Syphacia obvelata infections and reproduction of male domestic mice Mus musculus domesticus on a sub-Antarctic Island

2003 ◽  
Vol 77 (3) ◽  
pp. 247-253 ◽  
Author(s):  
B. Pisanu ◽  
J.-L. Chapuis ◽  
R. Périn
Keyword(s):  
Breeding Season ◽  
Reproductive Activity ◽  
Reproductive Season ◽  
Reproductive Status ◽  
Host Susceptibility ◽  
Mus Musculus Domesticus ◽  
Biological Factors ◽  
Male Activity ◽  
Syphacia Obvelata ◽  
Activity Indices

AbstractThe reproductive activity of feral male mice on an island of the sub-Antarctic Kerguelen archipelago was influenced by biological factors depending on periods within the breeding season. After having controlled host reproductive activity indices for body size, i.e. age, and body condition effects, Syphacia obvelata prevalence did not vary with host reproductive status or age either during the beginning or the middle–end of the reproductive season. Considering the beginning of the breeding season, worm abundance was more pronounced in males the year following a strong winter crash of the population than in years when high over wintering survival occurred. During the middle–end of the breeding season, males with the highest reproductive status were more infected than males with a lower reproductive status in years when oldest individuals dominated the population. It is suggested that this situation was due to an endocrine related increased host susceptibility partly influenced by a change in the age structure of the population, and that an increase in worm transmission was not directly related to male activity concurrent with reproductive status, nor to population density.

Seasonal reproductive activity in the pterobranch hemichordate Rhabdopleura compacta

2008 ◽  
Vol 88 (5) ◽  
pp. 1033-1041 ◽  
Author(s):  
Atsuko Sato
Keyword(s):  
Sexual Reproduction ◽  
Reproductive Biology ◽  
Reproductive Activity ◽  
Anatomical Structure ◽  
Reproductive Season ◽  
Reproductive Status ◽  
South Coast ◽  
Phylogenetic Position ◽  
The South ◽  
Filter Feeders

Pterobranchs are small marine filter feeders in the phylum Hemichordata. Their phylogenetic position and anatomical structure has resulted in pterobranchs featuring in many scenarios concerning the evolution of chordates. Despite this interest, the basic reproductive biology of pterobranchs is still poorly known. To address this issue, the reproductive season of Rhabdopleura compacta was investigated by collecting specimens in 2004–2007 from a population growing on disarticulated bivalve shells off the south coast of Devon, UK. I analysed reproductive status by categorizing shells according to the condition of the colonies growing on them. The frequency of shells having mature females was almost constant from spring to autumn among shells with active colonies. However, it was apparent that: (a) shells having mature females were more likely to be incubating embryos or larvae in June and July than other months; and (b) the production of embryos was high in June, and then decreased by July. Thus, despite the previous speculation that the species is capable of successful sexual reproduction throughout the year, the present study shows seasonality in reproduction of R. compacta, with at least a peak season during summer.

Division of parental duties confirms a need for bi-parental care in a precocial bird, the mute swan Cygnus olor

2015 ◽  
Vol 65 (2) ◽  
pp. 163-176 ◽  
Author(s):  
Radosław Włodarczyk ◽  
Piotr Minias
Keyword(s):  
Parental Care ◽  
Breeding Season ◽  
Time Budget ◽  
Empirical Support ◽  
European Population ◽  
Mute Swan ◽  
Cygnus Olor ◽  
Territory Defence ◽  
Male Activity ◽  
Reproductive Activities

Parental investment is much reduced in precocial species when compared with altricial species, which may explain a predominance of uni-parental care in this group of birds. In precocial wildfowl, bi-parental care is mostly restricted to arctic-breeding species, where the short reproductive season forces mates to cooperate in caring for the young, but a temperate breeding mute swan Cygnus olor is one of the few notable exceptions. In order to explain a need for bi-parental care in this species, we collected data on the time-budget of eleven swan breeding pairs from a Central European population. We found sex-related differences in the mean time allocated to incubation, movement, feeding, resting and aggression. Others behaviours (nest maintenance, alert and comfort) changed along the breeding season, but did not differ between sexes. Females were primarily responsible for providing care to the brood, whereas male activity focused on territory defence and family guarding. Females were exclusively responsible for incubation and they covered 85% of the total time allocated by parents to feeding cygnets. Nearly constant incubation in females limited possibilities for other activities, including foraging. Males allocated significantly more time than females to aggressive interactions, directed mainly towards other breeding pairs and non-breeders. A clear division of parental duties between sexes gave empirical support for the presence of bi-parental care in the mute swan, despite the fact that reproductive activities of this species are not constrained by the short length of the breeding season, as in arctic-breeding wildfowl.

Oestrous activity in three subtropical sheep breeds in Upper Egypt and response to long-day light treatment

1991 ◽  
Vol 116 (1) ◽  
pp. 139-143 ◽  
Author(s):  
A. M. Aboul-Naga ◽  
H. Mansour ◽  
M. B. Aboul-Ela ◽  
M. T. Mousa ◽  
Ferial Hassan ◽  
...  
Keyword(s):  
Breeding Season ◽  
Seasonal Changes ◽  
Nile Delta ◽  
Reproductive Activity ◽  
Light Treatment ◽  
Continuous Exposure ◽  
Upper Egypt ◽  
Sheep Breeds ◽  
Awassi Sheep ◽  
Long Day

SUMMARYOestrous activity in local Rahmani and Ossimi sheep and imported subtropical Awassi sheep at different times of the year in Upper Egypt and the effect of continuous exposure to long-day conditions from July till December on this activity was studied in 1986. The three breeds differed substantially in oestrous activity but differences did not seem to be directly related to latitude of origin. Rahmani ewes from the Nile Delta were mostly cyclic all year round; the percentage coming to oestrus each month never fell below 70%. Ossimi ewes originating from mid-Egypt had a very long breeding season; 74% had an anoestrous period of 68·8 days (v. 27% for Rahmani ewes). All Awassi ewes, except one, had an anoestrous period of 96·5 days on average.Awassi ewes also showed more response to continuous exposure to long days (14 h) than Ossimi ewes, seen in a shorter reaction interval and a greater decrease in the percentage of ewes coming into oestrus (27 and 90% in control and treated Awassi ewes, respectively). The results indicated that changes in daylength, although small in subtropical regions, may be a major factor controlling seasonal changes in reproductive activity in subtropical sheep breeds, the more seasonal breed being more responsive to changes in daylength. The possibility of selection within these breeds for continuous reproductive activity is also indicated.

Evaluation of Different eCG Doses + Progesterone to Induce Reproductive Activity During the Transitional Reproductive Season in Anestrous Creole Goats

2020 ◽  
Author(s):  
F. G. Véliz-Deras ◽  
S. Zúñiga-García ◽  
G. Calderón-Leyva ◽  
J. Otal-Salaverri ◽  
S. Moreno-Avalos ◽  
...  
Keyword(s):  
Chorionic Gonadotropin ◽  
Reproductive Behavior ◽  
Reproductive Activity ◽  
Reproductive Period ◽  
Reproductive Season ◽  
Reproductive Seasonality ◽  
Experimental Protocols ◽  
Equine Chorionic Gonadotropin ◽  
Experimental Treatments ◽  
Different Doses

Background: Goats from subtropical and temperate latitudes show reproductive seasonality. For this reason, the products obtained from goats also shows the same seasonality, reducing the finances of goat keepers. Several studies have focused on reducing reproductive seasonality through the use of hormonal protocols based on progestogens, in addition to the use of equine chorionic gonadotropin (eCG) hormone, used for its double biological activity that ensures an optimal response to induce estrus and pregnancy in goats. The objective was to assess whether reduced doses of eCG are effective in inducing reproductive activity in anestrous goats. Methods: During the transition reproductive period (June), mix-breed Creole goats (n=39), were treated with intramuscular progesterone (P4), later, the experimental treatments, consisting in different doses (50, 100, 50+50 or 200 IU) of equine chorionic gonadotropin (eCG) were applied. After the application of the experimental protocols, the reproductive activity of the goats was evaluated. Result: This study shows that one dose of 100 IU of eCG effectively induced reproductive behavior in anestrous Creole goats towards the end of the seasonal anestrus. This protocol makes the use of exogenous hormones more efficient, with reduce doses, decreasing expenses and is practical use by goat producers.

Association between melatonin receptor 1A (MTNR1A) gene polymorphism and the reproductive performance of Mediterranean Italian buffaloes

2012 ◽  
Vol 24 (7) ◽  
pp. 983 ◽  
Author(s):  
S. Luridiana ◽  
M. C. Mura ◽  
M. Pazzola ◽  
M. Paludo ◽  
G. Cosso ◽  
...  
Keyword(s):  
Gene Polymorphism ◽  
Genetic Marker ◽  
Breeding Season ◽  
Reproductive Performance ◽  
Reproductive Activity ◽  
Allelic Frequency ◽  
Genotypic Frequency ◽  
Melatonin Receptor ◽  
Reproductive Seasonality ◽  
Long Photoperiod

A melatonin receptor 1A (MTNR1A) gene polymorphism in adult buffaloes has been reported to affect reproductive seasonality. Consequently, the aim of the present study was to assess whether this polymorphism can affect age at first conception and the interval between first and second calving in Mediterranean Italian buffaloes. The allelic frequency of the C and T alleles was 0.44 and 0.56, respectively, whereas the genotypic frequency was 26% for C/C, 40% for C/T and 34% for T/T. The average age at first mating was approximately 20 months, whereas that at calving was approximately 32 months. The largest number of calvings of primiparous buffaloes was recorded between June and October. No associations between genotype, first mating and subsequent calving date were found. The duration from first to second calving was longer in buffaloes with the C/C genotype compared with those with the T/T and C/T genotypes (P < 0.01). The period of calving for buffaloes with the C/C genotype was mainly from July to September, whereas that for buffaloes with the T/T genotype was largely from March to May. The MTNR1A gene had no effect on the age of first conception in Mediterranean Italian buffaloes. Rather, the association between the T/T genotype and reproductive activity during days with a long photoperiod indicates that this polymorphism may be considered a genetic marker to identify buffaloes that are able to reproduce out of the breeding season.

Behavioural asymmetries and cohesive mother–offspring sociality in bushy-tailed wood rats

1992 ◽  
Vol 70 (3) ◽  
pp. 597-604 ◽  
Author(s):  
Richard A. Moses ◽  
John S. Millar
Keyword(s):  
Breeding Season ◽  
Adult Female ◽  
Reproductive Status ◽  
Habitat Patch ◽  
Agonistic Behaviour ◽  
Rock Outcrops ◽  
Neotoma Cinerea ◽  
Behavioural Asymmetries ◽  
Behavioural Interactions ◽  
Resource Patches

Bushy-tailed wood rats (Neotoma cinerea) are usually confined to highly clumped resource patches (i.e., rock outcrops), and potentially compete for limited den sites within outcrops. Adults may breed on the same outcrop over several years, and philopatric yearlings usually breed in proximity to close kin. We investigated the influence of kinship and reproductive status on the nature and stability of wood rat sociality. Behavioural interactions among mother–offspring and adult female – nonkin dyads from the wild were quantified in a neutral arena during (i) the autumn when offspring were immature subadults, and (ii) the following spring, when all dyad members were reproductively active. Nonkin dyads were characterized almost entirely by agonistic behaviour. Virtually all amicable behaviour was directed toward close kin, and most interactions among kin dyads were amicable. Further, these strong kin-based behavioural asymmetries did not differ between the autumn and the subsequent breeding season, and could not be explained by postweaning familiarity (i.e., residency on a common habitat patch) alone. Wood rat sociality appears to be characterized by two elements: (i) divisive agonism directed toward nonkin, and (ii) stable, cohesive relationships among close kin (mother–offspring). Possible causes and consequences of sociality in bushy-tailed wood rats are discussed.

An evaluation of methods for improving reproductive performance in summer lambing ewes

1990 ◽  
Vol 1990 ◽  
pp. 163-163
Author(s):  
E King Margaret ◽  
L M Mitchell ◽  
J S M Hutchinson ◽  
R Glatt ◽  
M F Ibraheem
Keyword(s):  
Breeding Season ◽  
Late Pregnancy ◽  
Reproductive Activity ◽  
Winter Period ◽  
Embryo Survival ◽  
Exogenous Melatonin ◽  
The Past ◽  
The Subject ◽  
Natural Breeding ◽  
Endogenous Melatonin

Manipulation of seasonality in the ewe has been the subject of extensive research over the past few years. Demand for continuous supply of home-bred lamb has encouraged producers to breed their ewes both earlier and later in their natural breeding season. Extending the breeding season to a Summer (May/June) lambing has proved a low input system reducing the requirement for concentrate feeding in late pregnancy and eliminating the need for housing during the winter period (Stone, 1988). However, Summer lambing involves mating ewes in January when fecundity may be declining. Exogenous Melatonin has been shown to be effective in advancing the breeding season by extending the length of time that significant levels of Melatonin are present in the blood. It may also have a beneficial effect on embryo survival (Wigzell et al, 1986; Kennaway et al, 1987). In Summer lambing ewes, where endogenous Melatonin is in decline during tupping in January, the introduction of exogenous Melatonin may result in continued reproductive activity and aid implantation of embryos.

scholarly journals Reproductive status of Camelus bactrianus during early breeding season in India

2015 ◽  
Vol 4 (1) ◽  
pp. 61-64 ◽  
Author(s):  
S Vyas ◽  
N Sharma ◽  
FD Sheikh ◽  
S Singh ◽  
DS Sena ◽  
...  
Keyword(s):  
Breeding Season ◽  
Reproductive Status ◽  
Camelus Bactrianus
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