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Brief communication: birth month influences reproductive performance in contemporary women.

BACKGROUND: Season of birth has been reported to affect later reproduction in samples of pre-modern women and contemporary men. METHODS: To examine whether the effect of birth date is also valid in contemporary women, we investigated the association between birth month and measures of reproductive performance (number of live-born children, % childless individuals) in a representative sample of contemporary Austrian women. RESULTS: Among reproducing women, birth month is significantly associated with the number of live-born children (n = 2839, P = 0.032). On average, women born in summer months have fewer children than women born during the remainder of the year. No association between birth month and the percentage of childless individuals was found. CONCLUSIONS: As has been reported in pre-modern women, month of birth also appears to affect later reproduction in contemporary women.

Austria↗

Reproductive performance of Coopworth ewes following oral doses of zearalenone before and after mating.

The reproductive performance of Coopworth ewes after administration of zearalenone was determined in two trials. In Trial I, zearalenone was administered to groups of 33 ewes at rates of 0, 1.5, 3.0, 6.0, 12.0 and 24.0 mg/ewe/day for 10 days, starting on Day 7 of the oestrous cycle before mating. There was a linear decline (P less than 0.001) in ovulation rate with dose of zearalenone; also cycle length decreased and duration of oestrous increased with increasing dose levels. Reductions in the incidence of ovulation and in fertilization were seen only at doses of 12 and 24 mg. In Trial 2, groups of 50 ewes were given the same range of doses of zearalenone for 10 days, starting 5 days after mating to entire rams. There was no effect of zearalenone treatment after mating on pregnancy rate or embryonic loss. These results indicate that the effects of zearalenone, administered orally, on ewe reproduction, at the dose levels examined, were restricted to ewes exposed before mating. Intakes of zearalenone of 3 mg/ewe/day or more during this period would be reflected as depressed ovulation rates and lower lambing percentages.

Administration, Oral↗

Abortion and reproductive performance of cattle in northern Nigeria: a questionnaire survey.

A survey on abortion and reproductive performance in cattle was carried out in the six northern States of Nigeria in 1972-73. Three hundred and ninetten herds with 8,970 breeding cows were sampled. One hundred and thirteen herds reported abortion (35 per cent); the lowest incidence was in local herds in Kano State and the highest was on government ranches. Twenty-six herds reported recurrent or chronic abortion. The majority of abortions in non-government herds was not reported to local veterinary authorities (75-8-100 per cent). Average age at first conception in government herds was 2-5 years and 3-5 years in local herds. The percentage of calf crop was highest in the government herds (67 per cent) compared with local Fulani herds (34-2-54-5 per cent) and the pregnancy rate was almost double in the government herds. The percentage of Fulani herds reporting repeat breeding varied from 16-6 to 58-8. Although the survey gave no information as to the causes of abortion or the financial loss, it indicated that bovine abortion was more widespread in the northern states of Nigeria, than previously thought.

Abortion, Veterinary↗

The reproductive performance of farmed fallow deer (Dama dama) in New South Wales.

Observations on the reproductive performance of fallow deer on 47 farms in New South Wales were made over 6 consecutive years. The minimum fawning rate for does varied significantly (p less than 0.001) between years, the corresponding fawning percentages varying from 75.0% to 96.4%, with an overall mean of 88.8%. The weaning rate also varied significantly (p less than 0.001) between years, the corresponding percentages varying from 65.0% to 89.1% with a mean over 6 years of 81.4%. Weaning rates were low given the known high fertility of fallow deer. The ratio of male to female fawns at weaning varied significantly (p less than 0.05) between years, although the ratio was exactly 1:1 for all births recorded over the 6-year period. The mean birthweights for female and male fawns were 4.01 kg +/- 0.61 (n = 330) and 4.23 kg +/- 0.72 (n = 348) respectively. Mean birthweights varied significantly (p less than 0.001) between the sexes and between years. There was a greater difference between birthweights of male and female fawns in years with higher mean fawn birthweight. Fawn birthweights generally approximated 10% of the pre-rut weight of their mother. Handling of newborn fawns for tagging and weighting did not increase the chance of mismothering and rejection. The mean weaning weight for doe fawns and buck fawns over 6 years was 18.7 kg (n = 227) and 21.2 kg (n = 231) respectively, with a mean birth to weaning interval of 108.4 +/- 4.89 (n = 458). Growth rates of male fawns from birth to weaning were significantly higher (p less than 0.01) than for female fawns, and the growth rates of fawns were significantly different (p less than 0.01) between years.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Consumption of a high fat diet impairs reproductive performance in Sprague-Dawley rats.

Rats made obese by cafeteria feeding have poor reproductive outcomes. To investigate this phenomenon in animals fed a more nutritionally adequate diet, female rats were fed either a high fat (HF) (modified AIN-76A, 35 g fat/100 g diet) or a control (C) (AIN-76A, 5 g fat/100 g diet), diet, beginning at 27 d of age. To assess reproductive performance, rats were studied at d 0, 5 and 18 of pregnancy and on d 3 of lactation. Pregnancy rates were significantly (P < 0.001) lower in the high fat-fed rats than in the control-fed rats (56.4 and 89.1%, respectively). There was no difference between groups in total pregnancy weight gain or the proportion of weight gained during pregnancy that was retained by the dam. High fat-fed dams tended to gain weight more rapidly early in gestation than control-fed dams and then less rapidly than control-fed dams during the last week of gestation. Litter number and pup weight at birth did not differ between groups, but of high fat-fed pups had significantly higher (P < 0.04) mortality rates than pups of control-fed dams (16.5 and 7.7%, respectively) over the first 3 d of life. Control-fed dams experienced the expected reduction (P < 0.05) in plasma insulin concentrations between the end of pregnancy and early lactation, but high fat-fed dams did not. Thus, physiological mechanisms controlling distribution of metabolic fuels may not be functioning properly in high fat-fed dams. Therefore, consuming a high fat diet reduces a rat's capacity to conceive and ability to maintain her litter during the perinatal period.

Animals↗

Response of broiler breeder females to feed restriction below recommended levels. 1. Growth and reproductive performance.

Arbor Acre broiler breeders were used to determine the effects on growth and reproductive performance of quantitative feed restriction below breeder recommended levels. Feed treatments were: 8% above standard (+8%); standard feeding program (STD); and 8 (-8%), 16 (-16%), and 24% (-24%) below standard. Proportional decreases in feed allocation resulted in corresponding decreases in body weight, frequency of double-yolked eggs, and number of days in production. Egg weight, fertility, hatchability, and female mortality to 64 wk of age were not significantly (P greater than or equal to .05) affected by the reduction in feed intake. Shell quality was significantly improved with the -16 and -24% feed treatments. A delay in sexual maturity caused a significant (P less than or equal to .05) decrease in average rate of lay (%hen-day) but not in total settable eggs for treatments -16 and -24% to 64 wk of age.

Animals↗

Reciprocal recurrent selection for 21-day litter weight of crossbred gilts. II. Reproductive performance of purebred females producing purebred and two-way cross litters and performance of purebred and crossbred pigs.

This paper reports estimates of correlated genetic change in reproductive performance of purebred gilts producing two-way cross litters and purebred sows producing purebred litters as well as postweaning performance of two-way cross and purebred pigs produced during reciprocal recurrent selection (RRS) between Line 8 (Duroc) and Line 9 (Beltsville No. 1) for 21-d litter weight production of crossbred gilts. A randomly mated control line developed from a crossbred foundation was maintained to monitor environmental change. Data were adjusted for age of dam, inbreeding of dam, inbreeding of litter (or pig) and linear and quadratic effects of day born within season. The traits evaluated were: litter size, litter weight and average pig weight/litter at birth and weaning (42 d); postweaning average daily gain; age at 90.7 kg and backfat thickness at 90.7 kg. Two data sets were analyzed; the first set included seven seasons of data with purebred gilts producing two-way cross litters, and the second set included seven seasons of data with purebred sows producing purebred litters. No estimates of environmental trend were significant in either set of data. In the first data set, only the estimate of genetic change in backfat thickness of two-way cross pigs was significant and it was in the desired direction. All other estimates were small and did not approach significance. In the second data set, estimates of genetic trend were greater in Line 9 than in Line 8.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Effect of acetyl salicylic acid in drinking water on reproductive performance of Japanese quail (Coturnix coturnix japonica).

The impact of acetyl salicylic add (ASA) on reproductive performance during periods of heat stress was studied in Japanese quail (Coturnix coturnix japonica). During a season when daily high temperatures averaged between 34 and 40 degrees C, four treatments each containing four replicates of five males and five females were given 0, 0.5, 1.0, or 1.5 g/L ASA in drinking water from 34 to 45 wk of age. At 39 wk of age control quail were lighter than quail fed ASA. Quail receiving 1.5 g/L ASA exhibited increased fertility, hatchability, and egg production and decreased late dead and total embryonic mortality. Early dead embryos, pips, chick weight, and egg weight were not different among treatments. The lumen of uterovaginal junction sperm host glands (UVJSHG) from control quail was apparently devoid of spermatozoa, whereas quail receiving 1.5 g/L ASA had the greatest apparent accumulation of spermatozoa. Control caudal infundibulum host glands (CPOI) were devoid of spermatozoa in contrast with CPOI from quail receiving ASA. Results show that UVJSHG lumens from quail receiving 1.5 g/L ASA had larger inside diameters than other treatment groups. However, the CPOI inside diameter and the outside diameters of both UVJSHG and CPOI were not affected by ASA. Adding 1.5 g/L ASA to the drinking water of quail under heat stress improved body weight, fertility, hatchability, embryonic mortality, egg production, egg specific gravity, and sperm storage capacity.

Animals↗

Maximum likelihood estimation of the parameters of the prior distributions of three variables that strongly influence reproductive performance in cows.

Ovulation detection rate, pregnancy rate, and embryo loss rate greatly affect the reproductive performance of cows. A previous model described the separate effects of these variables on the resulting calving patterns and assumed that the variables have the same value for all cows belonging to the same herd. This is not a realistic biological assumption, so the beta distribution is used to introduce "between-cow" variation in the three variables. Two approaches are used to find maximum likelihood estimates of the parameters of these prior beta distributions. The first considers sequences of ovulations, artificial inseminations, and pregnancies, separately. For both ovulation detection rate and pregnancy rate this approach considers the number of "successes" of each event for a particular cow (e.g., in the case of an ovulation, a success is a detection), and conditions on the total number of occurrences of that event in the cow, so that beta-binomial distributions are considered. However, for embryo loss rate the number of pregnancies required until a particular cow calves is considered, so that a beta-geometric distribution results. If the cow is removed before she calves, a censored sequence will result. The second approach considers the sequences of ovulations, artificial inseminations, pregnancies, and embryo losses, together, which will stop only when the cow calves. Otherwise, if she is removed before that time, a censored sequence will result. In this case, a joint distribution, with three independent prior beta distributions, is considered. The results of the analysis of data from 22 herds are discussed.

Animals↗

Reproductive performance of gilts and sows in temperate versus subarctic and arctic zones of Norway.

The reproductive performance of gilts and sows from two regions in Norway was investigated in a retrospective analysis of data from the litter recording system. In the Northern region (North; between 65 degrees N and 71 degrees N), there are extreme shifts in natural photoperiod between winter and summer. In the Southern region (South; between 59 degrees N and 60 degrees 30'N), photoperiodic changes are less dramatic. Gilts were 8 days older at first mating or insemination in the North than in the South (P<0.01). A significantly lower proportion of sows in the North were mated or inseminated within 5 days post-weaning than in the South, a difference present both among primiparous and multiparous sows (P<0.01). Overall farrowing rate in the North was lower than in the South, but litter size (total number born) among those pigs that farrowed was larger. After correction for year, month, breed and age at first service, there were still lower odds of farrowing for gilts in North than in South. Neither for primiparous nor multiparous sows were regional differences in farrowing probability significant when year, month, breed and weaning to service interval were included in the model. Gilts and primiparous sows had a lower probability of farrowing following insemination during summer or autumn months, but service month was not significantly related to the farrowing probability of multiparous sows. For gilts, litter size was positively related to age at first service. For sows, litter size was lowest at weaning to service intervals between 6 and 10 days. Total numbers of piglets born per litter were estimated to be 0.36, 0.38 and 0.55 larger in the North than in the South (differences in least square means; gilts, primiparous sows and multiparous sows, respectively) (P<0.01). Litter size was lower after service during natural long photoperiod than during the rest of the year.

Aging↗

Effects of gonadotrophin releasing hormone on reproductive performance of dairy cows with retained placenta.

The effects of gonadotrophin releasing hormone (GnRH) on the reproductive performance of dairy cows with retained placenta were studied. Three hundred and seventy-eight cows diagnosed as having retained placenta received intramuscular injections of either 2 mL sterile water or 200 micrograms of GnRH in 2 mL sterile water between day 8 and day 14 postpartum. Rectal palpation was performed at the time of treatment and ten to 20 days after treatment in order to determine the rate of uterine involution. Thereafter, monthly rectal examinations were carried out until insemination. Pregnancy diagnosis was made by rectal palpation at 40 days or more after breeding. Using the entire experimental population, there were no significant differences between GnRH-treated and control cows for the rate of uterine involution, the occurrence of reproductive problems, the interval from parturition to first observed estrus, the interval from parturition to first insemination, the interval from parturition to conception, the number of services per conception, the total number of services per cow regardless of conception and the incidence of culling for infertility. When the data for herds in which breeding began earlier in the postpartum period (herds having a mean less than or equal to 80 days from parturition to first service for retained placenta cows) were considered, the GnRH treatment resulted in a significantly shorter (p less than or equal to 0.01) calving to conception interval as compared to control cows. Also, there was a significant reduction (p less than or equal to 0.05) in the total number of services per cow regardless of conception and a significant reduction in the interval from parturition to first service.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Effectiveness of photoperiod stimulation on reproductive performance of sheep housed continuously indoors on an accelerated breeding schedule.

Over five breeding periods, the reproductive performance (fertility, prolificacy and fecundity) of three strains of sheep housed continuously indoors was measured. The sheep were maintained as two separate flocks, A and B, with similar genetic background on an eight month accelerated breeding schedule under one of three lighting regimes, abrupt, contracted or constant, to induce ovarian activity. Overall fertility to one estrus was 59%. For flock A, fertility was greatest under the contracted lighting regime and lowest under the constant lighting regime; the opposite was true for flock B. Among the three strains, fertility was lowest for the Dam 2 strain in flock A. Prolificacy averaged 1.8 lambs per ewe lambing and was similar under each of the three lighting regimes. Fecundity (averaging 106%), the number of lambs born per 100 ewes exposed to rams, generally followed the pattern of fertility.

Animals↗

Reproductive performance of caged Beltsville Small White turkeys as affected by choline, bird density and forced molting.

Reproductive performance was determined on Beltsville Small White hens housed 2 or 3 per cage for 10 weeks and then changed to 1 or 2 per cage for 10 additional weeks. Hens were then molted and data collected for a second production cycle of 18 weeks. Hens were fed a basal diet calculated to contain 1230 mg./kg. of choline, or supplemented with choline chloride to provide 1900, 2570 or 3240 mg. of choline per kg. of diet. Variations in production, fertility and hatch were observed between the first and second 10 week periods of the first laying cycle, but differences were affected more by two high choline levels than by number of hens per cage. When data was combined to show the effects of choline supplements for the entire 20 weeks, there were no significant differences in egg production or hatch of fertile eggs due to choline levels. However, significantly lower fertility resulted in groups fed choline at the level of 2570 or 3240 mg./kg. during this 20 wk. laying cycle. During the second production cycle (one hen per cage), choline supplements improved egg production, increased egg weight, depressed fertility and had no effect on hatch of fertile eggs. When data from the first and second production cycles were combined, there was no significant effect of choline on production or hatchability, but all groups supplemented with choline had significantly lower fertility than the basal group, indicating that 1230 mg./kg. of choline was adequate.

Animals↗

Reproductive performance of couples discordant for hepatitis B and C following IVF treatment.

PURPOSE: To examine the reproductive performance of hepatitis B (HBV) and C (HCV) discordant couples following IVF-ET. METHODS: A retrospective cohort study of 25 IVF-ET cycles in HBV and HCV discordant couples was performed. Thirteen patients in the study cohort were discordant for HBV (10 males and 3 females), and 12 (9 males and 3 females) for HCV. Twenty-seven consecutive age matched patients comprised the control group. All patients underwent controlled ovarian hyperstimulation using the long downregulation protocol followed by IVF or ICSI. RESULTS: Patients in the three groups (HBV, HCV, and controls) had similar ages, and day 3 FSH concentrations. Despite comparable response to COH, and similar fertilization, and cleavage rates in the three groups, couples discordant for HBV or HCV had significantly poorer implantation and pregnancy rates (7.7%, 0% respectively) compared with controls (41%). CONCLUSIONS: Despite comparable response to COH, HBV and HCV positive discordant couples, have significantly lower implantation and pregnancy rates compared with age-matched controls.

Adult↗

Effects of calving induction on subsequent milk yield and reproductive performance of cows from seasonally mated New Zealand dairy herds.

AIM: To identify some production and reproductive effects of calving induction in seasonally calving herds. METHODS: Forty seasonally calving herds entered on the DairyMAN management information system and whose milk yield and reproductive data were recorded, including pregnancy diagnosis results, were included in the study. Cows with an induced parturition were compared with normally calving contemporaries that had the same lactation number and calved at the same time. RESULTS: Milk yield was 1.2 +/- 0.2 litres/cow/day less over the entire lactation for cows induced to calve, with the greatest difference being 2.5 +/- 0.4 litres/cow/day measured in early lactation. The effects on milkfat and protein yield were similar, with 0.04 +/- 0.01 kg/cow/day less milkfat (p < 0.0001) and 0.03 +/- 0.01 kg/cow/day less protein (p < 0.0001). A higher milkfat percentage (+ 0.09 +/- 0.04 %) (p < 0.0001) and protein percentage (+ 0.10 +/- 0.02%) (p < 0.0001) for cows that were induced to calve reduced the effect of a lower milk yield on milkfat and protein production. The first service conception rate for cows induced to calve was 54.4 +/- 3.3%, which was significantly less (p = 0.03) than for cows that calved normally (59.5 +/- 3.3%). Cows induced to calve had a pregnancy rate at the end of mating of 91.4 +/- 2.1%, which was also significantly less (p <0.0001) than for cows that calved normally (93.6 +/- 1.7%). The 21-day submission rates were not significantly different between groups. CONCLUSIONS: This study indicates that, under some New Zealand management conditions, the induction of calving is associated with reduced daily milk yield and inferior reproductive performance.

Journal Article↗

Etiologies and subsequent reproductive performance of 100 couples with recurrent abortion.

From 1958 through 1977, 100 couples with documented recurrent reproductive failure were evaluated in the reproductive endocrine unit of the Medical College of Georgia. All couples underwent cytogenetic studies, radiologic evaluation of the Müllerian system, and timed endometrial biopsy. Recurrent pregnancy wastage was found to be associated with genetic disorders in 25 couples. Müllerian anomalies in 15, endocrine anomalies in 23, and negative findings in 37. The subsequent reproductive performance of each group is reviewed.

Abortion, Habitual↗

Genetic trends for milk yield of Jerseys and correlated changes in productive and reproductive performance.

Estimates of genetic trends in 24 measures of milk and constituent yields, somatic cell counts, and reproduction were obtained from 935 records of 374 Jerseys in a single herd. Data were obtained from a designed project for single-trait selection from 1969 through 1987. One line was subjected to selection solely for milk yield and included 259 cows; an unselected control line included 115 cows. Estimates of trends were based on differences in linear phenotypic trends between lines for first lactations, all lactations, and for 305-d and total records. The genetic changes in milk yield for these four data sets were 1.22 to 1.48%/yr (36.8 to 41.0 kg per cow yr) and 0.54 to 1.64%/yr for five constituent yields. Except for the percentages of minerals plus lactose, all constituent percentages decreased by 0.05 to 0.60%/yr. The ratios of protein to fat and solids-not-fat to fat increased 0.30 to 0.54%/yr, respectively. The number of services required per conception increased (0.17%) in first parity records and in all data (0.69%). The intervals from parturition to first estrus and from parturition to first service decreased in first lactation (1.19 and 0.82%) annually but increased (1.25 and 0.01%) in all data. Age of heifers at first estrus decreased by 0.44% annually. Most of the five measures of somatic cells decreased in first lactations but increased for all data. Estimates of realized genetic correlations of 14 measures of constituent yield and composition (four correlations each) agreed well with values expected from the literature. The results quantified change in milk yield, constituent yields and percentages, reproductive performance, and somatic cell counts in a single herd and should prove useful in the development of selection programs for dairy cattle.

Aging↗

Dietary protein restriction during lactation in primiparous sows with different live weights at farrowing: II. Consequences on reproductive performance and interactions with metabolic status.

The hypothesis that the restriction of dietary protein during lactation has different impacts on reproductive performance in light and heavy sows at farrowing was investigated, as well as the relationships between reproductive parameters and sow metabolic data. At farrowing, 38 primiparous sows were assigned to one of three groups: sows weighing 180 kg not restricted in dietary protein during lactation (180CP); sows weighing 180 or 240 kg restricted in protein (180LP and 240LP). Twenty-four sows were catheterized and serial blood samples were collected 1 d before and 1 d after weaning. The sows were inseminated at the first estrus after weaning and slaughtered at d 30 of gestation. Protein restriction reduced the proportion of sows that returned to estrus within 8 d after weaning in the 180LP sows (P < 0.03), but not in the 240LP sows. It also induced a reduction in ovulation rate in the 180LP sows (P < 0.05) and, to a lesser extent, in the 240LP sows (P = 0.12). When the sows were categorized according to return to estrus (WOI < or = 8 or > 8 d), basal and mean concentrations of LH increased after weaning only in sows with a short WOI. Sows with a delayed estrus exhibited a higher ratio of plasma tyrosine to large neutral amino acids (AA, P < 0.01). In conclusion, large body reserves at farrowing buffer, at least in part, the detrimental effect of a strongly negative nitrogen balance on reproduction. We suggest that the alteration of AA profiles induced by dietary protein restriction and body protein loss alters LH secretion via modifications of the neurotransmitters involved in GnRH secretion.

Animal Feed↗