Breeding Biology of Brushtail Possums Trichosurus vulpecula (Marsupialia, Phalangeridae) in Captivity.

1995 ◽  
Vol 18 (1) ◽  
pp. 1
Author(s):  
R.T. Gemmell
Keyword(s):  
Body Weight ◽  
Life Span ◽  
Post Partum ◽  
Young Female ◽  
Brushtail Possum ◽  
Lactation Period ◽  
In Captivity ◽  
In The Wild ◽  
The Mean ◽  
Reproductive Capability

The brushtail possum is a common arboreal marsupial that is well adapted to the Australian urban environment and to rearing in captivity. Data obtained from 100 female possums housed in a semi-captive colony over a 7 year period demonstrate the reproductive capability of this marsupial. The main breeding season is from March to June with a declining number of births occurring from July to October. The possums gave birth to 259 single young and one set of twins. The range of the lactation period was from 177 to 200 days with the birth of the subsequent young occurring at 188.4 ± 4.1 days post partum (SD, n = 5). The growth rate of the young female possum varied greatly after day 100 post partum, the mean body weight of possums at day 172, being 753.0 ± 76.2g (SD, n = 5) with a range of 685 to 851 g. Female possums, with a mean body weight of 2171 ± 388g, gave birth to their first litter on day 345.9 ± 69.3 days postpartum (mean, SD, n = 7). Although two female possums trapped in the wild were held in captivity for 64 and 63.4 months and one possum bred in captivity had a life span of 51.5 months, the mean life span was 21.0 ± 12.5 months (SD, n =3D 8), with a range of 14.3 to 51.5 months. This life span is very variable and it is of interest to determine if this is an artefact of captivity or is also observed in the wild.

Reproduction in the red-legged pademelon, Thylogale stigmatica Gould (Marsupialia : Macropodidae), and age estimation and development of pouch young

1994 ◽  
Vol 21 (5) ◽  
pp. 553 ◽  
Author(s):  
PM Johnson ◽  
K Vernes
Keyword(s):  
Age Estimation ◽  
Post Partum ◽  
General Pattern ◽  
Age Determination ◽  
Gestation Period ◽  
Growth Equation ◽  
In Captivity ◽  
In The Wild ◽  
The Mean

The reproduction of Thylogale stigmatica in captivity was studied and a predictive growth equation for age determination of the pouch young was developed. The general pattern of reproduction involved an oestrous cycle of 29-32 days, a gestation period of 28-30 days and a mean pouch life of 184 days. A post-partum oestrus and mating generally followed birth. Births were observed in all months in captivity, and from October to June in the wild. Mean age of weaning of young was 66 days following permanent pouch emergence, and the mean ages at maturity for females and males was 341 and 466 days, respectively.

The effect of body weight at calving on milk production and reproductive performance of Friesian × Zebu heifers

1987 ◽  
Vol 45 (3) ◽  
pp. 325-333 ◽  
Author(s):  
F. Deresz ◽  
C. M. Jaume ◽  
M. R. de Carvalho ◽  
C. A. González
Keyword(s):  
Body Weight ◽  
Post Partum ◽  
Live Weight ◽  
Grass Silage ◽  
Holstein Friesian ◽  
Significant Difference ◽  
Total Milk ◽  
Bean Meal ◽  
The Mean ◽  
Soya Bean Meal

ABSTRACTTwenty-six pregnant Holstein-Friesian × zebu heifers, arranged in pairs according to age, body weight, expected calving date and amount of zebu breeding, were allocated at random to two nutritional regimens during the last 12 weeks before calving. If was planned that the animals in treatment A should calve at a pre-calving live weight of 480 kg and those in treatment B should calve at 380 kg. The diet consisted of maize silage or elephant grass silage, soya-bean meal and minerals. During the first 21 days of the post-partum period both groups were given 6 kg concentrate per head daily. After this period, the feeding level was adjusted every 14 days according to the current milk yield. The mean total milk yields were 2132 kg and 1283 kg (P < 0·05) and the lengths of lactation were 239 days and 156 days (P < 0·01) for cows in treatments A and B, respectively. There was no statistically significant difference between treatments in the intervals from calving to first heat or calving to conception.

162 REPRODUCTIVE CYCLES, PREGNANCY AND REVERSAL OF LONG TERM ACYCLICITY IN CAPTIVE SOUTHERN WHITE RHINOCEROS AT HAMILTON ZOO

2009 ◽  
Vol 21 (1) ◽  
pp. 180 ◽  
Author(s):  
C. Morrow ◽  
S. Kudeweh ◽  
M. Goold ◽  
S. Standley
Keyword(s):  
Average Length ◽  
Young Female ◽  
White Rhinoceros ◽  
In Captivity ◽  
In The Wild ◽  
Embryonic Loss ◽  
Southern White Rhinoceros ◽  
Reproductive Cycles ◽  
Autumn And Winter

In 1999, the New Zealand captive population of Southern white rhinoceros (Ceratotherium simum simum) was increased with the addition of six wild-caught founders. We report on the breeding success of two females (est. 5 to 6 years at import) and a female born in 2000 (conceived in the wild). Fecal samples were collected 1 to 3 times per week from females (n = 3) for several periods (5 to 24 months) between 2000 and 2008. Reproductive cycles and pregnancy were characterized using fecal progestogen concentrations, observations of courtship behaviour and parturition dates. The average length of the reproductive cycle was 31.6 ± 0.6 days (range 26–38 days, n = 34 cycles). Four pregnancies were confirmed in one female with a sex ratio of 1 female to 3 males (including 1 male loss at an estimated 5 months of gestation), known gestation lengths were 514 and 507 days. In the non-reproducing adult female, long cycles (67.2 ± 1.3 days, n = 5) were detected in addition to regular cycles (31.9 ± 0.9 days, n = 13) during the first 3 years in captivity, consistent with previous reports (Schwarzenberger F et al. 1998 An. Repro. Sci. 53, 173–190; Brown JL et al. 2001 Zoo Biol. 20, 463–486). The absence of breeding behavior and low progestogen concentrations for an extended 4-year period was cause for concern for the Australasian Species Management Programme managers (Hermes R et al. 2004 An. Repro. Sci. 82–83, 49–60; Hermes R et al. 2006 Theriogenology 65, 1492–1515). In 2007, the social structure of the Hamilton Zoo rhinoceros group was altered by exchanging the breeding male and two male offspring for a wild-caught male from Auckland Zoo. Within two months of arrival the long-term acyclic female had resumed cycling and had conceived six months after introduction of the new male. The young captive-born female continued to have regular length cycles and mating was observed with the new male. Recently, early embryonic loss was determined by ultrasound in the young female having a long 70 day cycle determined by fecal analysis. Fecal progestogen concentrations were useful for diagnosing pregnancy after 3 months gestation with concentrations four times higher than luteal phase concentrations by 9 to 12 weeks after mating (n = 3). Two females exhibited seasonal acyclic periods characterized by low progestogen concentrations corresponding to decreasing daylength (autumn and winter months). Fecal progestogen monitoring of reproductive status and pregnancy combined with behaviour observations has provided valuable information for breeding management decisions and planning for parturition in this population. The reversal of long-term acyclicity and a resulting pregnancy that represents two original founders is particularly significant for the genetic diversity of the Australasian population of white rhinoceros.

Breeding Biology of the Agile Wallaby, Macropus agilis (Gould) (Marsupialia : Macropodidae), in Captivity

1976 ◽  
Vol 3 (2) ◽  
pp. 93 ◽  
Author(s):  
JC Merchant
Keyword(s):  
Sexual Maturity ◽  
Post Partum ◽  
Cell Types ◽  
Morphological Characters ◽  
Oestrous Cycle ◽  
Vaginal Smear ◽  
Vaginal Smears ◽  
Main Cell ◽  
In Captivity ◽  
The Mean

Female agile wallabies in captivity reached sexual maturity at about 12 months old and males produced mature spermatozoa by 14 months. Breeding was continuous throughout the year and birth and oestrus were recorded in every month. The mean length of the oestrous cycle was 32.4 days, and the mean gestation period 29.4 days. Females exhibited post-partum oestrus, usually mating within 1 day of birth. Sixty-four young born in captivity comprised 24 males, 30 females and 10 of unknown sex. If a pouch young were removed or lost, the quiescent blastocyst resumed its development, to birth about 26.5 days later. Failure or absence of the blastocyst was followed by an oestrus at about the time of the corresponding post-partum oestrus. Both the oestrous cycle and the interval between removal of a pouch young and oestrus were significantly longer than when a pregnancy intervened. The oestrous cycle was characterized by changes in the proportions of the main cell types in the vaginal smear, and by changes in the appearance of the urogenital opening and the pouch and teats. The approach of oestrus could not be predicted from vaginal smears but the post-oestrous condition was always recognizable even without mating. Young animals first left the pouch for short periods between the ages of 176 and 211 days, and left permanently between 207 and 237 days. Animals of known age were measured and the development of various morphological characters noted at weekly intervals from about birth until 12 months old.

Seasonal variation of red blood cell survival in desert bighorn sheep (Ovis canadensis cremnobates)

1984 ◽  
Vol 62 (7) ◽  
pp. 1227-1231 ◽  
Author(s):  
Jack C. Turner
Keyword(s):  
Body Weight ◽  
Seasonal Variation ◽  
Life Span ◽  
Blood Cells ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Desert Bighorn Sheep ◽  
The Mean ◽  
Ad Libitum ◽  
Free Ranging

The life-span of red blood cells (RBCs) in captive and free-ranging desert bighorn sheep was measured with [32P]diisopropylfluorophosphate. The mean winter RBC life-span (156.6 days) was not significantly affected by season for captive animals maintained on a high nutritional plane and water, ad libitum. Free-ranging bighorn demonstrated a significant (P < 0.001) difference between mean winter (155.9 days) and summer (203.9 days) RBC survival. Dehydration of captive bighorn significantly increased RBC survival, closely approximating that found in summer free-ranging animals. Desert bighorn RBCs exhibited an aseasonal facultative response to the availability of water. RBC life-span was significantly (P < 0.05) increased from 153.5 to 197.7 days in animals experiencing extreme dehydration. The large spleen, relative to body weight, may accommodate extensive fluctuations in total RBC volume measured during dehydration and rehydration, preventing premature RBC degradation and an increased water requirement.

Observations on the behaviour of the smoky mouse Pseudomys fumeus (Rodentia: Muridae).

2000 ◽  
Vol 22 (1) ◽  
pp. 35 ◽  
Author(s):  
RE Woods ◽  
FD Ford
Keyword(s):  
Social Interactions ◽  
Breeding Season ◽  
Wild Population ◽  
New South ◽  
Post Partum ◽  
Small Sample ◽  
Wild Populations ◽  
South Wales ◽  
In Captivity ◽  
In The Wild

This study examined aspects of behaviour in a captive colony of smoky mice, Pseudomys fumeus, over a two year period. Wherever possible behaviours observed in the captive population are compared to data collected in a study of a wild population in south-eastern New South Wales. This paper provides the first recorded observations of behavior in this species. Both captive and wild populations of P. fumeus display strictly nocturnal circadian activity rhythms. In the captive study, P. fumeus were found to exhibit social interactions similar to some previously studied Pseudomys species. However, in the wild, the species was found to communally nest during the breeding season, behaviour not observed in other Pseudomys from similar habitats. P. fumeus in captivity can have more than two litters in one breeding season which suggests that their reproductive parameters are more flexible than previous studies of wild populations have shown. Field data indicate that post-partum oestrus can occur in this species, and that gestation lasts for approximately 30 days, although these observations are based on a small sample.

Observations on the breeding and growth of the marsupial Perameles nasuta Geoffroy, with notes on other bandicoots.

1964 ◽  
Vol 12 (3) ◽  
pp. 322 ◽  
Author(s):  
AG Lyne
Keyword(s):  
Body Weight ◽  
Sexual Maturity ◽  
The Body ◽  
Cube Root ◽  
Single Individual ◽  
Age Changes ◽  
Breeding Activity ◽  
In Captivity ◽  
The Mean ◽  
The Right

A study has been made of 521 bandicoots (Perameles nasuta, 324; P. gunnii, 111 ; Isoodon obesulus, 86). Near Sydney, P. nasuta breeds all the year round with no indication of any peaks of breeding activity. Limited observations on P. gunnii and I. obesulus in Tasmania also suggest that births occur in every season of the year. Parturition of a single individual of P. nasuta was witnessed. Fifteen new-born specimens of this species were measured and body weight records were obtained for five of them. The average dimensions of these specimens, and consecutive measurements of three specimens born in captivity and of known age, were used to age pouch young of unknown age. Age changes in the appearance of P. nasuta are described and illustrated. Hair emerges on the trunk at about 40 days after birth and at 2 months the coat is similar to that of the adult. The rate of body growth is extremely rapid just prior to the opening of the eyes (usually at 45-48 days), and the young first appear outside the pouch several days later. The pouch contains eight teats, and the mean litter sizes were: P. nasuta, 2.44 (52 litters); P. gunnii, 2.23 (22 litters); I. obesulus, 2.33 (9 litters). In 47 litters of P. nasuta, 73 young were on teats of the left side compared with 46 on the right side of the pouch. The sexes were equally represented in the pouch young of the three species examined. In P. nasuta, sexual maturity is reached at about 450 g in females and about 650 g in males. The linear equivalence (cube root of the body weight) is used as an overall measure of size with which the parts of the body are compared.

STUDIES ON THE BIOLOGY OF THE MUSKRAT IN MANITOBA: PART I. OESTROUS CYCLE AND BREEDING SEASON

1952 ◽  
Vol 30 (4) ◽  
pp. 243-253
Author(s):  
J. A. McLeod ◽  
G. F. Bondar
Keyword(s):  
Breeding Season ◽  
Cycle Length ◽  
Oestrous Cycle ◽  
Minimum Time ◽  
Vaginal Smear ◽  
In Captivity ◽  
In The Wild ◽  
The Mean ◽  
Time Required ◽  
Mean Time

A study of oestrus in female muskrats was conducted during the summers of 1950 and 1951 as part of a five year investigation of the biology of the muskrat in Manitoba. Two captive females examined daily by the vaginal smear method from June 30 to Aug. 10, 1950, inconclusively indicated an oestrous cycle length of about 30 days which agreed with the findings of Beer on Wisconsin muskrats. In 9151 10 female muskrats of various ages and of different lengths of time in captivity were examined daily beginning on March 13 and continuing until August 15. The data obtained at this time showed a considerable variation in the lengths of the oestrous cycles in different females or, even, in the same individual from time to time. The minimum time required for the completion of an oestrous cycle was found to be two days while the maximum time observed was 22 days. On the basis of 136 complete oestrous cycles studied, the modal time was found to be approximately four days and the mean time 6.1 days. The longer cycles found by ourselves in 1950 and by Beer are interpreted as representing pseudopregnancies and not oestrous cycles. Failure of muskrats to mate in captivity or in the wild during the latter part of the summer is attributed to sexual inactivity of the males and not the females.

scholarly journals Nutrition–fertility interaction in lactating women of low income groups

1981 ◽  
Vol 45 (3) ◽  
pp. 461-467 ◽  
Author(s):  
K. Prema ◽  
A. Nadamuni Naidu ◽  
S. Neelakumari ◽  
B. A. Ramalakshmi
Keyword(s):  
Body Weight ◽  
Low Income ◽  
Post Partum ◽  
Income Group ◽  
Nutritional Intervention ◽  
Lactating Women ◽  
Maternal Nutritional Status ◽  
Low Income Groups ◽  
Group Population ◽  
The Mean

1. Duration of lactational amenorrhoea and interpreganancy interval were related to maternal body-weight in an urban low-income group population of 2250 women.2. Breast-feeding practices were similar in all the women, none of whom had received any nutritional intervention.3. In the study group the mean duration of lactation, lactational amenorrhoea and interpregnancy interval (months) were 20.7, 11.2 and 24.2 respectively.4. Mean duration of lactation was significantly shorter in women whose body-weights were over 55 kg. Duration of lactational amenorrhoea increased with increasing duration of lactation (r 0.5164).5. The duration of lactational amenorrhoea showed a progressive fall with increasing body-weight (r − 0.8139) even when duration of lactation was kept constant.6. The mean duration of post-partum amenorrhoea in women who did not lactate remained unaltered irrespective of body-weight.7. The findings suggest that maternal nutritional status modifies return of menstruation only in lactating women.

GROWTH IN THE YOUNG HYPOPHYSECTOMIZED GUINEA-PIG

1960 ◽  
Vol 20 (1) ◽  
pp. 36-47 ◽  
Author(s):  
BARBARA E. CLAYTON ◽  
JANET M. WORDEN
Keyword(s):  
Body Weight ◽  
Total Nitrogen ◽  
Guinea Pigs ◽  
Adrenal Glands ◽  
Young Female ◽  
Steady Increase ◽  
Thyroid Glands ◽  
Increased Sensitivity ◽  
The Mean ◽  
Insulin Hypersensitivity

SUMMARY 1. Following hypophysectomy, young female guinea-pigs showed an initial fall in body weight followed by a steady increase for many months, although the mean growth curve never reached that of intact guinea-pigs. There was proportionately more growth in length than in body weight. 2. After hypophysectomy the adrenal glands did not increase in weight when the animals grew. The concentration of ascorbic acid in the adrenals was unchanged by hypophysectomy. 3. After hypophysectomy the thyroid glands showed a smaller increase in weight than in intact guinea-pigs. 4. Closure of the epiphyses was usually delayed by hypophysectomy. 5. In relation to body weight the abdominal fat pads were smaller in hypophysectomized than in intact guinea-pigs. The carcass contained a slightly increased percentage of total nitrogen but the percentages of fat and carbohydrate were not significantly different from those of intact guinea-pigs. 6. Although the absolute weights of the livers were less in hypophysectomized guinea-pigs compared with intact ones, their relative weights were the same. Hypophysectomy resulted in an increased percentage in the fat content of the liver, and no change in the percentages of carbohydrate or total nitrogen. 7. Hypophysectomized guinea-pigs showed insulin hypersensitivity for at least 5 weeks after operation, although it was reduced by the administration of cortisol. Three months after hypophysectomy this increased sensitivity was lost.

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