Rear Teat Placement Research Articles

Body conformation traits in early-lactation associated with clinical mastitis and lameness in lactating Chinese holstein cows

BackgroundComprehending the correlation between body conformation traits of cows at the early stages of lactation and prevalent lactation diseases might facilitate the execution of selection and feeding strategies that prioritize cow health. This study aimed to evaluate the impact of body conformation traits on the incidence of clinical mastitis and lameness in Chinese Holstein cows. From a pasture herd of 1472 early lactating Chinese Holstein cows, we evaluated 20 body conformation traits. During lactation, this pasture herd was visited weekly to gather clinical mastitis and lameness data. A nine-point scale was used to determine the conformation traits of cows to clarify their linear characters, including frame capacity, rump (RU), feet and leg (FL), mammary system (MS), and dairy character. A longitudinal binary disease (0 = healthy; 1 = diseased) data structure was created by allocating disease records to adjacent official test dates. The impact of body conformation traits on the risk of developing diseases (clinical mastitis and lameness) was analyzed using the logistic regression models.ResultsCompared to cows with low total scores (75–79 points), those with high total scores (80–85 points) of body conformation traits had a significantly lower risk of mastitis (P < 0.001). The disease status (0 or 1: binary variable) of clinical mastitis in lactating cows was significantly impacted negatively by age (P < 0.05). The fore udder attachment (FUA), angularity, rear attachment height (RAH), and rear teat placement (RTP) were all significantly associated with clinical mastitis during lactation (P < 0.05). The rear leg-rear view (RLRV) was significantly correlated with correlated considerably (P < 0.05) with lameness during lactation. An ideal score of four points on the lameness risk dimension of the RLRV may indicate a low risk of lameness. Since the risk of mastitis decreased as this trait score increased, the RTP may be an ideal marker for mastitis risk.ConclusionsAccording to the study, clinical mastitis and lameness risks in cows can be estimated using their body conformation traits. Cows with more centrally located rear teats have a lower risk of mastitis. These results may help dairy farmers identify cows at high risk of disease early in lactation and aid in breeding for disease resistance in cows.

Type Traits of Holstein-Friesian and Red-Holstein Cows Raised Together in a Private Farm in Aydın Province

This study was aimed at comparing the conformation traits of two different cattle breeds such as Holstein-Friesian (HF) and Red-Holstein (RH) cows raised together in a farm in Aydın, Türkiye. In this study, 102 HF and 19 RH cows in different lactations numbers (LN) forming a total of 121 cows were used. The type traits were determined using Linear Type Traits (LTT) based on 9 points scoring system and non-linear 100 points method. The LTT were composed of body traits such as Stature (St), Chest Width (CW), Body Depth (BD), Rump Angle (RA), Rump Width (RW) and Body Condition Score (BCS); foot and legs traits: Rear Legs Set Angle (RLA), Rear Legs Rear View (RLV), Real Legs Knee Structure (RLS) and Foot Angle (FA); udder traits: Fore Udder Attachment (FUA), Rear Udder Height (RUH), Rear Udder Width (RUW), Central Ligament (CL), Udder Depth (UD), Rear Teat Placement (RTP), Fore Teat Length (FTL) and Mammary Acuity (MA); and according to the non-linear 100 points method: Dairy Strength (DS, 15%), Frame (20%), Foot and Legs (FL, 25%) and Udder (40%). The results of variance analysis showed that no differences between breeds and LN were found in body composite traits while, for Foot and Legs traits, only the RLA was found significant (P

Assessment of body conformation traits and their relationship with production performance of Sahiwal cows

Linear type scoring is key component in decision making process in the herd, as it focusses on the selection of animals with higher productive potential based on their body conformation/linear traits. The present study was carried out on 150 lactating Sahiwal cattle of first to fifth parity. Measurements on linear type traits were recorded 1 h before the evening milking at three different stages of lactation. The average score point of objective linear type traits was stature 5.77±0.08, chest width 4.59±0.10, body depth 5.24±0.10, rump width 5.56±0.09, rump angle 4.48±0.08, rear legs sets 4.81±0.12, foot angle 4.84±0.10, fore udder attachment 4.85±0.11, rear udder height 5.52±0.10, udder depth 5.31±0.08, rear udder width 4.27±0.09, central ligament 4.01±0.09, fore teat length 3.49±0.10, rear teat length 3.94±0.09, teat circumference 4.20±0.11, teat diameter 4.16±0.10 and udder balance 5.25±0.11. On the other hand, average score point of subjective linear type traits (1-9 scale) was angularity 4.69±0.09, rear leg rear view 5.05±0.06, body condition score 6.53±0.08, locomotion 4.88±0.06, fore teat placement 4.41±0.07 and rear teat placement 6.28±0.08. Most of the body conformation traits in Sahiwal cattle were falling under intermediate category and of desirable type. However, some traits like stature, chest width, body depth, rump width, angularity, central ligament, rear udder height, rear udder width and fore udder attachment expressed scope for further improvement.

Comprehensive genetic analysis of linear type traits for characterization of the Sahiwal cattle in an organized herd

Sahiwal is one of the most important dairy cattle breeds of the Indian subcontinent. A holistic and balanced approach to selection and breeding strategies must be adopted to bring about desirable genetic improvement in livestock, including indigenous cattle. The inclusion of linear type traits for dairy cattle selection in any breed improvement program has not been carried out in India so far. Therefore, this study was taken up to characterize Sahiwal cattle, on the basis of linear type traits. Data was collected on adult Sahiwal cows up to their 10thparity, maintained at Institute herd of Indian Council of Agricultural Research- National Dairy Research Institute, Karnal, Haryana from 2006-2021. Data were analysed using Least Squares Maximum Likelihood (LSMLMW), considering a sire model for the present study. Parity, season and period of calving were taken as fixed effect and age at first calving as covariable. Sire or animal was considered as random variable. Least squares means of objective linear type traits viz., stature was 125.97±0.68 cm, body length 136.58±1.01 cm, chest girth 173.04±1.14 cm, body depth203.40± 1.39 cm, rump angle 14.50±0.39 cm, rump width 20.62±0.28cm, udder depth 20.87±0.41 cm, rear udder height 18.38±0.33 cm, and teat length 6.16±0.24 cm. On the other hand, least square mean scores of subjective linear type traits (1-9 scale) viz. fore teat placement was 6.32±0.46, rear teat placement was 7.27±0.35,rear leg side view was 6.26±0.26, rear leg rear view was 6.28±0.27score, foot angle 6.86±0.27, angularity 34.97±0.50-degree, central ligament 6.55± 0.39, fore udder attachment 5.91±0.32, fore teat placement 6.32±0.46, and rear teat placement was 7.27±0.35. Parity had a significant (p&lt;0.05) effect on fore udder attachment and central ligament and teat length in Sahiwal cattle. Season of calving had the significant (p&lt; 0.05) effect, observed in case of udder depth in Sahiwal cattle. Period of calving had a significant(p&lt;0.05) effect on rump angle, udder depth, teat length, angularity and central ligament in Sahiwal cattle. Based on results of present study, it was observed that Sahiwal cattle establishes a balance between the scoring pattern of linear type traits, as the balance scoring of animals was desirable for better sustainability and production performance of a dairy cattle, on a longer run. Moreover, linear type traits have a better scope in selection process and genetic improvement programs that can be utilized as balanced and comprehensive approach for indigenous dairy cattle.

Genome-Wide Association Study for Body Conformation Traits and Fitness in Czech Holsteins.

The aim of this study was a genome-wide association study (GWAS) on conformation traits using 25,486 genotyped Czech Holsteins, with 35,227 common SNPs for each genotype. Linear trait records were collected between 1995 and 2020. The Interbull information from Multiple Across Country Evaluation (MACE) was included for bulls that mostly had daughter records in a foreign country. When using the Bonferroni correction, the number of SNPs that were either significant or approached the significance threshold was low-dairy capacity composite on BTA4, feet and legs composite BTA21, total score BTA10, stature BTA24, body depth BTA6, angularity BTA20, fore udder attachment BTA10. Without the Bonferroni correction, the total number of significant or near of significance SNPs was 32. The SNPs were localized on BTA1,2,4,5,6,7,8,18,22,25,26,28 for dairy capacity composite, BTA15,21 for feet and legs composite, BTA10 for total score, BTA24 stature, BTA6,23 body depth, BTA20 angularity, BTA2 rump angle, BTA9,10 rear legs rear view, BTA2,19 rear legs side view, BTA10 fore udder attachment, BTA2 udder depth, BTA10 rear udder height, BTA12 central alignment, BTA24 rear teat placement, BTA8,29 rear udder width. The results provide biological information for the improvement of body conformation and fitness in the Holstein population.

Genome wide association study of udder type traits and milk production traits in Gir cattle

This study investigated the association of genome wide association study of udder type traits and milk production traits in Gir cattle. Data for the current study were collected from 635 Gir cows reared by farmers in small-holder conditions, and blood samples were collected for the Genomic study. The data for the phenotypic correlation study on 305 day milk yield and udder type traits were analysed using the statistical software R (v3.4.0), and the genome wide association study was carried out using the PLINK (v1.90b4.4) software. The phenotypic correlation between udder type traits, such as central ligament, rear udder height, rear udder width, teat length, and teat thickness, and 305 day milk yield was low to moderate, but significant (p 0.05) and positive. Some traits, however, were negatively correlated, including fore udder attachment, fore teat placement, rear teat placement, and udder depth. A genome-wide association study using a customised SNP chip (INDUSCHIP1) with 45,024 SNPs distributed on 29 autosomes discovered 838 SNPs that were significantly related to nine udder type traits and 305 day milk yield. The majority of SNPs were under MAF class of 0.3-0.5 from 45,024 SNPs spread over 29 Bos Indicus autosomes. Thus, present study on udder type traits and 305 day milk yield and their GWAS in Gir cattle using INDUSCHIP1 a customised SNP chip has provided the base line data for incorporation of udder type traits in Genomic selection for overall genetic improvement of Gir cattle.

Estimated genetic parameters for all genetically evaluated traits in Canadian Holsteins

Genetic improvement is a crucial tool to deal with the increasing demand for high quality, sustainably produced dairy. Breeding programs are based on genetic parameters, such as heritability and genetic correlations, for economically important traits in a population. In this study, we estimated population genetic parameters and genetic trends for 67 traits evaluated on heifers and first-lactation Canadian Holstein cows. The data consisted of approximately 500,000 records with pedigree information collected from 1980 to 2019. Genetic parameters were estimated using bivariate linear animal models under a Bayesian approach. Analyses for the 67 traits resulted in 2,211 bivariate combinations, from which the estimated genetic parameters are reported here. The most highly heritable traits were fat percent (0.66) and protein percent (0.69), followed by stature (0.47). Lowest heritabilities (0.01) were observed for disease-related traits, such as lameness and toe ulcer, and calf survival. The genetic correlations between gestation length, calf size, and calving ease measured on both heifer and cows were close to unity. On the other hand, traits such as body condition score and pin width, cystic ovaries and sole ulcer, rear teat placement, and toe ulcer were genetically unrelated. This study reports genetic parameters that have not been previously published for Canadian Holstein cows, and provides updates of those previously estimated. These estimates are useful for building new indexes, updating existing selection indexes, and for predicting correlated responses due to inclusion of novel traits in the breeding programs.

The characteristic of economically important traits of dairy cows depending on type of body constitution

This study focuses on research of economically important traits of Ukrainian black-and-white dairy cows with different types of body constitution. The aim of the study was to differentiate dairy cows into constitution types and to identify the best types in terms of growth, exterior, milk productivity and reproductive capacity. The cows were differentiated into low-, mid- and high-capacity types of body constitution. Depending on their type the features of growth, exterior, milk productivity and reproduction capacity of primiparous have been studied. It has been established, that the intensity of growth of heifers from birth to 18 months depended on the type of their body constitution. Higher live weight, absolute and average daily gains were characteristic of heifers with low-capacity body constitution. Their live weight at the age of 18 months on average was 388.5 kg, it was on 30.9 kg and 60.3 kg (Р &lt; 0.01) more than live weight of mid- and high-capacity heifers. The advantages of low-capacity heifers in average daily gain during the growing period were 60 g and 117 g, respectively. The results of the exterior evaluation have shown that primiparous with the high-capacity type of body constitution had greater size and larger measurements primarily of the chest and barrel (Р &lt; 0.05–0.001).The higher values of linear evaluation were also observed in cows with the high-capacity type, which were characterized by well-developed chest, wide rump, desired rear view of rear legs, firm udder attachment and strong central ligament. The power of influence of the type of body constitution on linear type traits ranged from 0.5 % (rear teat placement) to 46.2 % (chest width). Higher milk productivity was a characteristic of mid-capacity cows (an advantage of 305-d milk yield – 340–662 kg, milk fat yield – 9.0–21.0 kg, milk protein yield – 9.8–19.8 kg).The best results of reproduction capacity have been observed in cows with the high-capacity type of body constitution (calving percentage – 87.5 %)

Linear score of udder dimension and structural traits in White Fulani cattle

Linear descriptive scoring system is commonly used especially in cattle where number of analyses has been performed for selection purposes. The linear scoring of udder and structural traits of 700 White Fulani cattle of average age of 3 - 4 years was conducted in this study. These traits were subjectively scored through visual appraisal. Data were subjected to descriptive statistics and Pearson correlation. Result revealed that White Fulani cattle possess intermediate flank depth (6.40± 1.46); rump height (6.74± 1.31); rump length (5.94±1.23) and rump angle (5.26±1.29) but rump width (4.77 ±1.60) of the cattle was short and there were intermediate rear udder height (5.30±1.74), fore udder attachment (5.78±1.54), front teat placement (5.60±1.26), rear teat placement (5.40±1.34), teat length (5.01±1.95), teat placement side view (5.00±1.28) and udder balance (5.40±1.54), while, the cattle had short udder depth (4.90±1.95) and thickness of teat (4.93±1.83). Result further revealed that there was low or no correlation between udder type traits and structural traitsof the cattle. There was no or low correlation among udder traits except the moderate correlation between front teat placement and rear teat placement; moderate correlation between teat length and teat thickness. It was concluded that white Fulani cattle possess medium body and udder structure and no or low correlation between udder dimension traits of the cattle and their structural traits which may be suitable selection markers to improve White Fulani cattle milking ability particularly among pastoralists.

10.4314/sajas.v40i5.65295

Genetic correlations between first calving interval (CI) and linear type traits in South African Holstein and Jersey cattle were estimated to assess the possibility of using type information as selection criteria for CI. All linear type traits routinely evaluated under the National Genetic Evaluation Programme (18 for Jersey and 17 for Holstein) were considered. Data were obtained from the National Dairy Animal Recording Scheme and comprised records of 30 503 Holstein cows in 640 herds and 27 360 Jersey cows in 460 herds. Multiple-trait animal models were used to estimate parameters, based on the restricted maximum likelihood (REML) methodology. Fixed effects in the model varied depending on the individual trait. Linear type traits reflecting body size generally had much higher correlations with CI than udder characteristics. Genetic correlations of CI with body size traits were mostly positive in both breeds, ranging from 0.04 ± 0.16 with bone structure to 0.51 ± 0.08 with body depth, dairy strength and rear leg set. Correlations between CI and body depth (0.51 ± 0.08), angularity (0.32 ± 0.08) and rump angle (0.32 ± 0.12) indicate that cows with deep, more angular bodies and low pins have longer CI. Genetic correlations with udder type traits were generally low, ranging from -0.01 ± 0.20 with udder width to 0.25 ± 0.11 with rear teat placement. The highest genetic correlations with CI were for rear leg rear view (-0.70 ± 0.34), body depth (0.51 ± 0.08), dairy strength (0.51 ± 0.09), rear leg set (0.51 ± 0.06), foot angle (-0.44 ± 0.04) and rump angle (0.32 ± 0.05) in the Jersey and rump height (0.31 ± 0.08), angularity (0.32 ± 0.08) and body depth in the Holstein (0.51 ± 0.08). These traits may therefore be used in the analysis of CI to carry out early prediction of fertility and increase the accuracy of evaluation.

Genetic parameters for linear type traits including locomotion in Italian Jersey cattle breed

This study aimed to estimate genetic parameters for 19 linear type traits related to frame, udder, and feet and legs, and for final score of 10,305 first-parity Jersey cows evaluated between 2004 and 2016. Since scoring of locomotion in Jersey breed started in 2009, a subset of 6853 animals was extracted from the original data and used to investigate sources of variation and heritability of locomotion score, and its associations with the other traits. Univariate animal models were used to estimate variance components of type traits and bivariate analyses were implemented to obtain genetic correlations between traits. Fixed effects were herd-year-classifier, season of evaluation, stage of lactation at scoring and age at calving, and the random effects were additive genetic animal and the residual. Herd-year-classifier was the major source of variation affecting the traits. Heritabilities were low with the only exception of a moderate heritability (0.32 ± 0.02) for stature. The lowest heritabilities were estimated for feet and legs traits with values between 0.04 ± 0.02 (rear leg set side view, rear leg set rear view and locomotion) and 0.07 ± 0.02 (foot angle). The final score had heritability of 0.20 ± 0.02. Genetic correlations were generally stronger than their phenotypic counterparts. Overall, frame traits were weakly correlated with feet and legs, and udder traits, except for rump width, which showed moderate correlations with almost all traits, and angularity which showed the greatest correlations with rear udder height (0.61 ± 0.10) and rear udder width (0.62 ± 0.11). Genetic correlations between locomotion and frame traits ranged from 0.08 ± 0.22 (angularity) to 0.32 ± 0.16 (stature). The strongest correlations were estimated between locomotion and other feet and legs traits, but also with front teat placement (0.97 ± 0.19) and with rear teat placement (0.88 ± 0.17). Results of the present study will be used to enhance genetic evaluation of linear type traits in Jersey cattle breed.

Association of longevity with type traits, milk yield and udder health in Holstein cows

Genetic associations were estimated between 305-day cumulative milk yield (MY305) and maximum somatic cell score (SCS) in the first lactation, stayability in the herd at 60 months of age (Stay60), and linear udder and feet and legs traits. First-lactation records of Holstein cows reared in intensive production systems in Brazil were used. The (co)variance components were estimated using a Bayesian approach. The heritability estimates were 0.24 ± 0.02, 0.08 ± 0.02 and 0.09 ± 0.03 for MY305, SCS and Stay60, respectively. The heritabilities of the linear traits ranged from 0.16 to 0.39 for udder traits and from 0.13 to 0.21 for feet and legs traits. Stay60 showed genetic correlations of -0.25 ± 0.12 with MY305, 0.11 ± 0.20 with SCS, 0.33 ± 0.16 with rear teat placement, and -0.47 ± 0.13 with a rear legs-side view. It is possible to promote early genetic gains in the longevity of animals by selecting for moderately correlated traits to obtain a good set of feet and legs, as well as well-positioned teats of medium length. Extreme milk yields are associated with a reduction in Stay60. SCS in the first lactation has practically no influence on Stay60. The maximum selection efficiency will be achieved by selecting directly by Stay60.

Traits other than production over lactations and production seasons in dairy cows milked once a day in New Zealand

ABSTRACTThe aim of this study was to evaluate traits other than production (TOP) over multiple seasons and lactations in Holstein-Friesian (F), Jersey (J) and crossbred (F × J) cows milked once a day (OAD) in New Zealand. Cows in different lactations were scored for 18 TOP during three consecutive seasons from 2013 to 2015. Overall, there was a decrease in scores for stature, body capacity, rump width, legs, rear teat placement and dairy conformation over seasons, and a simultaneous increase in the scores for rump angle, udder support, udder overall and body condition score. Most udder traits showed a gradual decrease over lactations. The results of this study showed that improvements in TOP can be made by selecting for a particular body conformation, which is due to a correlated response to selection over time. Jerseys better adapt to the shift from TAD to OAD milking than F × J and F due to their better udder conformation.

Genetic associations between reproductive and linear-type traits of Holstein cows in Brazil

This study aimed to estimate heritability, genetic, and residual correlations between reproductive traits such as age at first calving, calving interval, dry period, and first service period and linear type traits measured in Holstein cows born between the years 1990 and 2008 in Brazil. The (co)variance components were estimated by restricted maximum likelihood, using the MTDFREML software. The heritability for reproductive traits and linear-type traits ranged from 0.02 to 0.03 and from 0.07 to 0.40, respectively. Estimates of genetic correlations between reproductive and linear-type traits ranged from -0.23 (top line) to 0.28 (angularity) to age at first calving, from -0.54 (final score) to 0.34 (foot angle) to calving interval, from -0.23 (angularity) to 0.56 (stature) to dry period, and from -0.52 (final score) to 0.36 (height udder) to first service period. Direct selection for any of the reproductive traits implies low genetic gains by virtue of their low heritabilities. Among the linear-type traits, the final score, chest width, top line, angularity, teat length, udder attachment, rear teat placement were highlighted as good auxiliary traits to improve reproductive efficiency of Holstein cows in Brazil. The simultaneous selection for reproductive and linear-type traits can lead a higher genetic progress in the reproductive traits.

Anatomical characteristics of teats and premilking bacterial counts of teat skin swabs of primiparous cows exposed to different types of bedding

Bacterial populations of teat skin are associated with risk of intramammary infection and may be influenced by anatomical characteristics of teats. The objective of this study was to evaluate associations of selected anatomical characteristics of teats with bacterial counts of teat skin of cows exposed to different types of bedding. Primarily primiparous Holstein cows (n = 128) were randomly allocated to 4 pens within a single barn. Each pen contained 1 type of bedding [new sand (NES), recycled sand (RS), deep-bedded manure solids (DBMS), and shallow-bedded manure solids over foam core mattresses (SBMS)]. During a single farm visit udders (n = 112) were scored for hygiene and 1 front (n = 112) and 1 rear teat (n = 111) of each enrolled cow were scored for hyperkeratosis (HK). Teat length, teat barrel diameter, and teat apex diameter were measured and teat skin swabs were systematically collected for microbiological analysis. Linear type evaluation data for udders of each cow were retrieved for each cow. Teat position (front or rear) was associated with occurrence of clinical mastitis during the 12 mo before the farm visit and more cases occurred in front quarters. The proportion of udders that were classified as clean (score 1 or 2) was 68, 82, 54, and 95% for cows housed in pens containing NES, RS, SBMS, and DBMS, respectively. No association was found between HK score and teat position and no association was found between HK score and teat skin bacterial count. Bacterial counts of teat skin swabs from front teats of cows in pens containing RS and SBMS were significantly less than those of rear teats of cows in pens containing DBMS or NES. Teat skin bacterial counts were significantly greater for swabs obtained from teats of cows with udder hygiene scores of 3 and 4 as compared with swabs obtained from cows with cleaner udders. Of all udder conformation traits evaluated, only narrower rear teat placement was positively associated with bacterial counts on teat skin.

Genetic association between longevity and linear type traits of Holstein cows

Longevity is a desirable trait in the dairy industry because of its relationship to profitability. The aim of this study was to estimate genetic parameters for longevity measurements related to productive life, or life in the herd, and linear type traits of Brazilian Holstein cows born between the years 1990 and 2008. The (co) variance components were estimated by the restricted maximum likelihood method. The heritability for measurements of longevity and linear type traits ranged from 0.05 to 0.07 and 0.08 to 0.39, respectively. The genetic correlations between measurements of longevity and linear type traits ranged from -0.39 to 0.31. Direct selection for longevity does not necessarily lead to long-lived cows, due to low heritability. Indirect genetic selection for udder depth, bone quality, udder height, rear teat placement and conformation traits showed the highest genetic correlations with measurements of time between birth and last milk record and time from first calving to last milk record.

Random regression test-day model for clinical mastitis: Genetic parameters, model comparison, and correlations with indicator traits

The objective was to study genetic (co)variance components for binary clinical mastitis (CM), test-day protein yield, and udder health indicator traits [test-day somatic cell score (SCS) and type traits of the udder composite] in the course of lactation with random regression models (RRM). The study used a data set from selected 15 large-scale contract herds including 26,651 Holstein cows. Test-day production and CM data were recorded from 2007 to 2012 and comprised parities 1 to 3. A longitudinal CM data structure was generated by assigning CM records to adjacent official test dates. Bivariate threshold-linear RRM were applied to estimate genetic (co)variance components between longitudinal binary CM (0=healthy; 1=diseased) and longitudinal Gaussian distributed protein yield and SCS test-day data. Heritabilities for liability to CM (heritability ~0.15 from 0 to 305 d after calving) were slightly higher than for SCS for corresponding days in milk (DIM) in the course of lactation. Daily genetic correlations between CM and SCS were moderate to high (genetic correlation ~0.70), but substantially decreased at the very end of lactation. Genetic correlations between CM at different test days were close to 1 for adjacent test days, but were close to zero for test days far apart. Daily genetic correlations between CM and protein yield were low to moderate. For identical DIM (e.g., DIM 20, 160, and 300), genetic correlations were −0.03, 0.11, and 0.18, respectively, and disproved pronounced genetic antagonisms between udder health and productivity. Correlations between estimated breeding values (EBV) for CM from the RRM and official EBV for linear type traits of the udder composite, including EBV from 74 influential sires (sires with >60 daughters), were −0.31 for front teat placement, −0.01 for rear teat placement, −0.31 for fore udder attachment, −0.32 for udder depth, and −0.08 for teat length. Estimated breeding values for CM from the RRM were compared with EBV from a multiple-trait model and with EBV from a repeatability model. For test days covering an identical time span and on a lactation level, correlations between EBV from RRM, multiple-trait model, and repeatability model were close to 1. Most relevant results suggest the routine application of threshold RRM to binary CM to (1) allow selection of genetically superior sires for distinct stages of lactation and (2) achieve higher selection response in CM compared with selection strategies based on indicator type traits or based on the indicator-trait SCS.

Genetic Association Between Herd Survival and Linear Type Traits in Holstein Cows Under Tropical Conditions

The objective of this study was to estimate genetic parameters for survival measures from birth to 60 and 72 months of age, as well as survival up to 48 and 54 months after first calving. The genetic association of these measures with 20 linear type traits and final score in Holstein cows, born between years 1990 to 2004, was also evaluated. The components of (co)variance were estimated by Bayesian methods, using the programme THRG1BBS1F 90 in bivariate analyses, considering animal threshold model for measures of survival, and animal linear model for linear type traits. The mean posterior heritability for the measures of survival ranged from 0.09 to 0.15, and for those of the linear type traits ranged from 0.07 to 0.36. The posterior genetic correlation between linear type traits and measures of survival varied from -0.37 to 0.50, respectively. Indirect genetic selection for udder depth, rear teat placement, udder texture, bone quality, fore udder attachment, body depth and chest width may lead to correlated gains in longevity in Holstein cows under tropical conditions.

Appraisal of linear type traits in Sahiwal cattle

To define Sahiwal breed on the basis of linear type traits, 101 purebred Sahiwal cow available at Veterinary college, Durg were used. All the traits were scaled and scored as per the guidelines of International committee for animal recording, (2001). Thus, Sahiwal can be defined as breed of cattle having stature of 128.90 cm, chest width of 26.87 cm, body depth of 64.68 cm, rump angle of 9.59 cm, rump width of 15.40 cm, rear leg set (side view) of 158.740, rear leg set (rear view) of -4.81 cm, foot angle of 48.390, udder depth of 12.39 cm, rear udder height of 12.65 cm, udder balance of 0.54 cm, udder cleft of 1.76 cm, fore udder attachment of 127.380, teat length of 6.92 cm, fore teat placement of 5.34 score, rear teat placement of 6.37 score and teat thickness of 2.78 cm. It is having taller height at rump, narrower teat thickness and rest of the traits being intermediate. The age of an animal had shown to have significant effect on expression of some linear type traits, thus, should always be taken in to consideration while defining animals on the basis of linear type traits.

Relationships between functional herd life and conformation traits in the South African Jersey breed

The genetic relationship between conformation traits and functional herd life of the South African Jersey population was investigated. Data on conformation traits (n = 46 238) and functional herd life (n = 90 530) on registered South African Jersey cows calving between 1989 and 2008 were obtained from the Integrated Registration and Genetic Information System. Conformation traits were scored using a subjective linear scoring system ranging from 1 to 9, except for foot angle, with a maximum score of 8. Conformation traits included stature, chest width, body depth, dairy strength, rump angle, thurl width, rear leg side view, foot angle, fore udder attachment, rear udder height, rear udder width, udder support, udder depth, front teat placement, rear teat placement and front teat length. Genetic correlations between conformation traits and functional herd life were estimated by a series of bivariate analyses. Significant moderate to strong positive genetic correlations between most udder traits and functional herd life (0.23 to 0.63) were estimated. The most important udder traits related to functional herd life were fore udder attachment, rear udder height and udder depth. Most of the body structure traits had a low to moderate negative correlation with functional herd life (-0.04 to -0.27). However, rump angle and foot angle were estimated to have a moderate positive genetic correlation with functional herd life. The genetic relationships between functional herd life and conformation traits in the South African Jersey breed indicate that conformation traits could be used to enhance the accuracy of genetic evaluation for functional herd life. It is therefore recommended that current national genetic evaluation for functional herd life in the South African Jersey breed should include conformation traits.