Studies on the breeding season and reproduction of the ewe Part III. The breeding season and artificial light Part IV. Studies on the reproduction of the ewe Part V. Mating behaviour and pregnancy diagnosis

1952 ◽  
Vol 42 (3) ◽  
pp. 232-265 ◽  
Author(s):  
E. S. E. Hafez
Keyword(s):  
Breeding Season ◽  
High Frequency ◽  
Cycle Length ◽  
Mating Behaviour ◽  
Post Partum ◽  
High Ratio ◽  
Domestic Sheep ◽  
Artificial Light ◽  
Ewe Lambs ◽  
Breed Differences

During the course of three breeding seasons, daily observations of oestrus were undertaken on the following groups of ewes, all of which were running with ochred rams. One hundred and twenty ewes (pure bred and first-cross) of different breeds and ages, running with vasectomized rams under natural conditions. Twenty-eight grade Suffolk ewes fed on a submaintenance diet. Eighteen grade Suffolk ewes running with a fertile ram. Twenty ewes of several breeds exposed to artificial light.The effects of heredity (breed and individual), environment (season, year and nutrition), age and artificial light on the breeding season and related phenomena have been investigated. The results and conclusions were as follows:1. (a) There are breed differences in the extent of the breeding season, cycle length, incidence of silent heat and duration of heat (Table 29). (b) The duration of the breeding season is related to the geographical origin (latitude and altitude) of the breed, (c) The duration of the breeding season of the first-cross is intermediate between that of the two parents, (d) Individual differences in the number of oestrous cycles per ewe per season were more marked in the mountain breeds.2. (a) Of the ewe lambs, 79% exhibited oestrus during the shortest days only of the first breeding season. Their breeding season is not spread evenly about the shortest day as it is with adults. (b) The occurrence and length of the breeding season in ewe lambs is associated with early birth dates or with higher growth rates.3. (a) Significant differences exist between breeds in the age at first oestrus. (b) Ewe lambs born early in the season showed their first oestrus at later age and heavier weight than those born late.4. Annual differences in the duration of the breeding season, cycle length, incidence of silent heat and occurrence of first oestrus were negligible.5. (a) Submaintenance diet had no effect on the onset of the breeding season, but it converted oestrus into silent heat. Conception occurred less frequently after periods of underfeeding. (b) At high latitudes nutrition has only a minor effect on the breeding season of the ewe.6. (a) A constant high ratio of artificial darkness (8 hr. light: 16 hr. darkness) hastened the onset of the breeding season some 57 and 27 days in the two experimental groups. (b) A constant high ratio of artificial light (16 hr. light: 8 hr. darkness) hastened the end of the breeding season some 104 days on an average (in one experimental group), (c) There were breed differences in the latency of initiation and of cessation of the induced breeding season, (d) In the induced breeding season cycles of ovulation preceded the first oestrus, (e) Two thresholds of pituitary activity are suggested, one for the onset of ovulation, and the other for the manifestation of oestrus.7. (a) A high frequency of cycles outside the normal range (14–19 days) was observed in the mountain breeds and in ewe lambs. (b) The shortest average cycle length coincided with the shortest days of the year.8. A high frequency of silent heats (during the breeding season) was observed in the mountain breeds, in ewe lambs and during the second half of the breeding season.9. Oestrus was of longer duration in adults and yearlings than in ewe lambs.10. (a) Post-partum heat occurred in 56% of Suffolk ewes with an average lactation anoestrus of 35 days. (b) There is a relationship between the early onset of the breeding season and the incidence of post-partum heat, (c) Conception post-partum is partly inhibited by lactation.11. Mating behaviour was observed in animals of several breeds and ages (three patterns were recorded for ewes and eight patterns for rams).12. Irregular columnar cells in the vaginal smear of the ewe characterized late pregnancy.In addition, the breeding season of wild and domestic sheep was reviewed in relation to the environment with special reference to the length of daylight.

scholarly journals Mating sequence, dominance and paternity success in captive male tammar wallabies

Reproduction ◽  
2005 ◽  
Vol 130 (1) ◽  
pp. 123-130 ◽  
Author(s):  
Emily F Hynes ◽  
Carl D Rudd ◽  
Peter D Temple-Smith ◽  
George Sofronidis ◽  
Damien Paris ◽  
...  
Keyword(s):  
Breeding Season ◽  
Mating Behaviour ◽  
Post Partum ◽  
Tammar Wallaby ◽  
Male Dominance ◽  
Plasma Testosterone ◽  
Dominant Male ◽  
Male Mating ◽  
Adult Males ◽  
Equal Chance

The tammar wallaby (Macropus eugenii) is a small, promiscuous, macropodid marsupial. Females usually produce a single young each year and there is a clear dominance hierarchy between adult males. The dominant male usually mates first and then guards the female to prevent access to her by other males. In this study, agonistic encounters and mating behaviour were observed to determine male dominance hierarchies in six groups of captive tammars consisting of a total of 23 males and 50 females. Mating behaviour was observed immediately post-partum when females were in oestrus and was correlated with plasma testosterone concentrations. Male mating sequences were recorded, and the paternity of offspring was determined by using seven macropodid marsupial microsatellites. Rates of sexual checking and aggression by males housed with females in oestrus in the non-breeding season were lower than in the breeding season. These males also had lower concentrations of testosterone, but were still able to sire young. High testosterone concentrations neither ensured dominance nor appeared to control directly the level of sexual activity. Females usually mated with more than one male. The dominant male most often secured the initial copulation (60%), but the first-mating male did not always secure parentage, with second and third matings resulting in as many young as first matings. Using these data, we were unable to discount first sire, last sire or equal chance models of paternity in this species. Half the young (50%) were sired by the dominant α male, but of the remaining progeny, the β male sired more (35%) than γ and δ males (15%). Dominance therefore is only a moderately effective predictor of paternity in the tammar. Although the dominant males gained most first matings and individually sired half of the offspring, the subdominant males still contributed significantly to the population, at least in captivity.

A note on attainment of puberty of september-born early-maturing ewe lambs in relation to level of nutrition

1991 ◽  
Vol 53 (3) ◽  
pp. 407-409 ◽  
Author(s):  
F. Forcada ◽  
J. A. Abecia ◽  
L. Zarazaga
Keyword(s):  
Sexual Activity ◽  
Breeding Season ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Ewe Lambs ◽  
Early Maturing ◽  
Age At Puberty

The attainment of puberty in September-born early-maturing ewe lambs was studied at Zaragoza (latitude 41° 40' N). Thirty twin Salz females were allocated to two groups receiving two nutrition levels after 3 months of age: high (500 g/day lucerne hay and 500 g/day concentrate) (H) and low (500 g/ day lucerne hay) (L). Oestrus was detected daily by aproned rams. Corpora lutea were counted after oestrus and plasma progesterone levels monitored each week.In the first breeding season (January to February) the percentage of females showing sexual activity (silent emulation or oestrus and ovulation) was higher in the H compared with the L group (67 and 20%; P < 0/05). Nonpubertal oestrus before the main breeding season was detected in 67% of animals. In the main breeding season and for H and L groups respectively, percentage of females showing silent ovulation before puberty was 67 and 33% and mean age at puberty extended to 319 (s.e. 4-8) and 314 (s.e. 3·7) days. Ovulation rate at puberty was 1·73 (s.e. 0·13) and 1·33 (s.e. 0·15) respectively (P < 0·05).

The effect of stage of breeding season or pre-mating oestrogen and progestagen therapy on fertility in ewe lambs

1994 ◽  
Vol 59 (3) ◽  
pp. 429-434 ◽  
Author(s):  
N. F. G. Beck ◽  
M. C. G. Davies
Keyword(s):  
Breeding Season ◽  
Corpora Lutea ◽  
Oestrogen Therapy ◽  
Crown Rump Length ◽  
Ewe Lambs ◽  
Oestradiol Benzoate

AbstractAn investigation was conducted to determine the effect of mating at puberty or third oestrus or after pre-mating oestrogen and progestagen therapy, designed to mimic the changes that occur in plasma oestrogen and progesterone concentrations during the 1st, 2nd or 3rd oestrous cycles, on fertility in ewe lambs. Twenty-five ewe lambs were mated at puberty on mean date of 18 October and 21 were mated at third oestrus on 3 December. Of these, 28% and 81% of animals mated at puberty and third oestrus lambed, respectively (P < 0·05). A similar number of ewe lambs were mated within 24 h of ram introduction in the groups given one, two or three consecutive applications oestrogen and progestagen (25 μg oestradiol benzoate followed 48 h later by a progestagen pessary left in situ for days). Of the 43 corpora lutea, 21 were represented by viable embryos in the 37 animals holding to service after one application compared with 34 out of 46 corpora lutea in 40 animals given three applications (P < 0·05). Furthermore, embryo crown-rump length, embryo weight and amniotic sac width was greater (P < 0·05), on day of pregnancy, in animals given one compared with three applications of oestrogen and progestagen. These results demonstrate that fertility is improved in ewe lambs mated on third oestrus or after progestagen and oestrogen therapy designed to simulate three oestrous cycles.

Relative clauses in Agul from a corpus-based perspective

2020 ◽  
Vol 73 (1) ◽  
pp. 113-158
Author(s):  
Timur Maisak
Keyword(s):  
High Frequency ◽  
Relative Clauses ◽  
High Ratio ◽  
The Other ◽  
The Core ◽  
Text Corpora ◽  
The Asymmetry ◽  
Intransitive Verbs ◽  
Syntactic Restrictions ◽  
Locative Case

AbstractThis paper gives an account of participial clauses in Agul (Lezgic, Nakh-Daghestanian), based on a sample of 858 headed noun-modifying clauses taken from two text corpora, one spoken and one written. Noun-modifying clauses in Agul do not show syntactic restrictions on what can be relativized, and hence they instantiate the type known as GNMCCs, or general noun-modifying clause constructions. As the text counts show, intransitive verbs are more frequent than transitives and experiencer verbs in participial clauses, and among intransitive verbs, locative statives with the roots ‘be’ and ‘stay, remain’ account for half of all the uses. The asymmetry between the different relativization targets is also significant. Among the core arguments, the intransitive subject (S) is the most frequent target, patient (P) occupies second place, and agent (A) is comparatively rare. The preference of S and, in general, of S and P over A also holds true for most other Nakh-Daghestanian languages for which comparable counts are available. At the same time, Agul stands apart from the other languages by its high ratio of non-core relativization which accounts for 42% of all participial clauses. Addressee, arguments and adjuncts encoded with a locative case, as well as more general place and time relativizations show especially high frequency, outnumbering such arguments as experiencers, recipients, and predicative and adnominal possessors. Possible reasons for the high ratio of non-argument relativization are discussed in the paper.

Reproductive Biology and Development of the Water Rat, Hydromys chrysogaster, in Captivity

1982 ◽  
Vol 9 (1) ◽  
pp. 39 ◽  
Author(s):  
PD Olsen
Keyword(s):  
Breeding Season ◽  
Developmental Stages ◽  
Post Partum ◽  
Growth Curves ◽  
Gestation Length ◽  
Body Measurements ◽  
Sperm Production ◽  
Crown Rump Length ◽  
Rate Of Increase ◽  
Hydromys Chrysogaster

In a captive colony of H. chrysogaster most litters were born between September and March, although some were born in every month except June. Most females had regular oestrous cycles in the breeding season but there were isolated instances of oestrus in every month. In mature males, testes were scrota1 and there was full sperm production all year. There was some regression in weight of male accessory reproductive glands in the autumn and winter. Oestrus lasted 10 days (range 7-17), and its stages: pro-oestrus 1 day, oestrus 2 days, metoestrus 2 days, anoestrus 5 days. Some instances of delayed implantation were suspected. Gestation length was 34 days (33-41). Parturition was followed the next day by a postpartum oestrus, lasting 1 day. Lactation anoestrus was at least 3 weeks. Litter size was 3.29 � 1.26 (1-7) and the number of litters per breeding season was 2.6 � 0.97 (1-5). In the latter half of pregnancy there was a linear relationship between the crown-rump length of foetuses and gestation length. Young were born naked, blind and with the pinnae folded forward with edges attached to the head. The upper incisors emerged at 4 days, the lower incisors at 6 days, the auditory meatus opened at about 10 days, the eyes opened at about 14 days, some solids were eaten and young were more independent at about 3 weeks of age, and they were weaned at about 29 days. Phases in the rate of increase in weight were associated with each of these developmental stages. Females were first capable of breeding at 124 days (433 g); most matured about 240 days in the season following that of their birth. The testes descended in males between 90 and 120 days (475 g) but full sperm production did not occur until about 130-140 days. Females could breed for three seasons (until about 3.5 y old). Placental scars were visible for up to 6 months, but had sometimes disappeared at 4 months post partum. Growth curves of tail and weight were sigmoid, and those of other body measurements were exponential, as in the Rattus group of Australian rodents, and differing from the pseudomyine rodents. Body measurements showed a sigmoid relationship to the linear equivalence of body weight. Developmental events occurred earlier, in relation to growth, in Hydromys and Rattus lutreolus than in Pseudomys novaehollandiae.

Reproductive success of ewe lambs after a period of exposure to vasectomised rams

1988 ◽  
Vol 1988 ◽  
pp. 89-89
Author(s):  
N.Z. Al-Mauly ◽  
M.J. Bryant ◽  
F.J. Cunningham
Keyword(s):  
Reproductive Success ◽  
Breeding Season ◽  
Early Embryo ◽  
Ewe Lambs ◽  
Embryo Loss

The fertility of ewe lambs is usually lower than that of mature ewes. Early embryo loss has been implicated as a cause of reduced fertility, especially when matings occur at the pubertal oestrus (Hare and Bryant, 1985). The Introduction of vasectomised rams to ewe lambs may hasten the occurrence of puberty and, if the introduction of fertile rams is not advanced, mating may occur later in the breeding season with possible advantages to fertility. This experiment investigated the effects of a period of association with vasectomised rams preceding the introduction of entire rams upon (1) the occurrence of puberty, and (2) the fertility of ewe lambs.

scholarly journals Variations in Calcium Use by Birds During the Breeding Season

The Condor ◽  
2001 ◽  
Vol 103 (3) ◽  
pp. 592-598 ◽  
Author(s):  
André A. Dhondt ◽  
Wesley M. Hochachka
Keyword(s):  
Breeding Season ◽  
High Frequency ◽  
Molothrus Ater ◽  
Egg Laying ◽  
Surprising Result ◽  
Very High Frequency ◽  
Cyanocitta Cristata ◽  
Egg Formation ◽  
Calcium Sources ◽  
Very High

Abstract During the breeding season birds need increased amounts of dietary calcium during egg laying and nestling rearing. Passerines acquire calcium shortly before and during laying and do not store calcium for egg formation. Many passerines need to eat extraneous calcium in the form of snail shells or calcareous grit to acquire the element. However, very little is known about variation in the dependency of birds on extraneous calcium, and where this calcium is acquired. Using reports from volunteers who provided extraneous calcium sources at feeder sites across North America we documented that (1) the use of extraneous calcium varied during the breeding season; (2) the location in which species preferentially took the calcium varied with typical feeding location, aside from swallows which, somewhat surprisingly, favored calcium offered on the ground; (3) Brown-headed Cowbirds (Molothrus ater) did not visit calcium sites more often than other blackbirds; (4) calcium use varied among species with thrushes, wrens, and woodpeckers taking calcium only rarely, and swallows, pigeons, and corvids taking calcium frequently. The most surprising result perhaps was the very high frequency of calcium use in jays; Blue Jays (Cyanocitta cristata) may hoard calcium in the fall. Variaciones en el Uso de Calcio por Aves durante la Época Reproductiva Resumen. En la época reproductiva, las aves necesitan incrementar la cantidad de calcio en la dieta durante el período de postura de huevos y cría de los pichones. Las aves paserinas adquieren calcio poco antes y durante la postura y no lo almacenan para la formación de los huevos. Muchas aves paserinas necesitan ingerir calcio de fuentes externas como conchas de caracoles o cascajo calcáreo para adquirir este elemento. Sin embargo, se sabe muy poco sobre la variación en el grado de dependencia de las aves de calcio externo y sobre dónde adquieren este calcio. Con base en reportes de voluntarios que suministraron fuentes externas de calcio en comederos a través de Norteamérica, documentamos que (1) el uso de calcio externo varió durante la época reproductiva; (2) el sitio en donde las especies tomaron el calcio preferencialmente varió de acuerdo al sitio típico de alimentación, con excepción de las golondrinas, que de manera algo sorprendente, prefirieron el calcio ofrecido en el suelo; (3) Molothrus ater no visitó sitios con calcio con más frecuencia que otros ictéridos; (4) el uso de calcio varió entre especies: los túrdidos, troglodítidos y carpinteros muy rara vez tomaron calcio, mientras que las golondrinas, palomas y córvidos lo hicieron frecuentemente. Quizás el resultado más sorprendente fue la muy alta frecuencia de uso de calcio en Cyanocitta; C. cristata podría acumular calcio durante el otoño para uso futuro.

HIGH FREQUENCY OF 3:1 TETRAD RATIOS FOR THE PDX-1 LOCUS OF NEUROSPORA CRASSA

1969 ◽  
Vol 11 (1) ◽  
pp. 60-64 ◽  
Author(s):  
A. Radford ◽  
S. F. H. Threlkeld
Keyword(s):  
Neurospora Crassa ◽  
Gene Conversion ◽  
High Frequency ◽  
High Ratio ◽  
The Other ◽  
Linked Gene

Nine crosses, involving three alleles, were used in a study of recombination at the pdx-1 locus of Neurospora. In two of the crosses, an unusually high ratio of apparent gene conversion was observed, Two asci of the aberrant type were analyzed by means of prototrophs from backcrosses. In one case the ascus was confirmed as an example of genuine gene conversion. In the other, however, the original scoring of the ascus was found to be due to the presence of a closely linked gene capable of modifying the expression of the two conditional pdx-1 mutants used in the study.

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