scholarly journals 338 SYNCHRONISATION OF OVULATION IN MERINO EWES WITH GnRH IN THE BREEDING AND NON-BREEDING SEASON

2005 ◽  
Vol 17 (2) ◽  
pp. 320
Author(s):  
J. Reyna ◽  
P. Thomson ◽  
G. Evans ◽  
C. Maxwell
Keyword(s):  
Breeding Season ◽  
Transrectal Ultrasound ◽  
Breeding Seasons ◽  
And Control

The objective was to determine the effect of GnRH as an aid to synchronise the time of ovulation in Merino ewes during the non-breeding and breeding seasons as determined by transrectal ultrasound. Oestrus was synchronized in 20 nulliparous Merino ewes (11–12 months old; 2 replicates of 10 animals) during spring 2003 and autumn 2004 at Camden, NSW, Australia, using FGA sponges for 12 days (30 mg Ovagest, Bioniche Pty. Ltd., Armidale, NSW) and an i.m. injection of 400 IU of PMSG (Pregnecol, Bioniche Pty. Ltd., Armidale, NSW). Ultrasound evaluations of ovaries were recorded on VHS tapes every 12 h for 36 h starting at sponge removal (SR), then half of the animals received an i.m. injection of 40 μg synthetic GnRH (Fertagyl, Intervet Australia Pty. Ltd, Bendigo, VIC) and ultrasound evaluations were conducted every 6 h until 60 h. The positions of the largest follicles were recorded on ovarian maps and their growth was monitored. Time of ovulation was defined as the time of disappearance of the largest follicle from the ovary. Ten days after ovulation, the position and diameter of the CL was confirmed by ultrasound. Comparisons were made between treated and control animals, and between breeding and non-breeding seasons, using t-tests. During the non-breeding season ovulation took place from 42 to 54 h (mean 48 ± 2.83 h) vs. 42 to 60 h (mean 52.2 ± 5.69 h) after SR in GnRH-treated vs. control animals (P < 0.05), respectively. Ovulation was delayed in the breeding compared with the non-breeding season (P < 0.05), starting from 48 to 60 h after SR for treated (52.8 ± 3.79 h) and control animals (57.0 ± 4.24 h; P < 0.05). These results suggest that GnRH synchronized the time of ovulation compared with the controls but the time of ovulation was later in the breeding than in the non-breeding season.

The use of progesterone and serum gonadotrophin (P.M.S.) in the control of fertility in sheep. I. The hormonal augmentation of fertility in the ewe during the breeding season

1958 ◽  
Vol 50 (2) ◽  
pp. 123-151 ◽  
Author(s):  
I. Gordon
Keyword(s):  
Breeding Season ◽  
Dosage Level ◽  
Field Trials ◽  
Fertility Status ◽  
Normal Fertility ◽  
Freeze Dried ◽  
Breeding Seasons ◽  
And Control

1. Over four breeding seasons (1952–6) field trials, involving a total of 2504 treated and control ewes of nine breeds (Romney, Clun, Suffolk, Cheviot, Lincoln, Welsh Mountain, Ryeland, Southdown and Hampshire) were conducted in an attempt to increase flock fertility by injections of p.m.s. hormone. The hormone employed was in three forms of preparation: purified, freeze-dried and whole serum. Dosage levels from 250 to 1000 i.u. were injected subcutaneously.2. There is no evidence that the treatment affected the ability of the ewe to conceive.3. A significant increase in fertility was induced by treatment. The extent of the increase apparently depended on the dosage level and form of p.m.s. employed, and was found to be affected by the normal fertility status of the sheep undergoing treatment. At any given dosage level of p.m.s. the increases induced by treatment were greatest where flock fertility was very low.4. When used at comparable dosage levels, whole serum tended to be more effective in inducing superfertility than freeze-dried or purified serum. Freezedried serum tended to be more effective than purified serum.5. 1047 injected sheep that conceived to service at the treatment oestrus produced 1898 lambs (1·81 lambs per ewe); 997 control ewes that conceived at the same time produced 1506 (1·51 lambs per ewe).

106 Exogenous melatonin administration improves behavioural signs, serum melatonin, testosterone, and semen quality in male dromedary (Camelus dromedarius) camels

2021 ◽  
Vol 33 (2) ◽  
pp. 160
Author(s):  
S. Dholpuria ◽  
G. N. Purohit ◽  
S. Vyas
Keyword(s):  
Reaction Time ◽  
Breeding Season ◽  
Corn Oil ◽  
Semen Quality ◽  
Sperm Concentration ◽  
Serum Testosterone ◽  
Entire Study ◽  
Seminal Parameters ◽  
Breeding Seasons ◽  
And Control

The present study aimed to evaluate the effects of exogenous administration of melatonin to male camels on reproductive behaviour, seminal parameters, and serum concentrations of melatonin and testosterone during the non-breeding and subsequent breeding seasons. In September 2018, male camels (n=12) were randomly allocated to subcutaneous injections of either melatonin (MLT, 0.643 mg/kg; n=6) dissolved in corn oil, or plain corn oil; (control n=6). The camels were observed for behavioural signs of rut. A second dose of either MLT (1 mg/kg) or corn oil (control) was administered on 7 October 2018 subcutaneously, as camels did not show any change in behaviour until 6 October 2018, and the camels were again observed for behavioural signs of rut. Blood was collected from all camels on 1 September 2018, and then at weekly intervals until 7 January 2019. The serum was separated and stored until further assay of serum melatonin and testosterone using ELISA kits. Semen was collected from camels showing signs of rut period, and the reaction time, copulation time, and seminal parameters were evaluated. Data obtained was analysed by using the computer program SPSS (version 25; IBM Corp.), and means and standard errors were compared. Male reproductive behaviours (protrusion of soft palate, poll gland secretions, frequent urination, increased frothy salivation) were more pronounced in MLT-treated camels (83.33%) than in control camels (50%). Reaction time and copulation times were lower (112.81±30.06s and 229.8±37.91s) in MLT-treated camels than in controls (359.00±41.35s and 301.89±93.90s). Higher semen volume was observed in MLT-treated (5.34±2.06mL) than in control (3.11±1.75mL) camels (P&lt;0.01). Semen collected from MLT-treated camels had more gel formation (81.25%), significantly higher sperm motility (67.50±2.32%), and increased sperm concentration (326.56±38.67 million mL−1) compared with samples obtained from the control males (P&lt;0.01). Serum melatonin concentrations increased in both treated and control camels during the breeding season compared with concentrations before the breeding season. In MLT-treated camels, serum melatonin concentrations increased significantly and continued to be significantly higher than that in control camels for the entire study period (P&lt;0.01). Serum testosterone concentrations were higher in both MLT-treated and control camels during the breeding season compared with those during the non-breeding season (P&lt;0.01). We concluded that exogenous subcutaneous MLT administration improves sexual behaviour, seminal parameters, and serum testosterone concentrations during both the non-breeding and breeding seasons.

scholarly journals Estrus induction in the non-breeding season is not associated with hydrometra in dairy goats

2021 ◽  
Vol 10 (11) ◽  
pp. e21101119162
Author(s):  
Ana Lucia Rosa e Silva Maia ◽  
Joanna Maria Gonçalves Souza-Fabjan ◽  
Paulo Sergio Cerqueira Rangel ◽  
Luana Rangel Côrtes ◽  
Maria Emilia Franco Oliveira ◽  
...  
Keyword(s):  
Breeding Season ◽  
Transrectal Ultrasound ◽  
Reproductive Season ◽  
Dairy Goats ◽  
Control Light ◽  
And Control

This study aimed to compare the prevalence of hydrometra (HD) at the end of the reproductive season in goats subjected (HORM and LIGHT) or not (Control-HORM and Control-LIGHT) to estrus induction by either hormonal protocol or light program, respectively, in the non-breeding season. HORM-goats received intravaginal sponges (six days) associated with cloprostenol plus eCG 24 h before sponge removal while LIGHT-goats were submitted to 16 h of light and 8 h of darkness for 60 days. Pregnant goats from both groups gave birth at the early reproductive season and were evaluated by transrectal ultrasound ~45 days after the end of the season. The control goats (Control-HORM and Control-LIGHT) were also examined. There was no difference in the prevalence of HD between goats from HORM (8/31; 25.8%) compared to Control-HORM (4/26; 15.4%), or LIGHT (9/54; 16.7%) compared to Control-LIGHT (7/51; 13.7%), as well as between HORM and LIGHT groups. In conclusion, estrus induction with both hormonal and light protocols is not associated with the development of HD in dairy goats.

scholarly journals Evidence for use of both capital and income breeding strategies in the mangrove tree crab, Aratus pisonii

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jade Carver ◽  
Morgan Meidell ◽  
Zachary J. Cannizzo ◽  
Blaine D. Griffen
Keyword(s):  
Breeding Season ◽  
Breeding Strategy ◽  
Reproductive Period ◽  
Breeding Strategies ◽  
Mangrove Tree ◽  
Income Breeding ◽  
Aratus Pisonii ◽  
Breeding Seasons ◽  
And Storage ◽  
Capital And Income Breeding

AbstractTwo common strategies organisms use to finance reproduction are capital breeding (using energy stored prior to reproduction) and income breeding (using energy gathered during the reproductive period). Understanding which of these two strategies a species uses can help in predicting its population dynamics and how it will respond to environmental change. Brachyuran crabs have historically been considered capital breeders as a group, but recent evidence has challenged this assumption. Here, we focus on the mangrove tree crab, Aratus pisonii, and examine its breeding strategy on the Atlantic Florida coast. We collected crabs during and after their breeding season (March–October) and dissected them to discern how energy was stored and utilized for reproduction. We found patterns of reproduction and energy storage that are consistent with both the use of stored energy (capital) and energy acquired (income) during the breeding season. We also found that energy acquisition and storage patterns that supported reproduction were influenced by unequal tidal patterns associated with the syzygy tide inequality cycle. Contrary to previous assumptions for crabs, we suggest that species of crab that produce multiple clutches of eggs during long breeding seasons (many tropical and subtropical species) may commonly use income breeding strategies.

scholarly journals Density and Flock Size of the Raven (Corvus corax) In the Orawa - Nowy Targ Basin During Non-Breeding Season

Ring ◽  
2006 ◽  
Vol 28 (2) ◽  
pp. 119-125
Author(s):  
Michał Ciach ◽  
Dominik Wikar ◽  
Małgorzata Bylicka
Keyword(s):  
Breeding Season ◽  
Early Spring ◽  
Food Resources ◽  
High Density ◽  
Line Transect ◽  
Flock Size ◽  
Early Winter ◽  
Corvus Corax ◽  
Line Transect Method ◽  
Breeding Seasons

Density and Flock Size of the Raven (Corvus corax) In the Orawa - Nowy Targ Basin During Non-Breeding Season During the 2002/2003-2004/2005 non-breeding seasons the density of the Raven in the open habitats of the Orawa - Nowy Targ Basin was studied by line transect method. The results were analysed in four periods (autumn, early winter, winter and early spring). The median density of Ravens did not differ significantly between individual periods and was respectively: 3.5, 3.8, 4.8 and 3.8 indiv. / 10 km. Number of birds during particular controls varied from 1.0 to 24.8 indiv. / 10 km. However, while excluding flocks, the median density of single individuals and pairs of the Raven was considerably lower and in subsequent periods reached respectively: 2.2, 2.4, 2.2 and 1.7 indiv. / 10 km. Flock size did not differ significantly between individual periods. Single individuals and, less often, groups of two birds were recorded mostly. Small (3-5 indiv.) and medium (6-15 indiv.) flocks were recorded rarely and large flocks (16 indiv. and above) - only exceptionally. The high density and strong fluctuations of abundance of Ravens were determined by flocks presence, which was probably linked to irregular occurrence of food resources.

scholarly journals 75 Epigenetic marks within the swine placenta are differentially expressed due to season

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 33-33
Author(s):  
Robin Cheek ◽  
Lea A Rempel ◽  
Jeremy Miles
Keyword(s):  
Breeding Season ◽  
Random Effect ◽  
Chromatin Modification ◽  
Prenatal Development ◽  
Treatment Groups ◽  
Downstream Targets ◽  
Downstream Target ◽  
Expression Platform ◽  
Semen Storage ◽  
And Control

Abstract The objective of the current project was to validate expression of known chromatin modification genes and assess downstream targets in d45 swine placenta derived from seasonal semen collections and breedings and semen storage. Six treatment groups were developed based upon: season of semen collection (cool or warm), storage of semen (cooled-extended or cryopreserved), and season of breeding (summer or winter) with 8 litters per group as follows: 1) cool/cooled-extended/winter, 2) cool/cryopreserved/winter, 3) warm/cryopreserved/winter, 4) warm/cooled-extended/summer, 5) warm/cooled-extended/summer, and 6) cool/cryopreserved/summer. RNA was extracted from the placenta of a small, medium, and large fetus from each litter, pooled by litter, reverse transcribed, and used for qPCR. Three genes; ATF2, ASH2L, and SMYD3, were validated. Downstream gene targets, ILIB and NANOG, were also tested. Interactions and main effects were tested using the mixed procedure of SAS with boar as a random effect. Placental ASH2L had a tendency for increased expression from summer breedings (P &gt;0.05), similar to previous findings using a different expression platform. Placental expression of ATF2 was greatest (P&lt; 0.05) from placenta derived by summer breedings. A downstream target of ATF2, ILIB, had greater (P&lt; 0.05) placental expression from summer breedings and semen that was cooled-extended as compared to cryopreserved (P&lt; 0.05). Validation of placental expression of SMYD3 was greater from cooled-extended semen in contrast to cryopreserved semen (P&lt; 0.05). These data were unexpected, as previously we determined a difference by breeding season only. However, NANOG, downstream of SMYD3, had greater placental expression from summer breedings (P&lt; 0.05). The current study validated previous results indicating chromatin modification genes were primarily influenced predominantly by breeding season and to a lesser extent, semen storage techniques. Downstream targets were also influenced by breeding season likely influencing prenatal development. These data support that epigenetic modifications persist, even though modern swine systems regulate and control temperature and lighting.

Phenotypic plasticity of the montane vole (Microtus montanus) in unpredictable environments

1992 ◽  
Vol 70 (11) ◽  
pp. 2121-2124 ◽  
Author(s):  
Norman C. Negus ◽  
Patricia J. Berger ◽  
Aelita J. Pinter
Keyword(s):  
Phenotypic Plasticity ◽  
Breeding Season ◽  
Growth Rates ◽  
Adaptive Strategy ◽  
Severe Drought ◽  
Microtus Montanus ◽  
Age Cohort ◽  
Montane Meadow ◽  
Study Sites ◽  
Breeding Seasons

From 1987 to 1989, the cohort dynamics of Microtus montanus populations were studied at two montane meadow sites approximately 160 km apart, in northwestern Wyoming. The 1987 and 1988 breeding seasons differed markedly from each other. In 1987, melt off occurred in April, and the first cohort was born in May (cohort 1). The entire breeding season was favorable owing to frequent rainfall throughout the summer. Cohort 1 animals grew rapidly and females began breeding at 4–5 weeks of age. Likewise, cohort 2 (June) animals exhibited rapid growth and females were breeding at 7–8 weeks of age. Cohort 3 (July and August) animals grew more slowly and most entered the winter as prepubertal animals of subadult size. At the end of the summer, cohort 3 animals represented >70% of the voles recruited during the breeding season. In 1988, following melt off in late April, precipitation was below normal and the situation intensified to severe drought through the summer. The growth rates of cohort 1 and 2 animals were significantly lower than 1987 growth rates, and very few females attained sexual maturity. At the end of the summer, cohort 3 animals represented <25% of the total recruitment at both study sites. Such apparent phenotypic plasticity of growth and maturation appears to be an evolved adaptive strategy that is responsive to several environmental cues. Both study sites, although widely separated, exhibited virtually identical patterns throughout the study.

Effects of adults on survival and recruitment of Peromyscus leucopus

1987 ◽  
Vol 65 (10) ◽  
pp. 2519-2523
Author(s):  
Gregory H. Adler ◽  
Mark L. Wilson ◽  
Michael J. DeRosa
Keyword(s):  
Adult Female ◽  
Adult Male ◽  
Peromyscus Leucopus ◽  
Survival Rates ◽  
Adult Males ◽  
Control Grid ◽  
Young Males ◽  
Young Females ◽  
Breeding Seasons ◽  
And Control

A population of Peromyscus leucopus (white-footed mouse) in northeastern Massachusetts was manipulated for 3 years to determine the effects of adults on survival and recruitment. Two experimental grids were established, from which either all adult males or all adult females were removed continually. The effects of these two manipulations were compared with demography on a control grid. Manipulations had no apparent effect on breeding intensity of young, survival rates of adults, or residency rates of adults and young. Recruitment of adult males was higher on the adult male removal grid than on the control grid. Recruitment rates of adult males and of young males and young females were lower on the adult female removal grid than on the control grid. Survival rates of young males were higher on the adult female removal grid than on the control grid; this effect may have been due to either reduced adult female residency or adult male recruitment. All differences between experimental and control grids were noted only during breeding seasons. Adult males apparently limited recruitment of adult consexuals. The effects of manipulations on other measured parameters were inconclusive because of high immigration rates of adult males onto the adult male removal grid and reduced recruitment of adult males and decreased production of young on the adult female removal grid.

Flexibility of nuptial colouration in a unique ecotype of Threespine Stickleback (Gasterosteus aculeatus)

2021 ◽  
Author(s):  
Rachel Corney ◽  
Anne Haley ◽  
Laura Weir
Keyword(s):  
Breeding Season ◽  
Gasterosteus Aculeatus ◽  
Colour Change ◽  
Threespine Stickleback ◽  
Relative Role ◽  
Mate Quality ◽  
Breeding Seasons ◽  
Potential Signal ◽  
Intersexual Competition

Nuptial colouration in animals may serve as a signal of competitor and/or mate quality during breeding. In many temperate fishes, nuptial colouration develops during discrete breeding seasons and is a target of sexual selection. We examine nuptial colouration and behaviour of a unique ecotype of Threespine Stickleback (Gasterosteus aculeatus Linnaeus, 1758), wherein males turn from dull brown-grey to pearlescent white during the breeding season. The main goal of this work was to determine the relative role of white colouration in intersexual competition and mate choice. In a combination of a field and laboratory work, we found that males are brightest white when engaging in courtship activities in the presence of a female; this indicates that white colouration may be primarily related to enhancing signalling during mate attraction. White colouration intensity increased as the breeding season progressed and may be related to an influx of conspecifics. Colour change from cryptic grey to bright white occurred rapidly (< 90 seconds) and may be deployed to enhance behavioural signals. We conclude that bright white colouration in the white ecotype is a potential signal of mate quality and may have evolved from a previously existing capacity for colour plasticity in common Threespine Stickleback.

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