Estimation of genetic parameters and relationships between type traits and milk yield of Holstein cows in Turkey

ABSTRACT In this study, milk yield, reproductive yield, and type traits of 533 Holstein cows in the first lactation raised in 54 farms were examined. In the three-year study, phenotypic (rP) and genetic (rG) correlations between type traits and milk yield were estimated based on the variance elements and heritability of the type traits of Holstein cows in the first lactation. Linear identification and scoring systems have been applied to classify the cows according to type traits. Heritability and correlations were estimated with ASREML models. The type traits included stature, angularity, rump width, hocks, rear udder height, central ligament, teat length, body capacity, feet and legs, udder composite and final score for genetic correlations with 305-day milk yield were estimated as -0.49, -0.14, -0.93, 0.35, 0.40, 0.11, -0.65, 0.70, 0.31, 0.54, and 0.70, for phenotypic correlations were estimated as 0.28, 0.28, 0.30, 0.21, 0.35, 0.39, -0.06, 0.46, 0.48, 0.56, and 0.58 respectively. Among the phenotypic correlations between the type traits, especially the phenotypic correlations between the final score and various type traits were found to be high and significant. The fact that these traits are in high correlation with other traits and milk yield may enable these to be used as indirect selection criteria in the selection for milk yield.

Estimation of Genetic Parameters of Type Traits in First Parity Cows of the Autochthonous Cika Cattle in Slovenia

The aim of this study was to estimate genetic parameters of 26 individual and four composite type traits in first parity Cika cows. An analysis of variance was performed with the generalized linear model procedure of the SAS/STAT statistical package, where the fixed effects of year of recording, cow’s age at recording and days after calving as a linear regression were included in the model. The variance components for the direct additive genetic effect and the herd effect in all type traits were estimated using the REML method in the VCE-6 software package. The estimated heritabilities ranged from 0.42 to 0.67 for the measured body frame traits, from 0.36 to 0.80 for the scored autochthonous traits, from 0.11 to 0.61 for the scored body frame traits, and from 0.20 to 0.47 for the scored udder traits. The estimated heritabilities for the composite traits called “autochthonous characteristics”, “muscularity”, “body frame” and “udder” were 0.55, 0.19, 0.19, and 0.26, respectively. The estimated genetic correlations among the measured body frame traits were positive and high, while the majority of them among the scored body frame traits were low to moderate. The estimated proportions of variance explained by the herd effect for the composite traits “autochthonous characteristics,” “muscularity,” “body frame” and “udder” were 0.09, 0.28, 0.14, and 0.10, respectively. The estimated heritabilities for the type traits of first parity Cika cows were similar to those reported for other breeds where breeding values have been routinely predicted for a long time. All estimated genetic parameters are already used for breeding value prediction in the Cika cattle population.

​Discriminant Analysis to Characterize Mastitis Resistant and Susceptible Karan Fries Cows and Response Operating Characteristics Curve for Comparing Regression/ Discriminant Model

Background: The profitability in the dairy enterprises is strongly affected by udder health and, to a minor extent, by morphometry. The present study was conducted to differentiate mastitis susceptible and resistant animals based on udder and teat type traits infrequently exist. Methods: The study was undertaken in ICAR-NDRI, Karnal of Haryana. A discriminate model was applied to differentiate mastitis susceptible and resistant Karan Fries cows for the study. For meeting the objective; 123 Karan Fries cows were subjected to developing a reliable mathematical function/equation (discriminant functions) for the provision of maximum separation among the mastitis resistant and susceptible animals. The hypothesis was designed to know if these udder and type traits appeal to mastitis-resistant and susceptible animals. The hypothesis for testing the equality of covariance matrices was depicted as: H0: ∑1 = ∑2 Vrs H1: At least one pair of sigma’s ∑ is different. Result: The model included contributory factors such as fore udder length, central ligament, udder balance, shortest distance of floor from fore teat (SDFT), shortest distance of floor from rear teat (SDRT), fore udder attachment (FUA), teat direction, Rear legs rearview, Hock development, udder depth, and udder width constructed and was found to demonstrate 69.1 per cent accuracy with p less than 0.001 and the Karan Fries functions at group centroids are -0.169 and 0.443 respectively for mastitis resistant and mastitis infected animals. The model will facilitate 92.1 per cent of the cases to correctly classify for mastitis resistant animals and the remaining 7.9 per cent being misclassified into the mastitis group.

Combinations of Linear Type Traits Affecting the Longevity in Hungarian Holstein-Friesian Cows

Several research studies confirm the association of the linear type traits with longevity, but only with one trait at a time. The aim of our study was to analyse the influence of combinations for linear type traits on longevity in the Hungarian Holstein-Friesian cows. Data were provided by four herds; the filtered dataset consisted of 17,717 cows. From the 14 available linear type traits, the most important combinations were identified based on principal components and cluster analysis. From the six identified combinations, only three (chest width-body depth, fore udder attachment-udder depth, angularity-rear udder height) proved to have a significant effect on longevity. A wide chest and deep body caused a high-risk ratio of culling. The lowest risk ratio was observed with cows having intermediate chest width and intermediate body depth. Very angular cows having low rear udder height were at the highest risk of culling. The lowest culling risk was found in cows with a lack of angularity and high rear udder height. Weak and loose fore udder along with deep udder had increased culling risk. Strong and tight fore udder subclasses were the most favourable as their risk ratios decreased towards the shallowing of udder depth.

Genetic Profiling of PHKA2 Gene and its Association with Udder Type Traits in Indian Dairy Cattle

Background: The experiment aimed to investigate polymorphisms in exon 2 of the PHKA2 gene and investigate the relationship between identified single nucleotide polymorphism and udder type traits in Sahiwal cows. Udder morphometry is being used as a forecaster of production performance in cows since older times. Finding the variants associated with these traits in largely variable region of PHKA2 gene can prove to be highly beneficial. Methods: DNA isolated from Sahiwal cows was analysed by DNA sequencing. Nine udder type and five teat types were measured for each animal according to procedure followed by International committee of animal recording (2012). Result: Three SNPs g.124497381C greater than T, X:124497248 G greater than A and X:124497189 C greater than T were identified. Recessive homozygotes were negligible as mutant allele exhibited very low ranging frequency (from 0.02 to 0.08) for the targeted loci. Identified point mutation g.124497381C greater than T was found to be significantly (p less than 0.05) associated with distance between teats and central ligament, SNP X: 124497248G greater than A with rear udder width, fore udder attachment, udder depth, udder length and teat length (p less than 0.05) and SNP X: 124497189 C greater than T with udder length and rear udder height (p less than 0.05). Interaction of identified SNPs and udder traits highlighted the gene’s potential as a candidate gene for selecting for conformation traits in Indian Sahiwal cattle.

26 Are Subjectively Scored Linear Type Traits Suitable Predictors of Genetic Merit for Feed Intake in Grazing Holstein-friesian Dairy Cows?

Measuring dry matter intake (DMI) in grazing dairy cows using currently available techniques is invasive, time consuming, and expensive. An alternative to directly measuring DMI for use in genetic evaluations is to identify a set of readily available data sources that can be used in a multi-trait genetic evaluation with DMI. The objectives of the present study were to estimate the genetic correlations between readily available body-related linear type trait information and DMI in grazing, lactating Irish dairy cows and to estimate the partial genetic correlations between linear traits and DMI, after adjusting for differences in genetic merit for body weight. After edits, a total of 8,055 test-day records of DMI, body weight, and milk yield from 1,331 multiparous dairy cows were available, as were chest width, body depth, and stature scores for 47,141 first lactation dairy cows. In addition to considering the routinely recorded linear type traits individually, novel traits were defined as the product of two or three linear type traits as an approximation of rumen volume. The genetic variance of DMI, body weight, milk yield, and linear type traits were estimated using univariate animal linear mixed models. Sire linear mixed models were used to calculate genetic and phenotypic covariances. All linear type traits were moderately heritable (0.27 to 0.49) and genetically correlated (0.29 to 0.63) with DMI. The genetic correlations between the individual linear type traits and DMI, when the latter was adjusted for differences in the genetic merit for body weight, varied from 0.00 to 0.39. If the (partial) genetic correlations were validated with genetic evaluations, routinely available linear type trait records and live weight data could facilitate the selection of DMI in dairy cows, removing the need to capture large amounts of cost prohibitive feed intake phenotypes.

Genome-wide association study and transcriptome of olecranon-type traits in peach (Prunus persica L.) germplasm

Background The top of the olecranon honey peach (Prunus persica L.) fruit appears similar to an eagle’s beak. In this study, a single olecranon honey peach with a round-type fruit was observed in our fruit orchard. To explore the genetic mechanism of olecranon formation, we performed full-length transcriptome sequencing analysis of olecranon and round peaches as well as a genome-wide association study of the association of olecranon-type trait loci. Results The gene locus was 26,924,482 base pairs in NC_034014.1. Transcriptome sequencing showed that the clean sequencing data of each sample reached 7.10GB, with 14,360 genes and 23,167 transcripts expressed in both the olecranon honey peach and round peach. Among the 11 differentially expressed genes selected as candidate genes, six were highly expressed in olecranon peach and named as LOC18775282, LOC18772209, LOC18773929, LOC18772013, LOC18773401, and ONT.13798.5. Five genes were highly expressed in round peach and named as LOC18773079, LOC18773525, LOC18773067, LOC18775244, and LOC18772236. Notably, ONT.13798.5 was not previously identified. The genes were within 1 Mb up- or down-stream of the main genome-wide association study locus for olecranon-type traits. Conclusions This study revealed loci associated with olecranon and provides useful information for analysis and breeding of olecranon honey peach.

Effect of Linear Type Traits Influences on Survivability and Longevity of Sahiwal Cattle

Background: The linear type traits are the one of important tools for selection of milch cattle. The lifespan of cattle mostly depends on these linear type traits particularly feet and udder related traits. So it is necessary to measure the linear type traits and effect on longevity of Sahiwal cattle. Methods: The experiment was conducted on 86 Sahiwal cattle maintained in Bull mother experimental farm and government cattle breeding farm, Anjora, Durg (C.G.). The linear type traits in Sahiwal cattle were measured as per the recommendation of International committee for animal recording (ICAR). Result: The different linear type traits were studied the average value of stature 125.39±0.534, Chest width 27±0.49, rump angle 12.75±0.97, rump width 17.32±0.29, rear leg set (side view) 146.03°±0.91, rear leg set (rear view) -3.74±0.15, udder depth 18.97±0.43, udder cleft 2.77±0.95, rear udder height 24.06±0.45, fore udder attachment 130.50±1.75° and front teat position 3.61±0.13 cm. these linear type traits mainly affects the longevity and survivability of Sahiwal herds. The most of the traits were found to be intermediate type it leads to increase the longevity and fewer reproductive problems in the Sahiwal herds.

Effect of Non-genetic Factors on Udder and Teat Morphometric Traits in Sahiwal and Karan Fries Cows

Background: The present study was designed to find out the magnitude of environmental and other non-genetic factors affecting the linear udder and teat type traits in Sahiwal and Karan Fries cows. Methods: Total eight udder morphometric traits and seven teat morphometric traits were measured in 87 Sahiwal and 166 Karan Fries cows. The data regarding milk yield, stage of lactation, parity and season of calving for all Sahiwal and Karan Fries cows were collected. Result: In Karan Fries cows, udder and teat type traits were significantly affected by parity and stage of lactation, while in Sahiwal cow udder and teat type traits were significantly affected by parity only. Teat circumference was significantly affected by season and stage of lactation. The results indicated that parity and stages of lactation were important sources of variation for most of linear udder and teat type traits.