REGIONAL DIFFERENCES IN REPRODUCTIVE TRAITS OF THE SNOWSHOE HARE

1966 ◽  
Vol 44 (5) ◽  
pp. 953-961 ◽  
Author(s):  
Lloyd B. Keith ◽  
Orrin J. Rongstad ◽  
E. Charles Meslow
Keyword(s):  
Litter Size ◽  
Adult Female ◽  
Regional Differences ◽  
Reproductive Traits ◽  
Geographic Range ◽  
Lepus Americanus ◽  
Species Range ◽  
Snowshoe Hare ◽  
Breeding Female ◽  
Genetically Determined

Reproductive characteristics of the snowshoe hare (Lepus americanus) over its principal geographic range were summarised. The onset of breeding each spring was chronologically similar throughout a major portion of the species' range, although Alaska hares tended to be about 2 weeks later than those elsewhere. Mean litter size increased significantly from south to north, and studies with captive snowshoes demonstrated that such regional differences are genetically determined. Both the average number of litters, and the average number of young, per adult female per year were greatest at intermediate latitudes. It is suggested that regional differences in mean litter size reflect the general "fitness" of the breeding female and (or) her young relative to their particular environment, as governed by the physiological consequences of species adaptation and of reproduction.

scholarly journals Estimating snowshoe hare population density from pellet plots: a further evaluation

2001 ◽  
Vol 79 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Charles J Krebs ◽  
Rudy Boonstra ◽  
Vilis Nams ◽  
Mark O'Donoghue ◽  
Karen E Hodges ◽  
...  
Keyword(s):  
Population Density ◽  
Strong Relationship ◽  
Geographic Range ◽  
Lepus Americanus ◽  
Snowshoe Hare ◽  
Fecal Pellets ◽  
Density Estimates ◽  
Snowshoe Hares ◽  
Pellet Counts ◽  
Hare Population

We counted fecal pellets of snowshoe hares (Lepus americanus) once a year in 10 areas in the southwestern Yukon from 1987 to 1996. Pellets in eighty 0.155-m2 quadrats were counted and cleared each June on all areas, and we correlated these counts with estimates of absolute hare density obtained by intensive mark–recapture methods in the same areas. There is a strong relationship between pellet counts and population density (r = 0.76), and we present a predictive log–log regression to quantify this relationship, which improves on our previously published 1987 regression, particularly at low hare densities. The precision of density estimates can be improved most easily by increasing the number of sets of quadrats in an area (one set = 80 plots), rather than increasing the number of plots counted within one set. The most important question remaining concerns the generality of this relationship for snowshoe hares living in other habitats in the eastern and southern portions of their geographic range.

scholarly journals The impact of maternal genetic merit and country of origin on ewe reproductive performance, lambing performance and ewe survival

2021 ◽  
Author(s):  
N Fetherstone ◽  
N McHugh ◽  
T M Boland ◽  
F M McGovern
Keyword(s):  
New Zealand ◽  
Birth Weight ◽  
Litter Size ◽  
Country Of Origin ◽  
Reproductive Traits ◽  
Gestation Length ◽  
Genetic Merit ◽  
Genetic Groups ◽  
One Year ◽  
The Impact

Abstract The objective of this study was to investigate the impact of the ewe’s maternal genetic merit and country of origin (New Zealand or Ireland) on ewe reproductive, lambing and productivity traits. The study was performed over a four year period (2016 to 2019) and consisted of three genetic groups: high maternal genetic merit New Zealand (NZ), high maternal genetic merit Irish (High Irish) and low maternal genetic merit Irish (Low Irish) ewes. Each group contained 30 Suffolk and 30 Texel ewes, selected based on the respective national maternal genetic indexes; i.e. either the New Zealand Maternal Worth (New Zealand group) or the €uro-star Replacement index (Irish groups). The impact of maternal genetic merit on reproductive traits such as litter size; lambing traits such as gestation length, birth weight, lambing difficulty, mothering ability, and productivity traits such as the number of lambs born and weaned were analyzed using linear mixed models. For binary traits, the impact of maternal genetic merit on reproductive traits such as conception to first AI service; lambing traits such as dystocia, perinatal lamb mortality and productivity traits such as ewe survival were analyzed using logistic regression. New Zealand ewes outperformed Low Irish ewes for conception to first AI (P<0.05) and litter size (P=0.05). Irish ewes were more likely to suffer from dystocia (6.84 (High Irish) and 8.25 (Low Irish) times) compared to NZ ewes (P<0.001); birth weight and perinatal mortality did not differ between groups (P>0.05). Lambs born from NZ ewes were 4.67 (95% CI: 1.89 to 11.55; P<0.001) and 6.54 (95% CI: 2.56 to 16.71; P<0.001) times more likely to stand up and suckle unassisted relative to lambs born from High or Low Irish ewes, respectively. New Zealand and High Irish ewes had a greater number of lambs born and weaned throughout the duration of the study compared to their Low Irish counterparts (P<0.001). New Zealand ewes tended to be more likely to survive from one year to the next compared to Low Irish ewes (P=0.07). Irish ewes of high maternal genetic merit outperformed their Low counterparts in total number of lambs born and weaned per ewe, but performance did not differ across other traits investigated. This highlights the importance of continuous development of the Irish maternal sheep index to ensure favourable improvements in reproductive, lambing and productivity traits at farm level. Overall, results demonstrate the suitability of NZ genetics in an Irish production system.

scholarly journals Northern Goshawk, Accipiter gentilis, Exploits a Beagle Hound, Canis familiaris, as a "Beater" to Catch a Snowshoe Hare, Lepus americanus

2007 ◽  
Vol 121 (3) ◽  
pp. 329
Author(s):  
John T. Neville
Keyword(s):  
Canis Familiaris ◽  
First Record ◽  
Lepus Americanus ◽  
Accipiter Gentilis ◽  
Snowshoe Hare ◽  
Northern Goshawk

During a winter Snowshoe Hare (Lepus americanus) hunt with a beagle hound (Canis familiaris), I observed an adult Northern Goshawk (Accipiter gentilis) exploiting the running, barking hound as a “beater” and use strategic locations for attacks. The hawk made three attacks on a hare being pursued by the hound, and subsequently caught and killed it. To my knowledge, this report represents the first record of a Northern Goshawk using this behavior to capture prey.

scholarly journals Association of RBP4 Genotype with Phenotypic Reproductive Traits of Sows

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
A. Marantidis ◽  
G. P. Laliotis ◽  
M. Avdi
Keyword(s):  
Litter Size ◽  
Negative Impact ◽  
Reproductive Traits ◽  
Retinol Binding Protein ◽  
Rapid Improvement ◽  
Retinol Binding Protein 4 ◽  
Reproductive Characteristics ◽  
Pcr Rflp ◽  
Hardy Weinberg Equilibrium ◽  
Rbp4 Gene

PCR-RFLP was applied to a commercial crossbred pig population in order to investigate the association between polymorphism (SNP) of Retinol-binding protein 4 (RBP4) gene and reproductive performance. 400 sows were genotyped and 2000 records of reproductive traits were used in order to retrieve information about the allele frequencies and the association of the RBP4 gene with main reproductive characteristics of the population. A deviation from the Hardy-Weinberg equilibrium was observed as a result of the AB genotype excess. In addition, the AA genotype saw statistically significant higher values of (i) the total number of born piglets (p<0.05), (ii) the number of piglets born alive (p<0.01), and (iii) the number of weaned piglets (p<0.01). The number of the mummified piglets and the number of the piglets born dead did not differ between the various RBP4 genotypes. Interestingly, the AA genotype had a negative impact (p<0.05) on the number of piglets born dead, resulting indirectly in a larger litter size. In conclusion, the AA genotype and in extension the A allele of RBP4 gene are in favor of producing larger litter size, suggesting that the RBP4 gene may be used in Marker-Assisted Selection (MAS) programs for a rapid improvement of the reproductive characteristics in pigs.

scholarly journals Reptilia, Serpentes, Dipsadidae, Gomesophis brasiliensis (Gomes, 1918): distribution extension in state of Santa Catarina, Brazil

Check List ◽  
2010 ◽  
Vol 6 (3) ◽  
pp. 414 ◽  
Author(s):  
Vanessa Barbisan Fortes ◽  
Elaine Maria Lucas ◽  
Vinícius Matheus Caldart
Keyword(s):  
Rio Grande ◽  
Wide Distribution ◽  
Geographic Range ◽  
Species Range ◽  
Rio Grande Do Sul ◽  
Aquatic Habitats ◽  
The West ◽  
Santa Catarina ◽  
Distrito Federal ◽  
South Brazil

The Brazilian burrowing snake, Gomesophis brasiliensis, occurs in aquatic habitats such as swamps, from Minas Gerais and Distrito Federal until Rio Grande do Sul. In spite of this wide distribution, the species’ geographic range still remains unclear. This note reports the occurrence of G. brasiliensis in the municipality of Vargem Bonita, state of Santa Catarina, south Brazil, extending the species’ range ca. 80 km to the west in this state.

scholarly journals Akkaraman Koyunlarında Gebeliği Son Döneminde Yapılan Ek Yemlemenin Kuzularda Doğum ve Çeşitli Dönemlerdeki Canlı Ağırlıklar Üzerine Etkisi

2017 ◽  
Vol 5 (11) ◽  
pp. 1353
Author(s):  
Emre Şirin ◽  
Ümit Uçan ◽  
Uğur Şen ◽  
Ercan Soydan
Keyword(s):  
Wheat Straw ◽  
Litter Size ◽  
Survival Rates ◽  
Reproductive Traits ◽  
Late Gestation ◽  
Control Group ◽  
Supplemental Feeding ◽  
Feed Supplement ◽  
Birth Season ◽  
Birth Type

This study was carried out to determine of effect of supplemental feeding during the late gestation on birth and other weights of lambs from Akkaraman sheep breed raised in Kırşehir. Data were collected from 554 Akkaraman lambs from 580 Akkaraman sheep which were born during 2015 birth season. Akkaraman sheep were divided into two groups. Wheat straw is given to both groups during pregnancy. Supplemental feeding group group (EYG), was given to concentrated feed supplement (400 g/animal) in addition to wheat straw during the last gestation period. Control group (KG) was given only wheat straw during pregnancy. In this study, the live weights, survival rates of the lambs in various periods and reproductive traits of Akkaraman ewes were investigated. The averages of reproductive traits of Akkarman sheep such as sterility, fertility, twins, abortion, fecundity and litter size in EYG and KG groups were %12, %9, %86, %91, %13, %5, %2, %0, 0.96, 0.95 and 1.12, 1.04, respectively. The survival rates of lambs on 90th days and 150th days in EYG and KG groups were determined as 84, 80% and 91, 91%, respectively. The means of the birth, 90 and 150. days age live weights in EYG and KG groups were found as 5.82±0.06 kg, 30.94±0.44 kg, 34.47±0.44 kg and 3.43±0.04 kg, 30.17±0.04 kg, 30.96±0.38 kg respectively. The effects of supplemental feeding, sex and birth type were found to be significant on the 120. days age on birth and live weights of sheep. The effects of birth type were found to be significant on the 90. days age live weights of sheep. As a result, supplemental feeding during the late gestation are increased live weights.

scholarly journals Association of non-synonymous SNPs of <i>OPN</i> gene with litter size traits in pigs

2015 ◽  
Vol 58 (2) ◽  
pp. 317-323 ◽  
Author(s):  
T. Kumchoo ◽  
S. Mekchay
Keyword(s):  
Litter Size ◽  
Reproductive Traits ◽  
Snp Markers ◽  
Strong Linkage Disequilibrium ◽  
Nucleotide Polymorphisms ◽  
Large White ◽  
Single Nucleotide ◽  
Pcr Rflp ◽  
Polymerase Chain ◽  
Acid Exchange

Abstract. Osteopontin (OPN) gene is a secreted phosphoprotein which appears to play a key function in the conceptus implantation, placentation and maintenance of pregnancy in pigs. The objectives of this study were to verify the non-synonymous single nucleotide polymorphisms (SNPs) and their association with litter size traits in commercial Thai Large White pigs. A total of 320 Thai Large White sows were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Three SNPs at c.425G> A, c.573T> C and c.881C> T revealed amino acid exchange rates of p.110Ala> Thr, p.159Val> Ala and p.262Pro> Ser, respectively, and were then segregated. These three SNPs were significantly associated with total number born (TNB) and number born alive (NBA) traits. No polymorphisms of the two SNP markers (c.278A> G and c.452T> G) were observed in this study. Moreover, the SNPs at c.425G> A and c.573T> C were found to be in strong linkage disequilibrium. The association of OPN with litter size emphasizes the importance of porcine OPN as a candidate gene for reproductive traits in pig breeding.

scholarly journals Potential connectivity among American lobster fisheries as a result of larval drift across the species’ range in eastern North America

2017 ◽  
Author(s):  
Brady K. Quinn ◽  
Joël Chassé ◽  
Rémy Rochette
Keyword(s):  
Fisheries Management ◽  
Management Strategies ◽  
Homarus Americanus ◽  
Geographic Range ◽  
Species Range ◽  
Eastern North America ◽  
American Lobster ◽  
Larval Release ◽  
Larval Drift ◽  
First Time

We used a bio-physical model to estimate for the first time the effect of larval drift on potential connectivity among American lobster (Homarus americanus) fisheries management areas over the geographic range of the species. The model predicted drift of larvae over distances of 50-805 km (mean = 129 km), which connected many management areas and caused marked spatial heterogeneity in retention and self-seeding versus export and import of larvae by different fisheries areas. Including mortality functions in the model resulted in less drift and settlement, and had complex effects on the amount, but not the incidence, of potential connectivity among fisheries. The model’s predictions received support from comparison of predicted settlement to landings six or seven years later in some (but not all) parts of the model domain. Although improvements are still needed to capture larval behaviours and spatial variability in larval release and mortality across the species’ range, this information is important to lobster fisheries management because the amount and direction of connectivity between fisheries can inform cooperative management strategies to sustain interconnected fisheries.

scholarly journals Molecular Characterization and Expression Profiles of the Ovine LHβ Gene and Its Association with Litter Size in Chinese Indigenous Small-Tailed Han Sheep

Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 460 ◽  
Author(s):  
Weimin Wang ◽  
Yongfu La ◽  
Fadi Li ◽  
Shijia Liu ◽  
Xiangyu Pan ◽  
...  
Keyword(s):  
Litter Size ◽  
Cdna Sequence ◽  
Expression Profiles ◽  
Follicular Development ◽  
Reproductive Traits ◽  
Granular Cells ◽  
Glycoprotein Hormone ◽  
Breeding Programs ◽  
Sheep Breeding ◽  
Qpcr Analysis

The luteinizing hormone beta polypeptide (LHβ) is a glycoprotein hormone secreted by basophilic granular cells of the adenohypophysis, and plays an important role in mammalian follicular development. In this study, we cloned and analyzed the cDNA sequence of the ovine LHβ gene. RT-qPCR analysis showed that ovine LHβ was widely expressed in tissues, with significantly higher expression in the hypophysis than that in other tissues (heart, liver, spleen, lung, kidney, rumen, duodenum, muscle, fat, hypothalamus, and sex glands) (p < 0.01). Hypophyseal expression of LHβ mRNA in lamb increased with age and reached a peak at 70 days, although a slight decrease was observed at 84 days of age. In addition, the synonymous mutation g.727C > T detected in the LHβ gene was confirmed to be significantly associated with the litter size (p < 0.01). Ewes carrying the TT genotype produced more lambs than those carrying the TC and CC genotypes (0.42 and 0.39 per delivery, respectively; p < 0.05). Our results confirm the association of ovine LHβ with litter size in Small-Tailed Han Sheep and implicate LHβ as a candidate for improving reproductive traits in agricultural sheep breeding programs.

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