China.
Zhu
Y L
YL
Xue
J H
JH
Zhang
S L
SL
Ma
Z
Z
Shi
Z D
ZD
D000818:Animals; D000906:Antibodies / Q000097:blood; D002417:Cattle / Q000196:embryology*; D002469:Cell Separation; D004958:Estradiol / Q000097:blood; D004971:Estrus; D005260:Female; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage; D007114:Immunization / Q000662:veterinary*; D007117:Immunization, Secondary / Q000662:veterinary; D007265:Inhibins / Q000008:administration & dosage / Q000276:immunology*; D007315:Insemination, Artificial / Q000379:methods / Q000662:veterinary*; D008297:Male; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D011994:Recombinant Proteins / Q000276:immunology; D012732:Sex Determination Analysis / Q000662:veterinary*; D013094:Spermatozoa; D013480:Superovulation
D000906:Antibodies; D011994:Recombinant Proteins; C094377:inhibin-alpha subunit; D011374:Progesterone; D004958:Estradiol; D007265:Inhibins; D005640:Follicle Stimulating Hormone