Field Trial Assessing the Use of Sex-Sorted Semen in Beef Cattle (original) (raw)
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Fertility in Dairy Cows After Artificial Insemination Using Sex-Sorted Sperm or Conventional Semen
Reproduction in Domestic Animals, 2014
The aim of this study was to compare pregnancy per artificial insemination (P/AI) after timed AI with sex-sorted sperm (SS) or conventional semen (CS) in lactating dairy cows. Cyclic cows (n = 302) were synchronized by Ovsynch and randomly assigned into two groups at the time of AI. Cows with a follicle size between 12 and 18 mm and clear vaginal discharge at the time of AI were inseminated with either frozen-thawed SS (n = 148) or CS (n = 154) of the same bull. A shallow uterine insemination was performed into the uterine horn ipsilateral to the side of probable impending ovulation. Pregnancy per AI on Day 31 tended (p = 0.09) to be less for SS (31.8%) than CS (40.9%). Similarly, P/AI on Day 62 was less (p = 0.01) for cows inseminated with SS (25.7%) compared with CS (39.0%). The increased difference in fertility between treatments from Days 31 to 62 was caused by the greater (p = 0.02) pregnancy loss for cows receiving SS (19.2%) than CS (4.8%). Cow parity (p = 0.02) and season (p < 0.01) when AI was performed were additional factors affecting fertility. Primiparous cows had greater P/AI than multiparous cows both on Day 31 (41.7% vs 25.0% in SS and 53.0% vs 31.8% in CS groups) and on Day 62 (33.3% vs 20.5% in SS and 48.5% vs 31.8% in CS groups). During the hot season of the year, P/AI on Day 31 was reduced (p = 0.01) in the SS group (19.6%) when compared with the rates during the cool season (38.1%). In conclusion, sex-sorted sperm produced lower fertility results compared to conventional semen even after using some selection criteria to select most fertile cows.
Animal Reproduction Science, 2013
The present study evaluated the use of sex-sorted sperm upon estrus detection (ED) or following timed artificial insemination (TAI) in lactating dairy cows. Additionally, the effect of the presence of a corpus luteum (CL) at the beginning of the TAI protocol was verified. Cows (539 crossbred Gir × Holstein and 87 Holstein) were classified according to the presence or absence of CL by ultrasonography exam. Cows with a CL were randomly assigned into one of two groups (CL-ED/AI or CL-TAI), and cows without a CL (NoCL-TAI) received TAI. Cows from the CL-ED/AI group received 500 mg of cloprostenol intramuscularly and were inseminated 12 h after ED in the following five days. Cows from the TAI groups (CL or NoCL) received TAI. Cows receiving CL-ED/AI had a lower (P < 0.0001) service rate (45.1%, 101/224) than TAI groups (CL-TAI = 94.2%, 180/191 and NoCL-TAI = 97.2%, 205/211). However, cows receiving AI upon ED (CL-ED/AI = 31.7%, 32/101) presented higher (P = 0.03) pregnancy per AI (P/AI) than cows bred following TAI (CL-TAI = 19.4%, 35/180 and NoCL-TAI = 23.9%, 49/205). Despite the lower P/AI, cows receiving TAI presented greater (P = 0.07) proportion of pregnant cows at the end of the reproductive program (CL-TAI = 18.3%, 35/191 and NoCL-TAI = 23.2%, 49/211) than those inseminated upon ED (14.3%, 32/224). There was no effect (P = 0.45) of the presence of a CL at the beginning of the synchronization protocol on P/AI. Thus, the use of TAI programs, regardless of the presence of CL in the beginning of the synchronization protocol, increases the service and pregnancy rates but reduces the P/AI when compared to the use of sex-sorted sperm upon ED.
A Field Study on Fertility and Purity of Sex-Sorted Cattle Sperm
Journal of Dairy Science, 2007
The study assessed the fertility and purity of sexed semen used for inseminating Holstein-Friesian heifers in commercial dairy herds. Sex-sorted semen from 4 proven Holstein-Friesian bulls and available under commercial conditions was used on nulliparous Holstein heifers reared on 61 dairy farms of northern Italy. Data from 536 artificial inseminations with pregnancy diagnosis and 258 calvings were analyzed using the logistic regression procedure. The effects of year and season of insemination or calving, age at insemination or calving, heifer inbreeding, and the sperm dose used for insemination on the probability of a positive pregnancy diagnosis or of the birth of a female calf, respectively, were studied. The overall pregnancy rate for sexed semen was 51% and was affected by year of insemination and bull. Heifers inseminated with sexed semen from 2 bulls had lower pregnancy rates than heifers inseminated with sexed semen from other bulls. Purity of the sexed sperm, based on the proportion of female calves, was 87% and this percentage was not affected by explanatory variables included in the logistic regression. The results demonstrate that bulls differ in terms of fertility of their sexed semen. Careful selection of the insemination sires used for sorted semen is advisable for avoiding low fertility inseminations.
Reproduction in Domestic Animals, 2020
The effect of delaying the time of insemination with sex-sorted semen on pregnancy rate in Holstein heifers Contents The objective of the study was to evaluate the interval from onset of estrus to time of artificial insemination (AI) to obtain the optimum pregnancy rate with sex-sorted semen in Holstein heifers. Heifers in estrus were detected and inseminated only by using heat-rumination neck collar comprised electronic identification tag at the age of 13-14 months. Heifers (n=283) were randomly assigned to one of three groups according to the timing of insemination at 12-16h (G1, n=97), at 16.1-20h (G2, n=94) and at 20.1-24h (G3, n=92) after reaching the activity threshold. The mean duration of estrus was 18.6±0.1h and mean peak activity was found at Accepted Article This article is protected by copyright. All rights reserved 7.5±0.1h after activity threshold. The mean interval from activity threshold to ovulation was 29.4±0.4h. The overall pregnancy per AI (P/AI) was 53.0% at 29-35 days and 50.9% at 60-66 days after AI. There was a significant reduction between G1 (13.8±1.4h) and G3 (7.9±1.4h) related to the intervals from AI to ovulation time. Sex-sorted semen resulted in significantly higher P/AI at 29-35 days when heifers inseminated in G3 (60.9%) after estrus than those inseminated in G1 (49.5%) and G2 (48.9%). In terms of fertility, when the temperature humidity index (THI) was below the threshold value (THI≤ 65) at the time of AI, there was a tendency (≤65; 57.2% vs >65; 47.1%) for high pregnancy rate. There was no effect of sire on P/AI. In addition, the inteaction of the technician with the time of AI was found significant, and three way interaction of technician, sire and time of AI was tend to be significant on pregnancy rate. Thus, in addition to delaying the time of insemination (between 20.1 and 24h) after estrus detection, THI and experienced technician were also found to be critical factors in increasing fertility with the use of sex-sorted semen in Holstein heifers.
Tropical Animal Health and Production, 2010
Breeding records, including 649 inseminations during fall and winter at a dairy farm in a subtropical area of Western Mexico (24º N; 24°C, mean annual temperature 24°C) were analyzed to document effects of sex-sorted semen from commercial Gyr bullls, estrus synchronization protocol, inseminator, sire and environmental conditions on fertility of crossbred cows (Holstein × Gyr). Percentage of services resulting in pregnancies decreased sharply when sex-sorted semen was used (22.7 vs. 37.7%; P < 0.01). Although statistically not significant (P = 0.31), cows whose first insemination was in November experienced a numerically greater reduction (21 percentage points) in pregnancy rate compared to cows whose first insemination occurred in December. Substantial increases in services per pregnancy (4.71 ± 1.35 vs. 2.13–2.43; P < 0.01) were associated with the warmer month of the study period, November, compared to other winter months. Pregnancy rates of cows regardless of semen category (33%) were not affected by sire, temperature–humidity index and estrus synchronization protocol. Cows inseminated by one inseminator had higher pregnancy rates (P < 0.01) than cows inseminated by other two technicians. The sorted sperm produced 91% (142/156) female offspring. It was concluded that, under the field conditions of the present study, pregnancy rate with sexed semen was 15 percentage points lower than pregnancy rates using conventional semen, with 91% of female calves derived from sexed sperm.
The objective was to compare conceptions rates of Holstein cows and heifers after artificial insemination (AI) with 2.1 or 3.5 × 10 6 sex-sorted sperm or 15 × 10 6 conventional sperm. Ejaculates collected from 7 Holstein sires were cryopreserved conventionally at 15 × 10 6 sperm per dose or sorted to 90% purity for Xchromosome-bearing spermatozoa using flow cytometry and cryopreserved at either 2.1 or 3.5 × 10 6 sperm per dose. All treatments were processed in an egg-yolk (20%), Tris, glycerol (7%) extender and packaged in color-coded 0.25-mL French straws. Straws (n = 700 straws/dosage per sire) were packaged and distributed in aliquots of 12 (4 straws/sperm dosage) to 69 Holstein herds with an across-herd goal of achieving ~50% use in heifers and cows. Straw color was recorded in the on-farm recordkeeping system at the time of AI and retrieved by electronic download. Data for cows and heifers were analyzed separately. Among heifers, 6,268 services were retrieved from 45 herds (298 ± 4.2 services/sperm dose per sire; range: 244 to 344). Conception rate of heifers was influenced by the sire by treatment interaction. Conception rate of the 2.1 and 3.5 × 10 6 sex-sorted sperm dosages were comparable in 6 of 7 sires. Conception rate of both sex-sorted dosages were less than those of conventional semen for 6 of 7 sires. Across sires, heifer conception rates for 2.1 and 3.5 × 10 6 sex-sorted sperm dosages and 15 × 10 6 conventional dosages were 44, 46, and 61%, respectively. Among cows, 5,466 services were retrieved from 52 herds (260 ± 3.3 services/sperm dose per sire; range: 236 to 289). Conception rates of cows were influenced by herd, sire, and sperm dosage. Conception rates of the 2.1 and 3.5 × 10 6 sex-sorted sperm dosage were comparable for all 7 sires. Conception rates of 2.1 × 10 6 sex-sorted sperm dosage were less than those of conventional semen for 4 of 7 sires and conception rates of the 3.5 × 10 6 sex-sorted sperm dosage were less than those of conventional semen for 2 of 7 sires. Across sires, conception rates for 2.1 and 3.5 × 10 6 sex-sorted sperm dosages and 15 × 10 6 conventional dosages in cows were 23, 25, and 32%, respectively. In conclusion, these data could not confirm that a meaningful improvement in conception rates should be expected in cows or heifers from increasing sex-sorted sperm dosage from 2.1 to 3.5 × 10 6 sperm per dose.
Theriogenology, 2010
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Journal of dairy science, 2010
Use of sexed semen for artificial insemination of US Holstein heifers (1.3 million breedings) and cows (10.8 million breedings) in Dairy Herd Improvement herds was characterized by breeding year, parity, service number, region, herd size, and herd milk yield. Sexed semen was used for 1.4, 9.5, and 17.8% of all reported breedings for 2006, 2007, and 2008, respectively, for heifers, and for 0.1, 0.2, and 0.4%, respectively, for cows. For 2008 sexed semen breedings, 80.5 and 68.6% of use was for first services of heifers and cows, respectively. For cows, 63.1% of 2008 sexed semen use was for first parity. Mean sexed semen use within herd was the greatest for heifers in the Southwest (36.2%) and for cows in the Mideast (1.3%). Mean sexed semen use increased for heifers but changed little for cows as either herd size or herd mean milk yield increased. Availability of sexed semen was examined for Holstein bulls in active AI service; of 700 bulls born after 1993, 37% had sexed semen market...
Evaluation of sexed semen on conception rate in crossbred heifers and cows under field conditions
International Journal of Advanced Biochemistry Research, 2024
The present study was undertaken to evaluate the conception rate in dairy cows inseminated with sexed semen under field conditions. A total of 97 crossbred dairy heifers and cows, aged 16 months and above with a BCS 2.75-3.0 (5-point scale), were confirmed non-pregnant by transrectal palpation and assigned to different treatment groups. Cows (n=25) in estrus inseminated with conventional semen as Group I, heifers (n=30) in estrus inseminated with sexed semen as Group II, Cows (n=30) in their second lactation or beyond inseminated with sexed semen as Group III and heifers (n=12) in estrus inseminated with conventional semen as Group IV. Artificial insemination was performed on cows and heifers exhibiting estrus, characterized by the presence of clear cervico-vaginal mucus. Cows returning to estrus after insemination were re-inseminated according to their assigned group. Cows that did not return to estrus were subjected to pregnancy diagnosis at 30 days post-insemination using a Pregnancy Associated Glycoprotein (PAG) kit, with confirmation on the 45 th day through rectal palpation and ultrasound scanning. The comparatively lower conception rate with sexed semen can be improved by combining its use with effective farm management practices and targeting high-quality heifers and cows with excellent reproductive and productive performance.
Reproduction in Domestic Animals, 2022
There is increasing interest in calf gender pre-selection through the use of sexed semen by dairy and beef cattle farmers around the world when conducting artificial insemination (AI). Dairy and beef cattle farmers desire certain sex/gender (bull or heifer) calves from their cows; unfortunately, they have to wait for the cow to calve. Furthermore, there is a high demand for heifer calves by dairy farmers to use as replacement heifers (Seidel Jr & Schenk, 2008); meanwhile, dairy bull calves are susceptible to causing dystocia unlike