Parturition Rate Research Articles

The efficiency of injectable P4 combined with the male effect on the pregnancy rate of boer goats in the off-season

Goats are seasonally polyestrous, which implies that the kid production is restricted to once a year. However, through estrous cycle manipulation, the production can be distributed throughout the year. Therefore, the present study aimed to estimate the reproductive viability of Boer female goats after administration of injectable P4, either combined with the male effect or independently, during the off-season in the southern region of Paraná. The outcomes evaluated in the study included the pregnancy rate, parturition rate, twin births, number of births, and concentration of births. The study was conducted in a beef goat farm, using 72 goats randomly assigned to three experimental groups. In the G1 group (n=22), females were stimulated by the male effect, in the G2 group (n=25), the animals received 75 mg of P4 intramuscularly at the beginning of the experiment, and in the G3 group (n=25), the goats received 75 mg of P4 intramuscularly at the beginning of the experiment combined with the male effect. The goats were in a breeding season of 60 days. The pregnancy rate, parturition rate, percentage of twin births, and the number of kids born per group were evaluated. The use of injectable P4 showed a similar pregnancy rate to the other groups, with a higher concentration of births in the G1 and G3 groups, both of which were subjected to the male effect (p<0.05). Furthermore, more studies should be carried out using different P4 concentrations.

Estimating the cost of young stock mortality in livestock systems-An application to sheep farming in Ethiopia.

In sub-Saharan Africa, pre-weaning young stock mortality (YSM) is in the order of 20 to 30% across most livestock species and production systems. High YSM has significant economic implications for livestock keepers, but few studies provide estimates of the "cost of YSM." This study explores a bio-economic herd modeling approach to estimate the "cost of YSM" at farming/livestock system level. The static zero-growth version of DYNMOD was used to calculate the annual physical and monetary output of a sheep flock consisting of 100 breeding females at different levels of lamb mortality. Production parameter values and prices were taken from recently published research. Calculations were carried out for values of lamb mortality decreasing from 30% to 0% in 5% intervals, with 20% representing the "baseline" YSM. Calculations were repeated for a "high" fertility scenario (100% vs. 59% parturition rate) to gauge the sensitivity of the cost of YSM to another parameter determining flock productivity. The relation of revenue per head and YSM is close to linear over the range of analyzed YSM with 1% decrease in YSM resulting in an increase in revenue per animal of approximately 1%. At the higher fertility rate, the absolute cost of YSM to sheep farmers is higher while the relative increase in revenue per animal resulting from YSM reduction is lower. The estimated difference in revenue of the 100-ewe flock between the 20% and 0% lamb mortality scenarios (at baseline fertility) amounts to approximately USD 90 per additionally surviving lamb, which is far above its market value. Reduced lamb mortality ultimately impacts flock revenue through increased sales of "mature" animals, which embody the value of a lamb plus the revenue/profit from raising it to marketable age/weight. The modeling results suggest that foregone profit is an important component of the systemic "cost of YSM." Consequently, expected profit per animal, in addition to its current market value, is essential for estimating the absolute cost of YSM at farming system level.

Modeling the economic performance of small ruminant pastoralist flocks and financial impact of changes in reproductive performance and mortalities in Kajiado county, Kenya

This study investigated the economic performance of pastoralist small ruminant flocks in Kajiado county, Kenya, and the financial impact of mortalities and changes in performance indicators. A survey of 129 pastoralist small ruminant flocks captured production and economic data for a 12-month period via interview. Simulation models were then developed for flocks with different performance levels and trading activities. Their gross margins, and the financial impact from mortalities, were estimated. Sensitivity analyses were conducted for select performance indicators to assess their relative economic importance. On average, pastoralists who were not purchasing supplementary feed (79% of flocks) had gross margins of KSh 3,016 – KSh 3,123 per reproductive female. Goat production generated 2.43–2.51 times greater returns than sheep production. High efficiency mixed flocks achieved 2.04–2.06 times greater returns than medium efficiency flocks, and 12.19–14.25 times greater returns than low efficiency flocks. Pastoralist-only flocks had 3.82–4.01 times greater returns than pastoralist-traders. Financial losses due to mortality were on average 17.81% of the starting flock value. Fecundity and abortion rates in sheep, and parturition rate in goats, had the greatest economic impact. The developed models could support decision-making toward improving the economic performance of pastoralist flocks and the evaluation of interventions and external shocks.

Effect of different starting doses of FSH on laboratory and clinical outcomes in patients with moderate AMH level.

IVF and ICSI-ET are widely used ART for addressing infertility which have been developed and improved over the last four decades. COS is a crucial step in IVF/ICSI-ET, whereby medications stimulate the ovaries to produce multiple eggs. The success of the procedure depends on the number of eggs retrieved, and individualized ovarian stimulation protocols based on factors like age and ovarian reserve can optimize the chances of obtaining mature oocytes. The optimal starting dose of FSH at moderate AMH levels remains a topic of debate., tThis study aims to compare different starting doses of FSH in clinical outcomes by analyzing data from a single center. This retrospective study collected clinical material from patients with moderate AMH levels at 1.2 ~ 4.5ng/mL who received IVF/ICSI-ET under a follicular phase long protocol from July 2018 to December 2021 at Guiyang Maternal and Child Health Care Hospital, China. The patients' clinical data were retrieved from the hospital's software database and divided into two groups based on FSH starting dose, as follows: lower starting dose group: FSH ≤ 150IU; and higher starting dose group: FSH > 150IU. Multiple laboratory and clinical outcomes were compared between the two groups. A total of 1784 patients with moderate serum AMH levels who received IVF/ICSI-ET under a follicular phase long protocol were enrolled based on eligibility criteria. In the population with moderate AMH levels, a lower starting dose of FSH might have more benefit than a higher starting dose in numbers of follicles with diameters ≥ 14mm and < 16mm, ≥ 16mm and < 18mm, and ≥ 18mm; numbers of retrieved oocytes, 2PNs, transferable embryos, high-quality embryos, and cleavage stage embryos transferred; and clinical pregnancy rate, intrauterine pregnancy rate, and parturition rate. Moreover, rFSH had a statistically significantly higher number of oocytes retrieved, number of 2PNs, and number of transferable embryos than that of patients who received uFSH. The starting dose of FSH in the moderate AMH population remains controversial and a higher starting dose may not lead to more benefit in laboratory and clinical outcomes.

Development and evaluation of an injectable slow-release progesterone formulation for estrus synchronization in ewes out of the breeding season.

This study was aimed at developing a type of slow-release progesterone micro-particles useable in a single intramuscular injection for estrus synchronization in non-breeding season ewes. A total of 66 ewes were randomly assigned into four groups: CIDR (n = 16): exposed to intravaginal CIDR for 12 days, and three experimental groups, i.e., T100 (n = 16), T150 (n = 17) and T200 (n = 17), receiving a single intramuscular injection of 100, 150 and 200 mg slow-release progesterone, respectively. Blood sampling was performed on all ewes at five different times, and the ELISA method measured progesterone levels. No significant differences were observed in progesterone levels among the groups in each sampling time. More than 90% of ewes in the CIDR, T100 and T150 groups and all those in T200 showed estrus behaviour, and the rate was not significantly different between groups. The difference in the mean interval from progesterone treatment to estrus was also insignificant. The parturition rate declined by increasing the dose of injected progesterone; although it was similar in CIDR and T100 groups, it decreased significantly in T150 and T200 . Since our injectable progesterone formulation was successful in the induction and synchronization of estrus in ewes out of the breeding season, it can be applied as an alternative to the conventional progesterone containing intravaginal devices.

PSXII-4 Estrus Synchronization and Artificial Insemination in Korean Black Goats Using Frozen-Thawed Semen

Abstract Korean black goat (Capra hircus coreanae) populations are dwindling and facing genetic erosion due to artificial insemination. Here, we introduced an estrus synchronization method for Korean black goats to enable crossbreeding with non-native breeds on small farms and investigated the application of estrus synchronization and artificial insemination in Korean black goats. Semen was obtained using electro-ejaculation and preserved using a conventional and simple freezing method. Pre- and post-freezing semen was analyzed using computer-assisted sperm analysis, as per the Food Standards Agency 2011 guidelines. The percentage of motile sperm in the electro-ejaculated samples declined significantly after freezing and thawing. However, this did not influence the artificial insemination results. In addition, the incubation period was positively correlated with sperm motility decline in the frozen-thawed sperm samples. Blood progesterone (P4) and estrogen (E2) concentrations were also analyzed to determine the optimal artificial insemination time in estrus-synchronized Korean black goats. The blood samples were collected from a jugular vein at approximately 0900 daily for 5 days. Subsequently, the serum was obtained using centrifugation and stored at -70°C until analysis. Although the P4 and E2 concentrations were generally unaffected by the estrous synchronization method, the controlled internal drug release + prostaglandin F2α + pregnant mare serum gonadotropin method yielded a 42.9% parturition rate after artificial insemination. In the present study, an offspring from an estrus-synchronized Korean black goat was successfully produced by artificial insemination using frozen-thawed semen. The successful cryopreservation of semen for artificial insemination was substantiated with sperm motility and pregnancy rates. In the future, additional studies of estrus synchronization for the artificial insemination of Korean black goats are needed. Our results are expected to significantly contribute to the Korean black goat breeding industry.

Effects of breeding season and estrus synchronization protocols on the fertility of anestrus swamp buffaloes (Bubalus Bubalis)

The present study aimed to investigate the seasonal calving pattern of the swamp buffaloes and to test various estrus synchronization protocols and breeding treatments to improve the reproductive efficiency of the anestrous female buffaloes. In Study 1, we first investigated the breeding records of female buffaloes in the Phayao Animal Breeding and Research Center (PABRC) from year 2004 to 2013, aiming to compare the calving rates in three different breeding seasons, i.e. winter season (Oct. – Jan., Group 1), rainy season (Jun. – Sep., Group 2), and summer season (Feb. – Apr., Group 3). We found that the best average calving rate was observed in the winter season (74%) compared to other seasons (11-15%). Therefore, all the protocols tested in Study 2 were only compared during the winter season. In Study 2, different synchronization protocols were compared based on the resulting conception rates and the cost of estrus induction for postpartum anestrous buffaloes under field conditions during the winter season. Sixty buffalo cows were allocated to the following treatment groups by completely randomized design. The estrous cycle of buffalo cows was synchronized by Norgestomet ear implant (Norgestomet, n=30, T1), controlled internal drug release (CIDR, n=30, T2), or ovulation synchronization (Ovsynch, n=30, T3) protocols. Results from Study 1 showed that, in the winter season, buffalo cows had the highest birth rate (74.1%, 291/393), compared to the rainy (14.8%, 58/393) and summer (11.2%, 44/393) seasons. The weaning weight of buffaloes born in the rainy season was greater than their summer and winter counterparts (p < 0.05). The average daily gain (ADG) of summer-born buffaloes was higher than those born in the rainy and the winter seasons (p < 0.01). Results for Study 2 showed no differences in behavioral estrus, clear mucus discharge and dilation of cervical passage among all treatment groups (p > 0.05). However, the pregnancy rate detected by ultrasonography 90 days after TAI and the parturition rate in the Ovsynch group were all 53.3%, which was higher (p < 0.01) than CIDR (40.0%) and Norgestomet (30.0%) treated groups. Moreover, the average cost for those cows treated with CIDR protocols was higher than those with Norgestomet and Ovsynch protocols. In conclusion, breeding in winter season can result in a better birth rate in swamp buffaloes. Adoption of the Ovsynch may have triggered the ovarian activity of buffaloes and have resulted in more than half of the anestrous postpartum swamp buffaloes becoming pregnancy and parturition, as well as simultaneously lowering the cost compared to other synchronization procedures.

Impact of co-transfer of embryos produced by somatic cell nuclear transfer using two types of donor cells on pregnancy outcomes in dogs.

ObjectiveThe present study analyzed the influence of co-transferring embryos with high and low cloning efficiencies produced via somatic cell nuclear transfer (SCNT) on pregnancy outcomes in dogs.MethodsCloned dogs were produced by SCNT using donor cells derived from a Tibetan Mastiff (TM) and Toy Poodle (TP). The in vivo developmental capacity of cloned embryos was evaluated. The pregnancy and parturition rates were determined following single transfer of 284 fused oocytes into 21 surrogates and co-transfer of 47 fused oocytes into four surrogates.ResultsWhen cloned embryos produced using a single type of donor cell were transferred into surrogates, the pregnancy and live birth rates were significantly higher following transfer of embryos produced using TP donor cells than following transfer of embryos produced using TM donor cells. Next, pregnancy and live birth rates were compared following single and co-transfer of these cloned embryos. The pregnancy and live birth rates were similar upon co-transfer of embryos and single transfer of embryos produced using TP donor cells but were significantly lower upon single transfer of embryos produced using TM donor cells. Furthermore, the parturition rate for TM dogs and the percentage of these dogs that remained alive until weaning was significantly higher upon co-transfer than upon single transfer of embryos. However, there was no difference between the two embryo transfer methods for TP dogs. The mean birth weight of cloned TM dogs was significantly higher upon single transfer than upon co-transfer of embryos. However, the body weight of TM dogs did not significantly differ between the two embryo transfer methods after day 5.ConclusionFor cloned embryos with a lower developmental competence, the parturition rate and percentage of dogs that remain alive until weaning are increased when they are co-transferred with cloned embryos with a greater developmental competence.

Productive and reproductive performances of smallholder West African shorthorn Lagune cattle herds under village conditions in Southern Benin.

The West African shorthorn Lagune cattle has long been incriminated as of low productivity and subjected to gradual replacement or indiscriminate crossbreeding with zebu breeds. But there are still insufficient studies reporting the productive and reproductive performances of this breed under village conditions. This study aimed to evaluate the productive and reproductive performances of the Lagune cattle herds kept under village conditions in two agroecological zones in Southern Benin. Sixteen herds (seven in the Oueme Valley zone and nine in the Pobe zone), chosen from a previous retrospective survey, were regularly visited on a bi-monthly basis between January 2018 and February 2019. At the first visit to each selected herd, all animals present were identified, their ages determined through their dentition, and their breeding history recorded. At each subsequent visit, information on calving, birth weights, herd entries and exits, disease incidence, and changes in the physiological status of the animals were recorded. In addition, all suckling calves from birth to 6months of age were weighted and measured. The average age at first calving was 37.2 ± 3.5months and varied from 3 to 4years. With no significant variations between agroecological zones, the parturition rate, fertility rate, fecundity rate, and abortion rate were, respectively, 74.3% ± 10.7, 77.0% ± 12.0, 68.9% ± 9.1, and 2.7% ± 1.4. The overall annual mortality rate and perinatal mortality rate were 8.4% ± 3.1 and 7.3% ± 2.7, respectively. The annual offtake rate was 12.9% ± 4.3 and varied significantly (P ≤ 0.05) between zones. The average birth weight varied significantly (P ≤ 0.05) between sex and was 10.2 ± 0.7kg and 10.8 ± 0.9kg for female and male, respectively. The average daily body weight gain of calves, calculated over the period from birth to 6months of age, was 160.5 ± 8.5g/day. In addition to environmental conditions, individual farmers' management practices varied significantly among herds and probably influenced the recorded reproductive and productive performances. The estimates of reproductive parameters obtained in this study suggest a good reproductive ability of the Lagune breed which could be improved with better management conditions.

Impact of selection for birth weight variability on reproductive longevity: A mice model.

Uniformity, understood as a similar performance in relevant livestock traits, such as birth weight within the litter, is being included as one of the selection objectives in breeding programmes, especially for polytocous livestock species. A divergent selection experiment for birth weight within‐litter variability in mice during 23 generations showed that homogeneous animals were better for litter size, survival and feed efficiency but less heavy than heterogeneous animals. The aim of this study was to compare the reproductive longevity in both divergent lines as time to the end of the reproductive period. Two generations from both lines with an initial number of 43 females and 43 males were mated one to one and stayed together to have consecutive parturitions until the end of the reproductive life. Females were discarded when the time elapsed from the last parturition was longer than 63 days. The time to the end of the reproductive period between both lines was compared by fitting a Cox proportional hazard regression model adjusting for line, generation and its interaction. The rate of parturitions in both lines was also compared using a Prentice–Williams–Peterson model adjusted for the same effects. The low variability line was associated with a higher parturition rate, e.g., adjusted hazard ratio was 2.93 (95% CI 2.17–3.94). The Cox model showed that the low variability females also presented benefits of time to the end of the reproductive period, with an adjusted hazard ratio of 0.26 (95% CI 0.16–0.41). The median of reproductive days was 55.50 in the high variability line whilst the median was 252.50 days for the low variability females. The homogeneous line presented important reproductive advantages suggesting higher robustness and animal welfare. Further research should confirm whether the findings presented here of a better performance in the low variability line could be properly applied to some livestock species.

Improving Rabbit Doe Metabolism and Whole Reproductive Cycle Outcomes via Fatty Acid-Rich Moringa oleifera Leaf Extract Supplementation in Free and Nano-Encapsulated Forms.

Simple SummaryUnder intensive rabbit production systems, due to the increased energy requirements of reproductive events, specifically pregnancy and lactation, rabbit does may confront several metabolic disorders as a result of energy imbalance. Moringa oleifera leaf ethanolic extract (ME) is one of the phytogenic extracts that has an impressive range of phytochemicals, specifically fatty acids (FAs). These phytochemicals may be biologically effective to support metabolism and reproductive functions of rabbit does during different reproductive cycle events. However, the high FAs content of ME makes them highly susceptible to lipid oxidation, diminishing their nutritional value and biological effects. In this study, we aimed to test the effects of FAs of ME either in a free-from or in a nano-encapsulated form on metabolism, immunity, milk production, milk composition, and reproductive performance of rabbit does during different physiological status (premating, mating, pregnancy, and lactation). The results showed that ME improved health, metabolism, immune functions, milk production and composition, and reproductive performance of rabbit does. These effects remained obvious even when a lower dose of ME was used in a nano-encapsulated form.The effects of free and nano-encapsulated ME supplementations on the metabolism, immunity, milk production and composition, and reproductive performance of rabbit does during premating, mating, pregnancy, and lactation were investigated. Multiparous rabbit does (n = 26 per group) received 50 mg of free ME (FME) daily, 25 mg of nano-encapsulated ME (HNME), or 10 mg of nano-encapsulated ME (LNME) per kilogram of body weight or were not supplemented (C) during a whole reproductive cycle. The ME contained 30 fatty acids with 54.27% total unsaturated fatty acids (USFAs). The fatty acid encapsulation efficiency of alginate nanoparticles was 70.46%. Compared with the C group, rabbits in all ME treatments had significantly increased body weight, feed intake, and glucose concentration and significantly decreased non-esterified free fatty acids and β-hydroxybutyrate concentrations. Rabbits supplemented with ME also had significantly increased white blood cell counts, phagocytic activity, lysozyme activity, and immunoglobulin G and decreased interleukin-1β concentrations. Moreover, ME supplementation significantly increased the concentrations of colostrum immunoglobulins, milk yield and energy content, and milk USFAs (omega-3 and 6). Rabbit does in the ME treatments had significantly higher conception and parturition rates and better litter characteristics than the C rabbit does. These results demonstrate the positive role of ME fatty acids on the health status and productive and reproductive performance of rabbit does at different physiological stages. Compared with the FME treatment, these parameters were further improved in rabbits that received nano-encapsulated ME at lower doses, illustrating how nano-encapsulation technology improves the bioavailability of ME.

A multi‐metric movement model for identifying elk parturition events

AbstractFor wildlife managers, identifying the time and location of ungulate parturition events is necessary to protect parturition habitat and inform population models. Current methods for identifying parturition events include neonatal capture and monitoring and visual analysis of location data, which are resource intensive and subject to biases. Recently, movement‐based analyses using the spatial and temporal patterns contained in location data have shown promise for identifying parturition behavior; however, questions regarding efficacy and best practice have limited the adoption of such movement‐based parturition models into management programs. We used location data collected between 2017−2018 from a California population of female Roosevelt elk with known parturition status to build a set of movement‐based models. We compared each model's ability to accurately classify individual's parturition status and identify the timing of parturition. The top model showed that within 72 hours of a parturition event, elk made smaller movements, had smaller home ranges, and had longer visits to individual locations. Of the 16 individuals in our study with known parturition status, our approach to classifying an individual's status was 81% accurate in cross‐validation, which increased to 100% accuracy when the complete dataset was used to train the top model. We then used the top, global and single‐metric models to establish probability thresholds and identify parturition events for collared‐elk with unknown parturition status. Our results align with a growing number of studies that have shown movement‐based parturition models are a reliable method that could augment or replace field‐based techniques for identifying parturition events and quantifying parturition rates in ungulate populations.

Comparative fecal steroid profile during pregnancy, parturition, and lactation between natural fertilization and embryo transfer in ocelots (Leopardus pardalis)

Despite the invaluable role that assisted reproduction technologies (ARTs) play in conservation, pregnancy and parturition rates by embryo transfer (ET) are low for most endangered felids. Thus, efforts to expand the knowledge on pregnancy biology and ET are still required. In this context, we examined fecal sex steroid metabolites (i.e., estrogens, glucocorticoids, and progestogens) of eight ocelots submitted to natural fertilization (NF) and ET in 22 pregnancies (19 NF and 3 ET). Fecal samples were collected and assessed for each pregnancy from estrous cycle, pregnancy, and lactation, totaling 155 days. In short, progestogen levels remained high and unchanged (P < 0.05) from conception until parturition for females maintained under NF. On the other hand, females submitted to ET exhibited changes (P > 0.05) in progestogen levels from conception until parturition, with a significant decrease during pregnancy (480.72 ng/day; r2 = 0.81; P < 0.0001). Significant changes between NF and ET also were noted in estrogen levels between the first and last thirds of pregnancy (P < 0.05), in which estrogen levels exhibited a negative correlation (P < 0.01) between themselves. Regarding glucocorticoids, significant changes (P < 0.01) were observed only in the first third of pregnancy between NF and ET, which we believe may be related to the handling for ovarian synchronization and ET. Besides hormonal changes, the pregnancy was more prolonged (2.5 days) and more prone to dystocia in ET than NF. Overall, 24 embryos were transferred into eight females (3/1), with three kittens being born from three distinct deliveries (i.e., 12.5% of embryos and 37.5% of females). Our findings have supported the great potential of production and transfer of long-term frozen embryos in ocelot conservation. However, they reveal possible effects of these biotechnologies on hormonal levels during pregnancy linked with low conception and parturition rates and dystocic cases in felids.

Comparison of some zootechnical performances of local and Red Maradi goats reared under smallholder production systems in the Sudanian zone of Benin

The aim of this research was to compare the zootechnical performances of indigenous and Maradi goats reared under village conditions in the Sudanian zone of Benin. A questionnaire survey was carried out between August and October 2019, using the 12MO, a retrospective method for estimating demographic parameters in tropical ruminant livestock population and the progeny history method. Information related to farmers’ socioeconomic characteristics, goat herd management practices and demographic parameters, and milk productivity from 198 does including 66 West African Dwarf (WADG), 68 Red Maradi (RMG) and 64 West African long-legged (WLLG) goats were collected in 80 smallholder farms. Pearson Chi-square and Kruskal-Wallis W tests were performed respectively on the categorical and continuous variables. The average herd size was about 16.7 ± 9.0; 5.8 ± 3.1 and 15.4 ± 7.4 heads respectively for WADG, RMG and WLLG. Bucks were absent in several herds where kids (47.9 ± 12.8%) and does (46.6 ± 12.8%) predominated. Prolificacy rates at first and second parturition varied significantly (P ≤ 0.05) among goat types and were respectively 165.2 ± 59.5% and 195.1 ± 66.9% for WADG; 160.3 ± 55.0% and 196.0 ± 53.9% for RMG; 134.4 ± 54.1% and 154.6 ± 51.0% for WLLG. Parturition rates were higher (P ≤ 0.05) in WADG (159.1 ± 49.5%) than in RMG (138.2 ± 49.0%) and WLLG (132.8 ± 47.3%). Likewise, productive rates were higher (P ≤ 0.05) in WADG (277.3 ± 142.3%) than in RMG and WLLG (204.4 ± 125.1% and 168.8 ± 102.2% respectively). Milking was only performed on RMG and the amount of milk collected per milking ranged between 0.6 and 1 liter per doe. Enhancing goat herds’ productivity could be achieved through improved general herd management practices.

Artificial Insemination in Sheep with Fresh Diluted Semen: Comparison Between Two Different Semen Extenders and Management Protocols

Timed artificial insemination (TAI) is a very important tool for reproductive programs in small ruminants, providing synchronized inseminations and more efficient use of superior males. The objectives of this study were to investigate the viability of different breeding protocols under sub-optimal conditions and out of the breeding season, and to compare the outcome of TAI in sheep with two different semen extenders. Ewes (n=575) were subjected to estrous synchronization by intravaginal sponges containing 30 mg of medroxyprogesterone acetate and PMSG. Ewes were divided into 5 groups according to the semen extender employed and to the breeding protocol: 1) egg yolk citrate AI reinforced by ram (EYC-RR); 2) Andromed AI reinforced by ram (AND-RR), where rams joined the flocks 3 hours after AI; 3) egg yolk citrate AI without ram exposition (EYC); 4) Andromed AI without ram exposition (AND). In all these groups vaginal AIs were performed 56±2 hours from sponge removal and PMSG injection; 5) natural mating (RAM) where rams were introduced 48 hours following sponge removal and PMSG injection. Pregnancy rate, parturition rate, and prolificacy were significantly higher (p&lt;0.05) in the EYC-RR and AND-RR groups than in the EYC and AND groups. The lambing rate was not different between groups. No statistical differences were observed between breeding farms or inseminating rams. This study showed that TAI with fresh semen diluted either with egg yolk citrate or with AndroMed could be an effective and feasible tool to increase lamb production and improve genetic merits of the sheep population out of the breeding season.

Improved efficiencies in the generation of multigene-modified pigs by recloning and using sows as the recipient.

This study was performed to improve production efficiency at the level of recipient pig and donor nuclei of transgenic cloned pigs used for xenotransplantation. To generate transgenic pigs, human endothelial protein C receptor (hEPCR) and human thrombomodulin (hTM) genes were introduced using the F2A expression vector into GalT-/-/hCD55+ porcine neonatal ear fibroblasts used as donor cells and cloned embryos were transferred to the sows and gilts. Cloned fetal kidney cells were also used as donor cells for recloning to increase production efficiency. Pregnancy and parturition rates after embryo transfer and preimplantation developmental competence were compared between cloned embryos derived from adult and fetal cells. Significantly higher parturition rates were shown in the group of sows (50.0 vs. 4.1%), natural oestrus (20.8 vs. 0%), and ovulated ovary (16.7 vs. 5.6%) compared with gilt, induced and non-ovulated, respectively (P < 0.05). When using gilts as recipients, final parturitions occurred in only the fetal cell groups and significantly higher blastocyst rates (15.1% vs. 21.3%) were seen (P < 0.05). Additionally, gene expression levels related to pluripotency were significantly higher in the fetal cell group (P < 0.05). In conclusion, sows can be recommended as recipients due to their higher efficiency in the generation of transgenic cloned pigs and cloned fetal cells also can be recommended as donor cells through correct nuclear reprogramming.

Effects of Hunting on a Puma Population in Colorado

Effects of Hunting on a Puma Population in Colorado

Efficiency of GnRH-Loaded Chitosan Nanoparticles for Inducing LH Secretion and Fertile Ovulations in Protocols for Artificial Insemination in Rabbit Does.

Simple SummaryNano-drug delivery systems can be employed for improving ovulation induction prior to artificial insemination (AI) in rabbits. In this study, different routes of administration and different doses of GnRH–loaded chitosan nanoparticles (GnRH–ChNPs) were assessed for inducing ovulation in rabbits, proving their usefulness to reduce the GnRH dose and animal handling and improving AI outcomes. The use of GnRH–ChNPs allows for the reduction of the conventional intramuscular GnRH dose to half without compromising fertility. However, the addition of GnRH–ChNPs to semen extenders, although successfully inducing ovulation, has negative impacts on fertility. Thus, more studies are needed to allow further adjustments.Gonadotropin-releasing hormone (GnRH)–loaded chitosan nanoparticles (GnRH–ChNPs) were used at different doses and routes of administration to induce ovulation in rabbits as an attempt to improve artificial insemination (AI) procedures and outcomes. In this study, the characteristics (size, polydispersity, loading efficiency, and zeta-potential) of GnRH–ChNPs and the GnRH release pattern were determined in an in vitro study. A first in vivo study assessed the pituitary and ovarian response to different GnRH–ChNPs doses and routes of administration (two i.m. doses, Group HM = 0.4 µg and Group QM = 0.2 µg, and two intravaginal doses, Group HV = 4 µg and Group QV = 2 µg) against a control group (C) receiving bare GnRH (0.8 µg). The HM, QM, and HV treatments induced an earlier LH-surge (90 min) than that observed in group C (120 min), whilst the QV treatment failed to induce such LH surge. The number of ovulation points was similar among treatments, except for the QV treatment (no ovulation points). A second in vivo study was consequently developed to determine the hormonal (progesterone, P4, and estradiol, E2) profile and pregnancy outcomes of both HM and HV treatments against group C. The treatment HM, but not the treatment HV, showed adequate P4 and E2 concentrations, conception and parturition rates, litter size, litter weight, and viability rate at birth. Overall, the use of GnRH–ChNPs allows for a reduction in the conventional intramuscular GnRH dose to half without compromising fertility. However, the addition of GnRH–ChNPs to semen extenders, although successfully inducing ovulation, has negative impacts on fertility. Thus, more studies are needed to explore this point and allow further adjustments.

EFFECT OF BAROMETRIC PRESSURE ON GESTATION LENGTH IN COWS

In an effort to determine the effects of barometric pressure on the length of gestation in cattle, two sets of data on calving dates with their corresponding barometric pressure readings were evaluated statistically. The first set of data were from three herds (367 calves), and were collected for two different periods - fall of 1979 and spring of 1980. Chi-square was used to test for significance. Result indicated that there was no significant difference between the rate of parturition in cattle and changes in barometric pressure (X2 = 7.331, df = 2, P 0.05). The second set of data were on the length of gestation for two herds (94 calves) of different breeds. The cows were artificially inseminated. Multiple regression was performed between (Y variables) the deviation of each gestation length from 283 days i.e. the average gestation length of cattle and X Variables, the average barometric pressures during four six - hour periods on days of parturition and for three days prepartum (1:00 - 6:00 a.m. day of birth; 6:00 – 12:00 p.m. DB; 12:00 6:00 p.m. DB; 6:00 - 12:00 a.m. DB; 6:00 – 12:00 a.m. D3).

Effect of Dietary Fish Oil on Semen Quality and Reproductive Performance of Iranian Zandi Rams.

The current study was conducted to evaluate the effect of dietary fish oil on the semen quality and fertility potential of Zandi rams. For this purpose, a total of 15 Iranian Zandi rams were randomly assigned into three equal groups. The first group was a negative control and were fed without oil supplement. The second group was a positive control, and their diet contained palm oil, and the last group had a diet containing fish oil. All the diets were isocaloric and isonitrogenous. The rams were fed for 70 days, and the semen smaples were collected every 10 days. In experiment I, the evaluated parameters included semen volume, sperm concentration, motility, membrane integrity, and viability. In experiment II, 210 Iranian Zandi rams received CIDR for 12 days and 400 IU of equine chorionic gonadotropin at the time of CIDR removal. Then, they were assigned into three equal groups and artificially inseminated with semen samples. According to the obtained results, the supplementation of ram diet with fish oil as a source of omega-3 fatty acids improved the semen volume, sperm concentration, total motility, progressive motility, viability, membrane integrity, pregnancy rate, parturition rate, and lambing rate of the rams (P≤0.05). In conclusion, fish oil as a dietary supplement for rams could be an effective strategy to improve the semen quality of rams for artificial insemination and other goals.