Factors associated with ruminal pH at herd level.

The objective of this study was to evaluate factors associated with ruminal pH at herd level. Four hundred and thirty-two cows of a Thuringian dairy herd were sampled before claw trimming using a rumen fluid scoop. Volume and pH of the rumen sample were measured, and lactation number, percentage of concentrates in the ration, days in milk (DIM), time of day, and daily milk yield were recorded. Rumen sampling was successful in 99.8% of the cows. The average sample volume was 25 mL. Rumen sample pH decreased with increasing percentage of concentrates in the ration. Ruminal pH decreased from calving to 77 DIM, and grew subsequently to 330 DIM. During the day, rumen pH followed a sinus curve, with maxima in the morning (0915 h) and afternoon (1533 h), and a minimum around noon (1227 h). Ruminal pH decreased with increasing daily milk yield. Lactation number interacted with daily milk yield on rumen pH. The percentage of concentrates in the ration, DIM, time of day, and daily milk yield were significant factors affecting ruminal pH at the herd level.

[Do cows drink calcium?]. / Trinken Kühe Kalzium?

The objective of this study was to investigate how well cows drink the Propeller calcium drink, and it's effect on blood calcium concentration. Drinking was tested in 120 cows right after calving, before cows drank anything else. 60 cows each were offered 20 liters of Propeller calcium drink or 20 liters of water. Cows drank the Propeller as good as water. 72% of all cows drank all 20 liters, 18% drank on average 8.2 liters and 10% drank less than 1 liter. Blood calcium concentration was studied in 16 cows right after calving. Eight cows each were offered 20 liters of Propeller calcium drink or no calcium drink. Blood calcium significantly increased ten minutes after Propeller intake and stayed significantly elevated for 24 hours. Without calcium drink blood calcium levels decreased significantly. Advantages of the new Propeller calcium drink over calcium gels or boli could be that cows now drink calcium themselves and that the Propeller increases blood calcium concentration rapidly and long lasting.

Investigations of milk quality from teats with milk flow disorders.

The objective of this study was to investigate the quality of milk from teats with milk flow disorders. Somatic cell count, pathogens, and signs of mastitis (>100,000 cells/ml and pathogens detected) were determined in the milk from all teats of the udder before treatment of the affected teat, as well as 1 and 6 mo later. Teats with milk flow disorders were compared to all of the other teats from the same udder. Before treatment, the SCC from affected teats was 4.3 million higher, the odds of detecting pathogens 6 times higher, and the odds of mastitis 11 times higher than in control teats (when adjusted for other significant explanatory variables). SCC and the risk of mastitis decreased after surgical treatment of the affected teats, whereas the chance of detecting pathogens was not affected. Six months after treatment, the SCC was 1.3 million higher, and the odds of mastitis 6.5 times higher than in control teats. Throughout the study period neither SCC, the odds of detecting pathogens, nor mastitis changed significantly in control teats. It may be concluded from this study that milk quality from teats with milk flow disorders is decreased before treatment and does not reach the milk quality from unaffected teats within 6 mo after treatment.

Comparative evaluation of SIMPL silicone implants and NIT natural teat inserts to keep the teat canal patent after surgery.

The objective of this study was the comparative evaluation of SIMPL silicone implants and NIT natural teat inserts to keep the teat canal patent after teat surgery. The study was performed on 100 teats of 97 cows treated surgically for milk flow disorders. After surgery, 53 teats were administered with SIMPL and 47 with NIT, and rested for several days. Before treatment and 1 and 6 mo later quarter milk flow and milk yield were measured with Lactocorders; quarter milk was examined for somatic cell count (SCC), pathogens, and signs of mastitis (SCC > 100,000 and pathogens detected). Half a year after surgery milk flow, milk yield and SCC were equal from teats that had been inserted with SIMPL or NIT. The odds of detecting pathogens or signs of mastitis in the milk was lower in SIMPL than in NIT teats at this point in time. SIMPL teats stayed in the herd as long as NIT teats. Based on the results, it may be expected that teats inserted with a SIMPL or NIT do not differ long term in regards to milk flow, milk yield, SCC, and risk of removal from the herd. After the use of SIMPL, fewer pathogens may be detected in the milk long term than after the use of NIT.

Metabolic aspects in the etiology of displaced abomasum.

Results of studies on metabolic variables that exist prior to the diagnosis of displaced abomasum (DA) indicate that subclinical ketosis is a risk factor for DA. Serum aspartate aminotransferase activity, serum and milk betahydroxybutyric acid concentrations, and milk fat-to-protein ratios were often elevated before the diagnosis of DA, and these variables may be used to predict DA. Prevention of subclinical ketosis may prevent DA.

Investigations on teat canal length in teats with milk flow disturbances.

The objective of this study was to evaluate teat canal length as a test for tissue ruptures in the area of the teat canal in teats with milk flow disturbances (Medl's test). A total of 133 dairy cows affected with milk flow disturbances in one teat were used for this study. The teat canal length of the affected teat was compared with the teat canal length of the contralateral teat of the same cow. Milk flow disturbances were diagnosed by endoscopy. Diagnoses were categorized as tissue ruptures in the area of the teat canal or other causes such as narrowing of the teat canal, or free foreign bodies in the teat cistern. The median teat canal length was 11 mm in teats with milk flow disturbances, and 8 mm in contralateral control teats. When the test criterion was lengthening of the teat canal by > or =2 mm, 79% of the teat canals with tissue ruptures tested positive (true positive), but 47% of teat canals without tissue ruptures also tested positive (false positive). When the test criterion was unchanged teat canal length, 47% of teat canals with tissue ruptures tested positive, and only 7% of teat canals without tissue ruptures tested positive. Thus, it is concluded that Medl's test may be useful in differentiating causes of milk flow disturbances. However, a more accurate diagnosis may be made by teat endoscopy.

Evaluation of eight cow-side ketone tests in milk for detection of subclinical ketosis in dairy cows.

The objective of this study was to evaluate eight cowside ketone tests when used with milk for detection of subclinical ketosis. A total of 469 dairy cows in the first week of lactation were studied. Twelve percent of these cows had subclinical ketosis, defined as >1400 micromol of beta-hydroxybutyrate/L of blood serum. The Pink test liquid and the Ketolac test strip were highly sensitive for subclinical ketosis when used with milk. The Uriscan and Rapignost test strips were poorly sensitive; the Ketostix, Ketur-Test, and Medi-Test-Keton test strips and the Acetonreagenz test tablet were insensitive for subclinical ketosis when used with milk. Pink and Ketolac milk ketone tests are potentially useful tools for use in a routine monitoring program to detect subclinical ketosis in early postpartal dairy cows.

Milk yield, somatic cell counts, and risk of removal from the herd for dairy cows after covered teat canal injury.

The objective of this study was to evaluate milk yield, somatic cell count (SCC), and risk of removal of a cow from the herd after covered teat injury. Teat injuries were diagnosed and treated by using endoscopy. After treatment, teats were rested for 3 x 3 d. Eighty-one cows referred to the Veterinary Clinic Babenhausen were used for this study. Each cow was matched to three herdmates by breed, age, and calving date. Data on milk yield and SCC were available from the records of the Bavarian milk control board. Test day milk yields and lactational milk yields were equal for cows with covered teat injury and herdmates in the lactation when the injury was diagnosed and in the subsequent lactation. Calving interval in the year the injury was diagnosed and the time cows lived in the herd were also equal. However, covered teat injuries significantly increased test day SCC by 128,000 cells/ml of milk. These injuries also significantly increased the odds of subclinical mastitis (SCC > 100,000 on test day) and the odds of violating European milk shipping regulations (SCC > 400,000 on test day). Because increased SCC was significantly associated with decreased milk yield, cows may not have fully utilized their milk yield capacity after covered teat injury.

The association between first DHI milk-test parameters and subsequent displaced abomasum diagnosis in dairy cows.

First Dairy Herd Improvement Corporation (DHI) test milk that was sampled prior to displaced abomasum (DA) diagnosis was used to examine the association between milk yield (kg), fat (%), protein (%), or fat/protein ratio and DA in dairy cows. 27 DA cases were matched to 3 controls per case by herd and calving date. Logistic regression was used to examine the effect of each milk parameter on the odds of DA, adjusting for lactation number and days in milk (DIM) at test. Higher odds of DA diagnosis was found with lower milk yield, higher milk fat percentage, lower milk protein percentage and higher fat/protein ratio. We conclude that milk yield, fat percentage, protein percentage and fat/protein ratio may be used to detect cows at risk for DA. Our findings also indicate that cows diagnosed with DA were energy deficient prior to DA diagnosis.

The association between selected metabolic parameters and left abomasal displacement in dairy cows.

The objective of this study was to examine the association between selected metabolic parameters and subsequent left displaced abomasum (LDA) diagnosis in dairy cows. Forty-four LDA cows sampled in the third week ante partum (a.p.) which was at a median of 34 days prior to LDA diagnosis, 36 LDA cows sampled in the first week post partum (p.p.) which was at a median of 14 days prior and 28 LDA cows sampled in the second week p.p., which was at a median of 9 days prior to LDA diagnosis were used. Each case was matched to 3 controls by herd and calving date. Data were available from a large field study. Aspartate-aminotransferase (AST) activity, the concentrations of beta-hydroxybutyrate (BHB), glucose, calcium and urea in blood, and the body condition score (BCS) were studied. Logistic regression was used to analyse the association between these parameters and subsequent LDA, adjusting for the effects of parity and pretreatment. A separate model was used for each sampling week and each parameter. In the third week a.p. none of the parameters were significantly associated with LDA. AST and BHB sampled in the first week p.p. and in the second week p.p. were significantly associated with LDA diagnosis. The higher the AST and BHB, the higher the odds of being diagnosed subsequently with LDA. The lower glucose and Ca in the second week p.p. the higher the odds of subsequent LDA diagnosis. Urea and BCS were not significantly associated with LDA in any of the weeks examined. We conclude that AST and BHB in the first and second week p.p. might be used as tests for subsequent LDA. Glucose, calcium, urea and body condition were either not significantly associated with LDA or significantly associated only in the second week p.p.; this may limit their use as tests for LDA.

In vitro motility disorders associated with displaced abomasum in dairy cows.

The objective of this study was to investigate in vitro abomasal motility in dairy cows diagnosed with displaced abomasum. Longitudinal muscle myenteric plexus preparations originating from the abomasal antrum of control cows, and cows diagnosed with left displaced abomasum (LDA), right displaced abomasum (RDA) or abomasal volvulus (AV) were used. In control preparations electrical field stimulation evoked an immediate cholinergic contractile response exceeding amplitude of basal contractions by 60%. In contrast, contractile activity was significantly inhibited during electrical stimulation in LDA, RDA and AV by 47%, 66% and 45%, respectively. This inhibition was reversed in the presence of L-NAME. The staining intensity of NADPH-positive myenteric neurones was significantly higher in displaced abomasa than in controls. Concentration-response curves indicated that preparations from displaced abomasa showed reduced sensitivity to acetylcholine. This study demonstrated motility disorders in displaced abomasa in vitro. The results suggested that abomasal displacement is associated with malfunctions at the level of the intrinsic nervous system combined with impaired cholinergic muscle responses. There appeared to be a predominance of nitrergic inhibitory mechanisms over excitatory mechanisms. These results might be of significance for diseases associated with gastric hypomotility and emptying disorders.

Analysis of survivorship after displaced abomasum is diagnosed in dairy cows.

The objective of this study was to analyze the survivorship of dairy cows after displaced abomasum was diagnosed. Survivorship from the calving preceeding diagnosis of displaced abomasum to removal from the herd was investigated for cows that were diagnosed with displaced abomasum compared with herdmates. For cows that were diagnosed with displaced abomasum, factors that affected survivorship from the diagnosis of the disease to removal were investigated. Data from a total of 135 cows that had been diagnosed with displaced abomasum and 373 controls matched by herd and lactation number were available from a database at the University of Guelph. The hazard rate of removal from the herd was estimated using proportional hazard regression adjusted for intraherd correlation. Diagnosis of displaced abomasum significantly increased the hazarad rate of removal from the herd. For cows that were diagnosed with displaced abomasum the hazard rate of removal increased as parity increased. However, the hazard rate decreased with recurrent displaced abomasum and with higher days in milk at diagnosis of the disease. Although the 305-d milk production of cows that were diagnosed with displaced abomasum was lower during the lactation when the disease was diagnosed, 305-d milk production was not associated with removal of cows with that disease from the herd. Milk production during subsequent lactations did not differ between cows that were diagnosed with displaced abomasum and control cows. Low milk production during the subsequent lactations increased the hazard of removal of cows with that disease from the herd.

Arginine in liquid contents of displaced abomasal in dairy cows.

Increased nitric oxide synthesis by abomasal neurons was related to disorders of abomasal muscle function in displaced abomasum in a previous study. Nitric oxide is synthesised from L-arginine. The objectives of the studies reported on here were to isolate factors associated with arginine in abomasal fluid and to evaluate the association between arginine in abomasal fluid and left displaced abomasum (LDA), right displaced abomasum (RDA) or abomasal volvulus (AV). Four cows fitted with abomasal cannulas were fed two different diets in succession. Abomasal samples were taken from 1.00 a.m. to 11.00 p.m. during each diet. The data were analyzed using three factor analysis of variance. Diet, sampling time and cow were significantly associated with abomasal arginine concentration. Diet and cow significantly affected abomasal arginine percentage, whereas sampling time had no significant effect. Cows diagnosed with LDA, RDA or AV and control cows were used to study the association between abomasal arginine and LDA, RDA or AV. Linear regression of arginine on LDA, RDA or AV, adjusting for age, time to calving, duration of illness and intraherd correlation was used for data analysis. Associations between arginine concentration and LDA or RDA, and between arginine percentage and LDA, RDA or AV were not significant. AV significantly increased abomasal arginine concentration. The findings do not support the hypothesis that arginine in abomasal fluid is related to abomasal displacement in dairy cows.

An evaluation of protein/fat ratio in first DHI test milk for prediction of subsequent displaced abomasum in dairy cows.

First DHI test milk that was sampled prior to displaced abomasum (DA) diagnosis was used to evaluate milk protein/fat ratio (PFR) for prediction of subsequent DA in dairy cows. Odds ratio, sensitivity, specificity, and likelihood ratio were determined. Twenty-seven DA cases were matched to 3 controls per case by herd and calving date. Milk was tested at a median of 19 d after calving, which was 8 d prior to the median time of DA diagnosis. Adjusted for parity and days in milk, a protein/fat ratio < or = 0.72 was 8.2 times more likely to come from a cow subsequently diagnosed with DA than a protein/fat ratio > 0.72. Using the cut off value of 0.72, the sensitivity of PFR for DA was 80% and the specificity was 68%. A receiver operating characteristics curve indicated that the minimum sum of false negative and false positive results was at a PFR cut off value of 0.72. The likelihood ratio indicated that protein/fat ratios < or = 0.62 are 3.8 times more likely to come from cows that are diagnosed subsequently with DA than from cows without DA. The protein/fat ratio in 1st DHI test milk may predict subsequent DA in dairy cows.

Evaluation of five cowside tests for use with milk to detect subclinical ketosis in dairy cows.

The objective of this study was to evaluate the characteristics of five ketone tests for use with milk to detect subclinical ketosis [defined as > 1200 mumol of beta-hydroxybutyrate (BHBA)/L of blood] in dairy cows. The tests studied were the Ketolac BHB strip to detect BHBA (Hoechst, Unterschleissheim, Germany) and four tests based on sodium nitroprusside to detect acetoacetate (Rothera tests) [Ketostix strip (Bayer, Etobicoke, ON, Canada), Bioketone powder (Societé d' Analyses Biopharmaceutiques, Laval, QC, Canada), Ketocheck powder (Great States, St. Joseph, MO), and Utrecht powder (University of Utrecht, Utrecht, The Netherlands)]. Milk samples (n = 529) from 266 cows in 25 Ontario dairy herds were used for this investigation. The Ketolac BHB strip at 50 and 100 mumol of BHBA/L of milk showed sensitivities of 92 and 72%, respectively. This test was more sensitive for subclinical ketosis than were any of the Rothera tests. The sensitivities of the Rothera tests were 43, 33, 28, and 5%, respectively, for Utrecht powder, Bioketone powder, Ketocheck powder, and Ketostix strip. The Rothera tests were highly specific, as was the Ketolac BHB strip at 200, 500, and 1000 mumol of BHBA/L of milk (specificity, > 97%). The prevalence of subclinical ketosis was highest during the first 6 wk of lactation, and a peak was detected during the 2nd wk of lactation. Of the tests evaluated in this study, Ketolac BHB strip was the most useful to monitor subclinical ketosis in dairy herds.

Evaluation of aspartate transaminase activity and beta-hydroxybutyrate concentration in blood as tests for prediction of left displaced abomasum in dairy cows.

OBJECTIVE: To evaluate aspartate transaminase (AST) activity and beta-hydroxybutyrate (BHB) concentration in blood obtained during the first or second postpartum (PP) week as tests for prediction of subsequent left displaced abomasum (LDA) diagnosis in dairy cows. ANIMALS: 36 cows with LDA tested at a mean 3 PP days, which was 7 to 22 days prior to LDA diagnosis (25, 75% quantiles), and 28 cows with LDA tested at 10 PP days, which was 5 to 18 days prior to LDA diagnosis, were matched to 3 controls per case by herd and calving date. Data were available from a large field study. PROCEDURE: Odds ratio, sensitivity, specificity, and likelihood ratio were determined for various AST and BHB cutoff values. RESULTS: AST, using cutoff values between 100 and 180 U/L, and BHB, using cutoff values between 1,000 and 1,600 mumol/L, were significantly associated with subsequent LDA diagnosis. When cutoff values were increased, odds ratio and likelihood ratio increased; however, sensitivity decreased and specificity increased. CONCLUSION AND CLINICAL RELEVANCE: AST activity and BHB concentration in blood obtained during the first or second PP week might be useful as predictors of subsequent LDA diagnosis.

[Examination of a novel wax teat bougie for treatment of wounds in the papillary lactiferous sinus of dairy cows with special regard to endoscopic documentation of mucosal reactions compared with conventional teat bougies and a teat cannula]. / Prüfung eines neuartigen Strichkanalstabes zur Behandlung von Strichkanalwunden unter besonderer Berücksichtigung der endoskopisch dokumentierten Schleimhautverträglichkeit im Vergleich zu konventionellen Zitzenstiften und Verweilkanülen.

The present study on a novel wax-teat bougie, developed by Dr. T. GEISHAUSER for treatment of wounds in the papillary lactiferous sinus of dairy cows, has been performed in two phases of investigation. In a first step, fourteen healthy dairy cows (Deutsch Schwarzbunt) in state of early lactation were dried off temporarily for five days, after checking milk samples of all quarters for six following-on days on their bacteriological status, number of somatic cells, conductivity and results of the California-Mastitis-Test (CMT). The drying off was performed on two Quarters with similar cell-count in milk samples each. In one teat of the selected pairs off udder quarters, the wax-bougie was applied (group I), the other corresponding udder quarters were used as a control (group II). After five days of drying off, lactation was started again after removing the bougies in treated quarters. For another five days milk samples out of the quarters in groups I and II were checked in the laboratory tests named above and mean values and increase differences of results were compared. Comparison of increase differences with t-test showed no statistically significant difference between drying off procedures with the wax-bougie and without any treatment in the parameters named above. Courses of counts of somatic cells, conductivity and CMT showed no significant differences between drying off probands by using the novel wax-bougie and drying off without further treatment. In the second phase of the study, fifteen lactating, healthy dairy cows as probands have been split in five groups. Three cows (twelve udder quarters) were dried off for five days by using the novel teat bougie (group D), in three groups (A,B,C) two different types of conventional teat bougies and one type of cannula were used, and, as a control three cows (group E) were dried off without any treatment. Before drying off the udder quarters and after starting lactation again, the condition of the mucosa in the teat papillary lactiferous sinus has been documented by means of endoscopy and the bacteriological status of milk samples has been determined. As a result all udder quarters dried off temporarily showed endoscopically detectable inflammatory-proliferating reactions in the mucosa of the papillary lactiferous sinus, whereas in cows treated with the novel wax-bougie (group D), as well as in the cows of the control group (E), there were no inflammatory reactions detectable at all. These different reactions, basing on the Fisher-test, have to be considered statistically significant (p < 0.001).

Fat/protein ratio in first DHI test milk as test for displaced abomasum in dairy cows.

First DHI test milk that was sampled prior to displaced abomasum (DA) diagnosis was used to evaluate milk fat/protein ratio (FPR) for prediction of subsequent DA in dairy cows. Odds ratio, sensitivity, specificity, predictive values, and likelihood ratio were determined. Twenty-seven DA cases were matched to three controls per case by herd and calving date. Milk was tested 18 to 23 days (95% CI) after calving, which was 9 to 17 days (95% CI) prior to DA diagnosis. Adjusted for parity and days in milk, a fat/protein ratio > or = 1.4 was 8.6 times more likely (95% CI, 2.8 to 26) to come from a cow subsequently diagnosed with DA than a fat/protein ratio < 1.4. Using the cut off value of 1.4, the sensitivity of the FPR for DA was 80% and the specificity was 69%. A response operating characteristics curve indicated that the minimum sum of false negative and false positive results was at an FPR cut off value of 1.4. The likelihood ratio indicated that fat/protein ratios > or = 1.6 are 3.3 times more likely to come from cows that are diagnosed subsequently with DA than from cows without DA. The fat/protein ratio in first DHI test milk might be useful as a test for subsequent DA in dairy cows.

[Endoscopic assessment of the mucosal tolerance of a new papillary duct bougie compared with conventional mammary cannulas]. / Endoskopische Prüfung der Schleimhautver-träglichkeit eines neuartigen Strichkanalstabes im Vergleich zu konventionellen Zitzenstiften und einer Verweilkanüle.

In this study on healthy, milking cows three per group a temporary drying off for five days, using two types of conventional teat bougies (group A, B), one type of a teat canula (group C) and one type of a novel wax-bougie, developed by Dr. Th. Geishauser (group D) was performed. As a control, three cows were dried off without using any teat bougies (group E). Before drying off the udder quarters, the condition of the mucosa in the teat papillary lactiferous sinus was documented by means of endoscopy. After five days, lactation was started and endoscopy was performed again. Endoscopical pictures and video tapes were evaluated for existence of inflammatory-proliferating reactions on the mucosa of the papillary lactiferous sinus. Comparison of the five groups with statistical methods (Fisher test) showed significant (P < 0.001) effects: all udder quarters, dried off temporarily by using conventional teat bougies and teat canulas (groups A, B, C) showed more or less severe alterations in the mucosa of the papillary lactiferous sinus, whereas in cows, treated with the novel wax bougie (group D) as well as in cows of the control group (E) there were no alterations detectable at all.

[Purulent inflammation of the fetlock joint in cattle--treatment by joint resection]. / Eitrige Fesselgelenkentzündung beim Rind-Behandlung durch Gelenkresektion.

A surgical method for the treatment of purulent inflammation of the fetlock joint in cattle is reported. The method involves opening of the diseased joint and complete removal of diseased tissues (articular resection). Three of four cattle with purulent inflammation of the fetlock joint could be successfully treated using this procedure. Following complete removal of the fetlock joint ossification took place. The use of the limb was little affected in all gait types following the ossification of the fetlock joint. One cow was not healed, since it was not possible to resect the affected tissues completely.