Comparison of electroejaculation and transrectal massage for semen collection in range and yearling feedlot beef bulls.
ABSTRACT Two experiments were conducted to compare electroejaculation (EE) and transrectal massage (RM) of the ampullary region for semen collection from beef bulls, and to determine the effect of semen collection method on semen traits. In experiment 1, semen was collected either by EE or RM randomly assigned on an alternate basis in 137 range beef bulls unaccustomed to being handled. The maximum time allowed for RM was 4 min and if no semen was obtained, EE was used. In experiment 2, semen was collected from 39 yearling feedlot beef bulls that were accustomed to being handled, by RM followed immediately by EE. The maximum time allowed for semen collection by both methods was 4 min. In both experiments, sperm concentration, percent of progressively motile sperm, percent of sperm staining alive, and sperm morphology were determined. In experiment 1, RM resulted in fewer (P<0.001) successful semen collections and fewer bulls with penile protrusion than EE (80.9% versus 100% and 54.4% versus 91.5%, respectively). The success of RM was not influenced by bull age or breed, or by the veterinarian performing the massage. Transrectal massage required more time (30s, P<0.001) for obtaining a semen sample and resulted in samples with lower sperm concentration (P<0.001), percent motile sperm (P<0.05) and percent live sperm (P<0.001) when compared to EE. In experiment 2, EE and RM were equally effective for obtaining a semen sample (97.4 and 94.9%, respectively), but the proportion of bulls exhibiting penile protrusion during semen collection was lower (P<0.0001) with RM compared to EE. Percent of sperm staining alive was also lower (P<0.01) in samples collected by RM. Sperm morphology (normal sperm, head defects, midpiece defects, proximal cytoplasmic droplets, and detached sperm heads) did not differ between samples collected by EE and RM. In conclusion, semen could be collected by transrectal massage from approximately 80% of range beef bulls and from 95% of yearling beef bulls accustomed to handling. Sperm morphology was not affected by the method of semen collection, but percent of motile sperm and live sperm were lower in samples collected by RM. A reduced ability to stimulate penile protrusion with RM precluded examination of the penis in a large proportion of bulls.
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ABSTRACT: This experiment was conducted to compare the accepted Field system of bull breeding soundness evaluation (BBSE) utilized by veterinarians in Canada with the centralized Swedish (Lab) system. To be classified as a satisfactory potential breeder, both systems require that bulls must have ≥70% morphologically normal sperm; however, minimum progressively motile sperm (≥60% - Field; ≥30% - Lab) and maximum sperm class abnormalities proportions differ (<20% - Field; <15% - Lab). Semen was collected by transrectal massage (TM) from 54 sexually mature beef bulls. The percent progressively motile sperm was determined within minutes of collection and these data were shared. Sperm morphology was evaluated independently utilizing slide staining and microscopic assessment techniques typically used for the evaluation of bull semen within the respective countries. Mean progressively motile sperm was 45% (±23.8%). The mean proportion of normal sperm recorded in the Field (83.6±12.1%) was greater than the Lab (71.1±18.2%) (P<0.001) with more sperm head abnormalities recorded in the Lab (13.6±11.4) than the Field (2.4±2.8) (P<0.01). The number of bulls exceeding the ≥70% morphologically normal sperm was 51 (94.4%) in the Field versus 36 (66.7%) in the Lab (kappa=0.21). Only 13 bulls were classified as satisfactory potential breeders by both systems (kappa=0.15). Efforts to improve and standardize the evaluation of bull sperm morphology are needed, and the use of ≥30% progressively motile sperm threshold for TM-derived samples is recommended.Animal reproduction science 06/2013; · 1.56 Impact Factor
- Journal of King Abdulaziz University-Science 01/2009; 21(2):419-440.
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ABSTRACT: The aim of the study was to determine if the breeding potential of 25-month old Bonsmara beef bulls could be predicted from production characteristics. Forty-one Bonsmara bulls were included in an on-farm performance test (also known as the Phase D growth test) for a period of 180 days. At an average age of 24.7 months the bulls were subjected to a libido test and overall breeding soundness evaluation (OBE). The bulls were categorised into independent breeding potential categories according to the scores they obtained for the measured reproductive traits. The categories included sperm morphology and motility. One-way ANOVA revealed that none of the production traits measured had a significant effect on the different breeding potential categories. A positive correlation (r = 0.33) was recorded between pre-weaning growth rate and percentage morphologically normal sperm, while a negative correlation (r = -0.36) was recorded between total acrosomal- and flagellar sperm defects and pre-weaning growth. A positive correlation was demonstrated between sperm motility and pre-weaning growth (r = 0.36), and a consequent negative correlation (r = -0.38) between the percentage aberrant sperm movement and pre-weaning growth. The correlation between the percentage morphologically normal sperm and percentage progressively moving sperm was r = 0.50, while the correlation between percentage morphologically normal sperm and aberrant and immotile sperm was r = 0.48 for both variables. The number of total defects correlated highly significantly with flagellar and acrosomal defects (r = 0.72 and r = 0.93, respectively) and correlated poorly with the total number of nuclear defects (r = 0.32). These results suggest that total sperm defects were mainly due to acrosomal and flagellar defects, rather than nuclear defects and as the percentage morphologically normal sperm decreased, the motility also decreased. High growth rates before weaning may have a positive effect, while high growth rates after weaning may have a negative effect on the breeding potential of a bull. None of the measured reproductive and production traits had a significant effect on libido score and thus, cannot be used to predict the libido of young extensively maintained bulls.South African Journal Of Animal Science 12/2009; 40(3):163-172. · 0.35 Impact Factor