Repeatability Estimates Research Articles

Estimation of genetic parameters for milking temperament in Holstein-Gyr cows

IntroductionDairy cattle with poor temperament can cause several inconveniences during milking, leading to labor difficulties, increasing the risk of accidents with animals and workers, and compromising milk yield and quality. This study aimed to estimate variance components and genetic parameters for milking temperament and its genetic correlations with milk yield in crossbred Holstein-Gyr cattle.MethodsData were collected at three commercial farms, resulting in 5,904 records from 1,212 primiparous and multiparous lactating cows. Milking temperament (MT), measured as the milking temperament of each cow, was assessed during pre-milking udder preparation (RP) and when fitting the milking cluster (RF) by ascribing scores from 1 (cow stands quietly) to 8 (the cow is very agitated, with vigorous movements and frequent kicking). The number of steps and kicks were also recorded during pre-milking udder preparation (SRPand KRP, respectively) and when fitting the milking cluster (SRFand KRF, respectively). Milk yield (MY) was obtained from each farm database. In two of them, MY was recorded during the monthly milk control (that could or could not coincide with the date when the milking temperament assessments were carried out) and in the remaining farm, MY was recorded on the same day that the milking temperament assessments were made. Genetic parameters were estimated using the THRGibbs1f90 program applying a threshold model, which included 89 contemporary groups as fixed effects, animal age at the assessment day and the number of days in milking as covariates, and direct additive genetic and residual effects as random effects.Results and discussionsThe heritability estimates were MT= 0.14 ± 0.03 (for both, MRPand MRF), MY= 0.11 ± 0.08, SRP= 0.05 ± 0.03, KRP= 0.14 ± 0.05, SRF= 0.10 ± 0.05, and KRF= 0.32 ± 0.16. The repeatability estimates were 0.38 ± 0.05, 0.42 ± 0.02, and 0.84 ± 0.006 for MTRP, MTRF, and MY, respectively; and 0.38 ± 0.02, 0.30 ± 0.07, 0.52 ± 0.02, and 0.46 ± 0.15 for SRP, KRP, SRF, and KRF, respectively. The estimates of most genetic correlation coefficients between MTRP-MTRFwere all strong and positive (MTRR-MTRF= 0.63 ± 0.10, MTRP-SRP= 0.65 ± 0.12, MTRP-KRP= 0.56 ± 0.16, MTRF-SRF= 0.77 ± 0.06, and MTRF-KRF= 0.56 ± 0.34) except for MY (MTRP-MY= 0.26 ± 0.26 and MTRF-MY= 0.21 ± 0.23). Despite the low magnitude of MT heritability, it can be included as a selection trait in the breeding program of Holsteins-Gyr cattle, although its genetic progress will be seen only in the long term. Due to the low accuracy of the genetic correlation estimates between MT and MY and the high range of the 95% posterior density interval, it cannot be affirmed by this study that the selection of a milking temperament trait will infer on milk yield. More data is therefore needed per cow and more cows need to be observed and measured to increase the reliability of the estimation of these correlations to be able to accurately interpret the results.

Estimation of genetic parameters for semen traits in Egyptian buffalo bulls

This study was conducted to characterize semen traits (ejaculate volume (VOL), mass motility (MM), sperm livability (LS), percentage of abnormal sperms (AS), and sperm concentration (CONC)) of Egyptian buffalo bulls and evaluate the importance of some nongenetic factors (year (YC) and season (SC) of semen collection and age of bull genetically and environmentally at collection (ABC)) affecting the investigated traits. A total of 7761 normal semen ejaculates were collected from 26 bulls from 2009 to 2019. Single-trait and bivariate repeatability animal models using Bayesian methods were used to estimate variance components, heritability, repeatability, and genetic correlations among the investigated semen traits. YC and ABC exerted significant effects on most semen traits, whereas SC exerted no significant effect on all the investigated semen traits. Heritability estimates were 0.08, 0.52, 0.51, 0.04, and 0.49 for VOL, MM, LS, AS, and CONC, respectively. Repeatability estimates were 0.14, 0.82, 0.79, 0.06, and 0.78 for VOL, MM, LS, AS, and CONC, respectively. The genetic correlations between MM and each of LS and CONC were highly significant (0.99 ± 0.01 and 0.95 ± 0.14, respectively), and that between LS and CONC was also highly significant (0.92 ± 0.20). The high heritability estimates for MM, LS, and CONC combined with the favorable high significant genetic correlations between these traits indicated that direct selection for MM may be an effective method to enhance semen quality in Egyptian buffalo bulls and consequently improve fertility.

Green and fast ultrasound-assisted extraction procedures for Fe, Mn, Mg and Ca analysis in cane syrups by FAAS

New methodologies for the analysis of Fe, Mn, Mg, and Ca content in cane syrups using FAAS combined with ultrasound-assisted extraction (UAE) were developed and validated. For multivariate optimization of UAE, a simplex-centroid mixture design and individual desirability functions were applied to achieve the best composition of extraction solvents (HNO3, HCl, and water). Under optimal conditions of ultrasound-assisted extraction (100 W, 37 kHz, 10 min, 5.0 mL of extraction solvent (ultrapure water for Fe and Mn and HNO3:H2O (75:25%, v/v), corresponding to a 1.19 mol L−1 HNO3 solution for Mg and Ca)), method validation showed good linearity, confirmed by regression analysis, and low LOD and LOQ values of 0.266–0.284 μg g−1 and 0.114–0.861 μg g−1. Estimates of repeatability and mean precision (RSD = 0.44–2.11%), Horrat values (0.07–0.26), and assessment of trueness by comparing sample preparation methods using a paired t-test demonstrated the excellent precision and trueness of the developed methods. The methods were applied to twenty-five cane syrup samples, and the results of the multivariate analysis showed that the metal ions can be used as indicators of geographical origin or contamination during manufacturing or processing, thus helping to ensure the food quality and safety of this sweetener.

Repeatability of crossover rate in wild sticklebacks

AbstractCrossovers in meiosis have an important role in sexual reproduction in ensuring the segregation of chromosomes and shuffling of genetic material. Despite their profound importance, little is known about heritability and repeatability of the crossover rate in the wild. We studied crossover rate variation in outbred nine- (Pungitius pungitius) and three-spined (Gasterosteus aculeatus) stickleback populations to estimate its heritability (h2) and repeatability (R). Based on crossover rate interpreted from parent–F1-offspring linkage maps created from single nucleotide polymorphism data, the repeatability of crossover rate was moderate at best, but higher in females (R = 0.24 and R = 0.33) than in males (R = 0.017 and R = 0.11) in both species. Owing to the low degree and variance of parental relatedness and low sample sizes, heritabilities could not be estimated with confidence. However, given that R sets the upper limit to h2, the heritability of crossover rate is indicated to be low in males. A review and comparison with the previously reported repeatability and heritability estimates revealed that the repeatabilities in stickleback females were relatively high, whereas those in males were very low. Collectively, our results and review of earlier estimates suggest low evolvability of the crossover rate.

Analytical verification of the Dymind D7-CRP automated analyser.

The aim of this study was to perform a verification of the Dymind D7-CRP automated analyser and compare it with established analysers. Analytical verification included estimation of repeatability, between run precision, within-laboratory precision, and bias in control samples with low, normal and high levels. The acceptance criteria for analytical verification were defined using the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) 2019 Biological Variation Database. Method comparison between the Dymind D7-CRP and the Sysmex XN1000 for haematological parameters and the Dymind D7-CRP and the Beckman Coulter AU680 for CRP values was performed on 40 patient samples. Analytical verification criteria were adequately met with the exception of monocyte count for repeatability and within-laboratory precision (13.4% and 11.5%, respectively, acceptance criteria 10.1%) and measurement uncertainty (23.0, acceptance criteria 20.0%) at low level, eosinophil count for BIAS at the low level (37.7%, acceptance criteria 25.2%), basophil count (BAS) for BIAS at the high level (14.2%, acceptance criteria 10.9%), and mean platelet volume (MPV) for repeatability (4.2% and 6.8%), between run precision (2.2% and 4.7%), within-laboratory precision (4.0% and 7.3%) (acceptance criteria 1.7%), and measurement uncertainty (8.0 and 14.6%, acceptance criteria 3.4%) at both the low and high concentrations. Method comparison showed no clinically significant constant or proportional differences for all parameters except BAS and MPV. The analytical verification of the Dymind D7-CRP showed adequate analytical characteristics. The Dymind D7-CRP can be used interchangeably with the Sysmex XN-1000 for all parameters tested, except BAS and MPV, and with the Beckman Coulter AU-680 for the determination of CRP.

Pattern and repeatability of ascarid-specific antigen excretion through chicken faeces, and the diagnostic accuracy of coproantigen measurements as compared with McMaster egg counts and plasma and egg yolk antibody measurements in laying hens

BackgroundA coproantigen enzyme-linked immunosorbent assay (ELISA) has recently been proposed for detecting ascarid infections in chickens. The excretion pattern of ascarid antigens through chicken faeces and the consistency of measurements over the course of infections are currently unknown. This study evaluates the pattern and repeatability of worm antigen per gram of faeces (APG) and compares the diagnostic performance of the coproantigen ELISA with a plasma and egg yolk antibody ELISA and McMaster faecal egg counts (M-FEC) at different weeks post-infection (wpi).MethodsFaecal, blood and egg yolk samples were collected from laying hens that were orally infected with a mix of Ascaridia galli and Heterakis gallinarum eggs (N = 108) or kept as uninfected controls (N = 71). Measurements including (a) APG using a coproantigen ELISA, (b) eggs per gram of faeces (EPG) using the McMaster technique and (c) ascarid-specific IgY in plasma and in egg yolks using an ascarid-specific antibody ELISA) were performed between wpi 2 and 18.ResultsTime-dependent significant differences in APG between infected and non-infected laying hens were quantified. At wpi 2 (t(164) = 0.66, P = 1.00) and 4 (t(164) = −3.09, P = 0.094) no significant differences were observed between the groups, whereas infected hens had significantly higher levels of APG than controls by wpi 6 (t(164) = −6.74, P < 0.001). As indicated by a high overall repeatability estimate of 0.91 (CI = 0.89–0.93), APG could be measured consistently from the same individual. Compared to McMaster and antibody ELISA, coproantigen ELISA showed the highest overall diagnostic performance (area under curve, AUC = 0.93), although the differences were time-dependent. From wpi 6 to 18 coproantigen ELISA had an AUC > 0.95, while plasma IgY ELISA showed the highest diagnostic performance in wpi 2 (AUC = 0.95). M-FEC had the highest correlation with total worm burden, while APG had highest correlations with weights and lengths of A. galli.ConclusionAscarid antigen excretion through chicken faeces can be measured with high accuracy and repeatability using a coproantigen ELISA. The antigen excretion increases over time, and is associated with worm maturation, particularly with the size of A. galli. Our results suggest the necessity of complementary use of different diagnostic tools for a more accurate diagnosis of infections.Graphical

Estimation Genetic Parameters of Semen Quality Traits in Iranian Holstein Bulls

For the design of any successful breeding program, knowledge about semen quality traits is greatly important and per-required. Reproductive performance is of paramount economic importance in the livestock industry, including dairy cattle production. Despite the importance of the quality of semen used in artificial insemination to the reproductive success of dairy herds, few studies have estimated the extent of genetic variability in semen quality traits. In this study, records collected by Jahed (station 1) and Sheykh Hasan (station 2) breeder centers from 1991 to 2013, were used to estimate variance components, heritability, and repeatability for sperm quality traits. Records information was analyzed by wombat software. Data were analyzed by using the repeatability model in three models, first by year-season-station, secondary by station, and third by year. In the first model, maximum heritability and repeatability (0.9755) estimated the total number of sperm in milt ejaculation trait. In the second model, maximum heritability (0.96), that was in Jahed center, estimated for total number sperm in milt ejaculation, maximum repeatability (1), that was in Jahed center, too, estimated for sperm volume and maximum repeatability (1), that was in both breeding centers, estimated for motility to post-thaw motile ratio trait. In the third model, maximum heritability and repeatability (0.54), estimated for (liveafmil) trait. Maximum heritability and repeatability estimates for the total number of post-thaw motile sperm per milt ejaculation trait were 0.19 and 0.32, respectively. The objectives of this study were to estimate genetic parameters of semen quality traits using data from routine semen collection in the Iranian Holstein.

Estimation of morphological variation in seed traits of Sophora moorcroftiana using digital image analysis.

Sophora moorcroftiana is a leguminous plant endemic to the Qinghai-Tibet Plateau. It has excellent abiotic stress tolerance and is considered an ideal species for local ecological restoration. However, the lack of genetic diversity in the seed traits of S. moorcroftiana hinders its conservation and utilization on the plateau. Therefore, in this study, genotypic variation and phenotypic correlations were estimated for nine seed traits among 15 accessions of S. moorcroftiana over two years, 2014 and 2019, respectively from 15 sample points. All traits evaluated showed significant (P< 0.05) genotypic variation. In 2014, accession mean repeatability was high for seed perimeter, length, width, and thickness, and 100-seed weight. In 2019, mean repeatability for seed perimeter and thickness, and 100-seed weight were high. The estimates of mean repeatability for seed traits across the two years ranged from 0.382 for seed length to 0.781 for seed thickness. Pattern analysis showed that 100-seed weight was significantly positively correlated with traits such as seed perimeter, length, width, and thickness, and identified populations with breeding pool potential. In the biplot, principal components 1 and 2 explained 55.22% and 26.72% of the total variation in seed traits, respectively. These accessions could produce breeding populations for recurrent selection to develop S. moorcroftiana varieties suitable for restoring the fragile ecological environment of the Qinghai-Tibet Plateau.

Estimation of repeatability and phenotypic correlation of reproductive traits in zebrafish Danio rerio

This study was conducted to estimate the repeatability and phenotypic correlation of reproductive traits of zebrafish Danio rerio, in captive condition. Breeding trials were conducted on 10 breeding pairs (2 male:1 female). The data on fecundity, fertility, hatchability and survival rate were recorded. The repeatability values were computed as a measure of consistency using the intra-class correlation coefficient. The repeatability estimates for fecundity, fertility, hatchability of total eggs, hatchability of fertilised eggs, survival rate of total eggs and survival rate of larvae were 0.701, 0.406, 0.336, 0.049, 0.295 and 0.314, respectively. Most of the reproductive traits analysed had moderate repeatability values barring the hatchability of fertilised eggs. The phenotypic correlation was calculated using the Pearson correlation method. The phenotypic correlations of fertility with hatchability of fertilised eggs; hatchability of total eggs; survival rate of total eggs and survival rate of larvae were highly significant (p≤0.01). This study provided valuable information on the consistency of reproductive parameters which would serve as model for conducting research in other fish species. Keywords: Genetic parameters, Phenotypic correlation, Repeatability, Reproductive traits, Zebrafish

Genetic and environmental parameters for behavioural responses towards humans in farmed ostriches

This study investigated the effect of human-ostrich interactions at an early age on behavioural responses towards humans later in life, as well as computed genetic parameters for behavioural responses towards humans. Responses recorded were a willingness to approach a human handler, allowing touch interactions with the handler, keeping a distance from the handler, wing flapping and excessive pecking directed at the handler at flock level. Ostrich chicks were exposed to human voice, gentle touch and visual interactions (HP1), to human voice and visual interaction only, without touch interactions (HP2), and limited human interactions (only daily provision of food and water and handling for routine husbandry practices; standard and foster). Foster chicks were reared by a breeding pair, while the general chick rearing practice at the farm was used for standard chicks. Behavioural responses to humans were subsequently investigated on 1 092 ostriches between the ages of 8–19 months. HP1 and HP2 birds were more inclined to approach the handler and allow touch interactions, while a lower number of birds from these treatments distanced themselves from the handler, compared to those that had limited interactions with humans. Males were more likely to approach, allow touch interactions, and engage in wing flapping, while they were also less likely to keep a distance from the handler than females. HP1 and HP2 birds were more likely to interact with, and less likely to distance themselves from a familiar than an unfamiliar handler. Heritability estimates ranged from 0.15 (wing flapping and excessive pecking) to 0.38 (approach and keeping a distance). Repeatability estimates ranged from 0.33 (wing flapping) to 0.55 (approach and keeping a distance). Human-ostrich interactions can thus be improved by integrating extensive human presence and regular gentle handling in the husbandry practices for ostrich chicks. Selection of breeder birds with a desirable temperament will fast-track domestication in this recently domesticated species.

Relationship between milk urea content and important milk traits in Holstein cattle

Breeding cattle with low nitrogen emissions has been proposed as a countermeasure against eutrophication due to dairy production. Milk urea content (MU) could potentially serve as a new readily measured indicator trait for nitrogen emissions by cows. Therefore, we estimated genetic parameters related to MU and its relationship with other milk traits. We analysed 4 178 735 milk samples collected between January 2008 and June 2019 from 261 866 German Holstein dairy cows during their first, second, and third lactations. Restricted maximum likelihood estimation was conducted using univariate and bivariate random regression sire models in WOMBAT. We obtained moderate average daily heritability estimates for the daily MU of 0.24 in first lactation cows, 0.23 in second lactation cows, and 0.21 in third lactation cows with average daily genetic SDs of 25.16 mg/kg, 24.93 mg/kg, and 23.75 mg/kg, respectively. Averaged over days in milk, the repeatability estimates were low at 0.41 in first, second, and third lactation cows. A strong positive genetic correlation was found between MU and milk urea yield (MUY; 0.72 on average). In addition, 305-day heritabilities were estimated as 0.50, 0.52, and 0.50 in first, second, and third lactation cows, respectively, with genetic correlations of 0.94 or higher for MU in different lactations. By contrast, the averaged estimates of the genetic correlations between MU and other milk traits were low (−0.07 to 0.15). Moderate heritability estimates clearly allow the possible selection for MU, and the near-zero estimates of genetic correlations indicate no risk of undesired correlated selection responses in other milk traits. However, a relationship still needs to be established between MU as an indicator trait and the target trait, defined as total individual nitrogen emissions.

GENETIC AND NON-GENETIC PARAMETERS FOR MILK PRODUCTION TRAITS OF DAMASCUS GOAT IN JORDAN

This study examined the effects of genetic and some non-genetic factors on total milk yield (TMY), test-day milk yield (TDM), pre-weaning (PRMY), and post-weaning milk yield (POMY) using a total of 1167 lactation records of (Damascus) does over the years of 1998 to 2001 at Al-Walla Agricultural Research Station, Ministry of Agriculture. The General Linear Model (GLM) was employed to analyze the data. TMY, TDM, PRMY, and POMY had respective overall averages of 280.3 kg, 1.45 kg, 135.7 kg, and 144.5 kg. Age, doe weight, birth type, and year of kidding all significantly influenced the variables under study. Heritability estimates were 0.22, 0.17, 0.17 and 0.26 for TMY, TDM, PRMY and POMY, respectively. The corresponding estimates of repeatabilities were 0.44, 0.50, 0.32 and 0.33. Genetic correlation between studied traits ranged between 0.52 and 0.91.

Joint estimation of relaxation and diffusion tissue parameters for prostate cancer with relaxation-VERDICT MRI

This work presents a biophysical model of diffusion and relaxation MRI for prostate called relaxation vascular, extracellular and restricted diffusion for cytometry in tumours (rVERDICT). The model includes compartment-specific relaxation effects providing T1/T2 estimates and microstructural parameters unbiased by relaxation properties of the tissue. 44 men with suspected prostate cancer (PCa) underwent multiparametric MRI (mp-MRI) and VERDICT-MRI followed by targeted biopsy. We estimate joint diffusion and relaxation prostate tissue parameters with rVERDICT using deep neural networks for fast fitting. We tested the feasibility of rVERDICT estimates for Gleason grade discrimination and compared with classic VERDICT and the apparent diffusion coefficient (ADC) from mp-MRI. The rVERDICT intracellular volume fraction fic discriminated between Gleason 3 + 3 and 3 + 4 (p = 0.003) and Gleason 3 + 4 and ≥ 4 + 3 (p = 0.040), outperforming classic VERDICT and the ADC from mp-MRI. To evaluate the relaxation estimates we compare against independent multi-TE acquisitions, showing that the rVERDICT T2 values are not significantly different from those estimated with the independent multi-TE acquisition (p > 0.05). Also, rVERDICT parameters exhibited high repeatability when rescanning five patients (R2 = 0.79–0.98; CV = 1–7%; ICC = 92–98%). The rVERDICT model allows for accurate, fast and repeatable estimation of diffusion and relaxation properties of PCa sensitive enough to discriminate Gleason grades 3 + 3, 3 + 4 and ≥ 4 + 3.

Analysis of Seed Amino Acids in Vegetable Soybeans Dried by Freeze and Thermal Drying

Vegetable soybean (Glycine max), known as edamame, has a high nutritional and market value. It is a relatively new crop in North America and Africa. The amino acid profile is important for the nutritional quality of edamame, and a challenge facing its genetic improvement is evaluating its amino acids rapidly. To explore a drying method suitable for the fast evaluation of edamame nutritional profiles, fresh seed samples of 20 soybean genotypes were dried using freeze, low- and high-heat drying methods, and their amino acid contents were analyzed by near-infrared reflectance (NIR) technology. Three-year results indicated that there were significant differences between the years of samplings and among genotypes for all amino acids. Significant differences existed between the drying methods for most amino acids except for leucine and the total amino acid. Low-heat drying at 65 °C and freeze drying showed similar results and were highly comparable to each other for ANOVA and repeatability estimation. The estimates of repeatability under the individual drying methods were 73–94%, except for tryptophan, cysteine and methionine; meanwhile, higher estimates (85–99%) were computed using the combined data of all three drying methods, with few exceptions. Two sulfur-containing amino acids were showed to be more sensitive to high temperature than the others. Six genotypes exhibited higher contents of all the 18 major amino acids and are recommended to be used for the nutritional quality improvement of edamame and other food-grade specialty soybeans. In conclusion, the low-heat drying method can serve as an alternative to freeze drying, and can be used in the large-scale drying of fresh edamame and in the evaluation of seed amino acids in research.

Sex and reproductive status affect sheltering and exploratory behaviours with high intra-individual variability in crayfish

Abstract The contexts in which individuals demonstrate behavioural consistency or variability have been the subject of research focus. We studied exploratory and sheltering behaviour in the crayfish F. virilis to understand how these behaviours vary by sex and reproductive readiness and to quantify the repeatability of these behaviours. Crayfish were tested in two sets of three rounds, one in the summer non-reproductive season and another in the autumn reproductive season. Reproductive crayfish spent more time outside the shelter and were more likely to accept a food item than non-reproductive crayfish. In the non-reproductive season, females spent more time outside the shelter than males, and over both seasons, females were more likely to seek and accept a food item. Repeatability estimates were low, indicating high intra-individual variability in these behaviours. Sheltering and exploratory behaviours were not correlated. This indicates sex or reproductive readiness have strong effects on both sheltering and exploratory behaviours.

Non-genetic effects and repeatability estimates of semen production traits in Murrah buffalo bulls.

The objectives of this study were to determine the repeatability estimates and the effect of ejaculate, season, period, age, and bull on semen production traits in Murrah buffalo bulls maintained in an organized semen station. A data set comprising 54,268 ejaculates from 76 Murrah buffalo bulls collected across 12 years were analyzed. The analysis of variables included non-genetic factors as the fixed effects and bull as the random effect. The repeatability was estimated by the restricted maximum likelihood method (REML) using WOMBAT program. The overall least-squares means for semen volume, sperm concentration, total sperm/ejaculate, mass activity, individual motility, post-thaw motility, and frozen semen straws/ejaculate were 2.65 ml, 1222.04 million/ml, 3030.10 million, 2.64, 67.45%, 51.73%, and 128.80 doses. The repeatability estimates were 0.27, 0.25, 0.22, 0.28, 0.34, 0.27, and 0.23, respectively. The studied non-genetic factors influenced (P < 0.01) all seminal traits. Likewise, variation (P < 0.01) due to individual bull was also observed. The first ejaculate was superior in terms of ejaculate volume, sperm concentration, total sperm/ejaculate, and frozen semen straws than the second ejaculate. The south-west monsoon and summer seasons were the best seasons with better semen quality and frozen semen production. Compared to the remaining periods, during Period V (2014-2016), greater values for most seminal traits were found. Bulls above 8 years of age expressed higher semen production than the younger bulls below 4 years, whereas the best performance was observed in the age group of 12 years and above. The repeatability estimates were low to moderate ranging from 0.22 for total sperm/ejaculate to 0.34 for individual motility. A significant (P < 0.01) positive correlation was observed between the seminal traits except the negative correlation in semen volume and total sperm/ejaculate. It was concluded that all the non-genetic factors considered in this study exerted influence on studied seminal traits. Therefore, appropriate management practices can be applied to improve semen quality and quantity.

Impact of parity differences on residual feed intake estimation in Holstein cows

Residual feed intake (RFI) has been used as a measure of feed efficiency in farm animals. In lactating dairy cattle, RFI is typically obtained as the difference between dry matter intake observations and predictions from regression on known energy sinks, and effects of parity, days in milk, and cohort. The impact of parity (lactation number) on the estimation of RFI is not well understood, so the objectives of this study were to (1) evaluate alternative RFI models in which the energy sinks (metabolic body weight, body weight change, and secreted milk energy) were nested or not nested within parity, and (2) estimate variance components and genetic correlations for RFI across parities. Data consisted of 72,474 weekly RFI records of 5,813 lactating Holstein cows collected from 2007 to 2022 in 5 research stations across the United States. Estimates of heritability, repeatability, and genetic correlations between weekly RFI for parities 1, 2, and 3 were obtained using bivariate repeatability animal models. The nested RFI model showed better goodness of fit than the nonnested model, and some partial regression coefficients of dry matter intake on energy sinks were heterogeneous between parities. However, the Spearman's rank correlation between RFI values calculated from nested and nonnested models was equal to 0.99. Similarly, Spearman's rank correlation between the RFI breeding values from these 2 models was equal to 0.98. Heritability estimates for RFI were equal to 0.16 for parity 1, 0.19 for parity 2, and 0.22 for parity 3. Repeatability estimates for RFI across weeks within parities were high, ranging from 0.51 to 0.57. Spearman's rank correlations of sires' breeding values were 0.99 between parities 1 and 2, 0.91 between parities 1 and 3, and 0.92 between parities 2 and 3. We conclude that nesting energy sinks within parity when computing RFI improves model goodness of fit, but the impact on the estimated breading values appears to be minimal.

Passive Directivity Detection Using Individual Biaxial Ultrasound Transducers.

Biaxial transducers are an emerging technology that can steer generated ultrasound waves using a single piezoceramic component. Simulations have also shown that biaxial transducers can passively estimate the direction of arrival (DOA) of sound waves when operating in the receive mode. This research seeks to experimentally verify biaxial directivity estimates and establish directivity as an independent parameter detected by biaxial transducers. Three cuboid ( 3.84×3.84×5.92 mm) biaxial piezoceramics with two pairs of orthogonal electrodes (one pair applied laterally and one pair applied in the polling direction) were manufactured and characterized. Each transducer was placed in a water tank where an independent hemispherical source was attached to a moveable arm and operated at 250 kHz. Terminal voltages were recorded for 81 source positions in a plane parallel to the transducer's front face and at a depth of approximately 9 cm. Collection was repeated three times per transducer to ensure reproducibility. In silico results were compared with the experimental results. Two derived metrics were then calculated using both the forward and lateral terminal voltages: the phase difference and amplitude ratio. Biaxial transducers demonstrate an ability to estimate the DOA of incident sound waves, independently of any time-of-flight (TOF) information. The phase difference and amplitude ratio complement each other to provide statistically significant and repeatable estimates over a range of 48° (from -24° to +24°). These results can be used to augment a variety of medical, geophysical, and industrial passive ultrasound imaging techniques.

Heritability of the elk hunting traits in the Finnish Jämthund population

ABSTRACT The aim of our study was to estimate the genetic parameters of elk hunting traits in the Finnish Jämthund population. The phenotype data included 40 402 trial observations recorded in Finland between 2012 and 2020 and the pedigree data included information of 34 495 Jämthunds. The genetic parameters of the elk hunting traits were estimated using a repeatability animal model. Season, place, and type of the trial, weather during the trial, and dog sex and age were considered fixed effects in the models, and trial judge and dog litter were treated as random effects. Variance components were estimated with the AI-REML method using the DMU-software. Heritability estimates were generally low (0.01–0.04). The highest estimated heritability was 0.04 for searching. Repeatability estimates for elk hunting traits varied between 0.04 and 0.14. Genetic correlations varied from very weak to very strong (−0.21–1.00) and were particularly strong between the barking traits.

Wind effects on the long‐distance migration of GPS‐tracked adult ospreys Pandion haliaetus from Germany

Birds that repeatedly visit distinct places along their migratory routes in consecutive years must be able to navigate to these places and respond appropriately to unfavourable wind conditions. This study analysed the migratory routes, repeatedly‐visited areas and responses to sidewinds of 15 GPS‐tracked adult ospreys Pandion haliaetus from northeast Germany migrating to their wintering sites in Africa and back. We determined stopovers and intermediate goal areas and performed repeatability estimations on timing and migratory paths in four regions. The orientation behaviour of the ospreys was analysed with regard to perpendicular wind components at each GPS point during autumn and spring migrations. Generalised linear mixed models were used to test the dependence of orientation behaviour on region and the distance to the next goal. The findings showed that ospreys demonstrate high fidelity to migratory paths in autumn and spring, as well as to the timing of migration in autumn; and sidewinds are predominantly compensated, especially when sidewinds are strong. Furthermore, during autumn migration, the proportion of compensation increases in most regions with decreasing distances to the next goal; however, during spring migration, drift behaviour was detected more often at smaller distances to the next goal than at higher distances in the regions Mediterranean and central Europe. In general, ospreys compensate for unfavourable sidewinds and utilise supporting tailwinds on their journeys to the wintering sites in Africa and back to central Europe.