Analysis Of Reproductive Traits Research Articles

Polymorphism of the Growth Hormone Gene (G.2141C>G) in Cattle Populations: Analysis of Reproductive Traits

Polymorphism of the Growth Hormone Gene (G.2141C>G) in Cattle Populations: Analysis of Reproductive Traits

Evolutionary systematics of the viviparous gastropod Sermyla (Gastropoda: Cerithioidea: Thiaridae), with the description of a new species

Abstract While most Cerithioidea are marine, some occur in brackish and freshwater habitats. Many members are systematically problematic due to variability or homoplasy in conchological characters, which has led to taxonomic redundancy, but also because of discrepancies between phylogenetic trees and morphologically distinguishable units as revealed in recent molecular genetic studies. We have chosen an evolutionary systematic approach and combine analyses of shell biometry and geometric morphometrics with the analyses of reproductive traits and molecular genetics based on mtDNA and AFLP markers in order to resolve the relationships among species of the genus Sermyla. We describe a new species from Sulawesi, Sermyla kupaensis sp. nov., which is characterized by a distinct reproductive strategy. This unique reproductive strategy corresponds with its distinct molecular genetic signal. However, it is not possible to distinguish S. kupaensis from S. riquetii based on shell morphology alone. We also provide data on the population structure of the endemic Australian species Sermyla carbonata, for which we found a drainage-based population structure. Overall, we present a new concept of the relationships among the species within the genus Sermyla based on morphological and genetic data.

Assessing the Effect of SNPs on Litter Traits in Pigs.

The reproductive ability of sows is the principle of continuous and efficient production, based on such traits as the number of piglets, the total number of parities, and the period of economic use. Currently, SNPs associated with the TNB and NBA are presented in the PigQTLdb. The aim of this work was the assessment of the SNP effects on the litter traits in Large White (LW, n = 502) and Landrace (LN, n = 432) sow breeds in a farm in Russia. 9 SNPs (SNP_1: rs80956812; SNP_2: rs81471381; SNP_3: rs80891106; SNP_4: rs81399474; SNP_5: rs81421148; SNP_6: rs81242222; SNP_7: rs81319839; SNP_8: rs81312912; SNP_9: rs80962240) were selected for the study. Associative analysis was performed using the GLM procedure in R version 3.5.1. The analysis of reproductive traits was carried out according to the results of the first parity, the second and subsequent parities, and totals for lifetime of sows. The significant effect on litter traits in LW was determined for SNP rs80956812, SNP rs81471381, SNP rs81421148, and SNP rs81399474. The significant effect on litter traits in LN was determined for SNP rs81421148 and SNP rs81319839. AKT3 gene was identified as perspective candidate gene, whose biological functions, as well as the results obtained in our work and in other studies, indicate its potential role in the reproductive process regulation in pigs. In general, the data obtained help to explain the genetic mechanisms of reproductive traits.

Analysis of Reproductive Traits in the Painted Stork (Mycteria leucocephala)

The aim of the present study was focused on analysis of reproductive traits in the painted stork (Mycteria leucocephala). The analysis of partial reproductive traits was intended to complete the knowledge necessary for ensuring reproduction of the painted stork in captivity on the required level. The observation was performed in the Zoo Zlín – Lešná from 2011 to 2014. The eggs were measured and weighed after laying and then in several‑day intervals. Other observed traits were hatchability of the eggs, number of raised young birds and their weight after hatching. During whole observation period, a total of 90 eggs of the painted stork were evaluated from 12 parental pairs. The average share of fertilized eggs was 38.9 %. Average length of eggs was 68.57 mm, average width was 46.43 mm and average weight was 79.79 g. Average weight loss of eggs during their incubation was 9.87 g. Average hatchability of all the laid eggs was 27.8 %. Average hatchability of the fertilized eggs was 71.4 %. A total of 23 young painted storks were hatched during the observation period. Their average hatching weight was 57.04 g. The overall number of 11 individuals were raised during the four years of observation.

Biological and morphological aspects of Branchiobdella italica (Annelida: Clitellata) in a native crayfish population of central Italy

The present study aimed to improve the knowledge of the biology of Branchiobdella italica, a symbiontic worm on the white-clawed crayfish Austropotamobius pallipes, with particular attention to the feeding strategy, infestation and colonization ability, and morphology. Branchiobdellids occurred most frequently on adult crayfish rather than juveniles, due to the larger size of the former that permit a higher colonization by epizoic organisms, and to the high moult rate of smaller crayfish. We did not observe massive infestations of branchiobdellids, and the few specimens found do not seem to influence crayfish health. The higher occurrence of branchiobdellids took place on the A. pallipes carapace where worms find trophic resources. Gut content analysis of B. italica showed a generalist feeding strategy. The presence of fungal hyphae found within the gut of B. italica could lead us to infer that branchiobdellids could contribute to limit the fungal growth on the exoskeleton or on eggs of their host. Histological analysis of reproductive traits does not show structural differences from those referred to previous descriptions; the observation of one or two ciliated funnels (not always two), and the absence of hooks or spines on the penis surface, represent the main exceptions. Additional studies are needed to assess the true nature of the symbiosis between branchiobdellids and their hosts.

Associations between polymorphism of the steroid 21-hydroxylase gene (<i>CYP21</i>) and litter size of Polish Large White × Polish Landrace sows* (short communication)

Abstract. research because of the large economic impact these discoveries could have on the swine industry. The steroid 21-hydroxylase (CYP21) gene is located on chromosome 7 in the middle of the swine leukocyte antigen class (SLA) is regarded as a "candidate – gene" reproduction traits. Associations between polymorphism of the steroid 21-hydroxylase gene (CYP21) and litter size of Polish Large White × Polish Landrace sows were analysed. The 21-hydroxylase genotypes of all 286 animals were determined using a PCR-RFLP procedure. The frequencies of genotypes and alleles of CYP21/NciI and CYP21/HaeIII were follows: 0.077 – AA, 0.308 – AB, 0.615 – BB and 0.231 for CYP21/NciIA, 0.769 for CYP21/NciIB; 0.010 – AA, 0.420 – AB, 0.570 – BB and 0.221 for CYP21/HaeIIIA and 0.779 for CYP21/HaeIIIB. The CYP21/NciI genotype was significantly associated with the total number of piglets born, born alive and alive at weaning in the 5th – 10th parities. The sows with BB genotype had significantly (P≤0.01) higher level of traits than the animals with AB genotype. Analysis of reproductive traits in dependence on CYP21/NciI genotypes showed the statistically significant differences (P≤0.05) in number of piglets died before the day of weaned in 2-4 parities. The lowest value of this trait was found for the sows with the AB genotype (2.05%), while the highest – for the pigs with BB genotype (3.54%). Associations between CYP21/HaeIII and reproduction traits were not observed.

Analysis of reproductive traits in crosses among maternal lines of rabbits

A crossbreeding experiment, between three maternal lines of rabbits, was carried out to estimate the effects of the crosses on reproductive traits. The experiment was designed as a complete diallel cross involving the lines, A, V and H, selected for litter size. A total of 1190 does, distributed between the nine types originating from the diallel cross, and born, reared and bred on the same com- mercial farm, were controlled. The recorded traits were the total number of young born, the number of born alive and the number of stillborn per litter (3759 records), and the interval between kindlings (2505 records). A repeatability animal model was used first to obtain the REML estimates of the com- ponents of variance. This was followed by a generalised least squares analysis and the estimates of the type of doe effects were obtained. Finally the differences among the lines within direct and maternal effects, and the corresponding values of the individual heterosis were estimated. Important differ- ences in the direct effects were found between lines V and A. All the maternal effects were not signifi- cant. Favourable heterosis (4-10%) was found for prolificacy traits in the crosses of line A with lines V and H, being the heterosis, very dependent on the performance and history of the lines involved. reproduction / crosses / maternal / lines / rabbits

Identifying Targets of Selection: A Multivariate Analysis of Reproductive Traits in the Great Tit

In order to identify the true targets of phenotypic selection, we carried out a multivariate analysis on three reproductive traits in an urban population of great tits in Tartu, south-east Estonia, using data collected during 1987-1994. Individuals laying large eggs consistently recruited more offspring into the breeding population, independent of the simultaneous effects of clutch size and laying date. However, the mean egg size of a clutch was not related to the occurrence of embryonal or nestling mortality, which points to the possibility that the relationship between egg size and recruitment rate was due to the effects of female quality. Early breeders tended to recruit more offspring into the breeding population, but the effect of laying date disappeared when egg size was incorporated into the model. This fact indicates that the primary target of selection was not laying date per se but some property of the female affecting both laying date and egg size. Selection on clutch size fluctuated in direction between years. Selection against large clutches operated above all on individuals with small eggs, suggesting that the fitness consequences of similar reproductive decisions are different for individuals of different quality.

Evaluation of the performance of british landrace pigs under tropical conditions of zimbabwe

British Landrace (BL) is used widely as a dam breed in producing crossbred sows for commercial pig production in Zimbabwe. This study was undertaken to evaluate the performance of BL under current level of management in Zimbabwe and to make recommendation for improvement of productivity.The records for this study were obtained from a nucleus/multiplier farm. The data included 720 litters from BL sows over the five year period 1983 - 1987. The reproductive traits analysed, number born alive (NBA), number weaned (NW), total litter weight at birth (TLWB) kg, at weaning (TLWW), age at first litter (AFL) days, days weaning to effective service (DWES) and farrowing interval (FI) days, were from both pure and crossbred matings. The performance data, daily gain (DG) and food conversion ratio (FCR) between 35 - 86 kg and k backfat thickness (BF) at 86 kg, were from 620 performance tested BL pigs. The data were analysed by least-squares procedures. The fixed effect included in the analysis of reproductive traits were the sire breed of the litter, the dam parity and the year and season of birth of litter. The effects considered for the performance data were the year and season of performance test and the sex. The season according to month of birth of litter, farrowing, rebreedlng or performance test was classified as cold (April - July), dry (August - November) or rainy (December - March). For all the traits, typical model included the above fixed effects and two-way Interactions.

An analysis of reproductive traits in beef cattle.

An analysis of reproductive traits in beef cattle.