Estrus detection programs practiced on most U.S. dairy farms are not intense enough to provide the information needed to accurately time insemination, thus preventing AI from obtaining its full conception rate potential. Herds (n = 17) participated in a trial designed to evaluate percent pregnant relative to various characteristics of estrus. Herds utilized HeatWatch® electronic estrus detection system to detect and record mounting activity for cows in estrus. Inseminations were performed daily during a three hour interval for all cows identified in estrus the previous 24 h. Model characterizing percent pregnant for cows (services = 2661) included effects of interval from first mount to AI (P < 0.01), mounts per estrus (P < 0.01), DIM at insemination (P < 0.01), herd (P <0.05), and season of AI (P < 0.05). As mounts per estrus and days in milk increased, percent diagnosed pregnant increased. Interval affected probability of pregnancy with highest odds ratios for percent pregnant occurring >4 to 16 h following onset of estrus. Model for heifers (n = 306) included linear effects of interval (P < 0.01), season (P < 0.05), and herd (P < 0.01). In dairy heifers, as interval from first mount to AI increased, percent pregnant decreased. Timing of insemination in dairy cows can now be performed relative to first mount of estrus, with highest probability of pregnancy occurring between >4 to 16 h after onset. If onset of estrus is not known, insemination should be performed at the next most convenient time within 3 h. / Master of Science

The objectives were to: 1) determine if im treatments of Lutalyse expedited the training of sexually inexperienced boars for semen collection and increased spermatozoal output, and 2) determine the effects of dietary L-carnitine supplementation on boar libido, semen quality, sperm production, and maintenance of sperm motility during liquid storage. Experiment 1 utilized lean-type, terminal-line boars (National Pig Development, Roanoke Rapids, NC) (n = 40; 177.4 ± 2.4 d of age and 112.8 ± 2.0 kg body weight) that had not previously experienced natural mating. Boars were individually moved twice weekly for 6 weeks (total of 12 training sessions) to a semen collection room equipped with an artificial sow. Upon entering the semen collection room, boars received in treatments of either deionized water (4 mL, n = 10) or Lutalyse at doses of 5 mg (n = 10), 10 mg (n = 10), or 20 mg (n = 10), and subsequently received a libido score of 1 to 5 (1 = no interest in the artificial sow; 5 = mounting the artificial sow and allowing semen collection). The percentages of boars successfully trained for semen collection during the experimental period were similar (P > 0.05) for controls (20%) and boars receiving 5 mg (30%), 10 mg (20%), or 20 mg (10%) of Lutalyse. Average libido score for boars receiving 10 mg Lutalyse (2.35 ± 0.08) was greater (P < 0.05) than for controls (2.14 ± 0.06). Libido score for the 20 mg treatment group were (1.78 ± 0.06) lower (P < 0.05) compared to the other treatment groups. Characteristics of ejaculates (volume, gel weight, sperm concentration, total spermatozoa) from control boars and boars treated with Lutalyse at doses of 5, 10, or 20 mg were similar (P > 0.05). For Exp. 2, the same group of boars was utilized in two similar trials (Trial 1, 1a, 1b: n = 9 for control and L-carnitine-treated boars; Trial 2, 2a, 2b: n = 10 for control and L-carnitine-treated boars). Boars were fed a fortified, corn and soybean meal-based diet at a rate of 2 kg/d. Boars that were randomly selected for L-carnitine treatment received the same diet mixed with L-carnitine to achieve supplementation of 500 mg/d. For 16 wk, semen was collected weekly via the gloved hand method and was analyzed for gel-free volume, gel weight, sperm concentration, sperm per ejaculate, and characteristics of sperm motility. Time to ejaculation (reaction time), duration of ejaculation, and number of false mounts were also recorded for each collection. Trials 1a and 2a were conducted during weeks 16 and 17 for each respective trial. Boars were collected once on 4 consecutive days, allowed 4 d of rest, and then collected again, to estimate daily spermatozoal production. At the end of 16 wk, a semen sample was also processed and extended in Beltsville Thawing Solution (BTS) to achieve a dilution of 3 x 109 spermatozoa/100 mL-dose for Trials 1b and 2b. The extended semen was stored in plastic bottles at 18°C and motility was evaluated daily for 7 d post collection. L-carnitine supplementation for 16 wk had no effects on semen volume, gel weight, total number of sperm cells per ejaculate, reaction time, or sperm motility (P > 0.1). Boars receiving the L-carnitine-supplemented diet displayed an increase in the number of false mounts before ejaculating and an increase in sperm concentration (P < 0.05) in Trial 2. A treatment by week interaction was detected for sperm concentration in Trial 2 (P < 0.005). Increased sperm concentrations in L-carnitine-treated boars were demonstrated after only one week of feeding the respective diets. Given that the production of a mature sperm cell requires 7 to 8 wk in boars, it is therefore difficult to conclude that differences in sperm concentration were due solely to treatment. Daily spermatozoal production was similar between control boars and boars supplemented with L-carnitine (P > 0.1) for both Trials 1a and 2a. L-carnitine supplementation did not affect percent motility in Trials 1b and 2b or sperm progressive motility in Trial 2b during 7 d storage (P > 0.1). A treatment by day interaction was determined for sperm velocity (P < 0.05) in Trial 2b. L-carnitine supplementation decreased mean sperm velocity significantly after 2 d of storage. Overall, L-carnitine had no beneficial effects on boar libido, semen quality, sperm production, or maintenance of sperm motility during liquid storage. However, Lutalyse increased libido scores, but did not affect the number of boars trained for semen collection or number of spermatozoa ejaculated. / Master of Science

A total of 1,644 A.I. sampled bulls born from 1984 to 1986 with first proofs from Winter 90 to Summer 91 were used to determine the accuracy of predicting DYD and PTA from different sources of pedigree information obtained before the bull had daughter information. Traits evaluated were milk, fat and protein. Pedigree sources considered were PA, PI, PTA_SIRE and PTA_DAM. Approximate weighted regression was used to determine which pedigree source predicted DYD or PTA with the highest accuracy (highest R²). For all traits, PA had a higher R² for DYD and PTA than PI. Regression coefficients were less than one for PA and PI. R² values for PA to predict first DYD milk, fat and protein were .17, .20 and .18, respectively. R² for PA to predict first PTA milk, fat and protein were .47, .54 and .49, respectively. Adding PTA_DAM to the model with PTA_SIRE resulted in a higher R² than the model with PTA_SIRE alone. As expected R² values were similar for PA and the model with PTA_SIRE and PTA_DAM. However, the weights for PTA_SIRE and PTA_DAM were less than .5. Higher weights and R²s for predicting PTA compared to predicting DYD resulted from the part-whole relationship between bull’s PTA and his PA. Overall, weights and R² were less than expected, but reasonable accuracy was obtained in estimating a young bull’s DYD and PTA from pedigree estimates. Accuracy of prediction varied depending on when the bull received his first proof. R² values of different groups of bulls based on the date of first DYD and PTA ranged from .06 to .20, .08 to .15 and .05 to .12 for predicting first DYD from PA for milk, fat and protein, respectively. Prediction accuracy in some groups of bulls was less possibly because of the limited number of sires and reduced variation in sire PTAs. Changes in evaluation procedures to expand the variance of extended records and to account for differences in within herd variance may have adversely affected the accuracy of prediction. The impact of the addition of granddaughters (son’s daughters) on the PTA of the dam was evaluated. Addition of granddaughter information decreased the average of dam’s PTA 70 kg, indicating the dams’ PTAs were generally inflated. Granddaughter information measured relative to PA of the son was useful to predict the change in the dam’s PTA at the AM evaluation the dam’s sons received first proofs. Regression coefficients ranged from .30 to .39, which were similar to the weights for w₃ in the PTA function. R for the regressions ranged from .33 to .72. Predicting further change in dam’s PTA (after the AM evaluation first granddaughter information was received) resulted in lower R? (.13 to .35) for additional granddaughter information. Evidence of bias and/or errors were found in bulls sampled outside the respective A.I. organizations’ designated sampling herds. These bulls had PAs that overestimated their DYDs for milk, fat and protein by 107 kg, 7.5 kg and 5.7 kg, respectively. The PAs of these bulls overestimated the PTAs by 97 kg, 6.8 kg and 4.5 kg for milk, fat and protein, respectively. Discrepancies were also found between average PTAs and DYDs and the PAs of bulls based on the rank of the dam’s PTA. Bulls from dams with lower PTAs tended to have PAs that underestimated their DYDs by 48 kg and .5 kg for milk and fat, respectively. These bulls had PAs that underestimated their PTAs for milk, fat and protein by 42 kg, .5 kg and .6 kg, respectively. Examination of bulls from high ranking dams for PTA milk, fat or protein revealed that bulls from dams with higher PTAs tended to have PAs that overestimated their DYDs by 65 kg, 5.3 kg and 4.5 kg for milk, fat and protein, respectively. The PAs of these bulls overestimated their PTAs by 49 kg, 4.2 kg and 2.9 kg, for milk, fat and protein, respectively. / Master of Science

This study was conducted to evaluate the efficacy of intravaginal progesterone (P4) inserts (CIDR) in synchronization protocols combined with timed artificial insemination (TAI) as related reproductive performance. In the first study, heifers were synchronized with CIDR inserts followed by TAI. Heifers in the estradiol cypionate (ECP) group were synchronized with a combination of ECP, CIDR, prostaglandin (PGF2α), and ECP (CIDR-ECP), while the gonadotropin-releasing hormone (GnRH) group was synchronized using a combination of ECP, CIDR, PGF2α, and GnRH (CIDR-GnRH). All heifers were bred at either 48, 56, or 72 hours (h) after CIDR removal. Overall pregnancy rate (PR) for synchronized heifers was 60.1%, and embryo survival rate (ESR) was 98%. Pregnancy rate for CIDR-ECP treated heifers was influenced by artificial insemination (AI) time. In conclusion, ECP or GnRH may be used effectively in a CIDR-based TAI program in heifers. In the second study, cows were synchronized with CIDR devices or Ovsynch. The CIDR group received a combination of ECP, CIDR, PGF2α, and GnRH, while the Ovsynch group was synchronized using a combination of GnRH and PGF2α. Cows were bred at either 0, 8, or 24 h after the final GnRH injection. Overall PR for first service was 30.5% with ESR of 82.8%. Overall resynchronization PR was 35.1% with an ESR of 84.8%. In conclusion, Ovsynch and CIDR-based protocols are equally effective in synchronizing ovulation in a TAI program and resulted in comparable PR. / Master of Science

Exogenous oxytocin aids in the transcervical passage of an AI pipette into the uterus of ewes, and it may be an effective adjunct to sheep AI procedures. Experiments were conducted to evaluate the effects of oxytocin on variables that may affect fertility. The results of this study indicate clearly that oxytocin dilates the cervix in ewes (Exp. 1) without affecting the movement of sperm to the oviducts (Exp. 3) or fertilization rate (Exp. 9). Oxytocin probably binds to uterine and cervical receptors (Exp. 6) and stimulates uterine tetany (Exp. 2) and prostaglandin release (Exp. 5). Because of the irregular arrangement of smooth muscle in the sheep cervix (Exp. 4), uterine tetany may physically dilate the cervix. Also, prostaglandin synthesis, primarily PGF2, may be involved in a chemical softening of the cervix. Most likely, a combination of uterine contractions and cervical softening allow dilation and transcervical passage of an AI pipette. Although oxytocin does not affect sperm transport (Exp. 3) or fertilization (Exp. 9), fertility after transcervical AI is decreased (Exp. 8). Cervical manipulation seems to decrease fertility, but the mechanism is unclear. Therefore, a greater understanding of the physiology of the sheep cervix is necessary before oxytocin-induced cervical dilation can be implemented with nonsurgical AI procedures in sheep. / Ph. D.

Two studies were conducted to investigate the role of the bovine cervix in filtering abnormal sperm. ln Study 1, semen containing high levels of abnormal sperm was vaginally deposited in 12 cows 80 hours after prostaglandin F₂α treatment. At slaughter, 4-, 8- or 12 hours post-insemination, sperm were flushed from the excised uteri with fixative. Pooled across times post-insemination, viability was greater for uterine vs inseminate sperm, based upon vital smears prepared from inseminate and uterine flush samples. Uterine levels of normal sperm, determined by differential interference contrast (DIC) microscopy, were greater than were inseminated. In Study 2, heifers were estrus synchronized in pairs using prostaglandin F₂α, then inseminated with semen containing high levels of abnormal sperm. In each pair, semen of high viability (Experiment 1, n=10) or low viability (Experiment 2, n=6) was deposited vaginally in one heifer and within the uterine corpus of the other. Using DIC microscopy, viability and morphology were coincidentally determined for sperm in samples from the fixed inseminate and the retrograde mucus, vaginal mucus, cervix, uterus and in vitro incubation of inseminate recovered and fixed 12 hours post-insemination. Uterine sperm quality did not differ between insemination sites, except lower uterine levels of live abnormal sperm alter intrauterine vs vaginal insemination of low viability semen probably due to disproportionately low viability of one abnormality. Sperm viability was enhanced and morphology unchanged in the uterus vs low viability inseminate, while sperm viability was unchanged and abnormal sperm subtly reduced in uterus vs high viability inseminate. Greater levels of live and live normal sperm were found deeper between cervical folds than at apical aspects of folds. Vaginal mucus sperm viability was lower compared to other tract locations and inseminate, especially after high viability insemination. Compared to inseminate viability, retrograde mucus sperm viability was high after vaginal insemination and low alter intrauterine insemination. Differential death of abnormal vs normal sperm neither with incubation of insemination in vitro nor, presumably, in vivo. Results show little evidence of cervical filtration based upon sperm morphology. Sperm retention in the female tract was predominantly related to sperm viability with only very subtle morphology effects. / Ph. D.

Doctor of Philosophy / Department of Animal Sciences and Industry / Jeffrey S. Stevenson / Four experiments were conducted in beef cows to determine factors that increased the probability of pregnancy per AI when cows are inseminated by appointment. Cows in all experiments were inseminated after a 7-d CO-Synch + CIDR program (100 μg GnRH [2 mL Factrel, Pfizer Animal Health, Whitehouse Station, NJ] 7 d before 25 mg PGF₂[subscript]α [d 0; 5 mL Lutalyse; Pfizer Animal Health]). Experiment 1 compared 1 vs. 2 inseminations and GnRH injection times at 60 and 75 h after the CO-Synch + CIDR program. Delaying AI until 75 h, according to interpretation of estrus-detection patches, for cows not in estrus by 60 h after CIDR insert removal increased (P < 0.05) pregnancy risk (PR) compared with cows not in estrus and inseminated at 60 h (51.4 vs. 41.7%), respectively. The necessity of GnRH injection concurrent with AI was tested in experiment 2. Cows displaying estrus by 65 h that were injected with GnRH had similar PR to cows in estrus and not treated with GnRH (61.9 vs. 60.4%), respectively. Cows in experiment 2 that did not display estrus, but were treated with a GnRH injection at 65 h and then inseminated at 84 h after CIDR insert removal had increased PR compared with similar cows not treated with GnRH (33.4 vs. 15.0%; P < 0.01), respectively. Experiments 3 and 4 were observational studies conducted to determine if blood metabolites glucose and beta-hydroxy butyrate (BHB experiment 3), or physical body and blood metabolites, (glucose, BHB, non-esterified fatty acids [NEFA], blood urea nitrogen [BUN], body weight, rump fat [RF], or BCS; experiment 4) were indicative of future reproductive success in suckled beef cows enrolled in a timed AI program. In experiment 3, plasma glucose concentration 10 d before AI was lesser (P = 0.01; 52.2 vs. 56.9 mg/dL) and serum BHB concentration was lesser (P < 0.01) in cows that became pregnant 35 d after timed AI than for cows that did not become pregnant (600 vs. 690 μM), respectively. Experiment 4 identified relationships between indicators and reproductive success including the finding that serum NEFA concentration 2 to 4 wk before AI is negatively correlated (P < 0.05) with PR to AI.

M.Sc. / Climate change, loss of habitat and over-exploitation of natural resources as well as the introduction of invasive alien species through human activities are resulting in an ever increasing risk of extinction of many plant and animal species. There are two major approaches to conserving threatened and endangered species. Firstly the large scale preservation of natural habitat and ecological processes, thereby protecting the species inhabiting the habitat. The second approach involves the ex-situ breeding of rare and endangered species. It is estimated that in the next 200 years approximately 800 mammalian species will require the assistance of breeding programs to ensure long term genetic viability. Biological Resource Banks (BRB) can potentially contribute to this challenge by providing a source of genes that can be used to counter the effects of external selection pressures, genetic drift and inbreeding depression in small or fragmented populations. These banks commonly contain biological materials such as cryopreserved sperm, embryos and cell cultures mainly as genetic and research resources. . Biological resource banks can potentially use these cryopreserved gametes together with assisted reproductive technologies (ART), such as artificial insemination (AI), in vitro fertilisation (IVF), embryo transfer (ET), intracytoplasmic sperm injection (ICSI) and nuclear transfer (NT) to maintain genetic heterogeneity in ex-situ and wild populations. Ascertaining the appropriate protocols for developing the ARTs necessary for non-domestic species is one of the major challenges faced by reproductive physiologists. Typically, there is very little available information about the processing of semen, the effects of diluents, concentration and type of cryoprotectants and freeze-thaw methods for sperm samples of non-domestic species. Procedures proven to be highly effective in humans and laboratory or domestic species, are frequently adopted and modified for use in related wildlife species. It is thus necessary to gain knowledge of the reproductive physiology of wildlife species in order to define effective protocols for the cryopreservation of biomaterials which assists in the conservation of South Africa‘s diverse wildlife species. Sperm quality assessment is a useful tool for assessing the reproductive health of free-ranging populations as well as for selecting individuals for future assisted reproduction programs.

Thesis (Ph.D. (Animal Production)) --University of Limpopo, 2018 / Pigs are of high economic importance, especially among the smallholder pig farmers as they contribute to human nutrition, food security, poverty alleviation, enhanced livelihood and creation of employment for the rural community. However, reproductive inefficiency is the main limiting factor due to inaccessibility to superior germplasm. Therefore, advances in reproductive technologies such as oestrus synchronization and artificial insemination (AI) offers unprecedented opportunities for livestock improvement for smallholder pig farmers. The first objective determined the status of pig productivity in smallholder farms of Gauteng Province prior to the introduction of advanced reproductive technologies (ARTs). The population was divided into four strata, namely West Rand, Ekurhuleni, Tshwane and Sedibeng district municipalities. A proportional stratified random sampling procedure was used to select 71 smallholder pig farmers with the assistance of extension officers from Gauteng Department of Agriculture and Rural Development (GDARD). The majority of the respondents were males (67%) and were above 50 years of age (67%), whilst 56% of the respondents had high school education. Majority of the respondents privately owned the farms (62%) and the farm infrastructure had facilities with low cost housing and modern facilities. Additionally, 47% of the respondents fed their pigs with feed swill. A large proportion of the respondents did not vaccinate their pigs (81%). Majority of respondents did not identify their pig herds (63%). Interestingly, majority of the respondents did not have breeding boars (73%) and sold their pigs at auctions (70%). The second objective determined semen characteristics evaluated by a Computer Aided Sperm Analyser® (CASA®) as a measure of boar fertility to be used for artificial insemination (AI). Sixteen ejaculates were collected from three Large White boars that are routinely used for semen collection purposes using the gloved-hand technique. The semen was extended with a commercial semen extender; Beltsville Thawing Solution, and the AI dose used consisted of 80mL semen sample (3×109 spermatozoa/mL). Aliquots of diluted semen were evaluated for spermatozoa motility using CASA®. Spermatozoa viability was evaluated using Synthetic Binding CD-14 (SYBR+)/Propidium Iodide (PI-), whereas spermatozoa morphology was evaluated using Eosin Nigrosin stain. The average semen volume, concentration and pH were 210 mL, 264.8 x 106 spermatozoa/mL and 7.1, respectively. The average values for total spermatozoa motility was 95.1%, ranging from 82.7 and 98.5%. However, XIX there were lower values found for progressive spermatozoa motility, ranging from 13.6 to 39.0%. The mean values for morphologically normal spermatozoa ranged from 47.8-60.9% and live spermatozoa ranged from 71.8-77.7%. The third objective determined sow fertility following AI at smallholder farms A total of 73 multiparous sows were artificially inseminated. Conception rates, farrowing rates, litter size and number born alive were recorded. The average conception and farrowing rates were 78.1 and 57.5%, respectively. Furthermore, AI resulted in acceptable fecundity (i.e., 11.8 litter size and 10.0 number of piglets born alive). The fourth objective determined the relationship between spermatozoa quality characteristics and sow fertility at smallholder farms in Gauteng Province. Of all fertility characteristics studied, conception rate was significantly related to total spermatozoa motility rate (r= 0.37, P<0.01), progressive motility (r= 0.31, P<0.01) and rapid motility (r= 0.40, P<0.01), although relatively low. There was a low negative relationship between spermatozoa morphological characteristics and fertility (P>0.05). The fifth objective determined the pre-weaning growth performance of piglets born following AI at smallholder farms of Gauteng province. Individual piglets were weighed using an electronic weighing scale. Litter size, number of piglets born alive, number of piglets weaned, the average piglet birth weight and average piglet weaned weight were recorded. The average litter size was 11.8 ± 0.2. The average birth weight and weaning weights were 1.9 and 6.2 kg, respectively. No significant differences were found between male and female piglets for all the growth performance characteristics. Piglets born during winter had a significantly higher (P<0.05) birth and weaning weight as compared to autumn and summer months. Season had a significant effect on birth and weaning weight (P<0.01). However, sex of piglets had no effect on all the characteristics recorded (P>0.05). The interaction between sex and season was only observed on the total number of weaned piglets (P<0.01). A highly significant positive correlation was found between litter size and number of piglets born alive (r= 0.86) and total number of piglets weaned (r= 0.50). A highly significant correlation was found between total number of piglets born alive and total number of piglets weaned (r= 0.55). In conclusion, the study demonstrated the potential benefit of adopting AI technology under smallholder production systems to disseminate superior genetic material to smallholder pig farmers in Gauteng Province. The total spermatozoa motility, progressive and rapid spermatozoa motility were the only spermatozoa motility characteristics significantly correlated XX with conception rate. Conversely, litter size and number born alive were not correlated with CASA® spermatozoa motility attributes. No relationships existed between spermatozoa morphological characteristics and fertility. The sex ratio percentage of piglets born following AI was 52:48% (females: males). The number of piglets born alive was 10.2 and 9.5 for number piglets weaned. Season influenced birth to weaning weight. However, sex had no significant influence at birth and weaning weight. Litter size affects the number of piglets born alive and weaned. The study showed that the introduction of advanced reproductive technologies improved productivity of pigs at smallholder pig farms in Gauteng Province. / Gauteng Department of Agriculture and Rural Development (GDARD) and Southern African Science Service Centre for Climate Change and Adaptive Land Management (SASSCAL

No abstract available. / Thesis (LL.M.)-University of Natal, Durban, 2001.