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Aging and reproductive performance in langur monkeys (Presbytis entellus).

Analysis of data on age and reproductive performance in 16 captive female Hanuman langurs (Presbytis entellus) shows that adult females under the age of 6 years and over the age of 19 years had the lowest rates of reproductive success as measured by the production of viable young that survived beyond 30 days of age. With the possible exception of one female, females over the age of 19 years experienced a variety of idiosyncratic reproductive problems but did not experience a true menopause as defined by total cessation of menstrual cycles. There was no support for the hypothesis that langur monkey females have evolved a lengthy postreproductive period.

Aging↗

Effects of age at first-pairing on the reproductive performance of Mongolian gerbils (Meriones unguiculatus).

Effects of age at first-pairing on the reproductive performance of the gerbil were studied throughout the reproductive life. Six groups of 7-30 female gerbils were paired monogamously with males at different ages. Out of 101 pairs in 6 groups, 79 (78.2%) produced 1 or more litters. The mean litter size at birth and mean weaning rate of 846 litters were 4.4 (totally 3,733 pups) and 67.4% (2,517 pups), respectively. Reproduction was compared in the 6 age groups. The littering rate (No. of females with litters/No. of female paired) was significantly lower in two groups in which mature females were paired with age-matched males (Group 4) or the oldest females with younger, sexually mature males (Group 6). The interval from pairing to the first litter was shortest in two groups in which mature females were paired with one month older, sexually mature males (Groups 3 and 5). Although the oldest pairs (Group 6) produced about 7 litters, the pairs from the other 5 groups produced about 10 or more litters throughout their reproductive life. The weaning rate was significantly higher in Group 6 (the oldest pairs) than in the younger groups. The effects of parity on reproduction were estimated from the data for the 61 pairs which produced more than 8 litters in the 6 groups. The number of pups at birth and the weaning rate were decreased in last 20-30% of the total parity in all 6 groups, although the age at the last litter in all groups was significantly different. The data suggest that any decline in reproduction may be due to not age but parity in the Mongolian gerbil.

Aging↗

Reproductive performance and milk production of Assaf sheep in an intensive management system.

The Assaf breed of dairy sheep, a stabilized cross of the Awassi and East Friesian breeds, has replaced the Awassi as the breed of choice in its country of origin, Israel, and has spread to other Mediterranean countries. In Israel the Assaf breed is managed under an intensive production system involving weaning lambs at birth, rearing them artificially, and milking ewes after parturition. There are several breeding periods in the year when ewes are mated following hormonally synchronized estrus. Records of 18,976 lactations from 5 farms were analyzed to investigate factors that influenced Assaf milk and reproductive performance. Lactation curves were fitted to each lactation, and a range of parameters and calculated values were analyzed. Daily milk yield records also were analyzed to describe a typical Assaf lactation and compared with those of the Awassi breed. Factors affecting age at first lambing also were studied. An average Assaf ewe kept under this intensive management regimen was found to produce 334 L of milk during a 173-d lactation. Mean litter size was 1.57 lambs/ewe lambing, and lambing interval was 272 d. Milk production was affected by litter size, with twin- and triplet-bearing ewes producing approximately 20 L more milk per lactation than single-bearing ewes. Day length was the major environmental variable influencing milk yield. The difference between midsummer and midwinter day lengths accounted for a difference in daily milk yield of 0.44 L in favor of summer. Ewe lambs that were mated for the first time at later ages produced more lambs and more milk due to greater early lactation characteristics. Milk production was found to be negatively associated with subsequent reproductive performance. Comparing these results with those from an earlier study in the Awassi breed, the Assaf was found to produce less milk during a shorter lactation than the Awassi, but its greater litter size made it a more profitable breed.

Age Factors↗

Evaluation of different protocols for prostaglandin synchronization to improve reproductive performance in dairy herds with low estrus detection efficiency.

The objective of this study was to evaluate different PGF2 alpha protocols against control protocols for herds with estrus detection efficiencies of 35, 55, and 75% using modeling and simulation: 1) PGF2 alpha treatments based on the presence of a corpus luteum diagnosed by rectal palpation, 2) PGF2 alpha treatments based on the presence of a corpus luteum diagnosed by an on-farm milk progesterone enzyme immunoassay, and 3) PGF2 alpha treatments based on a 14-d fixed treatment schedule without prior screening for ovarian status. After the start of each protocol, estrus detection efficiency was 75% for 7 d after treatment and 35 or 0% for the following week. For the third protocol, an additional modification at estrus detection efficiencies of 85 and 55%, respectively, in the 1st and 2nd wk after treatment was evaluated to establish a protocol for best case assumptions. All protocols improved reproductive performance relative to that of controls with estrus detection efficiencies of 35 and 55%. The mean number of days open was reduced from 124.3 d in the control herd to 95.9, 95.0, and 92.7 for the protocols based on rectal palpation, milk progesterone test, and the fixed treatment schedule, respectively. The protocols based on a fixed treatment schedule were superior to protocols based on rectal palpation and on-farm milk progesterone tests and resulted in better reproductive performance and a higher increase in net return per cow per year. Relative to a control herd with an estrus detection efficiency of 55%, it was cost effective to spend up to $10 per dose of PGF2 alpha, $9 per milk progesterone test, and $6 per rectal palpation.

Animals↗

Effects of supplemental vitamin E during the laying period on the reproductive performance of Taiwan native chickens.

1. One-day-old Taiwan Native Breeder female chicks were fed on maize/soybean growing diets without supplemental vitamin E from hatch to 17 weeks of age. After 17 weeks the birds (n = 300) were randomly assigned to 5 dietary treatments and fed on maize/soybean laying diets supplemented with 0, 40, 80, 120 and 160 mg/kg of vitamin E (dl-alpha-tocopherol acetate), respectively, until 46 weeks of age. The variates measured included: age at first egg, feed consumption (FC), feed efficiency (FE), egg production (EP), egg weight (EW), egg specific gravity (ESG), eggshell strength (ESS), fertility and hatchability. 2. The addition of 120mg/kg of vitamin E lowered the first EW (P<0.05); however, there was no significant difference in the age or body weight (BW) of pullets at first egg or mortality rate to 46 weeks of age among the treatments. FE and egg mass were improved (P<0.05) in pullets fed 80 mg/kg of supplemental vitamin E. A significant increase in EP was observed after peak EP in pullets given 80 mg/kg of supplemental vitamin E. However, this favourable effect decreased as supplemental vitamin E exceeded 80 mg/kg. 3. From 17 to 46 weeks of age, egg quality (ESG and ESS) decreased with age. However, there was no correlation between age and fertility or hatchability during the experimental period, suggesting that egg quality is more age-sensitive than reproductive performance for breeder pullets. 4. Compared with the control, fertility and hatchability of all eggs set for the treatment with 80 mg/kg supplemental vitamin E increased by 7.7 and 13.4%, respectively. There was no difference in the hatchability of fertile eggs. 5. These results suggest that using supplemental vitamin E during the laying period can improve the reproductive performance of breeder pullets. The addition of 80 mg/kg of vitamin E obtained the best performance in EP, egg mass, FE (feed/egg), hatchability and fertility.

Aging↗

Offspring sex-ratio and reproductive performance in heterogametic females of the South American field mouse Akodon azarae. Reproduction in heterogametic Akodon azarae females.

We have compared the breeding performance of homogametic (XX) and heterogametic (XY*) females of the South American sigmodontine rodent Akodon azarae under laboratory conditions. XY* females showed an enhanced reproductive performance when compared with normal, XX, females. The XY* females had a longer reproductive lifespan. They started to reproduce early, had more frequent litters, and stopped reproduction later than XX females. Their progeny showed a biased 1:2 male:female sex ratio which may be explained by the early loss of YY* zygotes after fertilization. However, litter size at birth was similar both in XY* and XX females, and no difference in ovulation rate was detected between them. This indicates that an "automatic" rather than an "evolved" reproductive compensation mechanism may be acting in heterogametic females. A separate study has shown that self-synapsis of both the X and Y* chromosomes takes place during meiosis, allowing the oocytes to escape from functional deterioration. It is suggested that self-synapsis and "automatic" reproductive compensation account for the preservation of fertility in heterogametic females in spite of the heteromorphic sex chromosomes and the early embryo loss they experience. However, these mechanisms do not account for the enhancement of reproductive lifespan. The possibility that an intrauterine position phenomenon is acting in A. azarae is discussed.

Animals↗

Chronic maternal methanol inhalation in nonhuman primates (Macaca fascicularis): reproductive performance and birth outcome.

The present study was designed to characterize maternal reproductive performance and early offspring effects following exposure to methanol (MeOH) vapor in a nonhuman primate model. The two-cohort study design used 48 adult female Macaca fascicularis (24/cohort) monkeys exposed to 0, 200, 600, or 1800 ppm MeOH vapor for approximately 2.5 h/day, 7 days/week prior to breeding and throughout pregnancy. Maternal body weight measurement, clinical observations and health assessments were conducted routinely throughout the study. Menstrual cyclicity was monitored during the pre-breeding and breeding periods and timed matings were conducted with nonexposed males. Females were monitored closely during the last month of pregnancy. At birth, infant physical characteristics were measured and a newborn health assessment was conducted. Methanol exposure did not alter menstrual cycles, the number of breedings to conception or conception rate. A total of 34 live-born infants were delivered (control=8, 200 ppm=9, 600 ppm=8, 1800 ppm=9). One female each in the control and 600-ppm group delivered a stillborn infant and a cesarean section (C-section) was required to deliver a hydrocephalic infant who died in utero in the maternal 1800-ppm group. Although not statistically significant, five MeOH-exposed females were C-sectioned due to pregnancy complications such as uterine bleeding and prolonged unproductive labor. These complications were not observed in the control group. The mean length of pregnancy in the MeOH-exposed groups was significantly decreased by 6 to 8 days when compared to controls. There were no MeOH-related effects on offspring birthweight or newborn health status. The consistent reduction in length of pregnancy observed in the MeOH females may reflect a treatment effect on the fetal neuroendocrine system. Given that the fetal hypothalamic--pituitary-adrenal axis controls pregnancy length in most species, these results suggest a modest but significant effect of MeOH on the biochemical events that control the timing of birth.

Administration, Inhalation↗

The use of multilevel models to evaluate sources of variation in reproductive performance in dairy cattle in Reunion Island.

Sources of variation in measures of reproductive performance in dairy cattle were evaluated using data collected from 3207 lactations in 1570 cows in 50 herds from five geographic regions of Reunion Island (located off the east coast of Madagascar). Three continuously distributed reproductive parameters (intervals from calving-to-conception, calving-to-first-service and first-service-to-conception) were considered, along with one Binomial outcome (first-service-conception risk). Multilevel models which take into account the hierarchical nature of the data were used to fit all models. For the overall measure of calving-to-conception interval, 86% of the variation resided at the lactation level with only 7, 6 and 2% at the cow, herd and regional levels, respectively. The proportion of variance at the herd and cow levels were slightly higher for the calving-to-first-service interval (12 and 9%, respectively) - but for the other two parameters (first-service-conception risk and first-service-to-conception interval), >90% of the variation resided at the lactation level. For the three continuous dependent variables, comparison of results between models based on log-transformed data and Box-Cox-transformed data suggested that minor departures from the assumption of normality did not have a substantial effect on the variance estimates. For the Binomial dependent variable, five different estimation procedures (penalised quasi-likelihood, Markov-Chain Monte Carlo, parametric and non-parametric bootstrap estimates and maximum-likelihood) yielded substantially different results for the estimate of the cow-level variance.

Animals↗

Effects of reciprocal ovary transplantation on reproductive performance of lethal yellow mice (Ay/a; C57BL/6J).

This study was conducted to determine whether reproductive failures in ageing, obese lethal yellow (Ay/a) females are due primarily to defects within Ay/a ovaries or to systemic defects which may operate outside the ovaries. Reciprocal ovary transplantation between control (a/a) and lethal yellow (Ay/a) females provided an experimental system to test the reproductive potential of not only Ay/a ovaries in control (a/a) females but also control (a/a) ovaries in mutant (Ay/a) females. Results on reproductive performance of all four combinations of grafts between Ay/a and a/a mice proved that Ay-induced reproductive failures are not due to intrinsic ovarian lesions but rather to defects operating extrinsically to the ovary. The hypothalamo-pituitary axis is a likely site for this reproductive lesion.

Aging↗

Effects of human and murine antisense oligonucleotide inhibitors of ICAM-1 on reproductive performance, fetal development, and post-natal development in mice.

The potential for reproductive toxicity of an antisense oligonucleotide designed to inhibit ICAM-1 was evaluated as part of the safety assessment for this compound. Since antisense compounds are often specific to the species in which they are intended to work, both the human and murine active ICAM-1 inhibitors were tested (ISIS 2302 and ISIS 3082, respectively). Male and female mice were treated prior to cohabitation, through cohabitation, gestation, delivery, and weaning. Mice were treated with 0, 3, 6, and 12 mg/kg ISIS 2302 or ISIS 3082 by daily i.v. injection. Reproductive indices evaluated included estrus cycling, sperm count and motility, fertility, litter parameters, fetal development, delivery, fetal body weight, lactation, and weaning. Behavioral assessment and reproductive capacity of the F1 generation mice was assessed on selected animals. Concentrations of oligonucleotide in selected maternal target organs, placenta, fetal tissues, and expressed milk were also measured. There were no changes in reproductive performance, litter parameters, fetal development, or postnatal development in mice treated with either ISIS 2302 or ISIS 3082. Maternal liver and kidney contained dose-dependent concentrations of oligonucleotide, but there was relatively little or no oligonucleotide measured in placenta, fetal tissues, or expressed milk. Neither the human nor murine-specific antisense inhibitor of ICAM-1 produced any reproductive toxicity in mice, and exposure of fetus or pups was negligible.

Animals↗

Lifetime reproductive performance of Mongolian gerbils (Meriones unguiculatus) with 1 or 2 ovaries.

The lifetime reproductive performance of Mongolian gerbils from which an ovary had been removed 7 days before pairing at 100 days of age was only slightly inferior to that of normal females. A general decline in fertility was evident only in the oldest females. The mean number of litters, young born and age at last parturition were 7.6 +/- 3.8, 37 +/- 20 and 462 +/- 196 days (2 ovaries) compared with 6.9 +/- 3.5, 30 +/- 16 and 417 +/- 142 days (1 ovary) respectively.

Animals↗

Dibromochloropropane (DBCP): an 8-year reevaluation of testicular function and reproductive performance.

The current study summarizes an 8-year reassessment of testicular function and reproductive performance in 15 workers with dibromochloropropane (DBCP)-induced azoospermia and oligozoospermia. Recovery of spermatogenesis was observed in four oligozoospermic and three azoospermic men whose plasma follicle-stimulating hormone (FSH) concentration was normal during the whole period. A marked increase in FSH and luteinizing hormone concentrations above the upper limit of normal was found in the azoospermic workers who did not recover. No significant changes in FSH concentrations were detected in both recovered and nonrecovered oligozoospermic men. Testosterone levels of all patients were normal at all times. Paternal exposure to DBCP was not associated with increased risk of fetal malformations or spontaneous abortion.

Chemical Industry↗

The influence of age on reproductive performance of the predatory ladybird beetle, Propylea dissecta.

The influence of age on reproductive performance of an aphidophagous ladybird beetle, Propylea dissecta was examined using male and female beetles of varying ages (1-30 days) after a single mating stimulus. All the intermediate (10 to 20 days old) and old (30 days old) age females mated with all intermediate and old age males, while only a fraction (0.29%) of younger females, 1 to 5 days old, mated with males of similar or older age. The willingness to mate was male age dependent. It increased sigmoidally with increase in adult age. Adult males were more willing to mate with females irrespective of age. Mating duration was longest amongst older adults (30 day-old males and 20 day-old females). Male age did not contribute to shaping the fecundity of the female ladybird. Fecundity was female age dependent and it increased with age up to 20 days and thereafter decreased. 20 day-old females were most fecund producing 867 eggs after a single mating. Progeny production was male age dependent and eggs sired by 20-30 day-old males had significantly higher viability than those sired by younger males. Prolonged mating increased fecundity and egg viability. The results reveal that males of intermediate age were better mates. This information may improve our understanding of the effect of aging on reproduction in ladybirds and may help mass-multiplication of the ladybird beetles using adults of optimal age.

Aging↗

Dibromochloropropane (DBCP): a 17-year reassessment of testicular function and reproductive performance.

The current study summarizes a 17-year reevaluation of testicular function and reproductive performance of 15 production workers with dibromochloropropane (DBCP)-induced testicular dysfunction. Sperm count recovery was evident within 36 to 45 months in three of the nine azoospermic and in three of the six oligozoospermic men with no improvement thereafter. A significant increase in plasma follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and a nonsignificant decrease in testosterone level were detected in the severely affected individuals. There was no increase in the rate of spontaneous abortions and congenital malformations among pregnancies conceived during or after exposure. A low prevalence of male infants conceived during paternal exposure was found as compared with the preexposure period (16.6% versus 52.9%; P<.025). Restoration of fertility was followed by a gradual increase of this value to 41.4%.

Adult↗

Protein and energy self-selection by turkey hens: reproductive performance.

1. The influence of protein and energy self-selection on the reproductive performance of turkey hens was investigated. Large White turkey hens were fed on either a complete diet (185 g CP/kg, 11.30 MJ ME/kg) or were provided with a choice between a high protein-low energy diet (348 g CP/kg, 7.74 MJ ME/kg) and a high energy-low protein diet (81 g CP/kg, 13.39 MJ ME/kg). 2. Egg production, egg weight, and the fertility and hatchability of eggs produced were not significantly affected by the dietary treatments (P greater than 0.05). 3. While energy intake was not significantly different between groups, protein consumption decreased by approximately 40% (P less than or equal to 0.001) among self-selecting hens compared to hens fed on the complete diet. This resulted in a 10% (P less than or equal to 0.05) reduction in the food intake in the self-selecting birds.

Animal Feed↗

Reproductive performance of Finnish Landrace and Suffolk sheep maintained indoors year-round.

The reproductive performance (fertility and prolificacy) of Finnish Landrace (Finn) and Suffolk sheep on an accelerated breeding program was evaluated. Both breeds were contained in each of two separate flocks housed indoors year-round on expanded metal floors in windowless buildings. The two flocks were bred alternately at 4-mo intervals in January, May and September. The sheep were exposed to either an abrupt (ALR) or constant (CLR) lighting regimen. Data from nine breedings during a 4-yr period were considered. Fertility was significantly higher for ewes in the ALR lighting regimen. Fertility was lower for ewes bred in September. For ewes that had lambed from breeding 8 mo earlier, fertility was higher for Finn ewes than for Suffolk ewes; however, similar fertility levels were observed in both breeds if the ewes had not lambed following the previous breeding. Higher prolificacy was observed in the Finn ewes than in the Suffolk ewes, but the differences in prolificacy varied with the month of breeding. The probability of a ewe having more than one lamb was significantly higher for Finn ewes than for Suffolk ewes in both January and May breedings, but was similar in September breedings. Incorporating the Finnish Landrace breed into an accelerated breeding program for sheep maintained indoors year-round is a practical way to increase the number of lambs born. Controlling daylength and dividing the flock into smaller flocks are also practical procedures to increase lamb production.

Animals↗

Factors influencing reproductive performance following previous ectopic pregnancy.

OBJECTIVE: To assess the factors that influence the reproductive performance in patients who had previous salpingectomy by laparotomy for ectopic pregnancy in the South-west Region of Saudi Arabia. METHODS: Fifty four patients who had pregnancies following salpingectomy for previous ectopic pregnancy were studied retrospectively at Abha Maternity Hospital in the Southern Region of Saudi Arabia. RESULTS: There were 130 ectopic pregnancies during the study period out of which 54 patients became pregnant subsequently. Of the subsequent pregnancies, there were 41 (80%) intrauterine pregnancies and 13 (20%) extrauterine recorded pregnancies. Out of the intrauterine pregnancies, 36 (88%) resulted in full term live births while abortion occurred in 5 (12%) of the cases. The risk of a 2nd ectopic pregnancy seemed to be positively related to the age of the patient and also the interval between the previous ectopic and new pregnancy, while it was negatively related to the parity of the patient. The mean age of the patients was 27.89 years and the mean parity 2.74. Of the 13 patients who had extrauterine pregnancies, 4 (30%) were nulliparous while 9 (70%) had had between 1-5 children. In those patients who had a repeat ectopic pregnancy, the mean gestation of the ectopic pregnancy was 6.78 weeks while the interval between admission to hospital and surgery ranged between 1 to 48 hours with a mean of 21.85 hours. At the time of surgery, the fallopian tube was ruptured in 6 (46%) of the cases and these included patients who were nulliparous. They all had repeat salpingectomy. Conservative surgery was performed only in 2 (28%) of those whose fallopian tubes were not ruptured at the time of surgery. CONCLUSION: It seemed as if the probability of repeat ectopic pregnancy increased as the age of the patient increased and the interval between the previous ectopic gestation and new pregnancy is prolonged. At the same time the probability of another ectopic pregnancy decreased as the parity increased. The obstetric outlook following laparotomy for ectopic pregnancy seemed not to be very encouraging as the fertility rate was about 48% and therefore, efforts should be geared at managing patients with ectopic pregnancy laparoscopically. A larger multicenter study is needed to validate these findings.

Adolescent↗

The effect of postparturient urogenital diseases on the lifetime reproductive performance of sows.

To prove the effect of postparturient swine urogenital disease (SUGD) on reproductive performance, culled sows with SUGD in their previous history (n=1363) were subjected to retrospective lifetime production analysis. The sows were assigned to parity groups 1, 2 to 6, and >6. Bacterial flora of vulval discharges were evaluated. Parity 1 sows had a lower percentage of SUGD than did sows of parity 2 to 6 and parity >6 (P < 0.05 and P < 0.01, respectively). Compared with parity 2 to 6 sows, parity 1 and parity >6 sows had lower (P < 0.001) conception, farrowing and adjusted farrowing rates, lifetime average total born, live-born litter sizes, stillbirth rates, and weaning litter weights compared with animals culled for other reasons than SUGD. The conclusions are that high parity sows have a higher occurrence of postparturient SUGD and that higher parity sows with postparturient SUGD have a lower performance compared with lower parity sows with postparturient SUGD.

Animals↗