Simulation study of teat score in first-parity Gelbvieh cows: parameter estimation

Teat scores from 9,598 first-parity Gelbvieh cows were used to investigate the adequacy of grouping approaches to decrease score misclassifications or inconsistencies as well as to simplify the data collection process. The procedure was tested using simulated data and then validated using teat score records of Gelbvieh cattle. First-parity cows were considered to be 4 yr of age or younger at first calving, did not have multiple records within 280 d, and were at least 50% Gelbvieh. Producers scored cows within 24 h of parturition. Teat score, a subjective measure of teat size, ranged from 0 (very large) to 50 (very small). A linear mixed model that included herd-year, month of calving, and age at calving as systematic effects; regression on the percentage of Gelbvieh; and additive breeding values (BV) and residual as random effects was used to generate the data. Simulated data were analyzed using one of three scoring methods: all values (S50), 10 classes (S10), and five classes (S5). The 10 classes were formed by subdividing every five scores into a single class starting at score zero. Similarly, the five classes were formed by combining every 10 scores into one class. The average Pearson correlations, based on five replicates, between the true and estimated BV (systematic effects) were 0.36 (0.85), 0.35 (0.89), and 0.32 (0.87) using S50, S10, and S5, respectively. Average correlations between estimated BV (systematic effects) were 0.97 (0.95), 0.89 (0.92), and 0.92 (0.97) based on S50 and S10, S50 and S5, and S10 and S5, respectively. Field data were used to validate the simulation procedure. The field data were categorized into 10 classes (F10) and five classes (F5) as described for the simulated data. Pearson correlations between estimated BV (systematic effects) were 0.99 (0.93), 0.93 (0.88), and 0.93 (0.96), based on F50 with F10, F50 with F5, and F10 with F5, respectively. The extremely high correlations between predicted BV based on S50, S10, S5, F50, F10, with F5 suggest that a simplified score classification method could be adopted without compromising the expected genetic progress for the trait under consideration. Furthermore, the difference in corresponding Pearson correlations across the field and simulated data might suggest the presence of some inconsistencies or misclassifications of the actual scoring system.     

Genetic associations of teat cup attachment failures,incomplete milkings,and handling time in automatic milking systems with milkability,temperament, and udder conformation

Automatic milking systems (AMS) allow recording of alternative milkability measures. Our objectives were to estimate genetic parameters for teat cup attachment failures (AtF), incomplete milkings (IM), and handling time (HT), and their genetic correlations with box time (BT), udder traits and temperament. Teat coordinates were to measure udder conformation and teat placement. Genetic correlations were estimated between these traits and linear classification traits. Data on Swedish Holstein and Swedish Red cows in 19 AMS herds and 74 herds with conventional milking parlors were analyzed. HT and IM had low heritabilities, but that of AtF was 0.21–0.31. Genetic correlations between AtF and temperament were 0.44–0.71 (calm cows having low AtF). Short BT was weakly genetically associated with shallow udders with short and thin teats. High genetic correlations (0.91–0.98) were found between teat coordinate traits and linear classification traits. Thus, AMS records can be effectively used to select for improved milkability and temperament.     

Effects of postmilking teat treatment on the colonization of Staphylococcus aureus on chapped teat skin

Sixteen Holstein cows were used to test the effect of postmilking teat treatment on colonization and intramammary infection by Staphylococcus aureus on chapped teats. Treatments were (1) chapping the teat and using 1% I2/10% glycerin postdip solution, (2) 1% I2/10% glycerin postdip solution on nonchapped teats, (3) chapping the teat and using 10% glycerin postdip solution, (4) chapping the teat and not using a postdip solution. All mammary glands were free of S aureus teat skin colonization and intramammary infection at the start of the study. Teats selected for chapping were dipped in 1N NaOH prior to 3 applications of S aureus broth culture; cultures were applied at 12-hour intervals on all teats. Treatments were applied after each milking for 30 days and were initiated after the second broth dip. Teat skin swab specimens and milk samples were collected before treatment application. Teat skin condition was scored daily. Nonchapped teats (treatment 2) did not support skin or orifice colonization by S aureus. Treatment-1 teats healed most rapidly and supported less colonization in skin and orifice than did treatment-3 and -4 teats. Teat skin scores and skin colonization were lower for treatment-3 than treatment-4 teats. A correlation between teat skin colonization and teat skin conditions was found. Two intramammary infections were found in treatment-4 quarters and 1 in a treatment-3 quarter.(ABSTRACT TRUNCATED AT 250 WORDS)     

Removal of hair surrounding the teat and associated bacterial counts on teat skin surface, in milk, and intramammary infections

The effectiveness of monthly removal of hair surrounding teats on the reduction of teat skin surface bacteria, and the incidence of intramammary infection (IMI), was studied for 10 months in a dairy farm. A split udder design was used where hair was removed on one side, left or right, with the other side serving as a control. Controls and treatment sides were randomly applied in a systematic fashion to 218 cows. Standard milking time pre- and post-milking hygiene practices were applied to all udders during the trial. Collection of teat skin swab solutions preceded aseptic collection of milk samples, performed at monthly intervals, immediately prior to milking. Teat skin bacterial counts did not differ between control and treated teats. Incidences of IMI were similar for treatment when compared with control mammary quarters, as measured by total or by pathogen type. In a second study, the effect of hair removal on the bacterial content of milk was determined using 40 cows. Treatments and allocations were as described. Udder half milk, milk from both mammary quarters of each udder half, was combined and diverted into separate buckets. Buckets were thoroughly cleaned and sanitized between milkings. A portion of bucket milk was collected 24 h after removal of udder hair. The total milk bacterial counts, and counts of psychrotrophs and thermoduric organisms were not reduced by udder hair removal. Results do not suggest that removal of udder hair leads to an improvement in milk quality as determined by milk bacterial content in the herd studied.     

Postpartum supplemental fat, but not maternal body condition score at parturition, affects plasma and adipose tissue fatty acid profiles of suckling beef calves

Three-year-old Angus x Gelbvieh beef cows, which were nutritionally managed to achieve a BCS of 4 +/- 0.07 (479 +/- 36 kg of BW) or 6 +/- 0.07 (580 +/- 53 kg of BW) at parturition, were used in a 2-yr experiment (n = 36/yr) to determine the effects of maternal BCS at parturition and postpartum lipid supplementation on fatty acid profile of suckling calf plasma and adipose tissue. Beginning 3 d postpartum, cows within each BCS were assigned randomly to 1 of 3 treatments in which cows were all fed hay and either a low-fat (control) supplement or supplements with either high-linoleate cracked safflower seeds (linoleate) or high-oleate cracked safflower seeds (oleate) until d 61 of lactation. Diets were formulated to be isonitrogenous and isocaloric, and safflower seed supplements were provided to achieve 5% of DMI as fat. Total concentration of fatty acids in plasma did not differ (P = 0.48) due to maternal BCS at parturition. Percentage of 20:5n-3 in plasma tended (P = 0.06) to be greater for calves suckling cows with a BCS of 6 at parturition. No other differences (P = 0.12 to 0.99) were noted in calf plasma fatty acid profile due to maternal BCS at parturition. Likewise, no differences were detected for total fatty acid concentration (P = 0.88) in calf adipose tissue due to maternal BCS at parturition. Weight percentage of 14:1 (P = 0.001) was greatest in adipose tissue of calves suckling cows fed control and oleate; however, the percentages of 14:0, 15:0, 16:0, 16:1, 17:0, and 18:3n-3 were greater (P < 0.001) in adipose tissue from calves suckling cows fed control compared with calves suckling cows fed linoleate or oleate. Percentages of 18:0, 18:1trans-11, 18:2n-6, and cis-9, trans-11 CLA were greater (P < 0.001) in adipose tissue from calves suckling cows fed linoleate compared with calves suckling cows fed control and oleate. Calves suckling cows fed oleate had greater (P < 0.001) percentages of 18:1trans-9, 18:1trans-10, and 18:1cis-9 in adipose tissue than calves suckling cows fed control or linoleate. Calf plasma and adipose tissue fatty acid profiles were reflective of milk fatty acids. Because fatty acids play an important role in metabolic regulatory functions, changes in milk fatty acid profile should be considered when beef cows are fed lipid supplements.     

Selection for increased weaning or yearling weight in Hereford cattle. II. Direct and correlated responses

Selection was applied from 1964 to 1978 for increased weaning weight (WWL) or yearling weight (YWL) in two Hereford lines. An Angus line was maintained as an unselected control line (CL). Each line was maintained with 50 cows and four sires each year (two sires selected each year and used for 2 yr). Primary traits measured in the lines were birth weight (BW), preweaning daily gain (WDG), weaning weight (WW), weaning conformation grade (WG), weaning condition score (WC), weaning to yearling daily gain (YDG), yearling weight (YW), yearling conformation grade (YG) and yearling condition score (YC). Averaged over two methods, estimated genetic responses/generation (in standard deviation units) in WWL and YWL were: BW, .29, .26; WDG, .17, .15; WW, .22, .19; WG, .19, .26; WC, .12, .12; YDG, -.02, .04; YW, .08, .14; YG, .19, .16; YC, -.13, -.03. The realized heritability estimates were .23 and .15 for WW and YW, respectively. The realized genetic correlation between WW and YW was .69. Progeny from crosses of selected WWL and YWL sires to Angus cows had similar feedlot and carcass performance. At the end of the study, milk yield and composition were similar for mature cows in WWL and YWL.     

Teat lesions and their relationship to intramammary infections on small-scale dairy farms in Kiambu district in Kenya

Mammary gland quarters of 139 lactating dairy cows from small-scale dairy herds were examined visually and by palpation for teat lesions and by California mastitis test (CMT) and bacterial culture for subclinical mastitis. Teat lesions were observed in 97 teats. These included teat chaps (39.2%), teat papillomas (23.7%), teat erosions (22.7%), teat fistulae (5.1%), inverted teats (5.1%) and blocked teats (4.2%). According to the CMT, the prevalence of subclinical mastitis was 33.4% in all the mammary gland quarters, 71.0% in quarters with teat lesions and 24.5% in quarters without teat lesions. There was a significant (P < 0.01) association between teat lesions and the prevalence of subclinical mastitis. The mammary gland quarters with teat lesions were 7.2 times more likely to have a positive CMT (P < 0.01) and 5.6 times more likely to have bacterial organisms (P < 0.01) isolated from them than those without any teat lesions. The bacterial organisms most frequently isolated from the CMT-positive milk samples from both the mammary gland quarters with teat lesions and those without teat lesions were Staphylococcus aureus (50.0%), Streptococcus spp. (34.8%) and Arcanobacterium pyogenes (6.2%).     

中国荷斯坦牛部分乳房结构特性对泌乳性能的影响

本研究对规模化场奶牛乳房结构部分性状进行评价和测定,旨在分析其影响因素及其与泌乳性能的关系。现场评价和测定我国北方6个规模化奶牛场荷斯坦牛的乳房均衡(2 030条)、乳头长度(1 551条)和乳头位置评分(分前、后乳头,2 839条),使用SAS 9.2 GLM过程采用固定效应模型分析影响上述3个乳房性状的因素,同时分析3个单项性状对校正日产奶量和体细胞评分的影响。结果表明:场和胎次对3个乳房性状影响极显著(P0.01);前、后乳头位置和后乳头长度对校正日产奶量有显著影响(P0.05),校正日产奶量与前乳头位置评分值呈正比,与后乳头位置评分值呈反比;前乳头位置和长度对体细胞评分有显著影响(P0.05),体细胞评分随前乳头位置评分的增大而减小;5~5.5 cm的乳头长度对于校正日产奶量和体细胞评分都最佳。本研究结果为通过乳房性状选择、淘汰并提高奶牛的生产性能、乳房健康提供了参考。     

Effects of induced hypothyroidism on weight gains, lactation, and reproductive performance of primiparous Brahman cows.

Primiparous, spring-calving Brahman cows (BW = 425.0 +/- 13.8 kg, body condition score [BCS] = 5.0 +/- .2 units; SEM) were used to study the effects of thyroid manipulation on weight gain, milk production, and reproduction. Nine cows served as controls. Nine cows were induced to become hypothyroid by daily ingestion of 4 mg/kg BW of 6-n-propyl-2-thiouracil (PTU). Cows were stratified to treatment 1 d after calving based on season of birth, BW, BCS, calf sex, and calf sire. The treatment period lasted for 84 d and was followed by a 56-d posttreatment period. Cow BW, BCS, and calf weight were recorded twice weekly. Milk production was estimated at 14, 28, 56, 84, 98, 112, and 140 d after calving. Weekly blood samples were obtained for analysis of triiodothyronine (T3), thyroxine (T4), and progesterone (P4). Estrus was monitored twice daily with the aid of a fertile bull equipped with a chin ball marker. Hypothyroidism was effectively induced in all PTU cows during the treatment period. The PTU cows gained more (P = .002) weight (54.6 +/- 7.6 kg) and tended (P = .06) to increase body condition (.61 +/- .17 units) more than control cows (15.7 +/- 7.6 kg; .11 +/- .17 units) during the treatment period. Control calves gained at a faster rate (.85 +/- .04 kg/d; P < .01) than PTU calves (.70 +/- .04 kg/d) during the treatment period. Milk production was lower (P < .05) in PTU cows on d 56 and 84. During posttreatment all trends were reversed, and BW, BCS, calf weight, and milk production were similar between the two groups by d 140. Reproductive performance was not affected by induction of hypothyroidism. In conclusion, induction of hypothyroidism was successful in increasing cow weight and BCS gains and suppressing milk production during the treatment period, but these changes were not successful in improving reproductive performance of primiparous Brahman cows.     

Differences among breed crosses of cattle in the conversion of food energy to calf weight during the preweaning interval

The objective of this study was to determine whether F1 cows that differ in genetic potential for weight at maturity and milk yield vary in the conversion of food energy to calf weight gain. Food intakes and weight change data were recorded by pen for cows and calves from approximately 45 d postpartum. Cows assigned to the study were 7- to 9-yr-old F1s produced by top-crossing Angus, Hereford, Brown Swiss, Chianina, Gelbvieh; Maine Anjou, and Red Poll sires to either Angus or Hereford dams. Calves were sired by Simmentals. Experimental units were pens (10 to 12 cow/calf pairs); pen was replicated within breed of sire in each of 2 yr (n = 24). Calf weight gain and energy consumed by the dams differed among the F1s, as did the ratio of calf weight gain to energy consumed by the calf and cow. Angus or Hereford (35.8), Red Poll (35.7), or Maine Anjou (35.6) F1s produced more calf weight per unit of energy consumed (g/Mcal) by the cow and calf than Chianina (33.1) or Gelbvieh (33.7) F1 females; Brown Swiss cows were intermediate (34.3). Differences in food conversion efficiency exist among breed crosses. These differences seem to be associated with breed cross differences in genetic potential for milk yield and mature weight; an exception to this trend was the Maine Anjou.     

Clinical and ultrasonographic findings in the mammary gland of sheep

AIM: To compare clinical and ultrasonographic findings and assess the value of ultrasonography for evaluating the structure and condition of the teat and teat canal of sheep. METHODS: The mammary glands of 30 lactating ewes were examined clinically and using ultrasonography. The distance from the teat tip to the ground was measured and diagnostic images of the body of the gland, gland cistern and teat cistern were obtained using an 8.5 MHz frequency ultrasonic transducer. A California mastitis test (CMT) and bacteriological culture were performed on milk samples collected from each half of each udder. RESULTS: Udder parenchyma and teats were palpably normal in 27/30 (90%) ewes. Milk clots or abnormalities were evident in 4/30 (13%) udders, lesions in the glandular parenchyma and/or teats were evident by palpation in 3/30 (10%), and pathogenic bacteria were cultured from 2/30 (7%). In both of the latter cases, mastitis was diagnosed based on clotted and discoloured appearance of milk and highly positive CMT reactions. Ultrasonographic examination in these udders revealed non-homogenous regions in the glandular tissue and alternating areas of hyperechogenic and hypoechogenic tissue. Overall, highly positive CMT reactions were evident in milk from 14/30 (47%) left halves and 9/30 (30%) right halves (p=0.02). No relationship between teat-to-ground distances and CMT results was evident (p>0.05). Teat canal lengths ranged from 5.7-10.3 mm (mean=8.6; SD=1.3 mm) and the widths from 1.8-3.1 mm (mean=2.3; SD=0.4 mm). Milk sampled from ewes that had long (> or = 9 mm) or wide (> or = 2 mm) teat canals was highly positive to the CMT in 75% and 83% of cases, respectively. CONCLUSIONS: Ultrasonographic measurements of the length and width of the teat canal appeared to correlate with CMT results. The use of ultrasonography in evaluating the health of the udder of small ruminants holds promise for the future.     

Effects of supplementation with high linoleic or oleic cracked safflower seeds on postpartum reproduction and calf performance of primiparous beef heifers

Primiparous Angus x Gelbvieh (n = 36) rotationally crossed beef cows (initial BW = 487.9 +/- 10.5 kg, body condition score = 5.5 +/- 0.02) were utilized to determine effects of supplemental safflower seeds high in linoleic (76% 18:2) or oleic (72% 18:1) acid on cow BW change, body condition score, milk production and composition, calf weight gain, cow serum metabolites, and metabolic hormones. On d 3 postpartum, cows were randomly assigned to one of three isonitrogenous dietary supplements with equal total quantity of TDN: corn-soybean control supplement (n = 12); high-linoleate safflower seeds (n = 12); or high-oleate safflower seeds (n = 12). Safflower-seed supplements were formulated to provide 5% DMI as fat. Supplements were individually fed from d 3 postpartum through 90 d postpartum. Cows had ad libitum access to native grass hay (7.8% CP), trace-mineralized salt, and water. Date of parturition was evenly distributed across treatments with all cows calving within 14 +/- 0.8 d. There were no differences (P = 0.65) in total OM intake among treatments. Although cow BW change did not differ (P = 0.33) by treatment, supplementation influenced cow body condition score (P = 0.02) with linoleate-supple-mented cows in higher (P = 0.005) condition overall than oleate-supplemented cows (5.1 +/- 0.06 vs 4.9 +/- 0.06). Twenty-four-hour milk production did not differ (P = 0.68) among treatments. Percentage milk fat was not different at d 30; however, at d 60 and d 90 percentage milk fat was greater (P ( 0.05) in control and oleate-supplemented cows than in linoleate-supplemented cows. Calf BW gains (P = 0.27) and adjusted 205-d weights (P = 0.48) were not affected by supplement treatment. Supplementation did not influence serum concentrations of glucose (P = 0.38), NEFA (P = 0.61), GH (P = 0.29), IGF-I (P = 0.81), insulin (P = 0.26), or IGF-I binding proteins (P > or = 0.11). Days to conception did not differ (P = 0.40) among treatments. Although overall productivity of the primiparous cows and their calves was not altered by safflower-seed supplementation, differential effects were noted between supplements. Oleate supplementation increased percentage milk fat at d 60, and cow body condition score was lower than in linoleate-supplemented cows. Linoleate-supplemented cows had greater body condition scores by 90 d postpartum than either corn-soybean- or oleatesupplemented cows.     

Infrared thermography and ultrasonography to indirectly monitor the influence of liner type and overmilking on teat tissue recovery

Eight Danish Holstein cows were milked with a 1-mm thick specially designed soft liner on their right rear teat and a standard liner mounted under extra high tension on their left rear teat. Four of the animals were overmilked for 5 min. Rear teats were subjected to ultrasound examination on the first day and to infrared thermography on the second day. Teats were submersed in ethanol 20 min post-milking on the second day. Ultrasonography measurements showed that teat canal length increased by 30-41% during milking. Twenty minutes after milking, teats milked with modified standard liners still had elongated teat canals while teats milked with the soft liner were normalized. Overmilking tended to increase teat wall thickness. Approximately 80% of variability in teat canal length, from before teat preparation to after milking, could be explained by changes during teat preparation. Thermography indicated a general drop in teat temperature during teat preparation. Teat temperature increased during milking and continued to increase until the ethanol challenge induced a significant drop. Temperatures approached pre-challenge rather than pre-milking temperatures within 10 minutes after challenge. Teat temperatures were dependent on type of liner. Mid-teat temperatures post-challenge relative to pre-teat preparation were dependent on overmilking. Thermography and ultrasound were considered useful methods to indirectly and non invasively evaluate teat tissue integrity.     

B-mode ultrasonography of the bovine udder and teat

The udders and teats of cows were examined by brightness mode (B-mode) ultrasonography. A 5-MHz linear array transducer and a 5-MHz or 10-MHz mechanical sector transducer were used in the examinations. In lactating animals, the teat sinus, gland sinus, and lactiferous ducts were imaged easily. The scans also allowed visualization of the layers of the teat wall. The annular fold and the folding of the mucosa at the junction of the teat sinus and the papillary duct were seen best with the 5-MHz and 10-MHz mechanical sector transducers. In one cow lacking milk flow from one quarter, a mass at the junction of the papillary duct and the teat sinus was observed ultrasonographically. Surgical removal of the mass resulted in a return of milk flow from that quarter.     

Cow and calf performance on Coastal or Tifton 85 Bermudagrass pastures with aeschynomene creep-grazing paddocks

Cow and calf performance was determined in a 2-yr, 2 x 2 factorial, grazing experiment using Coastal or Tifton 85 (T85) replicated Bermudagrass pastures (4 pastures each; each pasture 4.86 ha), without or with aeschynomene creep-grazing paddocks (n = 4, 0.202 ha each, planted in May of each year, 13.44 kg/ha). On June 10, 2004, and June 8, 2005, 96 winter-calving beef "tester" cows and their calves were grouped by cow breed (9 Angus and 3 Polled Hereford/group), initial cow BW (592.9 +/- 70.1 kg, 2-yr mean), age of dam, calf breed (Angus, Polled Hereford, or Angus x Polled Hereford), calf sex, initial calf age (117 +/- 20.1 d, 2-yr mean), and initial calf BW (161.3 +/- 30.4 kg) and were randomly assigned to pastures. Additional cow-calf pairs and open cows were added as the forage increased during the season. Forage mass was similar for all treatment pastures (P > 0.70; 2-yr mean, 6,939 vs. 6,628 kg/ha, Coastal vs. T85; 6,664 vs. 6,896 kg/ha, no creep grazing vs. creep grazing). Main effect interactions did not occur for performance variables (P > 0.10; 2-yr means), and year affected only the initial and final BW of the calves and cows. The 91-d tester calf ADG was greater for calves grazing T85 than Coastal (0.94 vs. 0.79 kg; P < 0.01), and for calves creep grazing aeschynomene compared with calves without creep grazing (0.90 vs. 0.82 kg; P < 0.03). Calf 205-d adjusted weaning weights were increased for calves grazing T85 compared with Coastal (252.9 vs. 240.3 kg; P < 0.01) and for calves with access to creep grazing (249.9 vs. 243.3 kg; P < 0.05). The IVDMD of esophageal masticate from pastures had a forage x creep grazing interaction (P < 0.05; Coastal, no creep grazing = 57.4%; Coastal, creep grazing = 52.1%; T85, no creep grazing = 59.1%; T85, creep grazing = 60.0%), and IVDMD was greater (P < 0.05) for T85 than for Coastal pastures. Cows were milked in August 2004, and in June and August 2005, with variable milk yields on treatments, but increased milk protein (P < 0.05) for cows grazing T85 compared with Coastal pastures in August each year, contributing to increased calf gains on T85 pastures. These results complement previous research with T85 and indicate increased forage quality and performance of cattle grazing T85 pastures. Calf gains on T85 pastures and for calves on creep-grazed aeschynomene paddocks were high enough to influence the efficiency of cow-calf operations.     

Influence of milking technique and lactation on the bovine teat by means of ultrasonographic examination

The teats of Brown Swiss and Austrian Simmental cows, divided into two groups, one milked by means of an automatic milking system, the other using a conventional milking parlour, were examined monthly by ultrasonography. Aim of the study was to compare the effects of two different milking machines upon the structures of the bovine teat canal and wall by ultrasonography and thereby evaluate ultrasonography as a research tool for visualisation of different influences on the bovine teat. Length and thickness of the teat canal and teat wall thickness were measured and analysed. During lactation, teat canal length and thickness increased in both groups, teat canal length decreased in conventional milked cows at the end of lactation. Shorter and narrower teat canals were observed in automatic milked cows. Differences between the groups in teat canal length and thickness were determined in early lactation. During lactation teat wall thickness showed a slight increase. Automatic milked cows displayed thinner teat walls than cows milked in the milking parlour. Teat morphology was influenced by the number and duration of lactations, milk yield, quarter of the udder and time and date of examination. It was concluded that the effect of the two different milking machines caused significant differences in bovine teat morphology and that ultrasonography proved to be an appropriate method for visualising influences of the milking technique on the bovine teat.     

Reproductive performance in crosses of Angus, Santa Gertrudis and Gelbvieh beef cattle

Angus (A), Santa Gertrudis (S), and Gelbvieh (G) sires were mated to A and S dams to produce five mating types (A X A, S X S, S X A, A X S and G X A) in each of four calf crops. The study involved 501 matings. Overall means for the traits measured (calves born/cows exposed, Julian birthdate, calving ease, percentage of live calves at 24 h, birth weight, survival to weaning and gestation length) were 74.2%, 48.8 d, 96.4%, 33.2 kg, 95.4% and 283.8 d, respectively. Angus dams had a 14 percentage point (P less than .05) advantage over S dams for percentage of calves born/cows exposed. The effect of heterosis in crosses of A and S for percentage of calves born/cows exposed was negative (-11.1%) and approached significance. The percentage of calves born/cows exposed were 84.4, 70.4, 76.1 and 62.3 for the A X A, S X S, S X A and A X S mating types, respectively. Matings involving A sires and dams produced calves significantly earlier in the calving season than did matings involving S sires and dams. Matings involving S sires and dams produced calves with significantly longer gestation periods than matings of A sires and dams. Calving ease score and survival to weaning were not affected by breed of sire, breed of dam, age of dam, sex of calf, or the interaction of breed of sire X breed of dam. Percentage of live calves at 24 h indicated that straightbred S calves were significantly less viable at birth than the other four mating types.(ABSTRACT TRUNCATED AT 250 WORDS)     

Udder health in relation to udder and teat morphometry in Holstein Friesian × Sahiwal crossbred dairy cows

The present investigation involved 261 Holstein Friesian (HF) × Sahiwal cows to study the udder health as well as the udder and teat morphometry. The udder health was defined on the basis of bacteriology and California mastitis test of quarter foremilk. The morphometry parameters included udder fore depth (UFD, distance from the point where the fore udder merges within the abdomen to a point in front of the fore teats at the level of the udder base), udder rear depth (URD, distance from the bottom of the vulva to the base of the rear udder), udder depth (UD, level of the udder base with respect to hock joint), height of the udder from the floor, teat length, teat diameter (at mid of the teat barrel), teat-tip to floor distance and distance between the teats. The URD, UD and height of udder from the floor showed a significant (P?<?0.05) relation to the udder health with mastitic cows having larger URD, smaller udder distance from the floor and the udder base placed below the hock joint. The cows with teat length larger than 4.5 cm and teat diameter 3.0 cm or larger had significantly more quarters affected with mastitis. Further, cows with teats placed nearer to the floor were more susceptible to mastitis (P?<?0.01). No significant differences were found between healthy and mastitic udders with respect to UFD and distance between teats. It can be concluded that selection for optimum udder and teat morphometry in breeding programmes may help to reduce susceptibility to intramammary infections in HF × Sahiwal cows.     

Clinical and ultrasonographic findings in the mammary gland of sheep

AIM: To compare clinical and ultrasonographic findings and assess the value of ultrasonography for evaluating the structure and condition of the teat and teat canal of sheep.

METHODS: The mammary glands of 30 lactating ewes were examined clinically and using ultrasonography. The distance from the teat tip to the ground was measured and diagnostic images of the body of the gland, gland cistern and teat cistern were obtained using an 8.5 MHz frequency ultrasonic transducer. A California mastitis test (CMT) and bacteriological culture were performed on milk samples collected from each half of each udder.

RESULTS: Udder parenchyma and teats were palpably normal in 27/30 (90%) ewes. Milk clots or abnormalities were evident in 4/30 (13%) udders, lesions in the glandular parenchyma and/or teats were evident by palpation in 3/30 (10%), and pathogenic bacteria were cultured from 2/30 (7%). In both of the latter cases, mastitis was diagnosed based on clotted and discoloured appearance of milk and highly positive CMT reactions. Ultrasonographic examination in these udders revealed non-homogenous regions in the glandular tissue and alternating areas of hyperechogenic and hypoechogenic tissue. Overall, highly positive CMT reactions were evident in milk from 14/30 (47%) left halves and 9/30 (30%) right halves (p=0.02). No relationship between teat-to-ground distances and CMT results was evident (p>0.05). Teat canal lengths ranged from 5.7–10.3 mm (mean=8.6; SD=1.3 mm) and the widths from 1.8–3.1 mm (mean=2.3; SD=0.4 mm). Milk sampled from ewes that had long (≥9 mm) or wide (≥2 mm) teat canals was highly positive to the CMT in 75% and 83% of cases, respectively.

CONCLUSIONS: Ultrasonographic measurements of the length and width of the teat canal appeared to correlate with CMT results. The use of ultrasonography in evaluating the health of the udder of small ruminants holds promise for the future.     

Invasive teat surgery in dairy cattle: part I - surgical procedures and classification of lesions

A prospective study was performed to identify the nature and management of teat abnormalities in cows presented to a referral teaching hospital during a three year period. All cattle (n = 60) admitted to the Ontario Veterinary College for teat problems were evaluated by physical examination; in 53 teats, contrast radiography or xeroradiography were obtained. Surgery was performed on 52 teats from 51 cows and a prosthesis was implanted in 27 teats. Short term (under two weeks) complications included intraoperative bleeding (n = 6), milk leakage through the incision (n = 4), and failure to milk by machine in 26 cases. Histopathological diagnosis of sections taken from obstructive lesions included fibrous tissue (n = 8), normal mammary tissue (n = 3), fibropapilloma, mammary polyps, and inflamed mucosa (one each). The lesion could be classified into five types: 1) focal teat cistern obstruction, 2) diffuse teat cistern obstruction, 3) membranous obstruction, 4) diffuse teat and gland cistern obstruction, or 5) leakage of milk through an abnormal route (i.e. teat fistula, webbed teat, or lacerations).