Breeding Stage Research Articles

Manual Versus Semiautomated Bioacoustic Analysis Methods of Multiple Vocalizations in Tricolored Blackbird Colonies

Abstract Bioacoustic monitoring can reveal aspects of animal behavior because many species vocalize in association with certain behaviors. Despite this, bioacoustics remain infrequently used to monitor animal behavior because of lack of knowledge of how vocalizations relate to behavior and the challenge of efficiently analyzing the large acoustic data sets necessary to capture relevant behaviors. Vocalizations and associated behaviors have been previously established for the colonial tricolored blackbird Agelaius tricolor, but efficient analysis of the acoustic data remains a challenge. Previous work with tricolored blackbird acoustic data relied on manually listening to recordings, which is not practical on large scales. Using software to automatically detect vocalizations of interest has potential to reduce analysis time. However, automated detection is prone to errors often caused by faint vocalizations, overlapping calls, and background noise. Thus, incorporating components of manual and automated analysis of acoustic data sets remains essential. To address these challenges, we deployed autonomous recording units at three tricolored blackbird colonies in California from 2019 to 2021 and analyzed acoustic data using a manual and a semiautomated analysis method. Specifically, we used tricolored blackbird male song, male chorus, female song, hatchling call, nestling call, and fledgling call to determine the approximate timing of breeding stages and number of breeding attempts, or pulses, for each colony. We found that using a semiautomated approach was more time efficient than manual analysis, while using comparable numbers of recordings and obtaining equivalent information from the colonies. The odds of correct detections of vocalizations using the semiautomated method were generally lower for fainter vocalizations and colonies with high background noise. Overall, the semiautomated approach had tolerable rates of recall, precision, false positives, and false negatives. Our methodology adds to a growing body of literature addressing acoustic analyses, especially for colonial species and where questions of breeding phenology are important.

Optimizing selection of wheat genotypes through simulated individual BLUP and modified simulated individual BLUP

AbstractThe early stages of wheat breeding programs often contain large number of plants in segregating populations that must be selected. Selecting the best populations and plants in those stages is not an easy task, making it necessary to use robust methodologies that facilitate the selection process. The goals of this work were to evaluate different methods for the selection of individual plants in early wheat breeding stages, compare the efficiency of each method, and suggest the most suitable one for implementation in wheat breeding programs. An experiment with 56 F2 segregant populations derived from a complete diallel, together with eight parents, was conducted and evaluated for grain yield (g pL−1). Analysis of variance and mixed model analysis were applied to obtain the genetic parameters and predict genotypic values. Four selection strategies were designed: mass selection and other three mixed model‐based methods (individual best linear unbiased prediction [BLUPI]; simulated individual best linear unbiased prediction [BLUPIS]; and modified simulated individual best linear unbiased [BLPISM]). The genotypic variability among and within populations allowed the selection of superior genotypes. Simple linear regression analysis and Spearman correlation analysis allowed to conclude that BLUPIS and BLUPISM are equivalent to BLUPI. The BLUPIS and BLUPISM should be used because they easily indicate for the selection of plants in populations with positive genetic effects, dismissing the evaluation of individual plants.

Prevalence and distribution of antibiotic resistance in the water environment of sea bass (Lateolabrax maculatus) breeding area in spring in South China

Antibiotic resistance represents a global health crisis for humans, animals, and the environment. However, few studies address the abundance and distribution of the environmental bacterial antibiotic resistance associated with farmed fish during the early breeding stages and their relationship with aquaculture environment. In this study, culture-dependent methods and gene chip technology were respectively used to identify and detect cultivable heterotrophic antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) of water samples from 20 sea bass-rearing ponds in spring in Zhuhai, China. Meanwhile, the relationships among ARGs, ARB, and water nutrients were elucidated. The results showed that bacterial resistance to erythromycin and sulfamethoxazole with trimethoprim was generally high (mean 48.15% and 18.07%, respectively), whereas resistance to rifampicin, florfenicol, ciprofloxacin, and enrofloxacin was generally low (mean 5.46%, 2.16%, 1.43%, and 0.16%, respectively). Acinetobacter sp. (42.31%) and Pseudomonas sp. (25.74%) were the dominant ARB, and most cultivable ARB were opportunistic pathogens. The abundance of sul family genes was higher than that of other tested ARGs. ARGs and ARB were mainly affected by NO3– and PO43–, with PO43– generally positively correlated, whereas NO3– was negatively correlated, with ARGs and ARB. Thus, recommendations for the control of antibiotic resistance risk can be made by understanding the resistance profile of the aquaculture environment.

First description of injury feigning behavior in Godlewski's buntings.

Nest defense behavior helps ground-nesting birds improve their breeding success. Among such behaviors, injury feigning behavior (IFB) is one of the better ways to attract predators and protect birds' nests. IFB is generally associated with shorebirds in general and plovers in particular, however, through field observation, it has been found this behavior is also exhibited in bunting species when they facing the risk of predation. We attempt to explore the detailed description of this behavior in buntings and the factors that affect this behavior. Based on video-recordings of the nest defense behavior by the ground-nesting bird Godlewski's bunting (Emberiza godlewskii) against nest invaders, we explored the characteristic of IFB and differences in nest defense behavior during their brooding seasons. The results showed that female buntings had a distinct IFB: the wings of buntings incited within 60°-90° of the body, ran and called rapidly, pretending to be injured and unable to fly. The nest stage had significant and extremely significant effects on IFB and movement distance (MD), respectively. And IFB was more likely to occur in brooding (34.62%) than incubation period (16.42%). This indicates that there are significant differences in the IFB of buntings at different breeding stages.

육계의 생애주기 및 AI를 고려한 수급 및 가격 예측모형 개발을 위한 연구

This study analyzes the supply-demand and price prediction model considering the life cycle (breeding stage) of broilers. For this purpose, the supply and demand and price were predicted by considering the life cycle of broilers from the Parents Stock to the slaughter stage using Vector Error Correction Model and the Gated Recurrent Unit, based on the data for the last 10 years. Factors that did not affect the dependent variable were excluded through multiple regression analysis during the prediction process. As a result of the supply and demand forecasting, it was found that the forecast results through Vector Error Correction Model showed a small deviation compared to Gated Recurrent Unit. However, in the case of Gated Recurrent Unit, However, in the case of Gated Recurrent Unit, it was found that the accuracy of the prediction values and the similarity of the patterns improved as the number of learning times increased. On the other hand, in both models, the accuracy of the price prediction result was found to be quite low. For more accurate prediction, it is necessary to increase the size of the data through shortening of the data generation cycle and data segmentation for each broiler life cycle.

Regulation mechanism and functional verification of key functional genes regulating muscle development in black Tibetan sheep

Black Tibetan sheep is a branch of Tibetan sheep on the Qinghai-Tibet Plateau (QTP). It is mainly distributed in Guinan County, Qinghai Province. In order to accurately identify the core regulatory genes in the process of muscle development of black Tibetan sheep, further explore the physiological processes of growth, development and myogenesis of black Tibetan sheep, and carry out molecular breeding of black Tibetan sheep, this experiment took the unique black Tibetan sheep on the Qinghai-Tibet Plateau as the experimental object, and selected three stages of 4-month-old embryo (embryonic stage, MF group), 10-month-old(breeding stage, ML group) and 36-month-old (adult, MA group). The longissimus dorsi tissues of 3 sheep were taken at each stage to quantify the expression of genes during muscle development at different developmental stages. Meanwhile, overexpression and interference techniques were used to detect the role of core genes in the proliferation of primary muscle cells of black Tibetan sheep. In the process from embryonic stage to mature stage and adulthood, more than 1000 genes were up-regulated and more than 4000 down-regulated in black Tibetan sheep, while from breeding to adulthood, there were only 51 up-regulated genes and 83 down-regulated genes. About 998 genes were newly identified in each group. During muscle development from embryonic stage to mature stage to adulthood, two significant differential trend gene sets of Profile1 and Profile 6 were screened and identified, in which there were 121 and 31 core regulatory genes identified, respectively. In the trend of first decreasing and then stable expression in the whole development stage, 121 genes are core regulatory transcripts, which are mainly related to axonal guidance, cell cycle and other functions. 31 genes are core regulatory transcripts in the first rising and then stable expression, which are mainly related to biological metabolic pathway, oxidative phosphorylation and other processes. In the MF-ML stage, 75 genes were selected as the core regulatory gene set, the core genes were PTEN, AKT3, etc., and there were 134 differentially expressed genes in the ML-MA stage, and the core regulatory genes were IL6, ABCA1 and so on. In the MF-ML stage, the core gene set widely plays a role in cell components, cell matrix and other biological processes, while in the ML-MA stage, the core gene set widely plays a role in cell migration, cell differentiation, tissue development and so on. Adenovirus vector overexpressed and interfered with the core gene PTEN in primary muscle satellite cells of black Tibetan sheep shown that, interference and overexpression of PTEN would correspondingly increase and decrease the expression of other core genes, like AKT3, CKD2, CCNB1, ERBB3, HDAC2, but the specific interaction mechanism of each gene still needs to be further explored.

Поліморфізм мікросателітних локусів хромосоми 5H ячменю (Hordeum vulgare L.) і асоціації алелів з морозостійкістю

Barley (Hordeum vulgare L.) is a crop of great economic importance for many countries of the world, including Ukraine. One of the main reason limiting barley production in different regions of Ukraine is low-temperature stress. Prediction of frost resistance in the development and choice of resistant genotypes is one of the main tasks of the breeding. Applying the tools of molecular genetic analysis involves increasing the efficiency of traditional methods of identification and genotype screening with the necessary traits in a specific climatic area. The 5H chromosomal loci are a component of a complex system of genes involved in the formation of resistance to low negative temperatures. The polymorphism and allele distribution of nine microsatellite loci in chromosome 5H, which are localisation in the region of the key NT- resistance genes Fr-H1, Fr-H2 and close to these regions in 35 varieties of the autumn barley collection, were studied. Allelic polymorphism with the presence of two (UMB702) to five (Bmag0223) alleles was detected at the loci Bmag0223, Bmag0323, Bmag0760, GMS061 and UMB702. The frost resistance of 31 varieties with different durations of hardening was evaluated and essential differences between them were noted for this feature. According to the results of the analysis of polymorphism of microsatellite loci and data on evaluation of varieties for frost resistance, the connection of allelic differences of four out of five polymorphic loci with the level of frost resistance and hardening rates was revealed. Reliable associations were established between the presence of alleles Bmag0223, Bmag0323, Bmag0760, GMS061 and indicators of the level of frost resistance. Allelic differences at the UMB702 locus were not associated with differences in any of the traits. Alleles of the microsatellite locus Bmag0223 are recommended for negative choice of less frost-resistant barley genotypes at the early plant breeding stages.

Identification of the key morphological sweetpotato weevil resistance predictors in Ugandan sweetpotato genotypes using correlation and path‐coefficient analysis

AbstractSweetpotato weevils (SPWs) can cause up to 100% yield losses in sweetpotato (Ipomoea batatas). Nevertheless, there has been limited success in breeding for SPW resistance globally. This is attributed partly to difficulty in screening for resistance because resistance to the SPW is complex and is mediated by several resistance indicators. Measuring all these resistance indicators is costly and time consuming. To enhance efficiency in selection for SPW resistance, there is need to profile and identify key resistance indicators. Potentially, this will better enable breeders to timely and precisely select for SPW resistance. The objective of this study was to identify the most efficient morphological resistance indicators against SPW. Thirty sweetpotato genotypes that varied in resistance to SPW comprising local collections, released varieties, and breeding lines were evaluated at three locations for two seasons in Uganda using an alpha lattice design. Data were collected on storage root yield, SPW root and stem damage, and weevil resistance indicators such as vine vigor (VV), ground cover (GC), vine weight (VW), storage root neck length (NL), latex content, cortex thickness (CT), and dry matter content (DM). Genotype means for all measured traits varied significantly except for CT. Negative relationships were observed between SPW root damage and GC, VW, CT, VV, NL, and DM. However, path coefficient analysis showed storage root NL (direct effect of −0.43, p < 0.001) as the most important morphological resistance indicator. Therefore, NL could be the most reliable predictor of resistance to SPW among breeding clones, especially at early breeding stages.

Experimental study on the microseismic response characteristics of coal and gas outbursts

A microseismic monitoring simulation experiment of coal and gas outbursts was carried out to study the microseismic response characteristics of the coal and gas outburst process. The microseismic response characteristics were analyzed from the microseismic waveform and time frequency at each stage of the outburst process. The quantitative description of the outburst process was achieved by the statistical analysis of microseismic signals and the determination of the microseismic energy index of outburst hazards. The results showed that the coal and gas outburst process included four stages: preparation, start, development, and stop, and the outburst moment is at the development stage. The protruding hole in the experiment was an ellipsoid with a small mouth and large cavity. Frequency components were complex and extensive and tended to high frequencies at the prominent stage. The frequency of the microseismic response waveform at the moment of prominence was higher than that before and after prominence, but energy at the moment of prominence was not maximum. Sudden changes in amplitudes at the preparation and development stages had more outbursts, and the maximum equivalent energy at the moment of prominence was as high as 45,000 Hz. Compared with the local high amplitude at the preparation stage, the development stage presents an overall high amplitude. Although the start stage is calmer, it is a critical period for predicting outbursts, and the microseismic activity characteristics of the outburst stage differed significantly from those of the other three stages. Quantitative indices reflecting the risk strength of coal and gas outbursts at the breeding stage were defined from microseismic energy, and the outburst risk indices under experimental conditions were established. When L1 < 3.64, L2 < 0.16, and L3 < 5.74, the coal mass had a weak outburst risk; when L1 > 3.64, L2 > 2.33, and L3 > 5.74, it had strong outburst risks. The research results provide an idea for coal and gas outburst precursor information and dynamic early warning.

Detection and counting method of juvenile abalones based on improved SSD network

Detection and counting of abalones is one of key technologies of abalones breeding density estimation. The abalones in the breeding stage are small in size, densely distributed, and occluded between individuals, so the existing object detection algorithms have low precision for detecting the abalones in the breeding stage. To solve this problem, a detection and counting method of juvenile abalones based on improved SSD network is proposed in this research. The innovation points of this method are: Firstly, the multi-layer feature dynamic fusion method is proposed to obtain more color and texture information and improve detection precision of juvenile abalones with small size; secondly, the multi-scale attention feature extraction method is proposed to highlight shape and edge feature information of juvenile abalones and increase detection precision of juvenile abalones with dense distribution and individual coverage; finally, the loss feedback training method is used to increase the diversity of data and the pixels of juvenile abalones in the images to get the even higher detection precision of juvenile abalones with small size. The experimental results show that the AP@0.5 value, AP@0.7 value and AP@0.75 value of the detection results of the proposed method are 91.14%, 89.90% and 80.14%, respectively. The precision and recall rates of the counting results are 99.59% and 97.74%, respectively, which are superior to the counting results of SSD, FSSD, MutualGuide, EfficientDet and VarifocalNet models. The proposed method can provide support for real-time monitoring of aquaculture density for juvenile abalones.

Full-length 16S rRNA gene sequencing and machine learning reveal the bacterial composition of inhalable particles from two different breeding stages in a piggery

Bacterial loading aggravates the harm of particulate matter (PM) to public health and ecological systems, especially in operations of concentrated animal production. This study aimed to explore the characteristics and influencing factors of bacterial components of inhalable particles at a piggery. The morphology and elemental composition of coarse particles (PM10, aerodynamic diameter ≤ 10 µm) and fine particles (PM2.5, aerodynamic diameter ≤ 2.5 µm) were analyzed. Full-length 16 S rRNA sequencing technology was used to identify bacterial components according to breeding stage, particle size, and diurnal rhythm. Machine learning (ML) algorithms were used to further explore the relationship between bacteria and the environment. The results showed that the morphology of particles in the piggery differed, and the morphologies of the suspected bacterial components were elliptical deposited particles. Full-length 16 S rRNA indicated that most of the airborne bacteria in the fattening and gestation houses were bacilli. The analysis of beta diversity and difference between samples showed that the relative abundance of some bacteria in PM2.5 was significantly higher than that in PM10 at the same pig house (P < 0.01). There were significant differences in the bacterial composition of inhalable particles between the fattening and gestation houses (P < 0.01). The aggregated boosted tree (ABT) model showed that PM2.5 had a great influence on airborne bacteria among air pollutants. Fast expectation-maximization microbial source tracking (FEAST) showed that feces was a major potential source of airborne bacteria in pig houses (contribution 52.64–80.58 %). These results will provide a scientific basis for exploring the potential risks of airborne bacteria in a piggery to human and animal health.

Differential kleptoparasitic interactions of Himalayan Vulture Gyps himalayensis with conspecifics and heterospecifics during various stages of breeding

Reports of kleptoparasitic events involving Gyps himalayensis (Himalayan Vulture) are limited. In this article we document intraspecific and interspecific kleptoparasitic interactions at nesting sites, and analyse factors influencing this behaviour. The study was carried out at Hirpora Wildlife Sanctuary of Kashmir Himalaya, at an elevation of about 2,546 m. We observed 61 instances of food theft involving conspecifics (n = 12) and heterospecifics (n = 49). The highest number of incidents were observed during the chick rearing period (n=40), followed by incubation (n = 10) and pre-laying periods (n = 5). We observed the highest number of attacks at nesting sites (n = 30) and the lowest in flight (n = 9).

Sex-mediated changes in foraging behaviour according to breeding stage in a monomorphic seabird adapted to rural habitats

Sex-mediated changes in foraging behaviour according to breeding stage in a monomorphic seabird adapted to rural habitats

Evaluation of a Sugarcane (Saccharum spp.) Hybrid F1 Population Phenotypic Diversity and Construction of a Rapid Sucrose Yield Estimation Model for Breeding.

Sugarcane is the major sugar-producing crop worldwide, and hybrid F1 populations are the primary populations used in breeding. Challenged by the sugarcane genome's complexity and the sucrose yield's quantitative nature, phenotypic selection is still the most commonly used approach for high-sucrose yield sugarcane breeding. In this study, a hybrid F1 population containing 135 hybrids was constructed and evaluated for 11 traits (sucrose yield (SY) and its related traits) in a randomized complete-block design during two consecutive growing seasons. The results revealed that all the traits exhibited distinct variation, with the coefficient of variation (CV) ranging from 0.09 to 0.35, the Shannon-Wiener diversity index (H') ranging between 2.64 and 2.98, and the broad-sense heritability ranging from 0.75 to 0.84. Correlation analysis revealed complex correlations between the traits, with 30 trait pairs being significantly correlated. Eight traits, including stalk number (SN), stalk diameter (SD), internode length (IL), stalk height (SH), stalk weight (SW), Brix (B), sucrose content (SC), and yield (Y), were significantly positively correlated with sucrose yield (SY). Cluster analysis based on the 11 traits divided the 135 F1 hybrids into three groups, with 55 hybrids in Group I, 69 hybrids in Group II, and 11 hybrids in Group III. The principal component analysis indicated that the values of the first four major components' vectors were greater than 1 and the cumulative contribution rate reached 80.93%. Based on the main component values of all samples, 24 F1 genotypes had greater values than the high-yielding parent 'ROC22' and were selected for the next breeding stage. A rapid sucrose yield estimation equation was established using four easily measured sucrose yield-related traits through multivariable linear stepwise regression. The model was subsequently confirmed using 26 sugarcane cultivars and 24 F1 hybrids. This study concludes that the sugarcane F1 population holds great genetic diversity in sucrose yield-related traits. The sucrose yield estimation model, ySY=2.01xSN+8.32xSD+0.79xB+3.44xSH-47.64, can aid to breed sugarcane varieties with high sucrose yield.

Stable Isotope Differences among Species, Sexes, and Breeding Stages of Laysan and Black-Footed Albatrosses in the Western North Pacific

In order to understand the diet of Laysan Albatross Phoebastria immutabilis and Black-footed Albatross P. nigripes in western North Pacific waters, we investigated isotopic differences between species, sexes and breeding stages. We measured carbon and nitrogen isotope ratios in the muscles and livers of albatrosses (caught during Japanese pelagic longline fishing) and in their potential prey. Both δ 13C and δ15N of Black-footed Albatross were higher than those of Laysan Albatross. Delta13C of both species differed seasonally and δ13C was lower during the incubation period than during the chick-provisioning and non-breeding periods. The δ 13C and δ15N levels of males did not differ from those of females in either species. Our results suggest that Black-footed Albatross forages on higher isotope prey items and/or Laysan Albatross forages on lower isotope prey items other than squid and fish and that δ13C varies in response to seasonal variation in prey availability. This implies that Black-footed Albatross forages more on discard from the fishing industry than does Laysan Albatross; this in turn may be related to the areas of operation sea area of the longline fisheries in the western North Pacific. In conclusion, it is important for conservation of these two albatross species to monitor their diets and foraging areas and to identify the species-specific high-risk areas where albatross bycatch is most likely.

How Female-Female Competition Affects Male-Male Competition: Insights into Postcopulatory Sexual Selection from Socially Polyandrous Species.

AbstractSexual selection is a major driver of trait variation, and the intensity of male competition for mating opportunities has been linked with sperm size across diverse taxa. Mating competition among females may also shape the evolution of sperm traits, but the effect of the interplay between female-female competition and male-male competition on sperm morphology is not well understood. We evaluated variation in sperm morphology in two species with socially polyandrous mating systems, in which females compete to mate with multiple males. Northern jacanas (Jacana spinosa) and wattled jacanas (J. jacana) vary in their degree of social polyandry and sexual dimorphism, suggesting species differences in the intensity of sexual selection. We compared mean and variance in sperm head, midpiece, and tail length between species and breeding stages because these measures have been associated with the intensity of sperm competition. We found that the species with greater polyandry, northern jacana, has sperm with longer midpieces and tails as well as marginally lower intraejaculate variation in tail length. Intraejaculate variation was also significantly lower in copulating males than in incubating males, suggesting flexibility in sperm production as males cycle between breeding stages. Our results indicate that stronger female-female competition for mating opportunities may also shape more intense male-male competition by selecting for longer and less variable sperm traits. These findings extend frameworks developed in socially monogamous species to reveal that sperm competition may be an important evolutionary force layered atop female-female competition for mates.

Male‐specific nocturnal song functions similarly to day song in a diurnal bird species

AbstractHistorically, birdsong research has been biased towards song of male birds at dawn and during the day, even though some diurnal birds sing at night. To address this gap, we studied how song in the willie wagtail, Rhipidura leucophrys—a diurnal species with prolific male‐specific nocturnal song during the breeding season—varies with time of day, breeding status and simulated intrusions. We recorded male nocturnal and dawn song over three breeding seasons and examined how this related to fertile and non‐fertile breeding stages of females. To test whether song functions for territory defence, we simulated territorial intrusion experimentally in both sexes with daytime and nighttime playback of male and female song. To test whether nocturnal song could function for mate guarding or post‐pairing mate attraction, we describe the mating system of willie wagtails using molecular genetic methods. We showed that both nocturnal and day song of male willie wagtails has roles in mate attraction and territory defence, while day song by females functioned primarily for territorial defence. Males increased song behaviour during fertile periods of resident females, suggesting possible roles in mate stimulation and mate guarding. Males and females responded similarly to simulated daytime intrusions and no differences were seen in male responses dependent on the time of day. We found 10%–14% of offspring were fathered by extra‐pair males, suggesting song may also function for mate guarding and post‐pairing mate attraction. In a species with small repertoires and simple songs like the willie wagtail, differences between males in overall song output achieved through nocturnal singing may be important in mate attraction and territory defence.

Prevalence of pleuromutilin antibiotic resistance genes in different laying hen breeding stages in China.

Antimicrobial resistance is a rapidly evolving and extremely complex issue, particularly due to the use of various types of antimicrobials within human, animal, and environmental sectors. Pleuromutilin antibiotics are used to prevent and control respiratory diseases in the rearing stage of hen chicks, but the current status of pleuromutilin resistance in the laying hen breeding process is unclear. ATP-binding cassette transporters encoded by lsa(A), lsa(E), lsa(C), and vga(D) can be transferred by plasmids and transposons, thereby posing a potential dissemination risk. To investigate pleuromutilin resistance genes in the laying hen production chain in China, 95 samples from five environmental types were collected in four breeding stages to determine the abundances of the main resistance genes by qPCR, i.e. lsa(A), lsa(E), lsa(C), and vga(D). The abundance (5.16 log10GC/g) and detection rate (100%) of lsa(E) was highest in all of the samples, thereby suggesting high contamination with the lsa(E) gene across the large-scale laying hen breeding environment and feces. The lsa(A) (6.02 log10GC/g) and lsa(E) (6.18 log10GC/g) genes were most abundant in flies, and the abundance of vga(D) (4.50 log10GC/g) was highest in dust (P<.05). In addition to feces, flies and dust were important sources of contamination with pleuromutilin resistance along the laying hen production chain. In summary, we determined the abundances of four pleuromutilin resistance genes in the laying hen production chain and provided direct evidence of pleuromutilin resistance transmission and environmental contamination. In particular, the chicken breeding stage needs further attention.

Prolactin promotes crop epithelial proliferation of domestic pigeons (Columba livia) through the Hippo signaling pathway.

The purpose of this study was to investigate whether prolactin (PRL) regulates the proliferation of pigeon crop epithelium through the Hippo signaling pathway during the breeding cycle. Twenty-four pairs of adult pigeons were allotted to four groups by different breeding stages, and their crops and serum were sampled. Eighteen pairs of young pigeons were selected and divided into three groups for the injection experiments. The results showed that the serum PRL content and crop epithelial thickness of pigeons increased significantly at day 17 of incubation (I17) and day 1 of chick-rearing (R1). In males, the mRNA levels of yes-associated transcriptional regulator (YAP) and snail family transcriptional repressor 2 (SNAI2) were peaked at I17, and the gene levels of large tumor suppressor kinase 1 (LATS1), serine/threonine kinase 3 (STK3), TEA domain transcription factor 3 (TEAD3), connective tissue growth factor (CTGF), MYC proto-oncogene (c-Myc) and SRY-box transcription factor 2 (SOX2) reached the maximum value at R1. In females, the gene expression of YAP, STK3, TEAD3, and SOX2 reached the greatest level at I17, the expression profile of SAV1, CTGF, and c-Myc were maximized at R1. In males, the protein levels of LATS1 and YAP were maximized at R1 and the CTGF expression was upregulated at I17. In females, LATS1, YAP, and CTGF reached a maximum value at I17, and the expression level of phosphorylated YAP was minimized at I17 in males and females. Subcutaneous injection of prolactin (injected for 6 d, 10 μg per kg body weight every day) on the left crop of pigeons can promote the proliferation of crop epithelium by increasing the CTGF level and reducing the phosphorylation level of YAP. YAP-TEAD inhibitor verteporfin (injection for 6 d, 2.5 mg per kg body weight every day) can inhibit the proliferation of crop epithelium induced by prolactin by inhibiting YAP and CTGF expression. In conclusion, PRL can participate in crop cell proliferation of pigeons by promoting the expression of YAP and CTGF in Hippo pathway.

Yield and grain quality parameters in domestic and foreign varieties of soft winter wheat

Topicality. One of the main indicators that determine the commercial value of wheat grain, its baking and technological properties is the mass fraction of protein. The results of scientific research and agricultural production practices show that over the past 80–90 years in the southern regions of Ukraine, the protein content of winter wheat grain has decreased from 17–18 % to 10–12 %, and in unfavourable weather conditions, the amount of protein in grain can even decrease to 8.0–9.5 %. Improving the wheat grain quality is one of the challenges facing Ukraine today. Ukraine has a high position in the global grain market: its share in wheat exports averages 5 %. Purpose. To estimate the yield and biochemical parameters of grain quality of soft winter wheat at the current stage. Methods. Field trials were conducted according to the B. A. Dospekhov’s methodology of field experience. Agricultural technology of winter wheat cultivation is generally accepted for the Steppe zone of Ukraine. Accounting the yield was carried out according to the methodology of state variety testing the agricultural crops. The protein content in the grain was determined by infrared spectrometry and the Kjeldahl method. The level of protein sedimentation was determined by the SDS 30 method. Results. When comparing the obtained data on yield in the collection, it was found that modern domestic and foreign varieties (I, II, III group) in the optimal conditions of growing season had an average yield of 103–107 % higher than varieties of early stages of breeding. The soft winter wheat varieties developed by the Plant Breeding and Genetics Institute – National Center for Seeds and Cultivar Investigation are the leaders in terms of yield. Foreign varieties are not sufficiently adapted to local weather conditions, which significantly affects the realisation of yield potential. As a result of the negative correlation between yield and grain quality, with each stage of breeding, including in modern varieties, grain protein content decreases by 0.5–1.5 % along with yield growth. In terms of sedimentation level, the varieties of the Plant Breeding and Genetics Institute – National Center for Seeds and Cultivar Investigation prevail over the varieties of the early stages of breeding. The group of varieties of Ukrainian breeding has a great diversity in terms of sedimentation level. Foreign varieties have rather low sedimentation rates. The realisation of the genetic potential of grain yield and quality of the studied varieties depended on weather conditions and doses of mineral fertilisers. Conclusions. Given the negative correlation between yield and grain quality, the significant success of breeding in increasing the yield of Ukrainian and foreign varieties was accompanied by decreasing protein content at each stage of breeding by 0.5–1.5 %. Compared to the varieties of the early stages of breeding, the SDS-30 sedimentation index was the highest only in the varieties of Plant Breeding and Genetics Institute – National Center for Seeds and Cultivar Investigation, while domestic varieties of other research institutions were slightly inferior to the varieties of the early stages of breeding. The group of foreign varieties had the lowest sedimentation index. In addition to the genetic factor, such factors as weather conditions and rates of mineral nutrition have a great influence on the formation of grain yield and quality. Key words: wheat yield, wheat adaptability, grain protein content, sedimentation, fertilizers, biochemical parameters