Teat Conformation Research Articles

Could Milkability Parameters Serve as a Reliable Tool to Predict the Morphology of Teat Structures and Their Milking-Induced Changes?

The study aimed to explore if milkability parameters could reliably predict the dimensions of teat structures and their milking-induced changes. Ultrasonography repeatedly measured the teat structures of 48 Holstein cows from mid to late lactation. We found that milking-induced changes in each structure are affected by different milkability parameters. Regression models for teat canal change and length change were significant, and variability was found to be 46.03% and 21.50%, respectively. Similarly, the teat structure's dimensions significantly affected milkability parameters, which differed for each structure. However, regression models only explained between 3.36% (teat length) and 7.59% (cistern) of variability. The prediction potential, performed based on milkability, is limited if the initial dimensions of structures are not provided. If teat dimensions were measured at the beginning of the production life, automatically collected milkability data could be used to calculate milking-induced changes incurred with each milking and the development of teat dimensions over the production life. If perfected, this tool could provide alerts about critical milking-induced changes and risky teat conformation traits, as they have a proven effect on udder health and are reliable indicators of milking effectiveness.

A computer algorithm for scoring cow teats based on udder images

ABSTRACT In this work, we aimed to develop a computer algorithm for detecting and scoring cow teats according to udder images. In addition, by assessing three teat traits, i.e. the length, thickness, and placements, we scored them according to international standards. By applying the algorithm to 71 cows, we were able to detect all four teats in 62 of 71 (85%) cow udder images, and differentiate the front and rear teats in 56 of 62 (92%) udder images. Based on the three teat traits, we scored the teats of 56 cows. The final teat score was given by averaging the three scores for each cow. We discuss the limitations of the algorithm, and also the issues with teat conformation and image-taking itself, e.g. teats not facing perpendicular to the camera. In conclusion, we have developed the first computerised teat scoring system based on cow udder images. Further improvements require tuning parameters of the workflow and the image-taking process.

Udder and teat morphometry and its relationship with occurrence of intramammary infections in dairy cattle

Bovine mastitis, an inflammatory disease of the mammary gland, is often caused by bacterial infection and is a major health problem on dairy farms. A cross-sectional study of four herds was conducted to assess udder and teat-related risk factors for the development of intramammary infections in 243 lactating cows. Udder and teat morphometric parameters were determined through visual appraisal method. Intramammary infection was assessed using California mastitis test (CMT), Somatic cell count (SCC) and bacteriology of milk samples. The frequencies of udder conformations were 65.8%, 18.9%, 7.4% and 7.8% for desirable, pendulous, round and goaty-shapes, respectively. Teat conformation revealed that 76.0%, 5.3%, 6.6%, 4.5% and 7.5% for desirable, short, funnel, bottle and conical-shapes, respectively. There was a significant (p<0.01) effect of udder shape and teat-end shape on SCC level and intramammary infections. The mean SCC and mastitis infection levels for undesirable udder was significantly (p<0.05) higher as compared to the desirable shaped udder. Similarly, significant (p<0.05) higher level SCC was found in undesired teats compared to desirable teats. The overall proportion of quarter mastitis infection in all four farms revealed 1.23% for clinical and 36.52% for subclinical mastitis. Herd-wise subclinical mastitis prevalence showed 42.8%, 35.07%, 33.09% and 2.94% for farm A, C, B and C, respectively. The most frequently isolated bacterial species were Staphylococcus aureus (56.34%) followed by Escherichia coli (22.55%), Streptococcus agalactiae (9.86%) and Bacillus spp. (8.45%). In conclusion, undesirable udder and teats conformations were more susceptible to intramammary infection and these traits must be considered accordingly while selecting dairy animals for future milk production. Observed high occurrence of subclinical Staphylococcal mastitis needs improvements in milking hygiene, mammary gland health, regular screening of animals, and use of biosecurity as an intervention tactic to limit the spread of pathogens at dairy farms.

Influence of WDR41 and ANKRD31 gene polymorphism on udder and teat type traits and mastitis in Karan Fries cows

In the present study, the effect of genetic polymorphism of WD-repeat containing protein 41 (WDR41) and Ankyrin repeat domain containing protein 31 (ANKRD31) gene on 17 traits related to udder and teat type and mastitis in 123 Karan Fries cows was studied. Restriction Fragment Length Polymorphism (RFLP) was used to identify the SNP (410 bp and 475 bp) in PCR amplified product of intron 4 and exon 10 in WDR41 gene. Both of them were polymorphic with Guanine to Adenine transition, and three genotypes namely AA, AG and GG were observed. In ANKRD31 gene, RFLP was used to identify the SNP in 513 bp PCR amplified product of intron 24 and two SNPs were found. We report for the first time that intron 4 and exon 10 of WDR41 gene is significantly associated with udder depth (UD), udder balance (UB), central ligament (CL), teat circumference (TC), SFF and tear diameter (TD), rear udder width (RUW), and mastitis. SNP rs110012582 in intron 24 of ANKRD31 gene is associated significantly with UD, distance between left and right teat (DLR), SFF, and SNP rs473512406 with udder length (UL), udder width (UW), udder circumference (UC), fore teat length (FTL), rear teat length (RTL), distance between fore and rear teat (DFR), DLR and mastitis. This information can augment future studies to determine the role of WDR41 and ANKRD31 genes as a candidate gene marker with desired udder and teat conformation and mastitis. Thus, it is essential to work for better udder health and prevent the incidence of mastitis in the herd.

WITHDRAWN:Principal component analysis of linear udder type traits and their relationship with milk yield and composition in indigenous Sahiwal cattle.

Ahead of Print article withdrawn by publisher.

Proportional hazard models associated with the survival of dairy goats reared in a tropical environment

Abstract Increasing the functional life of a doe in order to keep the most productive females in the herd as long as possible can result in a reduction of replacement costs because of the better utilization of the animal in the production system. Thus, the objective was to evaluate the influence of environment effect, and morphometric and type traits on the culling that limits the stay of a doe of an exotic dairy goat breed reared in a tropical climate in the herd (stayability). The data utilized in the present study had information of 1439 Saanen does, born between 2000 and 2015, from 17 herds. The stay in the herd for longer than 28 months of age (STAY28), that is lack of culling, was defined as successful; the does’ records were then not censored (C = 1). On the other hand, does kept in the herd for less than 28 months had their records censored (C = 0), once we considered that she still would kid. Does sold to other farmers were considered censored. Information regarding birth year, birth season, herd, six morphometric traits, and 12 visual appraisal-scored traits were evaluated. The Cox proportional hazard rate and the Kaplan-Meier models were fitted to analyze the data. Birth year, body length, rump width, feet and legs soundness, udder, and teat conformation were the traits that affected STAY28. For each birth year, body length, and rump width, reductions of 4 %, 2 %, and 5 % were observed on the culling hazard of a doe, respectively. Does with great scores for traits related to the mammary system were prematurely culled from the herd. In conclusion, STAY28 can be used as a selection criterion based on the aforementioned morphological and type traits, since it is effective to early detect individuals that will stay longer and more productive in a herd. Therefore, these traits should be considered in breeding programs.

Prevalence, aetiology and risk factors of subclinical mastitis in goats in Bangladesh

• The udder half level prevalence of Subclinical Mastitis (SCM) in goat was high (50.9 %). • The most prevalent pathogens associated with SCM were Non-aureus Staphylococcus species (NAS) and S. aureus. • SCM was significantly higher in poor and fair body conditioned goats compared to cachectic goats. • Late lactation period, Jamnapari breed and goats with bottle shaped teats were found as significant risk factors for SCM. Goat production in Bangladesh has increased substantially during the last decades due to increasing demand for meat and milk. This growth in goat production is, however, reduced by different diseases, among which mastitis has significant adverse effect on milk production and milk quality and is associated with financial losses. Risk factors and aetiology of goat mastitis in Bangladesh are largely unknown, hampering the effective control of the disease. The current study was therefore undertaken to determine the prevalence of subclinical mastitis (SCM) in goats, describe the pathogens causing SCM and identify risk factors. One hundred and six goats from 88 household goat farms were included in the study. The estimated udder half level prevalence of SCM, based on the California Mastitis Test, was 50.9 % (95 % CI: 44.2–57.7 %). The most prevalent group of pathogens associated with SCM was non-aureus Staphylococcus species (NAS) and S. aureus. Our study depicted the odds of SCM to be significantly higher in poor and fair body conditioned compared to cachectic goats, goats in late lactation, Jamnapari breed and in goats with bottle shaped teats rather than conical or cylindrical teat shapes. This study shows that SCM in goats in Bangladesh is highly prevalent and suggests the importance of breeding for mastitis resistance, by selecting stronger breeds and goats with good udder or teat conformation.

Heritability of phenotypic udder traits to improve resilience to mastitis in Texel ewes

There are no estimates of the heritability of phenotypic udder traits in suckler sheep, which produce meat lambs, and whether these are associated with resilience to mastitis. Mastitis is a common disease which damages the mammary gland and reduces productivity. The aims of this study were to investigate the feasibility of collecting udder phenotypes, their heritability and their association with mastitis in suckler ewes. Udder and teat conformation, teat lesions, intramammary masses (IMM) and litter size were recorded from 10 Texel flocks in Great Britain between 2012 and 2014; 968 records were collected. Pedigree data were obtained from an online pedigree recording system. Univariate quantitative genetic parameters were estimated using animal and sire models. Linear mixed models were used to analyse continuous traits and generalised linear mixed models were used to analyse binary traits. Continuous traits had higher heritabilities than binary with teat placement and teat length heritability (h2) highest at 0.35 (SD 0.04) and 0.42 (SD 0.04), respectively. Udder width, drop and separation heritabilities were lower and varied with udder volume. The heritabilities of IMM and teat lesions (sire model) were 0.18 (SD 0.12) and 0.17 (SD 0.11), respectively. All heritabilities were sufficiently high to be in a selection programme to increase resilience to mastitis in the population of Texel sheep. Further studies are required to investigate genetic relationships between traits and to determine whether udder traits predict IMM, and the potential benefits from including traits in a selection programme to increase resilience to chronic mastitis.

A longitudinal study of factors associated with acute and chronic mastitis and their impact on lamb growth rate in 10 suckler sheep flocks in Great Britain

A 2-year prospective, longitudinal study of 10 suckler sheep flocks in Great Britain was run to identify factors associated with acute mastitis (AM) and chronic mastitis, and their impact on lamb growth rate. Data were collected on AM, intramammary masses (IMM; a marker for chronic mastitis), udder and teat conformation, teat lesions, body condition, ewe nutrition, litter size, lamb weight and general flock management. Each flock was visited twice each year, approximately 4 weeks before lambing and 9 weeks into lactation, for two years and all ewes present at a visit were examined. There were 7021 examinations in total. AM was reported in 2.1–3.0% of ewes/year; this ranged from 0.0% to 37.1% by flock. IMM were detected in 4.7% of ewes in pregnancy and 10.9% of ewes in lactation. Once an IMM had been detected there was an increased risk of future IMM although IMM were not consistently present. The majority of ewes had good udder conformation to suckle lambs. Factors associated with AM, IMM in pregnant and lactating ewes, udder conformation and lamb daily live weight gain were explored using mixed effect multivariable models. An increased risk of AM was associated with underfeeding protein in pregnancy (OR 4.05), forward pointing teats (OR 2.54), downward pointing teats (OR 4.68), rearing≥2 lambs (OR 2.65), non-traumatic teat lesions (OR 2.09); and marginally associated with the presence of IMM. An increased risk of IMM in lactation was associated with AM during lactation (OR 12.39), IMM in pregnancy (OR 4.79), IMM in the previous lactation (OR 4.77), underfeeding energy in pregnancy (OR 6.66) and traumatic teat lesions (OR 2.48). An increased risk of IMM in pregnancy was associated with IMM in the previous pregnancy, IMM in the previous lactation and underfeeding energy in the previous lactation (OR 2.95). Lower lamb daily live weight gain was associated with traumatic teat lesions, IMM in lactation (−0.01kg/day) and AM (−0.04kg/day). We conclude that inadequate nutrition is an important cause of mastitis in suckler ewes which farmers could address in part using current nutritional guidelines but further work is needed. The relationship between AM and IMM indicates that separating or culling ewes with IMM would help reduce AM.

Relationship of udder and teat conformation with intra-mammary infection in crossbred cows under hot-humid climate

Relationship of udder and teat conformation with intra-mammary infection in crossbred cows under hot-humid climate

Relationship of udder and teat conformation with intra-mammary infection in crossbred cows under hot-humid climate.

Aim:The present study was aimed to investigate the relationship of udder shape, teat-end shape, teat length, and teat diameter with intra-mammary infection in Jersey crossbred cows under hot-humid climate.Materials and Methods:A total of 24 lactating Jersey crossbred cows were evaluated for udder shape (pendulous/regular) and teat-end shape (flat/inverted/pointed) by visual examination, while teat length and teat diameter were measured using vernier caliper. Monthly milk sampling was done for 4 months of duration. Few quarters were found as blind or non-functional and so, a total of 366 quarter wise milk samples were collected at the monthly interval and subjected to somatic cell count (SCC) microscopically. The data on SCC were transformed into log scale and analyzed.Results:There was a significant (p<0.01) effect of udder shape and teat-end shape on SCC level. The mean SCC level for pendulous udder was significantly (p<0.05) higher as compared to the regular shaped udder. Similarly, significantly (p<0.05) a higher level of mean SCC was found in flat teat-end shape. A significant (p<0.01) correlation was found between SCC and teat length as well as teat diameter.Conclusion:In conclusion, pendulous udder, flat and inverted teat-end, very long and thick teat were more susceptible to intra-mammary infection in Jersey crossbred cows and these traits must be considered accordingly while selecting dairy animals for future milk production.

A longitudinal study of risk factors for teat lesions in 67 suckler ewes in a single flock in England

A longitudinal study of 67 suckler ewes on a commercial sheep farm near Wolverhampton, England was carried out from March to July 2010. Data on ewe teat lesions and udder and teat conformation were collected together with data on lamb health and weight at lambing and at 14-day intervals until lambs were 8–10 weeks old. Each ewe was examined on 4–5 occasions. Teat lesions were categorised as traumatic or non-traumatic based on appearance. Risk factors for the development of each type of teat lesion were investigated using mixed effect binomial regression models. The incidence of traumatic teat lesions was greatest 3–4 weeks after lambing with 27.9% new cases by udder half. There was an increased risk of traumatic teat lesions in 2 year old ewes (OR 3.5, CI 1.2, 10.5) compared with 6 year old ewes and in ewes with abnormal compared with normal teat placement, a wide or narrow udder width compared with a normal udder width, a heavy total litter weight, body condition score (BCS)<2.5, compared with BCS of 2.5 14-days previously, and in ewes with abnormal udder skin (waxy, dry or chapped) compared with normal udder skin. The incidence of non-traumatic teat lesions was greatest 7–10 weeks after lambing with 21.4% new cases. Non-traumatic lesions were more likely to occur in ewes with BCS=3 compared with BCS of 2.5. The risk factors for traumatic and non-traumatic teat lesions differ. Traumatic lesions are associated with teat and udder morphology, ewe age and BCS, and lamb growth rate, whereas non-traumatic lesions are associated with ewe BCS.

A cohort study of the associations between udder conformation, milk somatic cell count, and lamb weight in suckler ewes

A cohort study of 67 suckler ewes from 1 farm was carried out from January to May 2010 to investigate associations between udder conformation, udder half milk somatic cell count (SCC), and lamb weight. Ewes and lambs were observed at lambing. Ewe health and teat condition and lamb health and weight were recorded on 4 to 5 further occasions at 14-d intervals. At each observation, a milk sample was collected from each udder half for somatic cell counting. Two weeks after lambing, ewe udder conformation and teat placement were scored. Low lamb weight was associated with ewe SCC >400,000 cells/mL (−0.73kg), a new teat lesion 14 d previously (−0.91kg), suboptimal teat position (−1.38kg), rearing in a multiple litter (−1.45kg), presence of diarrhea at the examination (−1.19kg), and rearing by a 9-yr-old ewe compared with a 6-yr-old ewe (−2.36kg). High lamb weight was associated with increasing lamb age (0.21kg/d), increasing birth weight (1.65kg/kg at birth), and increasing number of days the ewe was given supplementary feed before lambing (0.06kg/d). High udder half SCC was associated with pendulous udders (9.6% increase in SCC/cm of drop) and greater total cross-sectional area of the teats (7.2% increase of SCC/cm2). Low SCC were associated with a heavier mean litter weight (6.7% decrease in SCC/kg). Linear, quadratic, and cubic terms for days in lactation were also significant. We conclude that poor udder and teat conformation are associated with high levels of intramammary infection, as indicated by increased SCC and that both physical attributes of the udder and SCC are linked to lamb growth, suggesting that selection of suckler ewes with better udder and teat conformation would reduce intramammary infection and increase lamb growth rate.

Lactating dairy cows adapt quickly to being milked by an automatic milking system

Transitioning a dairy herd to an automatic milking system (AMS) from a conventional parlor system may be stressful for the cow, as many changes occur during this process. Chronic stress may affect the welfare of the cow, and acute stress during milking can decrease milk yield. Therefore, it is important to quantify if and how long stress during adaptation to an AMS might persist. Seventy-seven cows with acceptable udder and teat conformation that would not interfere with adaptation to the AMS and that were lactating n=18, early [0 to 100 d in milk (DIM)]; n=27, mid (100 to 200 DIM); and n=32, late (200+ DIM) for the full duration of the project were chosen for observation. All cows had been milked previously in a double-6 herringbone milking parlor. Four stress-related behaviors [step-kick behavior both before and after attachment of teat cups, elimination (urination and defecation instances), and vocalization] were recorded during milking by trained observers, whereas milk yield was automatically recorded by the AMS. Data were collected for 24-h periods beginning on the day the cows transitioned to milking in the AMS (d 0), and on d 1, 2, 4, 8, 16, and 32 thereafter. Instances of elimination and vocalization were greater on d 0 compared with all other days (elimination: d 0=3.1±0.09, d 1=0.6±0.07, and 0±0 instances thereafter; vocalization: d 0=1.7±0.07, d 1=0.05±0.04, and 0±0 instances thereafter). Milk yield increased between d 0 (18.3±1.7kg) and d 1 (30.9±1.7kg). Primiparous cows (n=28) were more likely than multiparous cows (n=49) to display step-kick behaviors both before (8.3±2.5; 5.5±0.6, respectively) and after (15.6±2.4; 13.3±1.3, respectively) teat cup attachment during milking. Eight days after introducing the cows to the AMS, over 60% of the herd was milking voluntarily and 95% of the herd was milking voluntarily within a month, which suggests that cows did not find the AMS aversive. Greater elimination and vocalization behavior and lower milk yield on d 0 relative to subsequent days indicated initial stress and discomfort with the milking process in the new system; however, the cows appeared to adapt within 24h.

Competing risk analyses of longevity in Duroc sows with a special emphasis on leg conformation

A competing risk approach was used to evaluate the influence of several factors on culling risk for 587 Duroc sows. Three different analyses were performed according to whether sow failure was due to death during productive life (DE) or to one of two causes for voluntary culling: low productivity (LP) and low fertility (LF). Sow survival was analyzed by the Cox model. Year at first farrowing (batch effect) significantly affected sow survival in all three analyses (P < 0.05 for DE and P < 0.001 for LP and LF) whereas farm of origin accounted for relevant variation in the LP and LF analyses. LP culling increased with backfat thickness of more than 19 mm at the end of the growth period (P < 0.05), bad teat condition (P < 0.05) and reduced piglets born alive (P < 0.001). For the LF competing risk analysis, culling increased with age at first farrowing (P < 0.1). Special emphasis was placed on the influence of leg and teat conformation on sow survivability, although they did not affect sow failure due to DE (P > 0.1). The overall leg-conformation score significantly influenced sow longevity in LP (P < 0.001) and LF competing risk analyses (P < 0.001), showing a higher hazard ratio (HR) for poorly conformed sows (1.013 and 4.366, respectively) than for well-conformed sows (0.342 and 0.246, respectively). Survival decreased with the presence of abnormal hoof growth in LP and LF analyses (HR = 3.372 and 6.002, respectively; P < 0.001) and bumps or injuries to legs (HR = 4.172 and 5.839, respectively; P < 0.01). Plantigradism reduced sow survival in the LP analysis (P < 0.05), while sickle-hooked leg (P < 0.05) impaired sow survival in the fertility-specific analysis. Estimates of heritability for longevity related to LP culling ranged from 0.008 to 0.024 depending on the estimation procedure, whereas heritability values increased to between 0.017 and 0.083 in LF analysis. These analyses highlighted substantial discrepancies in the sources of variation and genetic background of sow longevity depending on the cause of failure. The estimated heritabilities suggested that direct genetic improvement for sow longevity seemed feasible, although only a small genetic progress was expected.

Effect of leg conformation on survivability of Duroc, Landrace, and Large White sows1

Sow longevity influences farm economy and can be considered an important indicator of animal welfare. Body features such as leg conformation can play a key role in sow longevity, although little is known about its effect on culling decisions. Within this context, longevity data from 587 Duroc, 239 Landrace, and 217 Large White sows were analyzed with special emphasis on the effect of leg conformation. Sow longevity was analyzed twice for each breed, testing the effect of a subjective overall score for leg conformation, or the presence or absence of 6 specific leg conformation defects. Each preliminary model also included a teat conformation score with 3 levels, farm or origin, backfat thickness at 6 mo of age, and 2 continuous sources of variation, namely the age at the first farrowing and the number of piglets born alive at each farrowing. Overall leg conformation score influenced (P < 0.01) sow longevity in Duroc, Landrace, and Large White sows, with a greater hazard ratio (HR) for poorly conformed sows (1.56, 2.16, and 1.79, respectively) than for well-conformed sows (0.32, 0.66, and 0.68, respectively). Abnormal hoof growth reduced survivability in Duroc (HR = 2.78; P < 0.001) and Landrace sows (HR = 1.88; P < 0.01); the presence of splayed feet (P < 0.05) or bumps and injuries (P < 0.001) increased the risk of culling in Duroc sows (HR = 2.08 and 3.57, respectively), whereas the incidence of straight pastern increased the HR in Large White sows (HR = 2.49; P < 0.01). In all 3 breeds, longevity decreased for plantigrade sows, with a greater HR in Duroc (HR = 3.38; P < 0.001) than in Landrace (HR = 1.53; P < 0.10) and Large White sows (HR = 1.73; P < 0.05). Teat conformation did not influence sow longevity (P > 0.10). Estimates of heritability for longevity in Duroc sows ranged from 0.05 to 0.07 depending on the algorithm applied. Leg conformation had a substantial effect on sow longevity, where an accurate removal of poorly leg-conformed candidate gilts before first mating could improve sow survival and reduce culling costs. These moderate estimates of heritability indicated that survivability of Duroc sows could be genetically improved by direct selection for leg conformation.

Relationship between udder and teat conformation and milk yield performance in dairy cows pre- and post-milking

The objectives of this study were to determine the relationship between udder floor area (UFA) and milk production traits in dairy cows, pre- and post-milking, as well as to examine the usefulness of a simple method of measuring UFA. The absolute reduction (AR, cm2) and relative reduction (RR, %) in UFA post-milking relative to pre-milking was calculated. Absolute reduction was influenced by breed and lactation stage, but not by parity of the cows (P &lt; 0.05). There was no effect of breed and stage of lactation on the RR of UFA. Moderate correlations were observed between absolute reduction of UFA and daily milk yield (r2 = 0.422), lactation milk yield (r2 = 0.426), and absolute fat yield (r2 = 0.515) (P &lt; 0.01 and P &lt; 0.05). Moderate and weak correlations were found between RR of UFA and daily milk yield (r2 = 0.335) (P &lt; 0.01), AR of the udder area and the 305-d lactation milk yield (r2 = 0.326) (P &lt; 0.10). It was concluded that measuring UFA using the method described may be useful for the selection of dairy cattle mammary conformation traits. Key words: Dairy cow, udder and teat conformation, milk production traits, measurement technique

The Importance of Udder and Teat Conformation for Teat Seeking by the Newborn Calf

Because antibody levels in colostrum and the efficiency of the intestinal absorption of these antibodies decrease with time after birth, late suckling newborn calves risk receiving inadequate passive immunity. The influence of the conformation and size of the udder and teats of the dam on the teat-seeking behavior of newborn calves with respect to the time they first suckle was studied in 42 cow-calf pairs housed in individual calving pens. A smaller distance from udder to floor (e.g., low slung udders) led to increased variation and a significant increase in the time spent teat seeking; it also had a significant effect on the time of the first suckle. The variation in the distance from udder to floor accounted for 24 and 15% of the variations in rank order of the calves with respect to duration of active teat seeking before first suckling and to the time to first suckle, respectively. The results of this study showed that calves born to cows or heifers with low slung udders cannot be expected to obtain colostrum soon enough by natural suckling. They should either be helped to suckle or be hand fed to ensure that they receive a good and adequate passive immunity.

RELATIONSHIPS OF TEAT CONFORMATION AND UDDER HEIGHT TO MILK FLOW RATE AND MILK PRODUCTION IN HOLSTEINS

Teat conformation characteristics, udder height, total milking yield, 2-min yield, 2-min yield adjusted for the linear and quadratic effects of total milking yield, and 305-day milk and fat yields were recorded on 377 Holstein-Friesian cows in 18 herds. Simple relationships of teat conformation measures and udder height to milk flow rate and production traits which were significant (P &lt; 0.05) were as follows. Mean 2-min, total milking, and 305-day milk yields were lower for plumb front teats than for front teats that were not plumb. Cows with plumb rear teats also had lower total milking yields. Cows with cylindrical teats, both front and rear, had lower total milking yields than cows with funnel teats. Teat length was positively correlated with total milking, 305-day milk and 305-day fat yields. Teat diameter measures taken at proximal, medial and distal locations of the teat were positively correlated with all production traits, and rear teat diameter measures were positively correlated with 2-min yield. Udder height was positively correlated with adjusted 2-min yield and negatively correlated with total milking, 305-day milk and 305-day fat yields. Least squares analyses, which corrected for the effects of herd, age of cow at calving, and stage of lactation, were conducted, and significant (P &lt; 0.05) effects were as follows. Cows with cylindrical teats produced 0.7–0.8 kg less total milk at milking than cows with funnel teats. Rear teat diameter was more highly related to milk production than front teat diameter. Proximal and distal diameter of the rear teat was positively associated with all three production traits, and medial rear teat diameter was positively associated with total milking and 305-day milk yields. Also, proximal diameter of the rear teat had a positive relationship with 2-min yield. Total milking yield was positively influenced by front teat proximal and medial diameters, but medial diameter had a negative effect on adjusted 2-min yield. Udder height influenced all traits. High udders had relatively higher milk flow rates but lower milk and fat production. Each centimetre increase in udder height was associated with a 46-kg decrease in 305-day milk. Heritabilities of 2-min yield, adjusted 2-min yield, 305-day milk yield and 305-day fat yield were 0.17, 0.27, 0.18, and 0.50, respectively.

HERITABILITIES OF TEAT CONFORMATION TRAITS AND THEIR RELATIONSHIPS WITH SOMATIC CELL COUNTS IN HOLSTEINS

Teat conformation characteristics were measured on 402 Holstein-Friesian cows in 18 dairy herds in western Quebec and eastern Ontario. The purpose of the study was to determine the effects of heridity on teat conformation traits as well as to examine phenotypic relationships between the traits and somatic cell count as a measure of udder health. Maximum likelihood estimates of heritabilities of teat conformation traits and cell count, transformed to a log scale, were low; usually less than 0.10. Exceptions were length of front teat (h2 = 0.44) and distance of udder to the floor (h2 = 0.41). Significantly higher cell counts were associated with teats that were long, wide, not plumb and bottle (as opposed to cylindrical or funnel) shaped. The most highly correlated trait with cell count was distance of udder to the floor (r = − 0.24). However, many of the significant gross relationships observed were jointly related with age of cow, and when the effects of age of cow at calving, stage of lactation and herd were removed, only length of rear teat and front and rear teat medial diameters had significant influences on cell count.