scholarly journals Non genetic factors affecting rabbit reproduction in Algeria

2010 ◽  
Vol 10 (3) ◽  
pp. 103-109 ◽  
Author(s):  
S. Belhadi ◽  
M. Boukir ◽  
L. Amriou

Environmental variability of reproductive traits has been investigated on a pool of 51 does of different origin in a rabbit breeding unit in Tizi Ouzou region. The objective was to estimate the effects of different factors such as kindling season, parity, physiological state of does, and number born alive on characters such as acceptation rate, conception and kindling rate by female, total born alive, stillborn, litter size at weaning, pre-weaning and post-weaning mortality and weekly litter weights from birth to weaning. Mean bunny weight at birth, at weaning and 70 days of age, litter weight at 70 days of age and total litter gain during lactation have also been considered. Results show that kindling season affects only litter size at weaning with favourable effect of autumn ad spring (7.8 vs 6.6). Highest mean weights at birth are recorded in autumn (16.2 g more than others) and highest litter weights at weaning during the three seasons other than summer (700 g more). The highest mean weight at 70 days is obtained in winter (1.9 Kg). For parity effect, we have recorded the greatest conception and kindling rates at the beginning of reproductive life (98.7 and 96.03% respectively). Other performances did not vary according to this factor. Lactating females at mating had the same acceptation, conception and kindling rate and similar litter sizes as no lactating; however, superior values were obtained for non lactating does for litter size. Moreover, differences due to effect of number born alive on weekly mean weights were significant. However, this effect fades down at 70 days of age.

2010 ◽  
Vol 18 (2) ◽  
pp. 111
Author(s):  
S.O. Oseni ◽  
B.A. Ajayi

<span style="font-size: small;"><span style="font-size: 13px; line-height: 14px;">Thi study evaluated the effect of female body weight at conception (FWC), season of mating (SM), type of mating (TM) and litter size at birth (LSB) on the litter performance in a heterogeneous Nigerian population of rabbits. Data on 116 litters from 10 bucks and 48 does across three parities were analysed. Reproductive traits evaluated included LSB, number born alive (NBA), litter sizes and weights at 7, 14 and 21 d post-kindling, pre-weaning survival rate (SR) and daily weight gain of kits from kindling to weaning (DWG). A fi xed linear model that included FWC (light and heavy does), TM (homospermic and heterospermic matings), LSB classes (low, medium and large) and SM (rainy or dry) was used. Results showed that heavier does at concenption showed higher performance for LSB and NBA (P&lt;0.05) than lighter does. Average weight of kits at kindling and at 28 d, as well as kit SR and DWG, were signifi cantly higher in low-sized litters, when compared with intermediate- and large-sized litters (P&lt;0.05). LSB, NBA and litter size at weaning were higher in litters produced by heterospermically mated does compared with homospermically mated does. Season of mating affected LSB and NBA (P&lt;0.05), being signifi cantly larger the litters in the rainy season.</span></span>


Author(s):  
N Fetherstone ◽  
N McHugh ◽  
T M Boland ◽  
F M McGovern

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&lt;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&lt;0.001); birth weight and perinatal mortality did not differ between groups (P&gt;0.05). Lambs born from NZ ewes were 4.67 (95% CI: 1.89 to 11.55; P&lt;0.001) and 6.54 (95% CI: 2.56 to 16.71; P&lt;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&lt;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.


2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
A. Marantidis ◽  
G. P. Laliotis ◽  
M. Avdi

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.


Author(s):  
Emre Şirin ◽  
Ümit Uçan ◽  
Uğur Şen ◽  
Ercan Soydan

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.


2015 ◽  
Vol 58 (2) ◽  
pp. 317-323 ◽  
Author(s):  
T. Kumchoo ◽  
S. Mekchay

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.


2021 ◽  
Author(s):  
Simon Benmaamar ◽  
◽  
Björn Brembs

Environmental variability during the development of an organism has known impacts on the expression of certain behavioural patterns. We used the fruit fly Drosophila melanogaster to investigate how different environmental conditions interact with the allelic variants of rover (forR) and sitter (fors) at the foraging locus to affect food-related behaviour of larvae. We discovered that larval density and nutrient availability were key environmental factors affecting the larval behaviour during early development. High larval density decreased the tendency of rovers to leave a food patch and reduced their travelled path lengths, such that rovers and sitters showed no more significant differences regarding their behaviour. Similar results were obtained when starving the larvae. Furthermore, cutting the availability only of specific nutrients such as sugar, fat or protein during development all affected larval foraging behaviour and locomotion.


2019 ◽  
Vol 65 (3-4) ◽  
pp. 77-84 ◽  
Author(s):  
Rida Sultanova ◽  
Ildar I. Gabitov ◽  
Yulai A. Yanbaev ◽  
Fitrat G. Yumaguzhin ◽  
Maria V. Martynova ◽  
...  

The management of beekeeping on forest lands is a vivid manifestation of the multifunctional use of forests, which is based on its target cultivation. The work shows the development of beekeeping, identifies factors affecting the sustainable development of this industry, sets priorities for increasing the efficiency of utilization of forest honey resources of the Southern Urals, including the main melliferous - Tilia cordata Mill. The nature and characteristics of the influence of weather and climatic factors on the growth of bee colonies, their physiological state, composition, age representation of natural melliferous woody plants, the onset dates and the duration of their flowering were determined. It was found that, of the silvicultural and inventory indicators, the composition and age, density and type of forest most strongly influence the yield of honey. The activities of forest care are close to them in terms of importance. A system of organizational measures has been proposed, through which high efficiency of using forest feed resources and sustainable development of beekeeping can be achieved: keeping an optimal number of bee colonies in an apiary - up to 150 hives, based on providing one bee colony of 50-60 thousand individuals with at least 130 kg of nectar; the location of apiaries in the 3-kilometer zone of growth of forest melliferous plants, taking into account the productive emergence of bees in the 2.5-3.0 km; establishing clear nomadic routes based on a geobotanic inventory of forest and agricultural melliferous plants. Increasing the target indicator - the nectar productivity of forests without a gap in their use both in space and in time - can be achieved by growing multi-tiered forests of different age from Tilia cordata Mill.


Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 460 ◽  
Author(s):  
Weimin Wang ◽  
Yongfu La ◽  
Fadi Li ◽  
Shijia Liu ◽  
Xiangyu Pan ◽  
...  

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.


2010 ◽  
Vol 37 (2) ◽  
pp. 261-264
Author(s):  
L. A. Bermejo ◽  
M. Mellado ◽  
J. Mata ◽  
J. R. Arévalo ◽  
L. De Nascimento ◽  
...  

2007 ◽  
Vol 28 (4) ◽  
pp. 509-515 ◽  
Author(s):  
Yuan-Ting Jin ◽  
Nai-Fa Liu

Abstract Phrynocephalus vlangalii, a toad-headed viviparous sand lizard, is endemic in the Northern Tibet (Qinghai) Plateau in China. Lizards were collected from 14 localities along the large altitudinal gradient (2289-4565 m a.s.l) to analyze the variation of reproductive traits among localities. Both litter size and mean offspring (scaled embryo) mass were positively correlated with female snout-vent length (SVL). Females produced fewer and larger offspring with increasing elevation when the effect of body size (SVL) was removed. This strategy may possibly be correlated with early survival and growth of offspring. The decreased litter size cline along altitudinal gradient might be correlated with more anatomical constraints at higher altitudes. The lizard has lower coefficient of variation (CV) of litter size at higher environments. Moreover, females from higher elevations had less reproductive investment (relative litter mass, RLM). Study concluded that P. vlangalii fit into the common pattern of higher elevation animals that have smaller clutches of larger offspring and lower reproductive effort.


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