Characteristics of Superovulated Cows: Treatment with Nutrition
Horizons Nutrition Factor Immune Product (NHNFI)
G.H.L. Marquezinia, V.R.G. Mercadantea, M.M. Wardb, A.R. Spell,
J. Carter, N. Paton, G. C. Lamb
North Florida Research and Education Center, University of Florida, Marianna, FL;
Nutrition Horizons, Lewisburg, OH;
Applied Reproduction Resources, Daphne, AL
Embryo Quality Characteristics: Summary
We evaluated the effects of the Nutrition Horizons Nutrition Factor Immune Product (NHNFI) on the quality, stage, and fertilization rate of embryos recovered from embryo donor cows. The cows were superovulated using follicle-stimulating hormone (NIH-FSH-P1) and were stratified by breed before being randomly assigned to one of two treatment groups:
1) The NHNFI group, which received six boluses of the product (n = 35).
2) The Control group, which received six placebo boluses containing wheat middlings (n = 37).
All donor cows underwent the same superovulation protocol. This was initiated by the insertion of a CIDR on day 0, followed by eight injections of FSH administered every 12 hours starting on day 4, and two injections of PGF administered 12 hours apart on day 7. Cows were artificially inseminated (AI) at 0 hours (with one unit of semen) and at 12 hours (with two units of semen) after detecting estrus. Boluses were administered into the esophagus using a balling gun, with two boluses given over three days: at CIDR insertion (day 0), at the first FSH injection (day 4), and at the third FSH injection (day 5).
Embryos were collected 7 days after the first detected estrus by a single embryo technician using a nonsurgical embryo collection procedure. The collected embryos were evaluated under a stereomicroscope and classified by stage and quality.
The total number of ova and transferable embryos collected per flush was not significantly different between the NHNFI and Control groups. The mean percentages of grade 1 and 2 embryos in stages 4, 5, or 6 were similar across treatments. Additionally, there were no differences in the number of degenerated or unfertilized embryos between the groups. However, the percentage of grade 1 embryos collected from the recovered transferable embryos tended to be higher (P = 0.062) for the NHNFI group (39.4%) compared to the Control group (23.4%). Conversely, the percentage of grade 2 embryos collected from the recovered transferable embryos was significantly greater (P < 0.05) for the Control group (76.6%) than for the NHNFI group (59.9%).
In conclusion, while the number of transferable embryos collected per flush did not differ between treatments, the quality of the transferable embryos was improved in donor cows that received NHNFI prior to embryo collection.
Embryo Quality Characteristics: Materials and Methods
Animals and Superovulation
Seventy-two embryo donor cows located in Marianna, FL, underwent a superovulation protocol. On day 0, the cows received a 2 mL combination injection containing estradiol and progesterone, along with a CIDR insert that contained 1.38 g of progesterone (Pfizer Animal Health, New York, NY).
On day 4, the cows were stimulated with eight decreasing doses of follicle-stimulating hormone (NIH-FSH-P1, Folltropin®-V, Bioniche Animal Health USA, Inc., Athens, GA), administered twice daily, 12 hours apart, over 4 consecutive days. Prostaglandin (PGF2α, 25 mg, Lutalyse, Pfizer Animal Health, New York, NY) was given 12 hours apart on day 7 of the protocol.
The cows were inseminated with a single unit of semen at the first observed estrus, followed by artificial insemination (AI) with two units of semen 12 hours later. All semen used in this experiment was collected and frozen by a certified service company following the guidelines of the North American Association of Animal Breeders.
Treatments
Rumen boluses were prepared using two different treatments: 1) the Nutrition Horizons Nutrition Factor Immune product (NHNFI) and 2) placebo boluses containing wheat middlings (Control). The boluses were inserted into the esophagus of each cow with a balling gun. Each cow received two boluses over three days: the first was administered at CIDR insertion (day 0), and the second was given during the first (day 4) and third (day 5) injections of FSH. After stratifying the cows by breed, they were assigned to either the NHNFI group (n = 35) or the Control group (n = 37). Two cows in the NHNFI treatment group did not respond to superstimulation and were excluded from the analyses.
Embryos were collected seven days after the first detected estrus. A single embryo technician performed a nonsurgical embryo collection procedure, and the embryos were evaluated under a stereomicroscope. The technician and the embryologist were blind to the treatments. Each embryo was assigned a developmental stage and quality grade according to the standards established by the International Embryo Transfer Society (Savoy, IL). The developmental stage codes were as follows: 4 = morula; 5 = early blastocyst; 6 = blastocyst; and 7 = expanded blastocyst. The quality codes were: 1 = symmetrical and spherical embryo mass with uniform blastomeres in size, color, and density, with at least 85% of the cellular material intact (excellent or good); 2 = moderate irregularities in the overall shape of the embryonic mass or in the size, color, and density of individual cells, with at least 50% of the cellular material intact (fair); 4 = dead or degenerating; and 5 = unfertilized.
Results
Table 1 summarizes the characteristics of superovulation and embryo quality. There were no differences in the total number of ova and transferable ova per flush between the NHNFI and Control groups. Additionally, the mean grades of embryos (grades 1 and 2, stages 4, 5, or 6) were similar across both treatments. No differences were observed in the number of degenerated or unfertilized embryos between the two groups.
However, there was a tendency for a greater percentage of grade 1 embryos collected compared to the total number of transferable embryos for the NHNFI group (39.4%) than for the Control group (23.4%), with a p-value of 0.062. On the other hand, the percentage of grade 2 embryos collected compared to the total number of transferable embryos was significantly higher for the Control group (76.6%) than for the NHNFI group (59.9%), with a p-value of less than 0.05.
This suggests that while the Control group has a higher percentage of grade 2 embryos, the NHNFI treatment may lead to an increased percentage of higher-quality grade 1 embryos compared to the controls.
Conclusion: Embryo Quality Characteristics
We can conclude that the number of transferable embryos collected per flush did not differ between treatments; however, the quality of transferable embryos was improved after embryo donor cows received NHNFI prior to embryo collection.
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