Timing of insemination and fertility in dairy and beef cattle receiving timed artificial insemination using sex-sorted sperm

Abstract

The objective was to evaluate the effects of timing of insemination and type of semen in cattle subjected to timed artificial insemination (TAI). In Experiment 1, 420 cyclic Jersey heifers were bred at either 54 or 60 h after P4-device removal, using either sex-sorted (2.1 × 10(6) sperm/straw) or non-sorted sperm (20 × 10(6) sperm/straw) from three sires (2 × 2 factorial design). There was an interaction (P = 0.06) between time of AI and type of semen on pregnancy per AI (P/AI, at 30 to 42 d after TAI); it was greater when sex-sorted sperm (P < 0.01) was used at 60 h (31.4%; 32/102) than at 54 h (16.2%; 17/105). In contrast, altering the timing of AI did not affect conception results with non-sorted sperm (54 h = 50.5%; 51/101 versus 60 h = 51.8%; 58/112; P = 0.95). There was an effect of sire (P < 0.01) on P/AI, but no interaction between sire and time of AI (P = 0.88). In Experiment 2, 389 suckled Bos indicus beef cows were enrolled in the same treatment groups used in Experiment 1. Sex-sorted sperm resulted in lower P/AI (41.8%; 82/196; P = 0.05) than non-sorted sperm (51.8%; 100/193). In addition, there was a tendency for greater P/AI (P = 0.11) when TAI was performed 60 h (50.8%; 99/195) versus 54 h (42.8%; 83/194) after removing the progestin implant. In Experiment 3, 339 suckled B. indicus cows were randomly assigned to receive TAI with sex-sorted sperm at 36, 48, or 60 h after P4 device removal. Ultrasonographic examinations were performed twice daily in all cows to confirm ovulation. On average, ovulation occurred 71.8 ± 7.8 h after P4 removal, and greater P/AI was achieved when insemination was performed closer to ovulation. The P/AI was greatest (37.9%) for TAI performed between 0 and 12 h before ovulation, whereas P/AI was significantly less for TAI performed between 12.1 and 24 h (19.4%) or >24 h (5.8%) before ovulation. In conclusion, sex-sorted sperm resulted in a lesser P/AI than non-sorted sperm following TAI. However, improvements in P/AI with delayed time of AI were possible (Experiments 1 and 3), and seemed achievable when breeding at 60 h following progestin implant removal, compared to the standard 54 h normally used in TAI protocols.

Conception rate of lactating cows and heifers (Bos taurus X Bos indicus) for sexed and conventional semen in artificial insemination

“…Furthermore, the conception rates for sexed semen were low even for crossbred animals, corroborating the results of other studies with other breeds, including beef cattle, which had low conception rates for insemination with sexed semen (Sales et al, 2011;Sá Filho et al, 2013). The conception rate for sexed semen insemination is between 60% and 90% lower than that observed for conventional semen (Dejarnette et al, 2009;Schenk et al, 2009;Dejarnette et al, 2010;Healy et al, 2013;) and the results of this study are within this range (61.1% -76.4%).…”

“…Several authors also observed a statistical difference when comparing sexed and conventional semen, for both estrus detection (Bodmer et al, 2005;Anderson et al, 2006;Sá Filho et al, 2013) and fixed-time artificial insemination (FTAI) (Sales et al, 2011;Mallory et al, 2013;Sá Filho et al, 2013). However, the use of sexed semen is recommended to reach best results after estrus detection (Mallory et al, 2013).…”

“…Another important factor affecting conception rates of sexed semen is the individual bull fertility, which is a cause for inconsistent results of several studies (Sales et al, 2011). Semen from different bulls reacts differently to the sperm sorting process (Dejarnette et al, 2008;Sales et al, 2011) in a matter that that interpretation of some results may be different when using a different bull (Mallory et al, 2013;Liu et al, 2015).…”

“…Physical and chemical stress during the sorting process can damage the sperm and accelerating the process of capacitation and acrosome reaction (Mocé et al, 2006). Hence, the combined effects of low sperm numbers and reduced semen quality has resulted in lower conception rate after AI compared to conventional semen (Anderson et al, 2006;Seidel Júnior and Schenk, 2008;Sales et al, 2011;Mallory et al, 2013;Sá Filho et al, 2013).…”

Assessment of different in vitro sperm challenges and in vivo fertility of bovine semen batches

“…In addition, BCS, AI technician, farm, breeding groups, and sire/semen quality are other factors affecting timed-AI outcomes (PERRY et al, 2007;SÁ FILHO et al, 2009;SALES et al, 2011;CELEGHINI et al, 2017). The absence of these effects (BCS, AI technician, and breeding groups) on CR in the present study may be due to the fact that breeding groups were well distributed across the timed-AI variables, all animals were cows in the same category (suckled multiparous Brangus cows), only two skilled AI technicians inseminated cows, and all animals presented small variation in BCS range (2.25 to 3.00).…”