Factors Affecting Fertility of Frozen Semen of Cow and Buffalo Bulls Under Field Conditions

Research Abstract

Summary and Conclusion During the last few decades attempts have been made to introduce the freezing technique in A.I. centers. The reasons for that are obvious and it is believed that by the use of frozen semen the genetically superior bulls will be used fully and improvement in production will be realized at a shorter period. It seems necessary therefore to evaluate the introduction of such practice under the Egyptian conditions of management. However, the fertility results are not only dependent on the fertility of semen but also on the fertility potentials of the recipient animals. Therefore, it seems essentials to evaluate the fertility results of both cattle and buffaloes after utilization of deep-frozen semen and study the factors affecting such results under field conditions. The present study is a modest attempt in this direction. The current study was conducted in four villages in Beni-Suef Governorate. 2021 animals were included and categorized into 590 Baladi cows, 198 Baladi heifers, 633 crossbred cows, 245 crossbred heifers, 259 Buffalo cows and 96 Buffalo heifers. These animals were owned sporadically by farmers. Gynaecological examination of all animals was performed and only the healthy ones were inseminated by frozen semen which obtained from Beni-Suef artificial insemination canter, Abbasia Buffalo frozen semen production unit, or imported from France. This study was carried out from January 1994 to April 1995. Pregnancy was diagnosed by rectal palpation 60-90 days following insemination day. Records including the name and address of the owner, breed, age, parity, postpartum service interval, condition of the last parturition and nature of the cervical mucus and insemination date. The bull number, date of semen processing and thawing regime were also included in these records. The data were subjected to statistical analysis by ANOVA test and least square means (LSM) using the statistical SAS software (1995). The results of the present study revealed the following: • About 44.9% of cattle and 23.8% of buffaloes were utilized artificial insemination in the area under study. • The overall mean conception rate (CR) in heifers was higher (55.84±1.74) than that recorded in cows (49.62±1.0). nearly the same trend was observed in Buffaloes, as the CR that recorded in B-heifers was (47.3±2.04) higher than that recorded for B-cows (44.23±2.41). • Both cattle and buffalo heifers required less number of services per conception (NSPC) than pleuriparous cows. • The seasonal variations exerted a significant effect on the CR in both cattle and buffaloes, where the highest CR were obtained during Autumn (56.09±1.04 &54.11±5.23) and winter (55.65±1.04 & 53.33±43.37) for cows and buffaloes respectively. The lowest CR were obtained during summer (39.76±2.38 & 32.64±6.65) and Spring (47.0±2.08 & 36.84±6.29) for cows and buffaloes respectively. However, the fertility results of heifers were not affected by season of insemination • Animals bred during Summer and Spring required more number of inseminations to become pregnant than those bred during Autumn and Winter. • The time elapsed from estrus detection till insemination exerted a highly significant effect on the CR in both cattle and buffaloes, and the higher CR were recorded in cows (65.76±1.26) and buffaloes-cows (54,65±3.23) when inseminations were carried out at 12-18 hours after the first estrus signs was detected, while the highest CR were recorded in heifers (69.74±3.72) and buffalo-heifers (61.85±3.65) when inseminations were done before 12 hours from first estrus detection. • Generally, animals inseminated after 18 hours from estrus detection required more inseminations per one conception. • The nature of the cervical mucus at the time of insemination exerted a highly significant effect on the CR in both cattle and buffaloes, where the highest CR was obtained in cows (70.35±1.27), heifers (75.06±2.31), buffalo-cows (53.65±4.92) and in buffalo-heifers (60.72±4.71) when inseminations were performed in the presence of clear and glassy cervical mucus, while inseminations that done in the presence of thin and watery cervical secretions resulted in significant lower CR (22.23±2.62, 31.13±5.72, 26.14±7.08 and 23.5±8.16) in cows, heifers, buffalo-cows and buffalo-heifers respectively. • Animals with thin and watery cervical secretions required significant a greater number of inseminations to become pregnant than animals with clear and glassy mucus, and those with scanty mucus at the time of inseminations. • Regarding the effect of parity, the highest CR were recorded in cows (62.95±1.31) and buffaloes (52.85±3.36) having 2-4 calvings, while primiparous and multiparous animals having more than 4 calvings the CR were decreased and the NSPC were increased. • Concerning the postpartum service intervals, the highest CR were obtained in cows (66.64±1.33) and buffaloes (47.36±3.78) and lower NSPC in cows (1.5±0.01) and buffaloes (2.1±0.05) when inseminations were done at 45-90 days postpartum. • The condition of the last parturition exerted a highly significant effect on the fertility in cattle and buffalo, where the highest CR were recorded for cows (60.89±1.09) and buffaloes (52.47±5.78) and the lowest NSPC for cows (1.64±0.01) and buffaloes (1.9+0.03) that calved normally. • The differences in CR an NSPC due to the effect of breed/genotype of cattle, semen source, service sire, and sequence of insemination were not significant. • A highly significant negative correlation coefficients between CR and the percentage of sperm head abnormalities (-0.87), total sperm abnormalities (-.79), percentage of abnormal acrosome (-0.77), % of proximal protoplasmic droplets (-0.77) and % of detached sperm heads 9-0.71). However, a significant positive correlations were obtained between the CR and live sperm % (+0.65), post hawing progressive forward sperm motility % (+0.56). Conclusions From the results of the current study and according to the used fertility measures we can conclude that: 1) -No significant differences in fertility results were noticed between Baladi cows and their crosses. 2) -No significant differences in fertility results were obtained between locally prepared and imported frozen bovine semen. 3) -The Winter and Autumn are the best breeding seasons. 4) -Heifers were less affected by seasonal variations. 5) -The best time to inseminate multiparous cows was 12-18 hours after estrus detection and was found to be < 12 hours post estrus detection to inseminate heifers. 6) -The fertility of heifers was higher, decreased after the first calving, then increased till reach maximum at 2-4 calvings, then gradually decreased. 7) -Dystocia, abortion, still birth, retained fetal membranes, vaginal and uterine prolapse were greatly negatively affect the subsequent fertility. 8) -Bulls recorded high fertility measures in the lab, recorded also t a great extent high fertility results in the field (in vivo).

Research Keywords

Factors Affecting Fertility of Frozen Semen of Cow and Buffalo Bulls Under Field Conditions