Calving date and its variability as a potential trait in the breeding objective to account for reproductive seasonality in alpacas

2020 ◽  
Vol 55 (7) ◽  
pp. 814-821
Author(s):  
Alan Cruz ◽  
Juan Pablo Gutiérrez ◽  
Richard Torres ◽  
Nora Formoso‐Rafferty ◽  
Renzo Morante ◽  
...  
Keyword(s):  
Reproductive Seasonality ◽  
Breeding Objective

scholarly journals The LEPR Gene Is Associated with Reproductive Seasonality Traits in Rasa Aragonesa Sheep

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2448
Author(s):  
Kenza Lakhssassi ◽  
Malena Serrano ◽  
Belén Lahoz ◽  
María Pilar Sarto ◽  
Laura Pilar Iguácel ◽  
...  
Keyword(s):  
Amino Acid Change ◽  
Leptin Receptor ◽  
Extreme Values ◽  
Reproductive Traits ◽  
Reproductive Seasonality ◽  
Synonymous Substitutions ◽  
Lepr Gene ◽  
Exon 20 ◽  
First Time

The aim of this study was to characterize and identify causative polymorphisms in the leptin receptor (LEPR) gene responsible for the seasonal variation of reproductive traits in sheep. Three reproductive seasonality traits were studied: the total days of anoestrous (TDA), the progesterone cycling months (P4CM) and the oestrous cycling months (OCM). In total, 18 SNPs were detected in 33 ewes with extreme values for TDA and OCM. Six SNPs were non-synonymous substitutions and two of them were predicted in silico as deleterious: rs596133197 and rs403578195. These polymorphisms were then validated in 239 ewes. The SNP rs403578195, located in exon 8 and leading to a change of alanine to glycine (Ala284Gly) in the extracellular domain of the protein, was associated with the OCM trait, being the G allele associated with a decrease of 12 percent of the OCM trait. Haplotype analyses also suggested the involvement of other non-synonymous SNP located in exon 20 (rs405459906). This SNP also produces an amino acid change (Lys1069Glu) in the intracellular domain of the protein and segregates independently of rs403578195. These results confirm for the first time the role of the LEPR gene in sheep reproductive seasonality.

scholarly journals Habitat characteristics and life history explain reproductive seasonality in lagomorphs

2021 ◽  
Author(s):  
Sandra A. Heldstab
Keyword(s):  
Life History ◽  
Reproductive Output ◽  
Quantitative Measure ◽  
Habitat Characteristics ◽  
Comparative Approach ◽  
Mean Annual Temperature ◽  
Season Length ◽  
Reproductive Seasonality ◽  
Birth Season ◽  
Birth Seasonality

AbstractLagomorphs show extensive seasonal variation in their reproduction. However, the factors causing this large variation have so far mostly been investigated intraspecifically and therefore provide only some exemplary comparisons of lagomorph reproductive seasonality. The present study applies both a categorical description (birth season categories 1–5) and a quantitative measure (birth season length in months) to summarize the degree of birth seasonality in the wild of 69 lagomorph species. Using a comparative approach, I tested the influence of 13 factors, comprising six habitat, five life history and two allometric variables on birth season length in lagomorphs. Leporids mainly show non-seasonal birthing patterns with high intraspecific variation. Their opportunistic breeding strategy with high reproductive output and their large distribution areas across wide latitude and elevation ranges might be the reasons for this finding. Ochotonids reproduce strictly seasonally, likely because they live at northern latitudes, are high-altitude specialists, and occur in limited distribution areas. The most important factors associated with variation in lagomorph birth seasonality are mid-latitude, mean annual temperature and precipitation of a species’ geographical range and life history adaptations including fewer but larger litters in seasonal habitats. Birth seasons become shorter with increasing latitude, colder temperatures, and less precipitation, corresponding to the decreasing length of optimal environmental conditions. Leporid species with shorter breeding seasons force maternal resources into few large litters to maximise reproductive output while circumstances are favourable. Since allometric variables were only weakly associated with reproductive seasonality, life history adaptations and habitat characteristics determine birth seasonality in Lagomorpha.

Reproductive seasonality in wild northern pig-tailed macaques (Macaca leonina)

Primates ◽  
2021 ◽  
Author(s):  
Florian Trébouet ◽  
Suchinda Malaivijitnond ◽  
Ulrich H. Reichard
Keyword(s):  
Reproductive Seasonality ◽  
Macaca Leonina

scholarly journals Comparison of two live-animal ultrasound systems for genetic evaluation of carcass traits in Angus cattle

2021 ◽  
Author(s):  
C J Duff ◽  
J H J van der Werf ◽  
P F Parnell ◽  
S A Clark
Keyword(s):  
Carcass Traits ◽  
Genetic Correlations ◽  
Subcutaneous Fat ◽  
Genetic Evaluation ◽  
Ultrasound Scan ◽  
Ultrasound Scanning ◽  
Eye Muscle ◽  
Angus Cattle ◽  
Breeding Objective ◽  
Two Systems

Abstract The improvement of carcass traits is an important breeding objective in beef cattle breeding programs. The most common way of selecting for improvement in carcass traits is via indirect selection using ultrasound scanning of selection candidates which are submitted to genetic evaluation programs. Two systems used to analyse ultrasound images to predict carcass traits are the Pie Medical Esaote Aquila (PIE) and Central Ultrasound Processing (CUP). This study compared the ability of the two systems to predict carcass traits for genetic evaluation in Australian Angus cattle. Genetic and phenotypic parameters were estimated using data from 1648 Angus steers which were ultrasound scanned twice with both systems, first at feedlot entry and then following 100 days in the feedlot. The traits interpreted from ultrasound scanning included eye muscle area (EMA), rib fat (RIB) rump fat (RUMP) and intramuscular fat (IMF). Abattoir carcass data were collected on all steers following the full feedlot feeding period of 285 days. For all ultrasound scan traits, CUP resulted in higher phenotypic and genetic variances compared to the PIE. For IMF, CUP had higher heritability at feedlot intake (0.51 for CUP compared to 0.37 for PIE) and after 100 days feeding (0.54 for CUP compared to 0.45 PIE). CUP predicted IMF also tended to have stronger correlations with the breeding objective traits of carcass IMF marbling traits, both genetically (ranging from 0.59 to 0.75 for CUP compared to 0.45 to 0.63 for PIE) and phenotypically (ranging from 0.27 to 0.43 for CUP compared to 0.19 to 0.28 for PIE). Ultrasound scan EMA were the only group of traits in which the heritabilities were higher for PIE (0.52 for PIE compared to 0.40 for CUP at feedlot intake and 0.46 for PIE compared to 0.43 for CUP at 100 days of feeding), however with similar relationships to the breeding objective carcass EMA observed. For subcutaneous fat traits of ultrasound RIB and RUMP, the heritabilites and genetic correlations to the related carcass traits were similar, with the exception being the higher heritability observed for CUP predicted RUMP at feedlot intake at 0.52 compared to 0.38 for PIE. The results from this study indicates that the CUP system, compared to PIE, provides an advantage for genetic evaluation of carcass traits in Angus cattle, particularly for the IMF and associated marbling traits.

KARYOTYPES AND REPRODUCTIVE SEASONALITY OF THE GENUS BANGIA (RHODOPHYTA) IN BRITISH COLUMBIA, CANADA1

1983 ◽  
Vol 19 (2) ◽  
pp. 136-145 ◽  
Author(s):  
Kathleen M. Cole ◽  
Beverly J. Hymes ◽  
Robert G. Sheath
Keyword(s):  
British Columbia ◽  
Reproductive Seasonality

Reproductive seasonality and the effect of the GnRH agonist deslorelin as a contraceptive in captive male Black Flying-foxes (Pteropus alecto)

2012 ◽  
Vol 77 (3) ◽  
pp. 652-661 ◽  
Author(s):  
D.F. Melville ◽  
G.M. O'Brien ◽  
E.G. Crichton ◽  
P. Theilemann ◽  
A. McKinnon ◽  
...  
Keyword(s):  
Gnrh Agonist ◽  
Reproductive Seasonality ◽  
Flying Foxes

scholarly journals Claw health and feed efficiency as new selection criteria in the Czech Holstein cattle Krupová Z., Wolfová M., Krupa E., Přibyl J., Zavadilová L.

2018 ◽  
Vol 63 (No. 10) ◽  
pp. 408-418 ◽  
Author(s):  
Z. Krupová ◽  
M. Wolfová ◽  
E. Krupa ◽  
J. Přibyl ◽  
L. Zavadilová
Keyword(s):  
Feed Intake ◽  
Feed Efficiency ◽  
Disease Incidence ◽  
Selection Index ◽  
Residual Feed Intake ◽  
Selection Response ◽  
Holstein Cattle ◽  
Breeding Objective ◽  
Economic Weights ◽  
The Impact

The objective of this study was to calculate economic weights for ten current breeding objective traits and for four new traits characterising claw health and feed efficiency in Czech Holstein cattle and to investigate the impact of different selection indices on the genetic responses for these traits. Economic weights were estimated using a bio-economic model, while applying actual (2017) and predicted (2025) production and economic circumstances. For the actual situation, the economic weights of claw disease incidence were –100.1 € per case, and those of daily residual feed intake in cows, breeding heifers, and fattened animals were –79.37, –37.16, and –6.33 €/kg dry matter intake per day, respectively. In the predicted situation, the marginal economic weights for claw disease and feed efficiency traits increased on average by 38% and 20%, respectively. The new traits, claw disease incidence and daily residual feed intake, were gradually added to the 17 current Holstein selection index traits to improve the new traits. Constructing a comprehensive index with 21 traits and applying the general principles of the selection index theory, a favourable annual genetic selection response was obtained for the new traits (–0.008 cases of claw disease incidence and –0.006 kg of daily residual feed intake across all cattle categories), keeping the annual selection response of the most important current breeding objective traits at a satisfactory level (e.g., 73 kg of milk yield per lactation, 0.016% of milk fat). Claw health and feed efficiency should be defined as new breeding objectives and new selection index traits of local dairy population.

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