The effect of 2 different premilking stimulation regimens, with and without a latency period, on teat tissue condition and milking performance in Holstein dairy cows.

The objectives of this study were to assess the effect of 2 different premilking stimulation regimens, with and without a latency period between tactile stimulation and the attachment of the milking unit, on the teat tissue condition and milking performance of dairy cows. In a randomized controlled crossover study, 145 Holstein cows milked 3 times daily were assigned to treatment (TRT) or control (CON) groups. Premilking udder preparation for the TRT group consisted of the application of a latency period resulting in a preparation lag time of 90 s. The only difference in the premilking udder preparation of the CON group was the absence of latency period; the milking unit was attached immediately after completion of the tactile stimulation. The average duration of total tactile stimulation in TRT and CON group was 8 ± 2 and 9 ± 2 s, respectively. The study lasted for 14 d and was split into 2 periods, each consisting of a 2-d adjustment period followed by 5 d of data collection. We assessed machine milking-induced short-term changes to the teat tissue by palpation and visual inspection postmilking. Electronic on-farm milk meters were used to assess milking characteristics (milk yield [kg/milking session], machine-on time [s], 2-min milk yield [kg], and duration of low milk flow rate [s]). Generalized linear mixed models were used to analyze the effect of treatment on the outcome variables. The odds of machine milking-induced short-term changes to the teat tissue were lower for cows that received a 90-s preparation lag time (TRT cows) compared with cows in the CON group (odds ratio [95% confidence interval; 95% CI] = 0.13 [0.08-0.20]). The least squares means (95% CI) values of cows in the TRT and CON groups were 15.4 (14.9-15.9) and 15.3 (14.8-15.8) kg, respectively, for milk yield, and 246 (239-253) and 253 (247-260) s for machine-on time. The 2-min milk yield was higher for the TRT compared with CON group cows at all the parity levels. The 2-min milk yields of animals in lactation 1, 2, and ≥3 were 5.7, 5.7, and 6.5 kg, respectively, in the TRT group and 4.6, 5.0, and 5.9 kg in the CON group. The TRT cows spent less time in low milk flow rate compared with CON cows at all parity levels. The durations of low milk flow rate of cows in lactation 1, 2, and ≥3 in the TRT group were 19, 17 and 13 s, respectively, and those in the CON group were 31, 22, and 15 s. In this study, cows that received a latency period, and thus were subjected to a 90-s preparation lag time had lower odds of exhibiting short-term changes to the teat tissue after machine milking, shorter machine-on time, higher 2-min milk yields, and lower durations of low milk flow rates. We conclude that consideration of latency period leading to a 90-s preparation lag time in the premilking stimulation regimen facilitated cows' milk-ejection reflex. This latency period can alleviate the adverse effects of vacuum-induced forces on teat tissue during machine milking, improve udder health, and promote animal well-being.

A randomized controlled trial to study the effects of an automated premilking stimulation system on milking performance, teat tissue condition, and udder health in Holstein dairy cows.

The objectives were to examine the effect of an automated premilking stimulation (APS) by means of a high pulsation frequency (300 cycles/min) without a reduction of the vacuum in the pulsation chamber or claw piece on (1) milking performance, (2) teat tissue condition, and (3) udder health in dairy cows. In a randomized controlled field study, Holstein cows (n = 427) from 1 commercial dairy farm with a milking schedule of 3 times per day were assigned to treatment and control groups over a 90-d period. Treatments consisted of a maximum of 80 s (APS80) or 99 s (APS99) of mechanical stimulation at a pulsation rate of 300 pulses per minute and a ratio of 25:75 (no reduction of the pulsation chamber or milking vacuum). Cows in the control group (CON) received traditional premilking stimulation by means of manual forestripping for 8 s. Milking characteristics were documented with on-farm milk meters. Short- and long-term changes in teat tissue condition induced by machine milking were assessed visually on a weekly basis. Composite milk samples were analyzed once per month to determine somatic cell count. Generalized linear mixed models were used to study the effect of the treatment on the outcome variables. We observed no meaningful differences in milk yield or milking unit-on time. Least squares means and their 95% confidence intervals (95% CI) for cows in the APS80, APS99, and CON groups were 13.5 (13.1-14.0), 13.2 (12.8-13.7), and 13.2 (12.8-13.7) kg for milk yield and 222 (213-231), 219 (210-228), and 223 (214-232) s for milking unit-on time, respectively. The effect of treatment on bimodality was modified by milk yield such that the odds of bimodality increased in the treatment groups with increasing milk yield. Compared with cows in the CON group, the odds ratios (95% CI) of bimodality were 1.08 (0.62-1.89) in the APS80 group and 0.89 (0.55-1.42) in the APS99 group at a milk yield of 11 kg and 2.0 (1.24-3.22) in the APS80 group and 2.08 (1.29-3.35) in the APS99 group at a milk yield of 16 kg. We observed differences in short- and long-term changes in teat tissue condition between the treatment and control groups. Compared with cows in the CON group, the odds (95% CI) of short-term changes were 1.87 (1.35-2.58) for the APS80 group and 1.49 (1.08-2.07) for the APS99 group, and the odds of long-term changes were 1.52 (1.24-1.85) for cows in the APS80 group and 1.59 (1.31-1.94) for cows in the APS99 group. The least squares means (95% CI) for somatic cell counts (log10-transformed) were 4.74 (4.68-4.81) for the APS80 group, 4.77 (4.71-4.83) for the APS99 group, and 4.79 (4.73-4.86) for the CON group. We conclude that the APS system tested here had no negative effects on milk yield or milking unit-on time. However, differences in bimodality and teat tissue condition suggest that the APS system did not provide sufficient stimulation to facilitate a gentle milk harvest and adversely affects teat tissue condition.

A randomized controlled trial assessing the effect of intermittent and abrupt cessation of milking to end lactation on the well-being and intramammary infection risk of dairy cows.

The objectives were to compare the effects of an intermittent milking schedule with a thrice daily milking schedule during the final week of lactation on the well-being, udder health, milk production, and risk of culling of dairy cows. We hypothesized that cows subjected to an intermittent milking schedule would experience less udder engorgement and pain, lower concentrations of fecal glucocorticoid metabolites (11,17-dioxoandrostanes; 11,17-DOA concentration) after dry-off, lower risk of an intramammary infection during the dry period, higher milk production and lower somatic cell count in the subsequent lactation, and lower culling risk compared with herd mates milked 3 times daily and dried off by abrupt cessation. In a randomized controlled field study, Holstein cows (n = 398) with a thrice daily milking schedule were assigned to treatment and control groups. The treatment consisted of an intermittent milking schedule for 7 d before dry-off (gradual cessation of milking, GRAD). Gradual-cessation cows were milked once daily until the day of dry-off, whereas cows in the control group (abrupt cessation of milking, APT) were milked 3 times daily until the day of dry-off. Udder firmness and pain responses of the udder 3 d after dry-off, as well as the percentage change in fecal 11,17-DOA concentration (3 d after dry-off compared with the dry-off day), were used to assess the well-being of the animals. Compared with cows in the GRAD group, the odds [95% confidence interval (CI)] of udder firmness were 1.55 (0.99-2.42) for cows in the APT group, and the odds of a pain response were 1.48 (0.89-2.44) for cows in the APT group. The least squares means (95% CI) of the percentage change in 11,17-DOA concentration were 129.3% (111.1-150.4) for the APT group and 113.6% (97.5-132.4) for the GRAD group. Quarter-level culture results from the periods before dry-off and after calving were compared, to assess the likelihoods of microbiological cure and new infection. Cows in the APT group had lower odds of a new intramammary infection in the dry period [odds ratio, 95% CI: 0.63 (0.37-1.05)], whereas we observed no meaningful differences in the microbiological cure likelihood among groups. The least squares means (95% CI) for somatic cell counts (log10-transformed) were 4.9 (4.8-5.0) in the APT group and 4.9 (4.8-5.0) in the GRAD group. The odds (95% CI) of clinical mastitis in the first 30 d postcalving were 1.32 (0.53-3.30) in the APT group compared with the GRAD group. We observed no meaningful differences in milk production at the first test date postcalving or the culling risk among groups. We conclude that the gradual-cessation protocol tested herein failed to significantly improve animal well-being, udder health, milk production, and survival in the tested study cohort. However, the observed differences in udder firmness, as well as the numerical differences in udder pain and the percentage change in fecal 11,17-DOA concentrations suggest that this line of research may be useful. Future research is needed to develop drying-off strategies that are appropriate for lowering milk production at the end of the lactation and improve animal well-being without compromising udder health.

The effect of 2 different premilking stimulation regimens, with and without manual forestripping, on teat tissue condition and milking performance in Holstein dairy cows milked 3 times daily.

The objectives were to study the effect of 2 different premilking stimulation regimens, with and without manual forestripping, on teat tissue condition and milking characteristics in dairy cows. In a randomized controlled crossover study, 130 Holstein cows milked 3 times daily were assigned to treatment and control groups. Premilking udder preparation for the treatment group consisted of: (1) predipping with 1% iodine, (2) sequential forestripping of 3 streams of milk per quarter, (3) wiping of teats, and (4) attachment of the milking unit. Premilking udder preparation for the control group was identical except that the forestripping step was omitted. The mean tactile stimulation durations were 16 s and 7 s for the treatment and control group, respectively. The time spent from first tactile stimulus (either forestripping or wiping of teats) to milking unit attachment was kept consistent at 90 s for both groups. The study lasted for 14 d with 2 periods, each consisting of a 2-d adjustment time followed by 5 d of data collection. Machine milking-induced short-term changes to the teat tissue were assessed by palpation and visually. The following milking characteristics were assessed with electronic on-farm milk meters: milk yield (MY), milking unit-on time (MUOT), 2-min MY (2MIN), and time spent in low milk flow rate (LMF). Generalized linear mixed models were used to describe the effect of treatment on the outcome variables. The odds of machine milking-induced short-term changes to the teat tissue were lower for cows that received forestripping compared with cows that were not forestripped (odds ratio = 0.31; 95% confidence interval = 0.22-0.42). Least squares means (95% confidence interval) for cows that were forestripped and animals that were not forestripped, respectively, were 12.7 (12.2-13.2) and 12.7 (12.2-13.2) kg for MY and 6.1 (5.8-6.4) and 5.6 (5.3-5.9) kg for 2MIN. There was an interaction between treatment and MY for LMF. Time spent in LMF for cows that were forestripped and received no forestripping, respectively, were 18 (17-20) and 24 (23-26) s for a MY level of 10 kg; and 13 (12-14) and 15 (14-16) s for a MY level of 15 kg. The effect of treatment on MUOT was modified by parity. Milking unit-on times for animals in first, second and third or greater lactation, respectively, were 230 (219-243), 249 (236-262), and 260 (249-272) s for cows that were forestripped, and 245 (232-258), 252 (239-266), and 268 (257-281) s for cows that received no forestripping. In this study, cows that were forestripped had shorter MUOT, higher 2MIN, lower LMF, and lower odds of exhibiting changes to the teat tissue after machine milking. We conclude that wiping of teats during premilking udder preparation alone and omitting forestripping of teats without compensating for the loss in stimulation time may not provide sufficient tactile stimulation to elicit the cows' maximum physiological milk-ejection capacity. This can aggravate the adverse effects of vacuum-induced forces on teat tissue during machine milking, diminish animal well-being, and possibly affect udder health.

In-vitro evaluation of a polyurethane compliant-layer glenoid for use in shoulder arthroplasty.

A polyurethane glenoid component has been designed and manufactured as part of a total shoulder arthroplasty (TSA) system based on compliant-layer (CL) technology. Compared with conventional TSA designs, this biomimetic approach offers reduced friction and wear and potentially improved longevity. In-vitro evaluation of the glenoid system has included loosening and stability tests, and wear measurement using a specially constructed wear simulator. The results obtained support the hypothesis that a CL glenoid design may provide improved resistance to dynamic loosening and rim erosion, and demonstrate superior wear performance over a standard ultra-high molecular weight polyethylene design. This study not only confirms the feasibility of a CL glenoid component but also highlights the potential to increase implant longevity, thereby allowing earlier surgical intervention before poor glenoid bone stock and soft tissue compromise the outcome of TSA.

Automated in-vitro testing of orthopaedic implants: a case study in shoulder joint replacement.

This investigation presents the design and preliminary validation of a single station simulator with biaxial motion and loading designed to mimic the kinematics of the glenohumeral joint during arm abduction in the scapular plane. Although the design of the glenoid holder allows the glenoid component to translate in all three axes, it is primarily loaded axially, which brings it into contact with the oscillating humeral head, but is also loaded superiorly to simulate common subluxation of the humeral head. Simulating arm abduction in the scapular plane simplifies component alignment and removes the need for anterior-posterior loading, thereby creating a stable joint without the need to simulate capsular constraints. In this more physiologically accurate simulator design, the load and motion profiles influence the contact kinematics, but the wear path is ultimately determined by the conformity and constraint designed into the bearing couple. The wear data are determined and correlated with clinically retrieved glenoid components, as well as previously reported in-vitro studies, thus verifying use of the simulator in testing alternative materials and designs. The key design features, as well as the improvements proposed through this study, can be incorporated into the design of test fixtures for any other orthopaedic implant such as the hip, knee, spine, elbow, and finger.

Improved growth and decreased morbidities in <1000 g neonates after early management changes.

OBJECTIVE: To test the hypothesis that three changes in the early management of extremely low birth weight (ELBW) neonates would decrease the incidence of extra-uterine growth restriction (EUGR) by 25%. The three early management practice changes (EMPC) included surfactant at delivery followed by immediate extubation to nasal continuous positive airway pressure (CPAP), decreased oxygen exposure and early parenteral amino acids. STUDY DESIGN: Historical cohort study of preterm infants

Sea-blue histiocytes and Gaucher cells in bone marrow of patients with chronic myeloid leukaemia.

A retrospective study of 211 bone marrow aspirates from patients with chronic myeloid leukaemia (CML) was undertaken to assess the incidence of Gaucher cells and sea-blue histiocytes. A significant correlation between the presence of these cells and prolonged survival was seen. Such storage histiocytes occurred most often during periods of relapsed chronic phase. This study shows that Gaucher cells and sea blue histiocytes are a common feature of CML and that their accumulation seems to be associated with a prolonged increase in leucocyte turnover.

Giant lymph node hyperplasia of the mediastinum and refractory anaemia.

An example is described of the syndrome of refractory anaemia in association with the plasma cell variant of giant lymph node hyperplasia of the mediastinum; the anaemia responded to removal of the lymphoid mass. The entity of giant lymph node hyperplasia is discussed and its relationship to the haematological syndrome is considered.

Hepatic and serum folates in patients fasting and after oral folic acid.

The hepatic folate in non-anaemic hospital patients was found to correlate poorly with the fasting serum folate. The rise in methylfolate in the systemic circulation following the absorption of folic acid was directly related to the folate content of the liver.

Red cell hypoplasia, thrombocytosis, and leucocytosis: myelodysplastic and proliferative syndrome.

Three patients with chronic red cell aplasia also showed thrombocytosis or granulocytosis, or both. All had morphological evidence of myelodysplasia on examination of bone marrow aspirate but none had a detectable chromosomal abnormality. These patients seem to provide evidence of a separate entity within the spectrum of myelodysplastic and myeloproliferative disease.

Construction of a database to identify Staphylococcus species.

A database was constructed for the routine identification of Staphylococcus species, isolated from man. The method comprised 15 conventional characterisation tests using substrates incorporated into agar plates and a multipoint inoculation system. The database was constructed from results of 125 reference strains and 1567 clinical isolates. In an evaluation trial, using a probability profile index generated from the database, 529 of 559 (94.6%) further clinical isolates were identified to species level. A further 20 (3.6%) gave low discrimination between two species. The proposed scheme was rapid, reliable, and inexpensive.

Detection of erythroid hypoplasia in myelofibrosis using erythrokinetic studies.

The iron kinetic model described by Ricketts et al was used to study haemopoiesis in chronic myelofibrosis. The clearance of 59Fe-labelled transferrin from the plasma was analysed to quantify total, effective, and ineffective erythropoiesis, denoted by the terms marrow iron turnover (MIT), red cell iron turnover (RCIT), and per cent ineffective iron turnover (IIT%), respectively, in 12 cases of this disease. The patterns obtained were variable: values for MIT ranged from 24.4 to 510 mumol/l blood/day; those for RCIT from 0.4 to 119 mumol/l blood/day; and those for IIT% from 67 to 98%. One noteworthy feature was the presence in two cases of functional erythroid hypoplasia; these were characterised by severely reduced values for MIT (24.4 and 28 mumol/l blood/day) and RCIT (0.4 and 8 mumol/l blood/day.) A systematic study of the erythrokinetic features of myelofibrosis may indicate that erythroid hypoplasia is a more common cause of anaemia in this disease than has been previously recognised.

Systemic mastocytosis, myelofibrosis and portal hypertension.

A case of systemic mastocytosis is described in which the finding on initial presentation was hepatosplenomegaly. No dermatological abnormality was present, and the bone marrow histology originally caused some confusion with primary myelofibrosis. The clinical course and the importance of distinguishing between these two diseases is discussed. The dermatological manifestation of systemic mastocytosis, in the form of urticaria pigmentosa, is well recognised, and alerts the physician to the underlying disease. In the absence of cutaneous signs, however, the diagnosis is less obvious. The case reported had predominantly marrow and splenic involvement by the disease process, giving rise to portal hypertension, and illustrates the problems of diagnosis which can arise.

Benign familial polycythaemia.

An English family suffering from thalassaemia minor is described. Three generations are affected, and all the affected members had a considerably raised red cell count in the presence of slight or moderate anaemia, obviously abnormal peripheral films, and only slightly reduced M.C.H.C. values; and each had a moderately raised haemoglobin A(2) level, though foetal haemoglobin levels were normal. The presentation of a family with erythrocytosis recalls the condition described in the older literature as benign familial polycythaemia which was, in some cases at least, thalassaemia minor. It is suggested that the presence of a raised red cell count is a more reliable distinguishing feature than the presence of target cells, or the serum iron level, in thalassaemia minor.

A case of IgD myeloma presenting as diffuse osteosclerosis.

A case of IgD myeloma accompanied by diffuse osteosclerosis is reported. A trephine biopsy specimen showed only reticulin fibrosis, but histomorphometric analysis of a full thickness transiliac bone biopsy specimen showed increased trabecular bone mass, with no local deposit of tumour. An excess of bone surfaces were covered by osteoid seams, all of which showed active mineralisation, indicating a relative increase in osteoblastic activity; osteoclasis seemed to be unaffected. It is suggested that the cause of the generalised osteosclerosis might be production of an osteoblast stimulating factor by the myeloma cells.

High incidence of type II autoantibodies in pernicious anaemia.

AIMS: To investigate the incidence of type II autoantibodies to intrinsic factor in pernicious anaemia. METHODS: Three hundred and forty four serum samples submitted for intrinsic factor antibody (IFAB) analysis on clinical or laboratory grounds were tested by an established radioassay and a new enzyme linked immunosorbent assay (ELISA) method for type I and total IFAB, respectively. Sixty of these were found to be positive by ELISA; this method was used to test further, 40 samples of adequate volume for types I and II antibodies. RESULTS: Type II antibodies were detected in 39 of the 40 sera tested. A comparative analysis indicated that seven samples contained pure type II antibody, being positive for total and type II by ELISA, but negative for type I by both the ELISA and radioassay technique. CONCLUSIONS: The occurrence of type II antibody, both alone and in combination with type I, seems to be more common than has previously been recognised, and emphasises the advantage of using a technique which will detect both types of antibody.

Comparative ferrokinetic study with initial and extended iron clearance models.

Erythrokinetic studies were performed on 10 patients with chronic myelofibrosis and 11 patients with myelodysplasia (MDS). Values for plasma iron turnover, marrow iron turnover, and erythron transferrin uptake were derived using two ferrokinetic models. One entailed analysis of the extended plasma iron clearance over a number of days, the other comprised analysis of the initial plasma iron clearance during the first few hours of the study. A close correlation was found between the variables quantifying total erythropoiesis (marrow iron turnover and erythron transferrin uptake) in the two methodologies. Functional classifications produced by both models and based on the values for plasma iron turnover, marrow iron turnover, and erythron transferrin uptake were compared. Both models identified functional heterogeneity in the group with myelofibrosis and functional homogeneity within the MDS group. Each method produced comparable data on erythropoiesis. The main reason for analysing the extended plasma iron clearance is to differentiate levels of effective and ineffective erythropoiesis. The short analysis presents the practical advantages associated with a one-day study. This could be further enhanced if the level of effective erythropoiesis could be clearly defined.

Two-colour immunoenzymatic technique using sequential staining by APAAP to evaluate two cell antigens.

AIMS: To extend the alkaline phosphatase-antialkaline phosphatase (APAAP) immunoenzyme single stain method to a more generally applicable double stain technique. This will allow two primary antibodies of the same isotype of IgG and specifically the nuclear antigen bromodeoxyuridine (BRdU) to be evaluated with a cell surface antigen identifier. METHOD: Sequential applications of the APAAP method showed two antigen sites by different dye couplings to a common alkaline phosphatase substrate, producing blue and red reaction products on the same slide. Antigens on different cell populations as well as those in different compartments of the same cell were analysed. The method allowed a surface antigen monoclonal to be revealed first, using an optimal fixative, before alcohol/gluteraldehyde fixation was used to start the second (BRdU) staining sequence. RESULTS: An analysis of double staining of T lymphocyte subsets (CD4 and CD8) showed no significant difference in the order of application of the primaries (n = 10) and no significant difference from their corresponding single stain results (n = 50), confirming the validity of the technique where antigens are exclusively distributed. Other examples, including antigens distributed in different compartments of the same cell, displayed discrete staining which implied validity. CONCLUSION: Double staining by APAAP with this technique seems to be applicable to those cases where antigens are exclusively distributed and includes cases where different compartments of the same cell are stained. It is especially useful in revealing antigens that require different fixation and preparation--that is DNA incorporated BRdU with a surface antigen. But it does seem to have a limited ability to produce a dual colour at a common site.

Simple method for granulocyte-macrophage cell culture and staining in soft agar: comparison with a standard research technique.

A modified, small volume, two phase, disc culture system for CFU-GM (seven and 14 days of incubation) was compared with a standard single layer system. The 1 ml single layer cultures were counted unstained in situ before both sets of cultures were transferred to glass slides for staining. Bone marrows were cultured from forty eight subjects, including normal controls and patients with acute non-lymphoblastic leukaemia, acute lymphoblastic leukaemia, and myelodysplastic syndrome. Observer error was least with the disc cultures, whereas variation between replicate cultures was similar for both methods. A high degree of correlation was found between the two methods for both day 7 (r = 0.90) and day 14 (r = 0.91) cultures. The number of colonies and clusters was higher with the disc system, indicating better cloning efficiency. Analysis of subsets of clinical groups showed similar patterns of abnormality with both systems. The simplicity of the method makes the use of this technology possible in most laboratories, and the superior morphological resolution may increase the clinical usefulness of such studies.