Torpor and hibernation in a basal placental mammal, the Lesser Hedgehog Tenrec Echinops telfairi

The patterns of heterothermy were measured in Lesser Hedgehog Tenrecs, Echinops telfairi, under semi-natural conditions in an outdoor enclosure during the austral mid-winter in southwestern Madagascar. The animals were implanted with miniaturized body temperature (Tb) loggers (iButtons) that measured body temperature every 42 min for 2 months (May and June). The tenrecs entered daily torpor on all 60 consecutive days of measurement, that is, on 100% of animal days, with body temperature closely tracking ambient temperature (Ta) during the ambient heating phase. The mean minimum daily Tb of the tenrecs was 18.44 +/- 0.50 degrees C (n = 174, N = 3), and never exceeded 25 degrees C whereas, apart from a few hibernation bouts in one animal, the mean maximum daily Tb was 30.73 +/- 0.15 degrees C (n = 167, N = 3). Thus during winter, tenrecs display the lowest normothermic Tb of all placental mammals. E. telfairi showed afternoon and early evening arousals, but entered torpor before midnight and remained in torpor for 12-18 h each day. One animal hibernated on two occasions for periods of 2-4 days. We consider E. telfairi to be a protoendotherm, and discuss the relevance and potential of these data for testing models on the evolution of endothermy.     

Relation between mating or ovulation and the duration of gestation in dogs

The effects of day of mating and litter size on gestation length in dogs were studied in 36 beagle bitches (age 2-10 yr). The day that plasma progesterone concentrations exceeded 2 ng/mL was considered the day of ovulation; dogs were randomly assigned to be bred once, 1-5 days after the estimated day of ovulation. The interval from mating to parturition was negatively correlated with the number of days from estimated ovulation to mating (P < 0.01). Gestation length (interval from ovulation to parturition) was almost constant at 63.9 +/- 0.2 days (mean +/- S.E.M.), with no significant relationship between the number of fetuses and the duration of gestation.     

Reproductive features of the Russian vole in laboratory breeding.

Reproductive features of newly bred Russian voles (Microtus rossiaemeridionalis) as a laboratory animal were studied. This species is a copulatory ovulator, and most couples copulated 6 to 16 h after pairing. The gestation period varied from 18 to 22 days (mean +/- SD: 20.6 +/- 0.9, n = 72), and the average litter size was 4.6 +/- 1.9 (n = 125). Compared with the litter size at the first parturition (3.6 +/- 1.6, n = 72), the litter size in the subsequent parturitions increased to 5.9 +/- 1.4 (n = 53). The animals exhibited postpartum estrus, and repeated pregnancy accompanied with suckling pups and parturition continuously in the laboratory condition unlike other vole species. In view of their complex stomach and good proliferation, the Russian voles were evaluated as a good laboratory animal, especially as a model animal for ruminant studies.     

Litter size and piglet traits of gilts with different prolactin receptor genotypes

Seventy-seven Large White x Meishan F2 crossbred gilts with prolactin receptor (PRLR) genotype AA (n = 26), AB (n = 36) and BB (n = 15) were compared for teat number (FTm), age at first estrus, gestation length (GL), litter size, and litter means of functional teat number (FTp), birthweight (BW), and pre-weaning growth rate (GR). Own placental information was available for 88% of 620 live-born piglets (62 gilts), since placentae were labeled during farrowing. The effect of PRLR genotype of the mother on average placenta weight (PLW) and placenta efficiency (EFF = BW/PLW), was therefore, also analyzed, PRLR genotype significantly (P < 0.05) affected age at first estrus and, as a result (since the gilts were inseminated at a fixed estrus number), age and bodyweight at insemination. Furthermore, PRLR genotype affected total number of piglets born (TNB, P = 0.056) and number of piglets born alive (NBA, P = 0.072), but it did not affect (P > 0.3) GL, BW or GR, neither before nor after correction for litter size. BB gilts were significantly younger at first estrus and younger and lighter at insemination than AA gilts (P < 0.05). AA gilts had larger TNB (P = 0.047) and tended to have a larger NBA (P = 0.062) than BB gilts. TNB was 11.4 +/- 0.7, 10.8 +/- 0.6, and 8.8 +/- 0.9; NBA was 11.1 +/- 0.6, 10.5 +/- 0.6, and 8.7 +/- 0.9; BW was 1309 +/- 40, 1277 +/- 34, and 1290 +/- 53 g; and GL was 113.6 +/- 0.3, 113.8 +/- 0.3, and 113.5 +/- 0.4 days for AA, AB and BB gilts, respectively. The effects on litter size and age at first estrus are independent effects. PRLR affected PLW (P = 0.050) and EFF (P = 0.066), resulting in a difference between AA and BB gilts. PLW was 160 +/- 9, 181 +/- 7 and 196 +/- 11 g and EFF was 7.6 +/- 0.2, 7.3 +/- 0.2 and 6.7 +/- 0.3 for AA (n = 19), AB (n = 29) and BB (n = 14) gilts, respectively. After correction for TNB, the differences disappeared. Functional teat number of the AA. AB and BB gilts was 15.35 +/- 0.22, 15.53 +/- 0.18, and 15.60 +/- 0.29, respectively, and was not affected by PRLR genotype (P = 0.7). Functional teat number of piglets from AA, AB and BB mothers was 14.20 +/- 0.10, 14.37 +/- 0.08, and 14.63 +/- 0.13, respectively. Piglets from BB mothers had on average larger numbers of functional teats compared to piglets from AA mothers (P = 0.028). In conclusion, PRLR gene is a major gene or marker for age at first estrus, litter size, and litter average of number of functional teats in the Large White x Meishan F2 crossbred gilts studied. The favorable allele for litter size (A allele) is the unfavorable allele for age at first estrus and for litter mean of functional teat number.     

Factors affecting gestation length in the Thoroughbred mare

In order to assist in the accurate prediction of the timing of parturition in the mare true gestation length, along with the potential effect of a number of factors, was investigated. Data from 433 Thoroughbred foal pregnancies were used. Sequential ultrasonic scanning allowed the true gestation length (fertilisation-parturition) to be ascertained, as apposed to previous work, which used the mating-parturition interval. An average gestation length of 344.1 +/- 0.49 days was evident. Colt foal pregnancies were significantly (P < 0.001) longer (346.2 +/- 0.72) than fillies (342.4 +/- 0.65). Month of birth had a significant effect on gestation length in all foals (P < 0.001). With foals born in January having the shortest gestation lengths and those born in April the longest. Mare age, year of birth, stallion age, stud farm and the interval between ovulation and mating had no significant effect. It is concluded that (i) the gestation length range (315-388 days), all resulting in viable foals is noteworthy and of clinical importance when considering the classification of dysmaturity in foals, (ii) mares carrying colt foals due to be born in the middle of the breeding season (April) are likely to have the longer gestation lengths.     

Effect of hypoxia on the initiation of secondary wool follicles in the fetus

The development of secondary wool follicles in single fetal sheep subjected to hypobaric hypoxaemia was studied. One group of pregnant ewes were exposed to 57.1 kPa from 30 to 135 days gestation. Fetal weights (mean +/- s.d.) for the hypoxaemic group (3.35 +/- 0.53 kg; n = 4) were significantly lower than for the controls (4.19 +/- 0.31 kg; n = 3, P less than 0.05). At 110 days gestation, a second group had arterial and venous catheters surgically implanted into the ewe and fetus and skin samples were taken from the fetus. At 120 days gestation (10 days after surgery) these animals were subjected to hypoxia for 20 days, at a level to maintain fetal carotid pO2 between 1.47 and 1.87 kPa (mean carotid pO2 for the control fetuses was 2.84 +/- 0.28 kPa). Fetal weight at 140 days was not significantly different in the hypoxaemic and control groups. Morphometric analysis revealed that the secondary to primary follicle ratio (S:P) was less in both groups of hypoxaemic fetuses than in their respective controls. Although hypoxia for 20 days did not significantly alter fetal weight, it produced a low S:P ratio similar to the longer-term hypoxaemic animals. It is concluded that hypoxia has a marked effect in reducing the initiation of secondary follicles in the last third of gestation.     

hCG treatment on day of mating improves embryo viability and fertility in ewe lambs

An investigation was conducted to determine the effects of supplementing hCG at mating time on luteal function, conceptus growth, placentation and reproductive performance in TexelxClun Forest ewe lambs. After oestrus synchronisation with progestagen sponges and PMSG ewe lambs were treated either with normal saline (n=102) or 150 IU of hCG (n=105) at mating time. At 25 days after mating 24 animals were slaughtered from each group to determine embryo viability and placental development. hCG significantly (P<0.05) increased crown-rump length (saline: 11.9+/-0.2 mm; hCG: 12.7+/-0.2 mm), amniotic sac width (saline: 11.4+/-0.4 mm; hCG: 12.0+/-0.3 mm) and the number of placentomes (saline: 90.8+/-7.3; hCG=122.4+/-6.3). Among the pregnant animals that were slaughtered on 25 days post-mating, ovulation rate tended to be higher in the hCG group compared to controls (saline: 1.16; hCG: 1.54). However, no difference was observed either in mean plasma progesterone concentrations (saline: 4.6 ng/ml; hCG: 4.9 ng/ml; sed 0.56) or in progesterone production from luteal slices when cultured in vitro (saline: 239.6+/-11.8 ng/mg; hCG: 263.2+/-13.6 ng/mg) between controls and hCG treated animals. Reproductive performance was also recorded in ewe lambs that were either treated with saline (n=78) or hCG (n=81). The total number of lambs born (saline: 38; hCG: 58) was significantly (P<0.05) greater in hCG group compared to saline-treated controls. Both lambing percentage (saline: 36%; hCG: 48%) and litter size (saline: 1.35; hCG: 1.48) tended to be greater (P<0.10) in hCG-treated animals compared to the controls. In conclusion, these data suggest that treatment of ewe lambs with hCG at the time of mating improves conceptus growth, placentation and number of lambs born.     

The colony structure and reproductive biology of the afrotropical Mashona mole-rat, Cryptomys darlingi

Cryptomys darlingi occurs in the mesic Miombo woodland of north-eastem Zimbabwe. It occurs in colonies of up to nine individuals, in which reproduction is limited to one of the largest males and the largest female in the colony.
Reproduction and details of colony size and number of breeding animals in a colony are described for five complete field-captured colonies.
In captivity, mating is not confined to a particular season, and up to three litters of pups are orn per annum. The reproductive female initiates the pre-copulatory behaviour. The gestation lengti is 56–61 days ( n = 2 ). The new-born pups are altricial and litter size is small = 1.7 ± 0.5 ( n = 6). In this case, the pups first left the nest 10 days after birth, began to eat solids when 14 days old, and were fully weaned at five weeks. They began to spar with each other when 36–40 days old, but did not disperse and were incorporated into the colony. This suggests that the Mashona mole-rat colonies are composed of a founding pair and at least three successive litters of pups.     

Embryo survival and recipient pregnancy rates after transfer of fresh or vitrified,in vivo or in vitro produced ovine blastocysts

The aim of this study was to assess the effect of production system and of cryopreservation of ovine embryos on their viability when transferred to recipients. The experimental design was an unbalanced 2 x 2 factorial design of two embryo production systems (in vivo versus in vitro) and two embryo preservation conditions prior to transfer (transferred fresh versus transferred after vitrification/warming). For the production of blastocysts in vivo, crossbred donor ewes (n=30) were synchronised using a 13-day intravaginal progestagen pessary. Ewes received 1500 IU equine chorionic gonadotropin (eCG) 2 days before pessary withdrawal, and were mated 2 days after pessary withdrawal and embryos were recovered surgically (6 days after mating). Blastocysts were produced in vitro (IVP) using standard techniques. Recipients (n=95) were synchronised using a progestagen pessary and received 500 IU eCG at pessary removal and were randomly assigned to receive (two per recipient) in vivo fresh (n=10), in vivo vitrified (n=10), in vitro fresh (n=35) or in vitro vitrified (n=40) blastocysts. Recipients were slaughtered at day 42 of gestation and foetuses recovered. Pregnancy and embryo survival rates were recorded and analysed using CATMOD procedures. Foetal weights and crown-rump lengths were recorded and analysed using generalised linear model (GLM) procedures. There were no statistically significant interactions between the effects of embryo production system and preservation status at transfer on pregnancy rate and embryo survival. The pregnancy rate following transfer of fresh IVP blastocysts was lower (P<0.07) than that of in vivo embryos (54.3% versus 90.0%, respectively). Vitrification resulted in a decrease in pregnancy rate, the effect being more pronounced in the case of IVP embryos (54.3-5.0%, P<0.001) compared with in vivo embryos (90.0-50.0%), although the absolute change was similar (49.3% versus 40.0%). Transfer of fresh IVP blastocysts resulted in a higher proportion of single (78.9% versus 33.3%) and lower proportion of twin (21.1% versus 66.7%) pregnancies than those produced in vivo. This was reflected in a significant difference in embryo survival rate (fresh: 32.8% versus 75.0%, P<0.01; vitrified: 2.5% versus 35.0%, P<0.001, for IVP and in vivo blastocysts, respectively). Similarly, all pregnancies resulting from the transfer of vitrified/warmed IVP blastocysts were single pregnancies, while 40% of those from vitrified/warmed in vivo blastocysts were twin pregnancies; this was reflected in an embryo survival rate of 35.0% versus 75.0%, respectively. There was a significant effect (P=0.0184) of litter size on foetal weight but not on foetal length (P=0.3304). Foetuses derived from the fresh transfer of IVP blastocysts were heavier (6.4+/-0.2g versus 5.8+/-0.2g, respectively, P<0.05) and longer (5.2+/-0.1cm versus 4.8+/-0.1cm, respectively, P<0.01) than those derived from fresh in vivo blastocysts. There was no difference in these parameters as a consequence of vitrification of IVP embryos. However, in vivo blastocysts subjected to vitrification resulted in heavier (6.6+/-0.3g versus 5.8+/-0.2g, respectively, P=0.055) and longer (5.2+/-0.1cm versus 4.8+/-0.1cm, respectively, P<0.05) foetuses than their counterparts transferred fresh.     

Studies of pericopulatory pregnancy blockage and the gestation period in deer mice (Peromyscus maniculatus)

It has previously been shown that female deer mice in cycling estrus that copulate with or are exposed to more than one male at the time of mating have a lower probability of delivering a litter than when mating with and being exposed to just one male. In the present research the effect of post-mating exposure to the bedding of a strange versus a familiar male was studied in females in postpartum estrus. In four experiments females in postpartum estrus were protected from pericopulatory pregnancy blockage, presumably by suckling-induced elevated prolactin levels. Varying female experience, number of ejaculations, and the presence of suckling pups had no effect on this protection. Thus, both the pericopulatory block and the Bruce effect (a more delayed type of pregnancy blockage) occur in cycling, but not suckling, females. This suggests that the two may have a common mechanism and leads to a new perspective in the search for adaptive significance. In addition, the subsequent gestation periods were prolonged in females nursing young; the length was affected by the number of pups weaned from the previous litter and the number of pups being carried.     

圈养大熊猫的繁殖特性和生命表

通过对最大的大熊猫(Ailuropoda melanoleuca)圈养种群——中国保护大熊猫研究中心的圈养种群的研究,总结了圈养大熊猫的繁殖生物学特性,编制了大熊猫的生命表。大熊猫是季节性繁殖的动物,每年春季3～4月发情交配,8月(30.49%)和9月(48.88%)产仔,每胎平均产仔1.5只,圈养繁殖大熊猫的雌雄比为1.11。大熊猫的妊娠期和幼兽的初生体重变化很大,分别平均为139.8天和142.6g。性成熟的年龄,雌性是5.7±1.1岁,雄性是5.8±0.58岁。根据圈养大熊猫的生命表计算出圈养种群的净增长率R0为0.209,世代周期T为9.187年,内禀增长率r为-0.170,周期增长率λ为0.844。     

Studies on the endocrinology of parturition: relative steroidogenesis in coexisting genetically dissimilar ovine fetuses, concomitant with the temporal patterns of maternal C18 and C19 steroids and prostaglandin F2 alpha release

Ovine embryos collected from two breeds of ewes possessing different gestational periods [Finnish Landrace (Finn), 145.5 +/- 1.4 days; Rambouillet (Ra), 150.7 +/- 1.3 days] were transferred to common, randomly selected recipients. Fetal plasma samples were collected from mixed-breed (MB, one Finn and one Ra; n = 6) and single-breed (SB, single Finn, n = 3; single Ra, n = 3) chronic fetal preparations during the last trimester. In the MB pregnancy, the Ra sibling had temporal patterns of androstenedione similar to those observed in the Finn co-twin; however, these particular changes were greatly accelerated in comparison to the same day of gestation in SB Ra fetuses. Similarly, temporal patterns of change in unconjugated estrone, estrone sulfate, and 17 beta-estradiol were accelerated by as much as 4.6 to 5 days in Ra fetuses of MB pregnancies when compared to Ra fetuses in the SB pregnancies (P less than 0.001), with no difference noted between Ra and Finn co-twins. Maternal progesterone concentrations changed from 8 to 2 ng/ml, androstenedione from 200 to 400 pg/ml, estrone from 65 to 250 pg/ml, and 15-keto-13,14-dihydroprostaglandin F2 alpha from 200 pg/ml to 6000 pg/ml over the last 4 or 5 days of gestation. Chronic fetal manipulation accelerated parturition, with mean gestational lengths in MB, SB Finn, and SB Ra pregnancies being 141.5 +/- 0.7, 141.7 +/- 0.7, and 149.3 +/- 0.9 days, respectively. In this study fetal endocrine changes were largely controlled in the MB pregnancy by the fetal co-twin exhibiting a shorter gestational period.     

Pregnancy in female house mice exposed to urinary chemosignals from other females.

Seven experiments were performed to investigate pregnancy termination, urinary chemosignals, and litter sex ratio variation in female house mice. Experiments tested the effects of urine from adult and prepubertal females, housed individually or in groups, on successful insemination and litter production by females treated at different times and for different periods during the 3 weeks before mating and during gestation. Treatment of females with urine from adult females housed eight per cage or with urine pooled from eight adult females housed individually for 2 or 3 weeks before mating resulted in fewer successful pregnancies and significantly more female-biased litters. Treatment with urine from adult or prepubertal females housed eight per cage or with urine pooled from eight mice housed individually for the first 6 days of gestation or throughout pregnancy resulted in a significant increase in the rate of pregnancy termination. These treatments resulted in lower body weights at birth and slower growth rates in all males and in some females. Puberty was delayed in female progeny from urine-treated dams in five of seven experiments, and these young females attained first oestrus at greater mean body weights than mice in other treatments. These findings indicate that, in mice, at high population density, communication via a urinary chemosignal can alter reproduction in recipient females. Availability of, and competition for, resources such as food would be greater at higher densities, possibly lowering the probability of reproductive success. Pregnancy termination and delays in reproduction and attainment of sexual maturity might lead to greater successful reproduction at a later time.     

Assessment of reproductive parameters in female Dwarf goat (Capra hircus) on the basis of progesterone profiles

A study was undertaken to look into the reproductive performance of female Dwarf goats reared under traditional conditions at NIAB Farm, Faisalabad, Pakistan. The serum progesterone profile was used to monitor various reproductive parameters (length of postpartum period, resumption of cyclicity, gestation period, prepartum period, parturition) in two lots of goats. Litter size, birth weight of kids and kidding interval were also observed. Most of the animals conceived within 15-59 days of postpartum period. All the does conceived at first or second estrus. During gestation period, higher levels of progesterone were maintained with wide variations falling in the range of 3-13 ng ml(-1). However, a few days before parturition a decline was noticed at 6+/-0.9 days and it reached to the basal level of 0.1 ng ml(-1) after the completion of parturition process. The length of gestation period was found to be 145.8+/-5 days in the first lot and 145.2+/-4 days in the second lot. A very short kidding interval (203.7+/-46 days) and considerably bigger litter size (1.8+/-0.8) was observed. All the parturitions were normal and a considerable weight gain (8.2+/-0.3 kg) of mothers was recorded during pregnancy. The initial birth weight of kids was averaged as 2.1+/-0.5 kg in the first and 1.6+/-0.2 kg in the second lot. It was concluded that Dwarf goat has short gestation length, postpartum period and kidding interval along with multiple births being common. Due to these factors, its reproductive efficiency can be exploited for efficient goat meat production.     

Precocious induction of luteal activation and termination of delayed implantation in mink with the dopamine antagonist pimozide

The effects of the dopamine antagonist pimozide on the preimplantation delay phase of mink gestation were investigated in field and laboratory trials. Three doses of 0.1 mg pimozide in acetic acid administered on the 7th, 9th and 11th days after mating abbreviated gestation in Pastel kit female mink to a mean (+/- SEM) of 45.5 +/- 0.5 days, 10 days less than that observed in mink treated with vehicle only (55.6 +/- 0.6 days). In laboratory trials, four doses of 0.1 mg pimozide on the 7th, 9th, 11th and 13th day after mating resulted in embryo implantation at a mean of 25 +/- 4.3 days after mating while vehicle-treated control animals had mean preimplantation delay of 37 +/- 3.1 days. Luteal activation in the pimozide-treated group, as indicated by a rapid increase in circulating progesterone, began within 2 days after the first pimozide injection. No increase was observed in vehicle-treated mink until 6 or more days after the initiation of injections or 13 days after mating. It was concluded that pimozide, presumably by permitting endogenous secretion of prolactin, can induce precocious luteal activation and embryo implantation in the mink.     

Reproductive function in aged female chimpanzees.

Reproductive function was evaluated in ten female chimpanzees (Pan troglodytes) aged 35-48 years. Forty-eight years is the longevity record for the chimpanzee. Data on cycle frequency and duration was available for seven animals. Most were cycling regularly until death, and all had experienced at least one menstrual cycle within one year of death. After exclusion of periods when the animals were pregnant or in postpartum amenorrhea, the mean cycle frequency (+/- standard error)/year was 9.54 +/- 0.20 in seven animals aged 15-25 (432 cycles analyzed) compared to 8.6 +/- 0.76 in the same animals at age 35 + years (405 cycles analyzed); this effect approached significance (p = 0.072, Mann-Whitney U-test). Cycle length of 16 cycles in each of seven animals aged 15-25 was 32.23 +/- 0.38 days. The same animals when aged over 35 had mean cycle lengths of 35.59 +/- 0.73. This difference was not significant, although cycle lengths clearly increased with age in some individual animals. In five aged animals for which mating data was available, appropriate exposure to a male occurred in 52 cycles, but only two pregnancies occurred; one pregnancy resulted in a live birth at age 38, the other in a stillbirth at age 40. This conception rate was 3.85% compared with 20% in the same animals aged 15-25. These data suggest greatly reduced fertility after age 35, although menstrual cycle frequency remained high. The persistence of menstrual cyclicity until death, which occurred due to natural causes at latest in the fifth decade, is in striking contrast to the human female in which menopause occurs in the fifth decade and death is often postponed for several more decades.     

Reproductive biology and postnatal development of the neotropical climbing rat, Tylomys.

Neotropical climbing rats (Tylomys), offspring of animals from Mexico and Panama, were maintained in the Michigan State University Museum-Live Animal Colony for the purpose of collecting data on reproduction. Vaginal smears indicated an estrous cycle 6.8 +/- 0.4 da under natural winter lighting, 12.0 +/- 2.5 da when exposed to a 12:12 light:dark cycle, and 4.3 +/- 0.3 da when utilizing an activity wheel and under a 14:10 lighting scheme. The earliest recorded mating for a female Tylomys was 90 da of age. The gestation period was 40.6 +/- 0.5 da, and there was no statistical difference between the gestation lengths of lactating and non-lactating females. The average litter size was 2.3 with a range of 1-4. Weight at birth averaged 20.2 +/- 0.3 g, or about 8% (litter about 16%) the weight of the adult. The daily instantaneous rate of growth (weight) for the first wk was about 5.6%. Graphs were presented indicating changes with time of weight, total body length, and tail, hind foot, and ear lengths. Young respond to loud noises at 6-14 da of age, and eye opening occurs slightly later, at 7-15 da of age. The young cling tenaciously to the female's nipples nearly continuously for the first 3 wk. Females did not perform any nest-building activities. Weaning occurred at approximately 3-4 wk of age.     

Induction of luteal activity and progesterone secretion in the nonpregnant one-humped camel (Camelus dromedarius)

Corpora lutea (n = 20) were detected in 5 one-humped female camels studied during a period of 4 months. Complete mating by a vasectomized male, male introduction into the pen of females without mating, or a progesterone decrease from a previous corpus luteum were followed by a similar progesterone pattern. A maximal plasma concentration of 4.5 +/- 1.5 ng progesterone/ml (2.7-8.8 ng/ml) occurred 8.55 +/- 1.32 days (6-11 days) after the inducing stimulus. Luteal regression, beginning 8.65 +/- 1.18 days after the stimulus, was completed at Day 11.55 +/- 1.05. Morphological development of ovarian structures, detected by rectal palpation, was in synchrony with the progesterone increase, but there was a prolonged period of regression. Females accepted mating up to 7 days after the ovulatory stimulus, when progesterone levels were as high as 3.5 ng/ml. This study establishes the absence of pseudopregnancy in the one-humped female camel, and offers opportunities for improving the management of reproduction. It also shows that ovulatory stimuli other than mating can be effective in these animals.     

Effect of dietary fat or starch supply during gestation and/or lactation on the performance of sows, piglets' survival and on the performance of progeny after weaning

Two trials were carried out to compare the effects of fat or starch inclusion in sow's diet on sow and litter performance. In each trial, sows were assigned to one of two treatments. In trial 1, the sows were fed diets containing either soybean oil (5%, treatment GL5) or cornstarch (11.3%, GL0) from day 35 of gestation to weaning. Daily net energy and nutrient allowance were equalised during gestation. In trial 2, the same treatments were applied only after farrowing (treatments L5 and L0, respectively). Within each trial, a batch of piglets was studied until slaughter. In trial 1, adipose cell development and total lipid content were determined on some pigs at weaning (n = 6/treatment) and at slaughter in dorsal subcutaneous adipose tissue (n = 13/group at least) and in muscle (n = 46/group at least). Piglets' birth weight was not affected by treatment in trial 1. Survival rates at birth and after 24 h of life were higher in treatment GL5 (4.0% v. 7.5% stillborn piglets in GL0 treatment, P < 0.05; 8.7% v. 12.6% of piglets alive at 24 h of age died in treatment GL0, P = 0.06). Subsequently, overall survival rate until weaning was higher in treatment GL5 (81.4% v. 75.7% of total born piglets, P = 0.03), but litter size at weaning was not significantly affected (11.3). Litter growth rate before weaning was increased when a fat-enriched diet was provided during gestation and lactation (+140 g/day per litter; P < 0.01) and to a lower extent when provided only after farrowing (+90 g/day; P < 0.05). Energy supply through fat did not decrease the mobilisation of the sow's body reserve and backfat thickness loss was even higher with treatment GL5 (P < 0.05). After weaning, pigs' average daily gain, feed : gain ratio and carcass lean content were not affected by the energy source supplied before and/or after farrowing. At weaning, the number of adipose cells in the dorsal subcutaneous adipose tissue and in the Longissimus dorsi muscle was higher in the GL5 pigs. Muscle lipid content at weaning did not differ between treatments, but it was higher at slaughter, around 110 kg, in the GL5 pigs (3.46% v. 2.58%, P < 0.001).     

Spontaneous preeclamptic toxemia of pregnancy in the patas monkey (Erythrocebus patas).

A disease characterized by edema, proteinuria, hypoproteinemia and hypertension was seen in late gestation in patas monkeys. The initial sign was edema of the perineum, ankles and lower trunk. The onset was abrupt, occurring 7 days or less prepartum. The affected animals were not depressed, and convulsions were not seen. In 6 of the 98 pregnancies during a 1-year period, symptoms of the disease were present. The highest incidence was manifested by primiparous animals with 3 of 36 pregnancies affected. Two of 38 second pregnancies and 1 of 24 third pregnancies were also affected. Five of the animals recovered spontaneously and were normal 14 days postpartum. Edema persisted for 30 days in one female. This animal continued to be hypertensive and had persistent mild proteinuria and hypoproteinemia. She was killed approximately 1 year postpartum due to severe renal disease. The spontaneous disease seen in patas monkeys resembled toxemia of pregnancy in humans more closely than the experimentally induced disease in other animals.