Effects of teat cistern mural biopsy and teatoscopy stab versus longitudinal incision with or without tube implant on incisional healing in lactating dairy cattle

Effects of teat cistern mural biopsy and full-thickness stab and longitudinal incisional healing were evaluated experimentally on clinically normal teats in 12 lactating dairy cattle. Each teat on each cow was assigned by Latin-square design to 1 of 4 surgical interventions: (I) teatoscopy only; (II) teatoscopy, stab incision, and mural biopsy; (III) longitudinal incision and mural biopsy; and (IV) longitudinal incision, mural biopsy, and tube implantation. Teatoscopy was done with a 4-mm OD arthroscope introduced through the teat canal and attached to a television camera. Teatoscopy was quicker to perform and provided a more detailed videotaped examination of the teat and gland cistern, compared with gross inspection through a longitudinal incision. In intervention-II cows, the Ferris-Smith biopsy instrument jaws introduced through a longitudinal 1-cm midteat stab incision were easy to visualize and manipulate accurately. Stab incisions closed with only 1 or 2 skin sutures healed without complications in all 12 teats. On palpation, stab incisions were significantly (P less than 0.01) less thick than longitudinal incisions at 8 weeks and were microscopically indistinguishable from the normal tissue. However, in 24 teatoscopically examined teats, 9 (38%) had microscopic evidence of teat canal injury and 12 (50%) of the quarters developed mastitis. This was attributed to trauma resulting from introduction of the arthroscope through the teat canal. Intervention III yielded satisfactory results with the least complications. All 12 longitudinal incisions healed by primary intention, and all teats remained patent. Mastitis developed in 4 (33%) quarters. Intervention IV caused considerable complications associated with the tube implant and no improvement in biopsy site healing, compared with interventions II and III. Eleven longitudinal incisions healed by primary intention. One incision dehisced, 2 (17%) tube implants dislodged, 2 (17%) became obstructed proximally, and irritations of the mucous membrane developed in 2 teats proximally and in 6 teats distally. Mastitis developed in 6 (50%) quarters. Longitudinal incisions healed with moderate submucosal fibrosis. All sutured incisions had multifocal microgranulomata in which suture material was in various stages of degradation. At 8 weeks, localized teat wall thickening could be detected at incisional and biopsy sites, but did not obstruct milk flow. Excessive granulation tissue was at the biopsy sites (72 total) at 2 weeks, and at this time, the sites were partially covered by metaplastic squamous epithelium. However, by 8 weeks, 71 (98%) of the areas were replaced by fibrous tissue with minimal protrusion into the teat cistern.     

Experimental reconstruction of teat mucosa by vestibular mucosal graft in cows. A histopathologic and radiographic study

Injuries to the teat in dairy cows can result in partial or complete obstruction of the teat lumen. Different treatment techniques have been used to restore normal function in injured teats, one of which is autogenous mucosal grafts. The purpose of this study was to evaluate the vestibular mucosa as a replacement for teat mucosa in severe teat injuries. Sixteen teats of four healthy, mature, non-gravid Jersey cows were randomly divided into two equal groups. Under high epidural analgesia and after surgical preparation a 1 x 1.5 cm piece of teat mucosa was removed. In group 1, the defect was replaced by a 2 x 2.5 cm vestibular mucosa, whereas in group 2, the defect was left open. In both groups, a sterile disposable teat cannula was inserted into the teat cistern following surgery. To evaluate luminal diameter, double contrast radiography with constant air pressure was performed every 25 days till day 125, after which the animals were slaughtered and teats removed for histopathological study (H&E staining). On the basis of radiographic examination, luminal narrowing in group 2 was significantly more severe than in group 1. Histopathologically, the entire mucosal grafts of group 1 were taken and a good adhesion could be seen between the graft and the host epithelium. In group 2, severe submucosal fibrosis and mucosal papilloid hyperplasia resulted in severe narrowing of the teat cistern. According to the results of this study, it can be concluded that using vestibular mucosal grafts with temporary insertion of teat cannula can be considered as a method of treating teat mucosal injuries.     

Treatment of teat obstruction in a cow by transfer of oral mucosa and temporary implantation of an intraluminal tube

A dairy cow was examined because of extensive obstruction of a teat cistern. The teat was treated by surgical resection of scar tissue, transplantation of an oral-mucosal autograft, and temporary implantation of a silastic tube. The silastic tube became dislodged from the teat, and was surgically removed 30 days after the initial surgery. The cow subsequently had 2 normal lactations. Prior to the third postoperative lactation, the cow developed severe udder edema. During lactation, the surgically treated teat became hard and was difficult to milk. The cow was then culled.     

Synchronization of estrus and reproductive performance of ewes treated with synthetic progestogens administered by subcutaneous ear implant or by intravaginal sponge pessary

Experiments were conducted to compare the efficacy of synthetic progestogens administered by subcutaneous ear implant or intravaginal sponge to induce a synchronized estrus in adult ewes and ewe lambs and to evaluate reproductive performance (fertility and litter size) to breeding at the synchronized estrus. Experimental animals were representative of three strains maintained in total confinement and exposed to a synthetic light regimen which alternated at intervals of 4 mo from 18 h day length to 10 h day length/24 h. Treatments were applied at different times of the year at the end of a low light cycle. Implants contained Norgestomet (3 mg) impregnated in a polymethacrylate polymer (Implant H) or impregnated in a silastic polymer containing 1.05 (Implant S1), 1.78 (Implant S2) or 2.60 mg (Implant S3) Norgestomet, respectively. Intravaginal sponges contained 40 mg Fluorogestone Acetate. Implants or sponges were left in situ for 12 d and 500 IU pregnant mares' serum gonadotropin was injected im at the time of removal. Following treatment with Implant H, 96% of ewes were judged to be in estrus at 48 h after implant removal. Fertility of adult ewes and ewe lambs (6 to 7 mo of age at time of breeding) at the synchronized estrus were similar after implant H or sponge treatment, but litter size was higher (P less than .05) for adult ewes treated with sponges. The percentages of adult ewes marked by rams within 60 h after removal of silastic implants or intravaginal sponges were similar. There was a tendency for ewe lambs to be marked later than adult ewes and for adult ewes treated with Implant S1 and Implant S2 to be marked earlier than ewes treated with Implant S3 or sponges. Higher percentages (P less than .05) of adult ewes and ewe lambs lambed to breeding at the synchronized estrus after treatment with Implant S2 or Implant S3, respectively, than after treatment with Implants S2 or sponges.     

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).     

Functional, radiographic, and histologic assessment of healing of autogenous osteochondral grafts and full-thickness cartilage defects in the talus of dogs.

A circular (5.5 mm diameter) full-thickness cartilage defect was created on the medial ridge of the talus in 12 skeletally mature dogs. In 6 dogs, the articular surface of the lesion was repaired, using an osteochondral graft obtained from the ipsilateral manus. The graft (digit I, first phalanx, distal articular surface and diaphysis) was contoured to obtain a press fit in the drilled talar recipient site. In 6 dogs, the lesion was not treated and healed by fibrous tissue replacement. Functional assessment (lameness, hock range of motion, joint stability, joint crepitus, and mid-femoral muscle circumference) was completed before surgery and at postoperative weeks 2 through 20. Radiographic assessment (periarticular soft tissue width, joint space width, osteophyte formation, and graft incorporation) was completed before surgery and at postoperative weeks 0, 6, 12, and 20. To facilitate histologic assessment, tissues were stained with toluidine blue and H&E. Histologic assessment of the articular surface on the surgically treated talus, ipsilateral tibia, and contralateral talus was completed, using a modification of the Mankin grading system. Subchondral bone was examined to assess graft viability and incorporation. Analysis of the ordinal data was completed, using a Mann-Whitney rank sum test. All dogs were fully weight bearing by postoperative week 7. Dogs without grafts had significantly (P = 0.036) better clinical function at postoperative week 6. Significant difference in functional assessment was not evident at postoperative week 20. Immediate postoperative radiographic assessment revealed significant (P = 0.005) difference between nongrafted and grafted groups. Significant difference was not observed at postoperative week 6, 12, or 20. All grafts appeared radiographically incorporated by postoperative week 12. All grafts restored joint surface congruity, whereas 3 of 6 nongrafted lesions had poor articular congruity. Of 6 grafts, 4 partially retained normal hyaline cartilage, resulting in significantly (P = 0.014) lower Mankin grades. Significant histologic differences between groups were not apparent when the apposing tibia and control talus were examined. Talar reconstruction by use of a phalangeal osteochondral graft is a viable surgical procedure. These data indicate that normal articular and subchondral architecture are more closely approximated by osteochondral reconstruction than by fibrous tissue repair.     

The Use of a Silicone T-tube to Treat Tracheal Stenosis in a Llama

A female llama was presented at 4 days of age with severe dyspnea resulting from bilateral choanal atresia. A tracheostomy was performed before surgical treatment of the airway obstruction. Although the choanal atresia was successfully corrected, tracheal stenosis secondary to mucosal necrosis, malacia of the cartilage rings, and proliferation of intraluminal granulation tissue at and distal to the tracheal stoma developed. The affected segment of the trachea was resected and an end-to-end anastomosis was performed, but the lumen again became obstructed by granulation tissue. A silicone "T-tube" was placed in the trachea to provide a patent airway and intraluminal support. The llama has done well for 12 months with this prosthesis, and the complications that are often seen with long-term use of traditional tracheostomy tubes have not developed.     

Suppression of IgA synthesis in chickens

Four different protocols were tested for the induction of IgA deficiency in chickens: (I) inoculation of anti-alpha intra-peritoneally (i.p.) on alternate days after hatching up to a period of three weeks; (II) bursectomy within 6 h and at 24 h after hatching; (III) in-ovo injection of anti-alpha on the 17th day of embryonation followed by bursectomy at 24 h of hatch and a single injection of anti-alpha i.p. on the day of hatching; (IV) as in III above but bursectomy within 6 h of hatch, followed by three further injections of anti-alpha on days 3, 10 and 34 after hatching. Treatment (I) produced temporary dysgammaglobulinemia during the period of treatment. Bursectomy at 24 h of hatch rendered 75% of the chicks IgA deficient up to four weeks of age. Early bursectomy within 6 h of hatch resulted in substantial improvement of IgA suppression. Such chicks, when tested at 4, 6 and 10 weeks of age, were found to be 81, 72 and 58.3% IgA deficient, respectively. With treatment (III) all the treated birds were IgA deficient at four weeks of age. However, as the birds grew older, IgA appeared in the serum so that at the age of 12 weeks only 27.3% were deficient. Treatment (IV) completely suppressed the IgA system of 13 out of 14 chickens. These chickens lacked both serum and secretory IgA as well as IgA-containing cells in their intestinal mucosa. Both IgG and IgM continued to be produced.     

Open drainage and delayed autogenous cancellous bone grafting for treatment of chronic osteomyelitis in dogs and cats

Ten dogs and 1 cat with 12 chronically infected bones were treated surgically by means of saucerization, primary internal or external rigid fixation, and open irrigation drainage. After formation of a healthy granulation bed, autogenous cancellous bone grafting and skin closure were performed. Eleven of 12 bones healed 4 to 7 weeks (mean, 4.8 weeks) after treatment, without recurrence of infection. Eight of 12 chronically infected bones had a polymicrobial infection, with 2 to 6 bacterial species isolated. Gram-negative bacteria were isolated from 7 of the 12 bones, and anaerobic bacteria were isolated twice.     

Arterial Grafting in the Horse An Experimental Study

The feasibility of repairing an arterial defect with a graft was evaluated in the horse. Arterial autografts, venous autografts, and expanded polytetrafluoroethylene (PTFE) vascular prostheses were used. Four 3 cm grafts of each type were used to replace a 3 cm section of medial palmar artery that had been removed from 12 forelimbs of 11 horses. Patency was assessed by arteriography performed 30 days after the grafting procedure. All four arterial autografts, one of four venous autografts, and two of four PTFE grafts were patent at 30 days. Thrombosis caused the failure of one venous autograft and two PTFE grafts. Fibrous replacement caused the failure of two venous autografts. Results indicate that arterial grafting is feasible in the horse.     

Adrenocortical function in the domestic cat during treatment with levonorgestrel

Levonorgestrel was administered via a subcutaneous, slow-release silastic implant to 10 queens. Five other queens served as controls. Their adrenocortical function was assessed by the adrenocorticotrophic hormone (ACTH) stimulation test before and after one, two, six and 12 months of treatment. In addition, the gross anatomy and histology of the adrenal gland were examined post mortem in six of the treated cats. In both the control and treated queens the plasma cortisol concentrations (pre and post ACTH) were significantly different (P<0·05) at different times. However, there were no significant differences between the plasma cortisol concentrations (pre and post ACTH) of the treated and control queens. No gross or microscopical abnormalities were visible in the adrenal glands of the treated queens.     

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)     

Autogenous osteochondral grafting for treatment of stifle osteochondrosis in dogs

Objective— To develop and assess clinical outcomes for osteochondral autografting for treatment of stifle osteochondrosis (OC) in dogs. Study Design— Retrospective case series. Animals— Dogs with stifle OC (n=10). Methods— Osteochondral autografting was developed and optimized in canine cadavers and purpose‐bred research dogs using the Osteochondral Autograft Transfer System (OATS). Dogs with stifle OC (n=10 dogs, 12 stifles) were then treated using the OATS system. Outcomes were assessed by radiography (n=12), magnetic resonance imaging (1), second‐look arthroscopy (9), lameness scoring (12), and telephone survey of owners (10 clients, 12 stifles) 6–15 months after surgery. Results— Complications were documented in 4 of the 12 stifles treated and included peri‐incisional seromas (3) and marked stifle effusion (1). Subjective assessment of follow‐up radiographs revealed evidence of integration of the grafts with maintenance of subchondral bone surface architecture. Subjective assessment of follow‐up MRI in 1 stifle revealed evidence for incorporation of grafts with restoration of articular surface contour. Second‐look arthroscopy 6–30 weeks after surgery revealed maintenance of articular cartilage at the graft site. Dogs were significantly (P<.001) less lame at follow‐up compared with preoperative scores. Based on follow‐up owner surveys, only 2 dogs had no pain or lameness; the other dogs were judged to have mild pain and/or lameness. All owners noticed improvement in the dogs' quality of life after surgery. Conclusion— Osteochondral autografting deserves consideration and further evaluation as a primary treatment option for stifle OC in dogs. Clinical Relevance— Osteochondral autografting for treatment of lateral femoral condylar OC lesions in dogs using OATS instrumentation is safe and results in improved function and quality of life based on owners' perception 6–15 months after treatment.     

Estradiol feedback inhibition of luteinizing hormone concentrations in the anestrous sow

The suppressive effects of exogenous 17 beta-estradiol (E2) on LH concentrations in sows that remained anestrus following weaning and in those that returned to estrus were evaluated. Four anestrous and four cyclic sows were treated subcutaneously with silastic implants containing E2 at 13 d after ovariectomy (d 0). Three anestrous and six cyclic sows received silastic implants without E2. Blood was collected at 6-h intervals from d -1 to d 12 and at 15-min intervals for 8 h on d -1, 2, 7 and 12. Sows were treated with 1 microgram GnRH/kg BW at the completion of each 8-h frequent sampling period. Blood was collected at intervals of 10 to 30 min for 3 h after GnRH treatment. Concentrations of E2 remained less than 5 pg/ml in sham-treated sows and were between 20 and 25 pg/ml in E2-treated females. Pulsatile LH concentrations was similar between anestrous and cyclic sows prior to implant treatment. Sham-treated anestrous sows had greater (P less than .05) pulse frequency and mean LH concentrations than E2-treated anestrous sows on d 2, 7 and 12. Differences in pulsatile LH concentrations between E2-treated and sham-treated cyclic sows were not detected. Pulse frequency was less (P less than .05) in E2-treated anestrous sows than in E2-treated cyclic sows on d 7 and 12. Peak LH concentrations were greater (P less than .05) in E2-treated cyclic sows than in E2-treated anestrous sows at each GnRH challenge. These results suggest that the hypothalamo-hypophyseal axis is more sensitive to the negative feedback effects of E2 in anestrous sows than in cyclic sows. In addition, chronic E2 treatment reduces pituitary responsiveness to GnRH to a greater extent in anestrous than in cyclic sows. Failure to return to estrus in swine may be due, at least in part, to an increased sensitivity of the hypothalamo-hypophyseal axis to the negative feedback effect of estradiol.     

Effects of hyperbaric oxygen on full-thickness meshed sheet skin grafts applied to fresh and granulating wounds in horses

OBJECTIVE: To determine the effects of hyperbaric oxygen therapy (HBOT) on full-thickness skin grafts applied to fresh and granulating wounds of horses. ANIMALS: 6 horses. PROCEDURES: On day 0, two 4-cm-diameter circular sections of full-thickness skin were removed from each of 2 randomly selected limbs of each horse, and two 4-cm-diameter circular skin grafts were harvested from the pectoral region. A skin graft was applied to 1 randomly selected wound on each limb, leaving the 2 nongrafted wounds to heal by second intention. On day 7, 2 grafts were harvested from the pectoral region and applied to the granulating wounds, and wounds grafted on day 0 were biopsied. On day 14, 1 wound was created on each of the 2 unwounded limbs, and the wounds that were grafted on day 7 were biopsied. All 4 ungrafted wounds (ie, 2 fresh wounds and 2 wounds with 1-week-old granulation beds) were grafted. The horses then received HBOT for 1 hour daily at 23 PSI for 7 days. On day 21, the grafts applied on day 14 were biopsied. RESULTS: Histologic examination of biopsy specimens revealed that grafts treated with HBOT developed less granulation tissue, edema, and neovascularization, but more inflammation. The superficial portion of the graft was also less viable than the superficial portion of those not treated with HBOT. CONCLUSIONS AND CLINICAL RELEVANCE: The use of HBOT after full-thickness skin grafting of uncompromised fresh and granulating wounds of horses is not indicated.     

Effects of extracorporeal shock wave therapy on desmitis of the accessory ligament of the deep digital flexor tendon in the horse

Objective: To evaluate the effects of extracorporeal shock wave therapy (ESWT) on collagenase‐induced lesions in the accessory ligament of the deep digital flexor tendon (ALDDFT) of horses. Study Design: Paired, blinded controlled study. Animals: Eight Thoroughbred horses (3 mares, 5 geldings; mean±SD weight, 464±26 kg, mean age, 8±1.7 years). Methods: Lesions were created in both ALDDFTs of all horses by injection of 2 × 10³ IU of collagenase type I. Percent lesion and structure (fiber alignment and echogenicity) were quantified with ultrasonographic imaging 3, 6, and 9 weeks after collagenase injection. After ultrasound examinations, ESWT (1000 shocks at 0.15 mJ/mm²) was applied to 1 ALDDFT in each horse. ALDDFT were harvested 15 weeks after collagenase injection and the microstructure, mRNA levels of collagen types I and III, and collagen and glycosaminoglycan content were evaluated. Results: There were no differences in percent lesion, echogenicity, or fiber alignment between control‐ and ESWT‐treated ligaments at each evaluation time; however, compared with 3‐week values, there was a significant increase in percent lesion and echogenicity for EWST treated ligaments at 6 weeks and significant decrease in both variables for treated and control ligaments at 12 weeks. Fiber alignment improved significantly at 9 weeks in controls and at 12 weeks in treated and control ligaments. Collagen type I mRNA levels were significantly higher in the ESWT treatment group compared with the control group 15 weeks after collagenase injection though differences in other mRNA levels, microstructure, and composition were not significant. Conclusions: Our results do not support an effect of ESWT on collagenase‐induced lesions in the equine ALDDFT.     

Effect of tissue adhesives and suture patterns on experimentally induced teat lacerations in lactating dairy cattle

Tissue adhesives and suture materials were evaluated for repair of experimentally induced teat lacerations in 6 lactating dairy cows. Group-1 teat lacerations were not closed and served as nonsutured controls. Group-2 lacerations were closed in three layers (mucosa, submucosa, and skin) by use of 3-0 polydioxanone. Group-3 lacerations were closed by use of N-butyl cyanoacrylate monomer tissue adhesive. Group-4 lacerations were closed by use of a combination of sutures and tissue adhesive. All cows were milked by machine. Healing was observed for 28 days, then cows were slaughtered, and teats were recovered for further study. Evaluation revealed failure of healing of all layers with formation of large fistulas in 3 of 4 nonsutured control teats in group 1. All 6 teat lacerations in groups 2 and 3 healed satisfactorily with no fistulas. Five of 6 teats in group 4 had partial healing of skin and mucosa with no fistulas, and 1 teat failed to heal and developed a small fistula. Data indicated that closure of experimentally induced teat lacerations with three layers of fine absorbable suture or closure with tissue adhesive alone gave good results and satisfactory healing of all layers. However, when sutures and tissue adhesive were used together, foreign body reaction was marked, and the skin and submucosa healed only partially. Sutures appeared to entrap the tissue adhesive, resulting in a foreign body reaction.     

Effectiveness of ivermectin against later 4th-stage Strongylus vulgaris in ponies

Twelve pony foals were reared worm-free and inoculated with Strongylus vulgaris. Approximately 8 weeks after they were inoculated, 6 foals were given ivermectin IM at a dosage rate of 200 micrograms/kg of body weight and 6 were given a placebo. All foals were necropsied 35 days after treatment. Ivermectin was 98.9% effective in eliminating later 4th-stage S vulgaris larvae located near the origin of major intestinal arteries and in reducing clinical signs and permitting resolution of lesions associated with verminous arteritis. One pony foal reared on pasture and with evidence of arteritis of the cranial mesenteric and ileocolic arteries on arteriography was treated with ivermectin at a dosage rate of 200 micrograms/kg of body weight. On arteriographs taken subsequently, there was evidence of regression of the lesion, and at necropsy 9 weeks after treatment, there was no arteritis or larvae in those arteries.     

Postpartum interval in beef cows shortened by enclomiphene

This study was designed to determine whether an anti-estrogen can block the negative effect of estrogens on luteinizing hormone (LH) release and therefore decrease the postpartum interval in suckled beef cows. In Exp. I, eight suckled postpartum beef cows were randomly assigned to treatment and control groups. Treatment cows received 1 g/d clomiphene citrate (im) from d 21 to 28 postpartum, while control cows were injected with saline. On d 28 postpartum, there was no difference (P greater than .05) in mean total and basal LH concentrations or LH pulse frequency between treatment and control cows. All control cows exhibited estrus on d 52 +/- 3; treatment cows exhibited estrus on d 134 +/- 12 (P less than .05). In Exp. II, 17 suckled cows were randomly assigned to three treatment groups: 1) control group (n = 6) receiving one empty implant, 2) 10-cm enclomiphene implant group (n = 5) and 3) 30-cm enclomiphene implant group (n = 6). The silastic implants were placed sc on d 20 and removed on d 29 postpartum. Mean total LH concentrations during d 24 to 29 postpartum in the 30-cm enclomiphene implant group were higher than the 10-cm implant (P less than .05) and control group (P less than .05). The postpartum period in the 30-cm enclomiphene group (45 +/- 6 d) was shorter than the 10-cm implant (94 +/- 24 d) and control (96 +/- 20 d) groups (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Prevention of intramammary infections in dairy cows by the use of a premilking teat dip method with a foaming iodophor dip agent

In this study we investigated the efficacy of premilking teat dipping with a foaming iodophor teat dip in a negative controlled field study. Incidence of new intramammary infections (IMI), incidence of clinical mastitis, influence on somatic cell count (SCC) and the characteristics of udder tissue and teats were used as parameters to evaluate clinical efficacy. Predipping was compared with a negative control using a split-udder experimental design. Right teats were predipped with a foaming disinfectant containing 0.27% iodine while left teats served as controls. The latter were conventionally cleaned with damp cloth towels and dried manually with disposable paper towels ("best cleaning practice"). All teats were dipped after milking with the same dip. There were no differences between treated and control quarters with respect to incidence of new IMI during the study period (treated quarters: 6.6% vs. untreated: 6.95%), incidence of clinical mastitis (30 cases in the treatment group vs. 39 cases in the control group) and geometric mean of SCC of quarter milk samples. Spectrum of detected pathogens was also comparable. Condition of udder tissue and teat ducts did not differ between treated and control quarters.