• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.3
• /
• pp.445-452
• /
• 2002

The main objective of modern reproductive technologies in pig reproduction is to increase reproductive efficiency and rates of genetic improvement. They also offer potential for greatly extending the multiplication and transport of genetic materials and the conservation of unique genetic resources in reasonably available forms for possible future use. The development and refinement of these technologies is concentrating on gamete and embryo collection, sorting and preservation, in vitro production of embryos, culturing, manipulation of embryos (splitting, nuclear transfer, production of chimeras, establishment embryo stem cells, and gene transfer) and embryo transfer. Also, the development of these novel technologies is facilitated by modern equipment for ultrasonography, microscopy, cryopreservation, endoscopy, and flow cytometry, microinjectiors, micromanipulators and centrifugation. The real impact on herd productivity will come from combining new reproductive techniques with powerful DNA technologies. The new reproductive techniques will allow a rapid turnover of generations, whereas the DNA technology can provide selection, which does not need phenotypic information when the selection decisions are made.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.8
• /
• pp.1093-1101
• /
• 2003

Reproductive data, such as numbers of days to the first estrus and A.I. service postpartum, number of days to conception, number of A.I. services required for conception, interval between the first estrus and first A.I. service and the average interval of A.I. service in Thai native-Friesian crossbred and pure Friesian dairy cows, were compiled in the National Dairy Training and Applied Research Institute in Chiang Mai, Thailand. The data were analyzed statistically and the effect of milk production on these reproductive traits was investigated. The reproductive efficiency of purebred cows was obviously inferior when compared with crossbred animals, in spite of special care being given to the purebred only in order to alleviate the effect of a tropical climate and provide better feeding. However, the regression analysis between reproductive and lactational parameters revealed a definite antagonistic effect of lactation on reproduction, especially in the purebred cows, which had a larger amount of milk production and longer lactation period. If these effects of lactation were eliminated, there would be no evident difference in reproductive efficiency between purebred and crossbred cows in the conditions of this study. Among the reproductive parameters examined, the number of days to the first estrus and interval between the first estrus and first A.I. service were less affected by breed difference and the magnitude of lactation than other reasons.

• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.11
• /
• pp.1550-1556
• /
• 2017

Objective: This study estimated the genetic parameters for productive and reproductive traits. Methods: The data included production and reproduction records of animals that have calved between 1979 and 2013. The genetic parameters were estimated using multivariate mixed models (DMU) package, fitting univariate and multivariate mixed models with average information restricted maximum likelihood algorithm. Results: The estimates of heritability for milk production traits from the first three lactation records were $0.03{\pm}0.03$ for lactation length (LL), $0.17{\pm}0.04$ for lactation milk yield (LMY), and $0.15{\pm}0.04$ for 305 days milk yield (305-d MY). For reproductive traits the heritability estimates were, $0.09{\pm}0.03$ for days open (DO), $0.11{\pm}0.04$ for calving interval (CI), and $0.47{\pm}0.06$ for age at first calving (AFC). The repeatability estimates for production traits were $0.12{\pm}0.02$, for LL, $0.39{\pm}0.02$ for LMY, and $0.25{\pm}0.02$ for 305-d MY. For reproductive traits the estimates of repeatability were $0.19{\pm}0.02$ for DO, and to $0.23{\pm}0.02$ for CI. The phenotypic correlations between production and reproduction traits ranged from $0.08{\pm}0.04$ for LL and AFC to $0.42{\pm}0.02$ for LL and DO. The genetic correlation among production traits were generally high (>0.7) and between reproductive traits the estimates ranged from $0.06{\pm}0.13$ for AFC and DO to $0.99{\pm}0.01$ between CI and DO. Genetic correlations of productive traits with reproductive traits were ranged from -0.02 to 0.99. Conclusion: The high heritability estimates observed for AFC indicated that reasonable genetic improvement for this trait might be possible through selection. The $h^2$ and r estimates for reproductive traits were slightly different from single versus multi-trait analyses of reproductive traits with production traits. As single-trait method is biased due to selection on milk yield, a multi-trait evaluation of fertility with milk yield is recommended.

• Clinical and Experimental Reproductive Medicine
• /
• v.50 no.1
• /
• pp.12-18
• /
• 2023

Propolis is a sticky natural product produced by honeybees. Research studies have discussed the effectiveness of propolis, directly or indirectly, for ameliorating reproductive toxicity in males; however, this research has not yet been reviewed. The current paper presents an integrative summary of all research studies in Scopus and PubMed that investigated the effects of propolis on semen quality, and hence on male fertility, in conditions of reproductive toxicity. The consensus indicates that propolis ameliorates reproductive toxicity and enhances semen quality in vivo in test animals. These effects may be attributable to the ability of propolis to reduce testicular oxidative damage, enhance testicular antioxidant defense mechanisms, increase nitric oxide production, reduce testicular apoptotic injury, and boost testosterone production. However, to generalize these effects in humans would require further research.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.6
• /
• pp.956-965
• /
• 1999

Genetic selection and sophisticated management technology have produced modern sows which excel in litter size and milk production. Recent research has identified nutritional innovations which may enhance productivity of the high producing sow. Selected research in three areas which have the potential to enhance reproductive performance are summarized in this report. First, preliminary evidence indicates that organic chromium may enhance litter size and conception rate. Secondly, high producing sows, particularly primiparous sows, required higher protein/lysine in late gestation and or lactation to optimize weaning weight and subsequent litter size. Valine and isoleucine, but not leucine, have been shown to enhance milk production. Phased feeding programs with diet cost partitioned toward gilts and away form parity 3 to 8 sows have been suggested as a means of improving reproductive performance in young sows. Lastly, recent research with sufficient sow numbers to document the effect of dietary fiber on reproductive performance has shown that sows fed fiber farrowed and weaned more pigs.

• Journal of Forest and Environmental Science
• /
• v.32 no.2
• /
• pp.113-119
• /
• 2016

The long lived iteroparous conifers produce male and female gametophyte for hundreds of years once they reach the reproductive stage, however, the production of seed is not frequent. This phenomenon of infrequent seed production in conifers is yet to be understood. An attempt to study this change in cone production in Cedrus deodara of Western Himalayas -a species reported to be mainly monoecious and rarely dioecious has been made. The observations recorded on selected trees of flowering/fruiting stage for four years at four different locations have shown the species to be dioecious with higher percentage of female trees during good seed year but with no definite or predictable pattern of reproduction in the trees. A decline in production of female trees was witnessed at all but one location immediately year after reaching the maximum (good seed year). The phenomenon of seed production has been observed to be cyclic and site specific. A change in the sexual behavior of the trees from male to female or vice-versa, male or female turning monoecious or vegetative and vegetative coming to reproductive was unpredictable.

• Journal of Animal Reproduction and Biotechnology
• /
• v.38 no.2
• /
• pp.47-53
• /
• 2023

Despite numerous advances in in-vitro embryo production (IVP), many documented factors have been shown to influence the development of mammalian preimplantation embryos and the success of IVP. In this sense, elevated levels of reactive oxygen species (ROS) correlate with poor outcomes in assisted reproductive technologies (ART) due to oxidative stress (OS), which results from an imbalance between ROS production and neutralization. Indeed, excessive production of ROS compromises the structural and functional integrity of gametes and embryos both in vivo and in vitro. In particular, OS damages proteins, lipids, and DNA and accelerates cell apoptosis. Several in-vivo and in-vitro studies report an improvement in qualityrelevant parameters after the use of various antioxidants. In this review, we focus on OS and the source of free radicals and their effects on oocytes, sperm, and the embryo during IVP. In addition, antioxidants and their important role in IVP, supplementation during oocyte in vitro maturation (IVM), in vitro culture (IVC), and semen extenders were discussed. Nevertheless, various methods for determining the level of ROS in germ cells have been briefly described. Still, it is crucial to develop standardized antioxidant supplement systems to improve overall IVP success. Further studies should explore the safety, efficacy, mechanism of action, and combination of different antioxidants to improve IVP outcomes.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.7
• /
• pp.949-956
• /
• 2005

The weekly ultrasound scanner (US) observations of reproductive organs in a commercial dairy herd with the popular stanchion style management were conducted for over 26 months. Based on reproductive records, the following were evaluated: 1) the effect of postpartum period commencement of US monitoring on herd reproductive efficacy, and 2) the effectiveness of a US monitoring-based diagnosis and subsequent treatments of reproductive disorders on postpartum reproductive efficiency. The reproductive parameters of cows, which were subjected to US monitoring between Days 30-40 (Day 0 = day of parturition), Days 41-50, Days 51-60, and above Day 61, were compared. The reproductive parameters of cows diagnosed as having reproductive disorders (RD) with US monitoring before or after the first artificial insemination (AI) were also compared. It was found that the day of commencement of US monitoring in cows diagnosed with and without RD significantly affected the period towards the first AI and the open period. In particular, cystic follicles and anoestrus detected either before or after the first AI significantly affected herd reproductive efficiency. The implementation of US monitoring improved reproductive efficiency by reducing the open period and increasing the number of milking cows in the herd. The results of this field trial indicate that the postpartum reproductive management of dairy cows with the use of the US monitoring system is one strategy to improve reproductive efficiency, especially in a high-yielding dairy herd reared stanchion management style.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.1
• /
• pp.67-71
• /
• 2006

A total of 120 male and 240 female quail (Coturnix coturnix Pharaoh) were used to determine the effect of feeding time on laying and reproductive performance of Pharaoh quail. They were fed ad libitum between 09:00 to 17:00 or full day, daily. Each female-male pair was housed in multiple-bird cages and colony cages. Initial and final body weight, quail-day egg production, feed consumption per egg and mortality were measured to determine laying performance of breeders. A total of 960 eggs were used to determine reproductive performance of quail in each treatment group. Eggs were incubated in a commercial setter and hatcher in standard conditions. Embryonic mortality, apparent fertility, hatchability of total and fertile eggs were calculated to determine the reproductive performance. Results indicated that feeding between 09:00 to 17:00 h reduced final body weight and egg production (p<0.001, p<0.001). Whereas, limited time of feeding improved hatchability of total (p<0.001) and fertile eggs (p<0.001) and reduced embryonic mortality (p<0.001) when compared with the effects of feeding full day. It was found that there were no significant differences for the egg production of quail housed in different cage systems. Quail caged in multiple-bird cages consumed less feed (p<0.01) compared to quail housed in colony cages. There were significant differences for the mortality (p<0.05), hatchability of total (p<0.001) and fertile eggs (p<0.001), and embryonic mortality (p<0.001) during the incubation due to main effect of cage systems. There were significant cage $systems{\times}feeding$ time interactions for hatchability of total and fertile eggs and embryonic mortality (p<0.001). As a conclusion; feeding from 09:00 to 17:00 reduced laying performance of quail and improved the reproductive traits compared to full day feeding of quail breeders. But, further investigations are needed to determine the optimum length of feeding time and egg production of breeders in quail fed limited time must be evaluated in comparison with its beneficial or detrimental effects.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.29 no.1
• /
• pp.128-134
• /
• 2014

Nesolynx thymus Girault (Hymenoptera: Eulophidae) is one among 20 hymenopteran parasitoids reported to attack the uzi fly, Exorista bombycis, which in turn infests the silkworm, Bombyx mori accounting a cocoon yield loss of 10-20%. A host of factors viz., age and size of host, age and size of parasitoid, availability of host, temperature and quality of host are reported to influence the reproductive efficiency of the parasitoids. In the present study an attempt was made to record the influence of foraging parasitoid density on their reproductive performance. Three day-old uzi pupae were offered to varying numbers (1 - 10) of 2 day old Nesolynx thymus adults for parasitization. The progeny production per pupa (84.44 - 132.77) increased significantly with increase in the number of foraging parasitoid adults (1 - 10) however, progeny production per female decreased. The sex ratio (M : F) (1:25.49 - 1:1.53) decreased significantly with increase in foraging parasitoid adults. The morphometric parameters except female abdomen width of first generation parasitoid showed significant negative correlation with number of foraging adults. However, correlation between the parasitoid size in first generation and their reproductive performance was nonsignificant.