The Small Mammals of Little Nourlangie Rock, NT. V. The Effects of Fire

1981 ◽  
Vol 8 (3) ◽  
pp. 515 ◽  
Author(s):  
RJ Begg ◽  
KC Martin ◽  
NF Price

Following a capture-mark-release program (February 1977-June 1979) on Dasyurus hallucatus, Antechinus bilarni, Zyzomys argurus and Zyzomys woodwardi, the study area was burnt to determine the effects of fire on these species. The area was described in terms of fuel characteristics and details of the fire were recorded. Post-fire trapping began July 1979 and continued until July 1980 (15,600 trap-nights). A. bilarni was the only species to suffer an increased mortality immediately after the fire, but the number of animals known to be alive declined over the year following the fire, for all species except D. hallucatus. The fire affected reproduction in all four species, but in different ways. Breeding in D. hallucatus was delayed by 1 month, and the mean number of young leaving the pouch per female was lower than before the fire. A higher number of resident females kept recruitment up. Litter size in A. bilarni was not affected, but a reduced number of resident females meant that recruitment was halved. Zyzomys argurus and Z. woodwardi showed few lactating and pregnant females in July-August following the fire, and the numbers of juveniles were lower than in the previous two years. Following the fire, no detectable differences in body weight were recorded, but all species except D. hallucatus changed their preferred habitat, moving to the Scree Slope. Z. woodwardi was most affected, and moved from the Closed Forest.

1981 ◽  
Vol 8 (1) ◽  
pp. 57 ◽  
Author(s):  
RJ Begg

In a capture-mark-release program on Antechinus bilarni at Little Nourlangie Rock, N.T., from February 1977 to June 1979, 34,800 trap nights were set, for a total catch of 174 males and 162 females. Breeding is strictly seasonal, with mating around late June. Pouch young are carried in August and September. Lactation continues until December, when free-living young are first trapped. Males show a seasonal increase in testes size, with a decrease after mating. There is no die-off of males; both males and females may survive for a second breeding season. Males undergo a second cycle of increase in testes size, and histological sampling revealed spermatogenesis during their second breeding season. Individual males and females were trapped for up to 24 and 25 months respectively; KTBA estimates are similar for both sexes. Both sexes continue to increase in body weight throughout life. although males lose weight substantially after each breeding season. Sex ratios dropped during October of each year because the activity and trappability of males dropped. Males were recaptured with the onset of the wet season. The preferred habitat was scree slope, at an altitude of around 40-55 m. Some seasonal shifts in habitat were probably related to food availability.


1981 ◽  
Vol 8 (2) ◽  
pp. 307 ◽  
Author(s):  
RJ Begg

A capture-mark-release program was conducted on Zyzomys woodwardi and Z. argurus at Little Nourlangie Rock, N.T. From February 1977 to June 1979, 34,800 trap-nights were set for a total catch of 205 male and 148 female Z. woodwardi, and 152 male and 118 female Z. argurus. Breeding peaked in March-May, but some young were born in most other months. Rats were classed as adults on the basis of body weight (Z. woodwardi adults >70 g; Z. argurus adults >29 g). Testes became scrota1 around this weight and remained so. Significantly more males than females were caught for both species, due to the greater mobility of males, as evidenced by their high transiency rates and greater mean distances between captures. Trappability dropped to almost zero around March-April, just before the breeding season, but this was not a result of mortality or emigration. There was a clear spatial separation between species. Z. woodwardi were caught most often in the Closed Forest and no Z. argurus were resident there. The latter were most common on the Scree Slope.


1968 ◽  
Vol 12 (2) ◽  
pp. 125-137 ◽  
Author(s):  
T. Morris

A study was made of reproductive performance and embryonic mortality in XO and XX females. In the stock used, the mean litter size of XO females (4·46) was greatly below that of XX ones (8·17). One series of pregnant females of both karyotypes was dissected after 15 days' gestation, and another series after 3½days' gestation. In the former, there was a significantly greater amount of embryonic mortality in XO females both before implantation and at the small and large mole stages. By far the greater amount occurred before implantation. The data from dissections after 3½ days' gestation concerned pre-implantation embryos, since normal embryos at this point are at the late morula or early blastocyst stage. The embryos from XO females contained a large group of obviously and characteristically abnormal ones; they comprised 60/280 of the embryos from XO females, compared with 4/189 of the XX ones. They appeared to have developed abnormally from a very early stage, probably the two-cell stage, and were considered to represent the missing OY class of zygotes. In addition, it was concluded that there was probably an abnormally low segregation of nullo-X gametes from XO females.


1979 ◽  
Vol 28 (3) ◽  
pp. 297-307 ◽  
Author(s):  
J. F. Quirke

ABSTRACTGroups of spring-born Galway (G) and Fingalway (F) ewe lambs were fed a concentrate diet either ad libitum (H) or at a restricted level (L) during the period 25 July to 16 October 1974 in order to induce differences in body weight at the start of the breeding season. The mean live weights of the GL, GH, FL and FH groups on 16 October 1974 were 37·8 ± 1·3, 44·6 ± 1·3, 35·1 ± 1·1 and 41·9 ± 1·2 kg respectively. More than 95% of the lambs in all four groups attained puberty before 28 February 1975. Galway ewe lambs reached puberty later in the breeding season and were older and heavier at puberty than Fingalways. Animals fed ad libitum were heavier at puberty and attained puberty earlier in the season and at a younger age than those on the restricted feeding regime.Both conception rate and litter size were lower in Galways than Fingalways. There was no evidence of any effect of the nutritional treatments on conception rate or litter size. The mean body weights at puberty for ewes which lambed and those which were barren were 41·9 ± 0·49 and 41·5 ± 0·78 kg respectively. The birth weight and growth rate of the progeny of the ewe lambs was similar for the two breeds and was not influenced by the previous nutritional treatment of the dams. The total lamb mortality between birth and weaning was 40·3%, and 72% of all deaths occurred within 48 h of birth. Losses among twins (48%) were particularly heavy.


Author(s):  
Vinaykumar R. H. ◽  
Gleeja V. L. ◽  
Gleeja V. L. ◽  
Gleeja V. L. ◽  
Gleeja V. L. ◽  
...  

A large variation in the gestation length can be expected when the gestation is calculated from the day of mating to birth. The present study was designed to assess the influence of different factors like litter size, breed, parity and age on gestation length in bitches. A total of 89 small sized bitches of different breeds having different age, parity and body weight, were selected for the study. The mean age, body weight and parity of the animals included in the present study were 3.00 ± 0.15 years (1 to 8 years), 9.9 ± 0.25 Kg (6 to 15kg) and 1.14 ± 0.10 (0-4th parity) respectively. The mean gestation lengths observed in different small sized breeds were 60.68 ± 0.55, 59.82 ± 0.54, 60.78 ± 1.74, 58.83 ± 1.35 and 58.17 ± 0.74 in the Pug, Beagle, Dachshund, French Bulldog and the Spitz, respectively. The mean litter size in the study was 4.34 ± 0.13 with a range of 2-8. The mean gestational length in animals having ? 3 litter size was 60.83 ± 0.64 days and 59.90 ± 0.43 days in animals having >3 litter size. Age limit of the animals ranged from 1 to 8 years with a mean of 3 ± 0.15 years. The mean gestation length in bitches aged ?3 years was 60.21 ± 0.23 days (n=63) and this was 60.15 ± 0.3 (n=26) days in bitches in the >3 years group. Mean gestational length observed in nulliparous bitches was 60.86 ± 0.4 days (n=29), while in multiparous bitches it was 59.90 ± 0.5 days (n=60). From the present investigation it could be concluded that no significant difference exists in gestational length between different breeds, litter size, age group and parity.


1978 ◽  
Vol 91 (2) ◽  
pp. 291-304 ◽  
Author(s):  
J. J. Robinson ◽  
I. McDonald ◽  
I. McHattie ◽  
K. Pennie

SUMMARYSeventy-eight Finnish Landrace × Dorset Horn ewes in lamb to Suffolk rams were slaughtered serially between 50 and 145 days of gestation. The mean litter size was 2·7. The daily feeding regime aimed to provide each ewe with 15 MJ of metabolizable energy (ME) in the first month of gestation and 9·4 MJ in the second and third. Thereafter the ewes were provided with a basal intake of either 9·6 MJ (low plane, LP) or 13·4 MJ (high plane, HP) plus 1·3 MJ for each foetus.For ewes with 2, 3 and 4 foetuses the mean percentage changes in maternal body weight over pregnancy were respectively — 5, — 10 and — 14 (LP) or + 3, — 2 and — 6 (HP). Changes in weights of blood, liver and the empty gastro-intestinal tract through gestation varied with the plane of nutrition but not with number of foetuses. In contrast, udder weight at parturition was dependent on number of foetuses but not on plane of nutrition.Increased hydration of the maternal tissues in late pregnancy tended to mask concurrent losses of body fat. For example, over the last 2 months, HP ewes carrying quadruplets lost on average 1·0 kg in body weight but 5·5 kg of (chemically determined) fat. The latter was lost at a rate which increased up to an average of 170 g/day over the last 2 weeks of pregnancy. Net changes in body protein were estimated to be relatively small, but there was some redistribution, including loss from muscle and gain by the udder. There was no evidence of any demineralization of the maternal skeleton.The practical significance of the changes in body composition is discussed, in particular that of the increasing rates of loss of body fat with increasing litter size. It is suggested that the dangers implicit in these rates of fat loss must be taken into consideration when deciding on dietary regimes and the timing of breeding cycles for highly prolific ewes, or indeed when embarking on a programme of increased prolificacy.


Rangifer ◽  
1993 ◽  
Vol 13 (4) ◽  
pp. 163
Author(s):  
Erik Ropstad ◽  
Gaute Helland ◽  
Helge Hansen ◽  
Dag Lenvik ◽  
Eva Tangen Solberg

In September 1990, a total of 69 calves with a minimum body weight of 46 kg were allocated into two groups, one treated with a single injection of 75 mg medroxyprogesterone acetate (N = 35), the other serving as control (N=34). Blood samples were collected for progesterone analysis in December 1990 and 1991. Udder palpation was performed in July and September 1990. Treated animals had significantly lower plasma progesterone levels in December 1990. The pregnancy rate as determined by udder palpation was 16.7% for treated animals and 48.3% for controls (P<0.01). All animals which were found to be pregnant had high progesterone levels (>5 ng/ml) the following winter. The mean body weight increase was 5.1 kg lower in females which kept their calves until September than in barren females (P<0.05). More than 50% of the pregnant females lost their calves during the summer.


Reproduction ◽  
2000 ◽  
pp. 49-57 ◽  
Author(s):  
SD Johnston ◽  
MR McGowan ◽  
P O'Callaghan ◽  
R Cox ◽  
V Nicolson

As an integral part of the development of an artificial insemination programme in the captive koala, female reproductive physiology and behaviour were studied. The oestrous cycle in non-mated and mated koalas was characterized by means of behavioural oestrus, morphology of external genitalia and changes in the peripheral plasma concentrations of oestradiol and progestogen. The mean (+/- SEM) duration of the non-mated oestrous cycle and duration of oestrus in 12 koalas was 32.9 +/- 1.1 (n = 22) and 10.3 +/- 0.9 (n = 24) days, respectively. Although the commencement of oestrous behaviour was associated with increasing or high concentrations of oestradiol, there were no consistent changes in the morphology or appearance of the clitoris, pericloacal region, pouch or mammary teats that could be used to characterize the non-mated cycle. As progestogen concentrations remained at basal values throughout the interoestrous period, non-mated cycles were considered non-luteal and presumed anovulatory. After mating of the 12 koalas, six females gave birth with a mean (+/- SEM) gestation of 34.8 +/- 0.3 days, whereas the remaining six non-parturient females returned to oestrus 49.5 +/- 1. 0 days later. After mating, oestrous behaviour ceased and the progestogen profile showed a significant increase in both pregnant and non-parturient females, indicating that a luteal phase had been induced by the physical act of mating. Progestogen concentrations throughout the luteal phase of the pregnant females were significantly higher than those of non-parturient females. Parturition was associated with a decreasing concentration of progestogen, which was increased above that of basal concentrations until 7 days post partum.


2019 ◽  
Vol 15 (02) ◽  
pp. 14-17
Author(s):  
K K Hadiya ◽  
A J Dhami ◽  
D V Chaudhari ◽  
P M Lunagariya

This study was initiated on 24 prepubertal Holstein x Kankrej crossbred heifers of nearly identical age (7-9 months) and body weight (130-140 kg) at University farm to evaluate the effect of high plane of nutrition on blood biochemical and minerals profile and the age at puberty. Twelve heifers were managed under routine farm feeding (control) and the rest 12 under ideal optimum feeding regime (treatment) that included extra 1 kg concentrate, 30 g min mix and ad-lib dry fodder. The body weight and ovarian ultrasonography together with blood sampling was carried out at monthly interval from 10 to 18 months of age to study the ovarian dynamics and blood biochemical changes. High plane of nutrition to growing heifers was beneficial in reducing the age of onset of puberty (by 2-3 months) compared to routine farm fed group. The mean plasma total protein and cholesterol concentrations showed a rising trend with significant variations from 10 to 16 months of age, where it got mostly stabilized indicating adult profile. The activity of enzymes GOT and GPT also rose gradually and significantly from 10 months till 14-15 months of age, and thereafter it remained more or less static till 18 months of age. The levels of both these enzymes were higher, with lower protein and cholesterol, in control than the treatment group from 15-16 months of age onwards. The mean plasma levels of both calcium and phosphorus increased gradually and significantly with advancing age till 16-17 months of age, with little higher values in supplemented than a control group. The plasma levels of zinc, iron, copper, and cobalt also showed rising trend with significant differences between 10th and 12th-14th months of age, and from 15th to 18th months of age the levels were statistically the same in all the groups with slightly higher values in the treatment group.


2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 101-102
Author(s):  
Kelsey L Batson ◽  
Hilda I Calderon Cartagena ◽  
Robert D Goodband ◽  
Jason C Woodworth ◽  
Mike D Tokach ◽  
...  

Abstract A total of 109 sows (Line 241; DNA, Columbus, NE) were used in a study to evaluate the effect of increasing phytase concentration in lactation diets on sow and litter performance. On d 107 of gestation, sows were blocked by body weight and parity and allotted to 1 of 3 dietary treatments of increasing phytase concentration (0, 1,000, or 3,000 FYT/kg; Ronozyme HiPhos 2700; DSM Nutritional Products, Inc., Parsippany, NJ). The control diet contained no phytase and was formulated to contain 0.50% standardized total tract digestible phosphorus (STTD P; 0.45% available P) and 0.62% STTD calcium (0.90% total Ca). The same STTD P and Ca concentrations were formulated for the phytase diets considering a release of 0.132 STTD P and 0.094 STTD Ca in both diets. Diets were fed from d 107 of gestation until weaning (d 18 ± 2). Litters were cross-fostered within treatment until 48 h post-farrowing to equalize litter size. Linear and quadratic response to phytase concentration was evaluated using the lmer function in R. There was no evidence for difference in sow body weight change, farrowing performance, wean-to-estrus interval, or litter size among dietary treatments. Sow average daily feed intake from farrowing to weaning tended to increase (linear, P=0.093) as phytase increased. Although not significant (linear, P =0.226), farrowing duration decreased as phytase increased. Litter weaning weight increased (quadratic, P=0.039) and overall litter gain increased (quadratic, P=0.047) with 1,000 FYT of phytase. In summary, sow feed intake tended to increase linearly with increasing phytase; however, feeding 1,000 FYT/kg maximized overall litter gain and weaning weight. This small-scale study suggests sow and litter performance benefits due to high inclusions of dietary phytase; however, a commercial trial with more sows is warranted to confirm these results.


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