Improvement Of Reproductive Performance Research Articles

Efficacy and Safety of an Inactivated Phase I Coxiella burnetii Vaccine to Control Q Fever in Ruminants: A Systematic Review

Q fever is a disease caused by Coxiella burnetii that affects many animal species and humans. In ruminants, the disease is responsible for several reproductive disorders (such as abortions, stillbirths, premature births, weak offspring, retained foetal membranes and infertility). An inactivated vaccine based on a phase I antigen of C. burnetii is available for cattle, goats and sheep. This review aims to summarise the scientific literature regarding the efficacy and safety of this vaccine to control the infection in these three domestic ruminant species. Forty-five publications and one experimental veterinary thesis reporting on experimental studies, case reports, mathematical modelling and intervention studies were selected according to the PRISMA guidelines. Although some studies lack control groups or statistical analyses, for all three species, published data show that vaccination often results in a reduction in abortions and an improvement in reproductive performance in comparison with absence of vaccination. There is also evidence, including in infected herds and animals, that vaccination is associated with a reduction in bacterial shedding, both in intensity and duration in comparison with absence of vaccination. For these reasons, in case of human outbreaks, vaccination is one of the pillars of control measures. Vaccination is generally well tolerated, despite the rare occurrence of mild, transient side-effects, such as hyperthermia and reduction in milk yield.

Effect of High Energy Diet Supplementation during Periparturient Period on Ovarian Steroids and Reproductive Performance in Vrindavani Cows

The objective of the study was to assess the effect of high energy diet supplementation during periparturient period on ovarian steroids and reproductive performance in vrindavani cows. Postpartum vrindavani cows (n= 20) of second to fourth parity with lactation yield of > 10 L/day were divided in to two groups (n=10 cow/group). Group I (CON) cows were fed with basal diet to serve as control. Group II (TRT) cows were provided with 20% extra concentrates in the form of energy. 20% additional concentrate diet was supplemented from second week to eight week after calving. Blood samples were collected at weekly interval from 4 week before calving to8weeks after calving. Blood samples were collected to determine estradiol (E2) and progesterone (P4) in the serum using RIA. Postpartum reproductive performance was assessed in terms occurrence of first postpartum estrus, calving to conception interval, conception rate and number of service per conception. Serum estradiol and progesterone concentration increased significantly(P<0.05) from 2 to 8 week postpartum in Group II as compared to Group I. Marked significant(P<0.05)improvement in the postpartum reproductive performance in terms of early occurrence of first postpartum estrus(67.0Vs 53.0), reduced calving to conception interval(85.87 Vs74.4), service per conception (1.62 Vs 1.2), days from calving to first AI(88.5 Vs 65.73), higher first AI conception rate(40 Vs 80%) and cumulative conception rate(88.52 Vs 65.73%) in group II as compared to group I. In conclusion, additional high energy diet supplemented group showed significant increased ovarian steroid hormonal concentrations and marked improvement in the reproductive performance in Vrindavani cows.

Customized modified therapies for ovarian cyst and persistent follicle followed with TAI in early postpartum dairy cows.

Postpartum ovarian dysfunction [ovarian cyst (OC) and persistent follicle (PF)] has been an important issue. Finding effective hormonal treatments to improve reproductive performance in dairy cows has become a necessity. Improve reproductive performance and ovarian activity in postpartum cows with specific customized treatment for OC and PFs. The study included 48 cows at 14 days P.P, which received two dosages of 500 μg IM cloprostenol, 14 days apart as presynchronization protocol. Ultrasound ovarian scans 14 days after the last injection for 4 weeks. The cows were divided into three groups according to ovarian status: OC (n = 14), PF (n = 12), and NE (n = 22). In the OC group, received 500 μg IM cloprostenol and 100 μg IM cystoriline, a second dose of cloprostenol 14 days later and a second dose of cystoriline 36 hours later, and AI after 24 hours (GnRH+ PG/PG/GnRH). In the PF group, was fitted with progesterone-releasing intravaginal device (PRID) for 9 days; the same day, they received 100 μg cystoreline then 500 μg cloprostenol 7 days later, after PRID removal AI 56 hours later (PRID + GnRH/PG). In the NE group, artificial insemination was implemented until 28 days depending on estrus detection. The ovarian activity was greatly affected by the customized treatments, leading to enhanced follicular and luteal activity, particularly after the PGF2α injection. The OC and PF groups showed substantial estrus responses of 71.43% and 75.02%, respectively, during AI time. While the NE group had an ovulation rate of 54.5% and a pregnancy rate of 31.8%, the treatment groups showed marked improvements in reproductive performance. The ovulation rates in the OC and PF groups were 71.43% and 75% and the pregnancy rates at the 1st artificial insemination were 64.28% and 66.7%. Improving reproductive performance and minimizing the time to first service are possible advantages of early case-specific treatment for postpartum cows with OC and PFs.

Konjac flour-mediated gut microbiota alleviates insulin resistance and improves placental angiogenesis of obese sows

Our previous study revealed that dietary konjac flour (KF) could remodel gut microbiota and improve reproductive performance of sows, but its underlying mechanisms remain unclear. This experiment aimed to investigate how dietary KF improves reproductive performance of obese sows. Here, 60 sows were assigned into three groups according to their backfat thickness: normal backfat sows fed with control diet (CON-N), high backfat sows fed with control diet (CON-H) and high backfat sows fed with KF inclusion diet (KF-H). The characteristics of sows and piglets were recorded. Next, fecal microbiota transplantation (FMT) was performed on female mice, followed by recording the characteristics of female mice. The results showed that compared with CON-H group, KF-H group showed downtrend in stillbirth rate (P = 0.07), an increase in placental efficiency (P < 0.01) and average piglet weight (P < 0.01); coupled with a decrease in the values of homeostasis model assessment-insulin resistance (P < 0.01); as well as an increase in placental vascular density and protein expression of angiogenesis markers (P < 0.01). As expected, sows fed KF diets had improved abundance and diversity of gut microbiota. More importantly, compared with CON-H(FMT) group, KF-H(FMT) group showed improvement in reproductive performance and insulin sensitivity (P < 0.05), as well as an increase in placental labyrinth zone and protein expression of angiogenesis markers (P < 0.05). Furthermore, we found a content increase (P < 0.05) of SCFAs in both KF-H group sow and KF-H (FMT) group mice. Overall, KF supplementation could alleviate insulin resistance, promote placental angiogenesis, and ultimately improve the reproductive performance of sows via gut microbiota remodeling.

Amelioration of Reproductive and Productive Performance in Animal and Poultry by Moringa Oleifera Free or Nano-Encapsulated

Improvement of reproductive performance is an honorable goal and is closely associated with increasing productivity. Therefore, as the reproductive efficiency improves, the herd net return and national income increase. The high cost of animal forage especially in dry or semi-arid countries, is a main limitation to animal production which is raised under extensive systems. Hence, utilization of alternative feed resources may be a reasonable and appropriate approach in low-input systems. Moringa Oleifera is a natural plant referred to as a nutrient, which contains substances that might have a favorable influence on animal reproduction and production. Leafy Moringa is considered a virtuous origin of proteins that are very consumable. Moreover, they are rich in Vitamin C, Vitamin A, iron, and Calcium which are necessary for the growth of livestock animals. Moreover, they include the percentage of fatty acid which is greater as compared to any woody plant fodder. Principally, almost all of the fatty acids present in Moringa are unsaturated fatty acids which are highly susceptible. Nowadays, nano-encapsulation technology is considered a promising strategy for drug delivery and is efficient in preserving bioactive components in products rich in nutrients. So that this review affords a collection of significant data and enlightens the information on the development of Moringa Oleifera Free or its nano-encapsulated form in amelioration of animal and poultry reproduction and production performance.

Effect of N-Acetyl Cysteine, Selenium and Zinc as Oral Nutritional Supplement on Reproductive Performance in Local Iraqi Ewes.

The study aimed to investigate the effect of the administration N-acytl cysteine to ewes with or without selenium and zinc on reproductive performance and the level of estrogen and progesterone hormones for local ewes. 24 local ewes were used, 3-5 of age and weighing 45-55 kg. They were randomly distributed to 4 groups, 6 ewes for each one. All ewes were treated six days before pushing the vaginal sponges and continued for 45 days. The Group 1 (T1) was treated with (10 mg N-acytl cysteine/kg body weight), Group 2 (T2) was treated with (10 mg N-acytl cysteine/kg body weight + 0.03 mg selenium/kg body weight), Group 3 (T3) was treated with (10 mg N-acytl cysteine/ kg of body weight + 0.03 mg zinc/kg of body weight) while the Group 4 (T4) was left without treatment (control group). The results showed a significant increased (p≤0.05) of treatment (T1) at the time of first estrus, followed by the control treatment, then treatment (T2, T3). Results recorded a significant increased (p≤0.05) of T1, T3 and T2 respectively in estrus rate. Furthermore, the treated group showed a significant increased (p≤0.05) compared with the control group in the fertilization %pregnancy, the percentage of twins, births and the number of births. The supplement N-acetyl cysteine with selenium or zinc led to an improvement in reproductive performance

Effect of Pre-partum Supplementation of Vitamin E and Selenium on Post-partum Reproductive and Productive Performance in Dairy Cows

Background: The study was planned to determine the effect of oral supplementation of vitamin E and Selenium on productive and reproductive performance in 40 Jersey cows and consequent effect on the growth of their progeny (calves). Methods: The experimental animals were divided into two homogenous groups (A and B). Animals in group A were given Vitamin E (200 mg) and Selenium (10 mg) daily orally; 250 days onwards prepartum for 21 days. The cows belonging to the group B were not provided these supplements and served as untreated control group. Result: Group A animals took significantly (P less than 0.01) less (2/3) time than those included in Group B for expulsion of the placenta. Additionally, lesser number of cows in Group A than those in Group B suffered from retention of placenta (ROP) indicating improvement of reproductive performance in the group with no significant effect on growth of calves and milk yield in the two groups. Therefore, from the experiment, it was concluded that supplementation of Vitamin E and Selenium to dairy cows during last month of pregnancy decreases time of placenta expulsion with no significant effect on the growth of their progeny (calves). The present study also concludes that higher number of animals may be taken for the experiment for a good dairy managemental programme.

Improvement in Reproductive Performance of Boron Supplemented Karan Fries Cows During Hot and Humid Season

Improvement in Reproductive Performance of Boron Supplemented Karan Fries Cows During Hot and Humid Season

The future of assessing bull fertility: Can the 'omics fields identify usable biomarkers?†.

Breeding soundness examinations for bulls rely heavily on the subjective, visual assessment of sperm motility and morphology. Although these criteria have the potential to identify infertile males, they cannot be used to guarantee fertility or provide information about varying degrees of bull fertility. Male factor fertility is complex, and the success of the male gamete is not necessarily realized until well after the spermatozoon enters the oocyte. This paper reviews our existing knowledge of the bull’s contribution from a standpoint of the sperm’s cargo and the impact that this can have on fertilization and the development of the embryo. There has been a plethora of recent research characterizing the many molecular attributes that can affect the functional competence of a spermatozoon. A better understanding of the molecular factors influencing fertilization and embryo development in cattle will lead to the identification of biomarkers for the selection of bulls of superior fertility, which will have major implications for livestock production. To see this improvement in reproductive performance, we believe incorporation of modern technology into breeding soundness examinations will be necessary—although many of the discussed technologies are not ready for large-scale field application. Each of the ‘omics fields discussed in this review have shown promise for the identification of biomarkers of fertility, with certain families of biomarkers appearing to be better suited to different evaluations throughout a bull’s lifetime. Further research is needed for the proposed biomarkers to be of diagnostic or predictive value.

Age‐related breeding success in little penguins: a result of selection and ontogenetic changes in foraging and phenology

AbstractReproductive performance typically improves with age, reaching a plateau at middle age and subsequently declining in older age classes (senescing individuals). Three potential non‐exclusive mechanisms can explain the improvement in reproductive performance with age: (1) selection (poor quality individuals are removed from the population with increasing age), (2) constraint (individual efficiency increases through experience), and (3) restraint (reproductive investment increases with age as the residual reproductive value decreases). While all three mechanisms received strong empirical support, few studies have aimed at teasing apart those hypotheses and understanding their underlying functioning. In little penguins (Eudyptula minor), we used a 19‐yr longitudinal dataset on breeding and foraging of more than 450 individuals to investigate the effect of age on breeding success. We separated within‐individual from among‐individual age effects using state‐of‐the‐art statistical methods (within‐subject centering and population change decomposition). We then assessed whether within‐individual changes in breeding resulted from ontogenetic changes in foraging performances, breeding phenology or access to mates and nest sites. Fidelity and assortative pairing explained the high correlation in male and female ages within a pair. Breeding performances followed a typical bell‐shaped curve with performance increasing up to 8 yr old, before reaching a plateau and subsequently declining after age 16. Both selection and within‐individual processes occurred, although within‐individual changes dominated differences in age‐dependent breeding success. The selective appearance had almost no effect (apart from ages 2–3), and selective disappearance mostly affected changes at old ages (above 16), although they were also responsible for the slight increase in reproductive performances from ages 5–8. Focusing on within‐individual changes, birds exhibited higher performances at middle ages, with birds foraging better, laying earlier and changing partner and nest less often. Their reproductive investment did not vary with age for females and slightly decreased for males. This supports the constraint hypothesis but not the restraint one. Finally, the increase in breeding performances at young ages was explained by the age‐related increase in foraging performances during chick‐rearing and advancement of laying. In contrast, reproductive senescence was defined by a general decrease in bird performances.

Cefacetrile and Rifaximin association might improve first service conception rate and reduce the number of services per conception in cows with clinical endometritis

Clinical endometritis (CE) is a serious disease leading to poor reproductive performances in lactating dairy cows, thus diminishing farm profitability. To preserve optimum reproductive efficiency, various strategies and therapeutic approaches have been proposed to manage cows with CE, often with contradictory results. Thus, investigating new paths to CE treatment is economically important. The aim of the present study was to test the efficacy of three therapeutic protocols on the clinical cure rate of CE, and improvement of reproductive performance. Cows with CE (n=42), 21–38 days in milk (DIM), were assigned to three treatment groups: PGF: cows (n=19) were treated systemically with two doses of d-cloprostenol, a PGF2α analogue, at 14-days intervals; CEFAX: cows (n=10) received an intrauterine infusion of the combined antibiotics Cefacetrile and Rifaximin; and NAX: cows (n=13) received systemic treatment with Ceftiofur crystalline free acid (CCFA). A control group included cows (n=36) free from CE (healthy group: HE). All cows were clinically re-examined after the end of the treatment protocol. The clinical cure rate was 73.7%, 80% and 69.2% in PGF, CEFAX, and NAX groups, respectively (P&amp;gt;0.05). The HE group had a significantly shorter calving to first service interval compared to CEFAX and PGF groups (P&amp;lt;0.05), however the difference was not significant with NAX group. The mean calving to fertilizing service interval (CFI) was slightly higher in all three treatment groups compared to the HE group, however the difference was not significant (P&amp;gt;0.05). CEFAX protocol resulted in shorter but not statistically significant CFI, compared to the PGF and NAX protocols. Services per conception rate were slightly lower (1.7) in the CEFAX group compared to HE (1.75), PGF (1.84) and NAX (2.23) groups, however these differences were not significant. First service conception rate and conception rate at 105 DIM did not differ statistically between the treatment groups. While the difference was not significant, CEFAX protocol had slightly better cure rate for CE, reducing the number of services per conception and boosting the resumption of ovarian activity after calving. Validating these finding on a larger herd size will improve the accuracy of these findings.

Altrenogest treatment during the last week of lactation on ovarian traits and subsequent reproductive performance of primiparous and multiparous sows

High-quality follicles result in larger corpora lutea (CL), producing more progesterone, and having a fundamental role in pregnancy maintenance. For some sows, follicular growth takes place during lactation, and follicle selection occurs under a catabolic environment. As altrenogest inhibits follicular development, this study aimed to evaluate follicular growth, CL size, estrus expression, and subsequent reproductive performance of sows treated with altrenogest during the last seven days of a three-week lactation. A total of 81 primiparous and 319 multiparous sows were allocated to two treatments: CONT (control group) and ALT (20 mg of altrenogest/day during the last seven days of lactation). Subsamples of 20 primiparous sows and 97 multiparous were randomly selected to evaluate follicular growth and 26 multiparous sows for serum progesterone analysis at day 21 of gestation. On day 21 of pregnancy, CL measurement was performed by ultrasound. Once in estrus, sows were post-cervically inseminated with pooled semen doses with 1.5 × 109 sperm cells at estrus onset and every 24 h during the standing reflex period. Sows not showing estrus until 10 days after weaning were considered in anestrus. The variables weaning-to-estrus interval, CL size, litter size in the subsequent cycle, and piglet birth weight were evaluated using the GLIMMIX procedure and compared using the Tukey–Kramer test. Anestrus, pregnancy, farrowing, and adjusted farrowing rate were evaluated as binary responses using logistic regression. Follicular size was analyzed as a repeated measure during treatment and after weaning. Treatment was considered as a fixed effect. During the treatment period, follicular size was smaller in ALT sows than CONT sows (3.29 vs. 3.52 mm; P < 0.001). However, after treatment, ALT sows showed a larger follicular size than CONT sows (5.30 vs. 5.03 mm; P ≤ 0.01). There were less ALT sows showing estrus than CONT sows on days three (1.03 vs. 4.57%) and four (55.38 vs. 68.02%) after weaning (P ≤ 0.05), respectively. At 21 days after insemination, ALT sows showed larger CL size and lower CL size variation (P < 0.01) than CONT sows. Anestrus rate, pregnancy rate, farrowing rate, adjusted farrowing rate, litter size in the subsequent cycle, piglet birth weight, litter birth weight, and birth weight variation did not differ between treatments (P ≥ 0.14). In conclusion, altrenogest treatment during the last week of lactation concentrated estrus expression on day five after weaning, larger follicle and CL sizes; however, with no improvement in reproductive performance.

Economic impact of adding a second prostaglandin F2α treatment during an Ovsynch protocol using a meta-analytical assessment and a stochastic simulation model

Incomplete luteal regression after treatment with a single dose of PGF2α during an Ovsynch protocol decreases fertility to timed artificial insemination (AI). An additional treatment with PGF2α 24 h after the first dose has been recommended to increase the proportion of cows with complete luteal regression and subsequent pregnancy per AI (P/AI). This is, however, associated with additional costs of labor and product. The objective was to develop a stochastic partial budget model to estimate the economic impact of an additional PGF2α treatment on d 8 during an Ovsynch protocol in primiparous and multiparous cows. A systematic review of the literature and a meta-analytical assessment was performed to evaluate the effects of adding a second PGF2α treatment during the Ovsynch protocol on P/AI in lactating dairy cows. Thirteen randomized controlled experiments from 11 published manuscripts including 9,735 cows were used. We were able to retrieve information regarding parity from 9 experiments from 7 manuscripts (2,367 primiparous cows and 5,356 multiparous cows). An additional dose of PGF2α yielded a 5.60 risk difference in P/AI [95% confidence interval (CI) = 3.69-7.52]. In primiparous cows and multiparous cows, an additional dose of PGF2α yielded a 4.24 (95% CI = 0.31-8.17) and a 5.31 risk difference in P/AI (95% CI = 2.75-7.87). Revenue was based on the associated improvement in reproductive performance because of an increase in P/AI multiplied by the value of a pregnancy (PGVAL). Median PGVAL was €252, ranging from €42 (fifth percentile) to €623 (95th percentile). Based on parity, median PGVAL was €205 (5th percentile = €43; 95th percentile = €651) and €264 (5th percentile = €88; 95th percentile = €598) for primiparous (n = 1,252) and multiparous cows (n = 3,003), respectively. Using a stochastic simulation model with 10,000 iterations, adding a second PGF2α dose on d 8 was more profitable (€7.76/cow; 5th percentile = €0.01; 95th percentile = €29.40) compared with a single PGF2α administration on d 7. In primiparous cows, adding a second PGF2α treatment was more profitable (€1.99/cow; 5th percentile = -€3.08; 95th percentile = €22.52) in 67% of all simulated iterations. In multiparous cows, adding a second PGF2α treatment was more profitable (€7.92/cow; 5th percentile = -€0.09; 95th percentile = €28.22) in 95% of all simulated iterations. In conclusion, there was a clear benefit of an additional PGF2α treatment during the Ovsynch protocol on P/AI (+5.6 percentage units). Despite additional costs for hormones and labor, an additional treatment with PGF2α on d 8 was more profitable in 95% of all scenarios because of the associated increase in fertility. It turned out, however, that adding a second PGF2α treatment was more profitable in multiparous cows compared with primiparous cows.

Drought effects on montane grasslands nullify benefits of advanced flowering phenology due to warming

AbstractWarming due to climate change is generally expected to lengthen the growing season in areas of seasonal climate and to advance plant phenology, particularly the onset of leafing and flowering. However, a reduction in aboveground biomass production and reproductive output may occur when warming is accompanied by drought that crosses critical water deficit thresholds. Tracking warmer temperatures has been shown to be species‐specific with unknown impacts on community composition and productivity. The variability in species’ ability to leverage earlier leaf unfolding and flowering into increased aboveground net primary production (ANPP) or increased investments into reproductive organs has heretofore been poorly explored. We tested whether phenological sensitivity to temperature, as a result of experimental warming, directly translated into increased plant performance, as measured by ANPP and flower abundance. In order to experimentally simulate climate warming, we translocated a total of 45 intact soil–plant communities downslope along an elevational gradient of 900 m within the European Alps from 1260 to 350 m asl and weekly recorded flower abundance and total green cover as well as cumulative biomass production at peak growing season. We found that advanced phenology at lower elevations was related to increased reproductive performance and conditional on whether they experienced drought stress. While a temperature increase of +1K had positive effects on the amount of reproductive organs for species with accelerated phenology, temperature increase going along with drier conditions resulted in plants being unable to sustain early investment in reproduction as measured by flower abundance. This finding highlights that the interaction of two climate change drivers, warming and drought, can push communities’ past resistance thresholds. Moreover, we detected biotic competition mechanisms and shifts toward forb‐depressed states with graminoids best taking advantage of experimentally altered increased temperature and reduced precipitation. Our results suggest that while species may track warmer future climates, concurrent drought events post a high risk for failure of temperature‐driven improvement of reproductive performance and biomass production in the European Alps.

Herd manager attitudes and intentions regarding the selection of high-fertility EBV sires in Australia

Reproductive performance in dairy cattle has declined over the last 50 years as an unintended consequence of selection for high milk yield. Since the early 2000s, dairy geneticists have released successive versions of fertility estimated breeding values (EBV) to assist in reversing this trend. At the herd level, fertility EBV can help managers accelerate improvements in reproductive performance by acting as a second selection criteria when used in tandem with a breeding index. However, use of the fertility EBV in sire selection currently varies between herd managers. The aim of this study was to better understand the reasons why herd managers choose or do not choose to select high-fertility EBV sires, using the Theory of Planned Behavior (TPB) as a social research framework. Thirty-five Victorian dairy herd managers were recruited as part of a larger study investigating the daughter fertility Australian Breeding Value and interviewed using a series of questions examining TPB constructs. The interviews were recorded and transcribed using template analysis. A wide range of herd manager types were enrolled into the study, with representation from diverse systems. Out of the 35 herd managers, 27 included fertility in their list of high-priority breeding objectives. A wide variation in results was consistent with previous studies that have demonstrated marked heterogeneity in herd manager attitudes toward bull selection. Herd manager-perceived barriers to selection of sires with high daughter fertility EBV included a lack of high daughter fertility bulls with other desirable traits, a lack of trust in the fertility EBV or in the Australian EBV system, difficulty in interpreting international proofs, information overload, semen prices, low bull reliability, and difficulty in understanding bull catalogs. Not all herd managers found the process problematic, however, particularly if a breeding consultant was employed to select all or most of the sires. Herd manager-perceived barriers for choosing to select daughter fertility as a breeding objective include a lack of awareness of the EBV, a lack of interest in genetics in general, low confidence in the impact of genetic selection for fertility, and a feeling that fertility was not important for their production system. The results of this study suggest that animal geneticists and on-farm service providers need to work together to allow the opportunities arising from appropriate use of fertility EBV to be realized more broadly across the dairy industry.

Growth, body composition and body wrinkle are favourably correlated with reproductive performance in 2-8-year-old Merino sheep

Context Despite the increased economic importance of reproductive rate in Australian Merinos, there have been low genetic improvements in reproductive performance over the past several decades. Genetically improving reproductive traits through direct selection is restricted by low heritability, low selection intensity directly on reproductive traits, high recording costs and lack of accurate maternal pedigrees in the majority of industry breeding programs. However, indirect selection via correlated traits may be useful as a supplement to direct selection or even on its own where reproduction records are not collected. Aims The aims of the present study were to determine whether various production and quality traits have the potential to be used as indirect selection criteria for genetically improving lifetime reproductive rate, but also whether their selection could be detrimental to reproduction via unfavourable correlations. Methods Reproductive traits studied included pregnancy rate (ewes scanned pregnant per ewe joined), fetal number (number of fetuses scanned per ewe joined), number of lambs born (per ewe joined), number of lambs weaned (per ewe joined) and ewe rearing ability (number of lambs weaned per fetuses scanned). Using data from the SA Selection Demonstration Flocks project (1997–2005), reproductive traits were modelled against various visual and production traits to estimate correlations. Key results Favourable genetic correlations with reproductive traits were estimated with adult ewe bodyweight (0.37–0.50), hogget eye muscle depth (HEMD, 0.40–0.57), fat depth (HFAT, 0.27–0.48) and hogget body (HBWS) and neck wrinkle scores (–0.13 to –0.50). However, the estimates for genetic correlations with hogget eye muscle depth and fat depth were lower when bodyweight was fitted as a covariate, being 0.11–0.35 and 0.17–0.32 respectively. Genetic correlations with ewe rearing ability were generally unfavourable (except those with hogget body and neck wrinkle scores, which were –0.24 and –0.15 respectively), but were either negligible (adult ewe bodyweight, hogget eye muscle depth, fibre diameter and fleece weight) or low in magnitude(fat depth). Unfavourable genetic correlations were observed between fibre diameter and reproductive traits (0.13–0.33). Fleece weight had negligible genetic correlations with all reproductive traits studied (–0.08 to 0.10). Predictions of response to index selection using indirect criteria of one or more of yearling weight, HBWS, HEMD and HFAT measurements projected substantial genetic gains in the number of lambs weaned per ewe joined (NLW). Without reproduction records on the dams of candidates for selection, indirect selection using all four indirect criteria (yearling weight, HBWS, HEMD and HFAT) was predicted to achieve 112–168% of the genetic gains of direct selection for NLW. When all indirect and direct criteria for NLW are combined as part of index selection, even larger gains for NLW are predicted (from 164–215% of direct NLW genetic gains). Conclusions Findings from the present study suggest that bodyweight, HEMD and HFAT and HBWS could be potentially beneficial as indirect selection criteria for lifetime reproductive rate. Selection for reduced fibre diameter is potentially detrimental to reproductive performance; however, selection for improved fleece weight is unlikely to have any effect on genetic gain for reproductive traits. Implications Use of indirect selection for lifetime reproductive could allow for genetic gain when either used with or without the direct selection criteria of reproduction records.

Effect of Melatonin and in Combination with CIDR on Reproductive Performance in anestrus lactating Iraqi buffaloes (Bubalus bubalis).

The present study was performed on 30 lactating Iraqi buffaloes suffered from ovarian inactivity diagnosed by rectal palpation during 60-90 days postpartum, aged between 3-6 years at Al-Thahab Al-Abiad village / Abu-Graib / Baghdad province during the period from February- June 2020 . The animals divided into three equal groups (10 buffaloes for each one). 1st group treated with melatonin implants (90mg/animals/SC) for 30 days but 2nd group treated with melatonin implants conjugated with CIDR (1.38 gm) in day 20 for 10 days, 3rd group without treatment (control group). The results in this study were recorded animal response 90%, 100% and 50% in 1st ,2nd and 3rd groups respectively with superior significantly (P&lt;0.01) for treated groups compared with control group and 8.26±1.33, 7.15±0.97 and 160.5±14.31 days which represented the duration of response in 1st ,2nd and 3rd groups respectively with significantly differences (P&lt;0.01) related with control, but the number of services per conception recorded insignificantly in all groups, while the pregnancy rate revealed significant differences (P&lt;0.01) in treated group compared with control group. Finally the days open recorded 153.6±6.72, 142.8±7.45 and 217.3±19.56 in 1st, 2nd and 3rd groups respectively with highly significantly (P&lt;0.01) in treated group compared with control group. In conclusion in present study, the role of melatonin in improvement of reproductive performance in anestrus lactating Iraqi buffaloes suffered from ovarian inactivity was safe and effective

Mathematical models of sow reproduction

Nutrition affects reproduction, but the physiological mechanisms are not known. Defining those mechanisms is a high priority for animal scientists. This paper briefly describes mathematical models developed to aid in elucidating those mechanisms and which may be applied to predict animal performance. Two types of mechanistic mathematical models of sows are described, based respectively on nutrient partitioning and on metabolic and physiological principles. The nutrient partitioning model is relatively mature but the metabolic/physiological model is still at an early stage of development. The use of such models in the design and evaluation of feeding programmes, in understanding the biological system and in improving research efficiency are outlined. These two models are now being used as described, and it is anticipated that they, and other models, will make important contributions to the marked improvements in reproductive performance in commercial pig production that is anticipated during the next few years.

Effects of flaxseed-rich diet on reproductive performance in estrous-synchronized Baluchi ewes.

The purpose of this study was to compare the effects of using different levels of flaxseed in diets on the reproductive performance of estrous-synchronized Baluchi ewes (para 3). Diets contained either basal diet (control) or different levels of extruded flaxseed (2%, 5%, 7%, 10%, and 12%) and were fed from lambing to 60 days after lambing. The ewe estrus cycles were synchronized using controlled internal drug release (CIDR) for 14 days starting from day 16 of fat supplementation. The rams were introduced 24 h after CIDR removal. The ewes fed control diets had the highest mean dry matter intake (1,800&amp;plusmn;35 g) which was declined with the increase of flaxseed levels. The experimental diets exerted no effects of urea concentration in blood plasma. However, plasma glucose concentration was lower (p &amp;lt;0.05) in the ewes fed the control diet and 2% flaxseed, compared to those in other groups. Nonetheless, there was no difference among the ewes fed 5%, 7%, 10%, and 12% flaxseed in terms of plasma glucose concentrations (p &amp;lt;0.05). The ewes fed 2% flaxseed had the highest level of plasma triglyceride concentration among other groups. In addition, the control group had the lowest level of plasma total cholesterol and low-density lipoproteins concentration in comparison to other groups (p &amp;lt;0.05). However, plasma nonesterified fatty acids and &amp;beta;-hydroxybutyrate concentrations were similar among the groups (P&amp;gt;0.05). The mean interval between CIDR removal and the exhibition of estrus ranged from 30 to 40 h with the shortest interval being recorded in the ewes fed 12% flaxseed (p &amp;lt;0.05). The control group had the lowest number of follicles on estrus day among other groups (p &amp;lt;0.05). Furthermore, the ewes fed 10% and 12% flaxseed had the highest ovulation, pregnancy, and lambing rates, compared to other groups (p &amp;lt;0.05). In conclusion, the findings revealed that feeding the ewes with 10% and 12% flaxseed resulted in the improvement of reproductive performance.

Long-Term Effect of Environmental Enrichment on Reproductive Performance of Swiss Webster Mice and Their Female Offspring.

Simple SummaryThe aim of this study was to evaluate the effect of the implementation of an environmental enrichment (EE) plan on reproductive performance in mice, applied during one year period in Swiss Webster breeders and their female offspring used as recipients for embryo transfer. Birth rate, litter size, pups’ weight at weaning, interlitter interval and time to first litter were compared against a control group that did not receive EE. In mice breeders, EE significantly increased pups’ weight compared to control group (p < 0.01), without changing any other reproductive parameters. In the offspring females used as recipients, EE did not modify reproductive parameters. Our results demonstrate that this enrichment plan, which is usually applied in mouse facilities for animal well-being, enhances pup’s weight at weaning, with no negative effects on the reproductive performance of Swiss Webster mice.The aim of this study was to evaluate the effect of an environmental enrichment (EE) plan on the reproductive performance of Swiss Webster mice and their female offspring used as recipients for embryo transfer. A total of 54 breeder mice and 60 F1 females, used as foster mothers, were allocated in two experimental groups to receive or not receive EE for physical well-being. Reproductive outcomes of the Swiss trios such as birth rate and pup number, litter size, pups’ weight at weaning, interlitter interval and time to first litter were analyzed. Environmental enrichment significantly increased pups weight from breeding trios compared to the control group (14.4 ± 0.1 vs. 13.8g ± 0.1, EE vs. control, respectively; p < 0.01). Other parameters did not differ between both groups. Reproductive parameters of female offspring used as recipients for embryo transfer did not differ among groups subjected or not to EE. These data demonstrate that the EE protocol applied in Swiss Webster breeder mice positively enhanced pups weight, and did not interfere with other reproductive outcomes. In conclusion, this study supports the implementation of EE plans usually applied for animal welfare in mouse facilities with slight improvement in reproductive performance.