Effect of concentrate level on feeding behavior and rumen and blood parameters in dairy goats: relationships between behavioral and physiological parameters and effect of between-animal variability.

This work aimed first to compare 2 diets differing in their percentage of concentrate [low (LO): 30% concentrate vs. High (HI): 60% concentrate] by measuring simultaneously feeding behavior, rumen parameters, blood and plasma parameters, and milk yield and composition in 8 mid-lactation goats. The second aim was to study the interrelationships between these variables and to analyze the between-animal variability to better understand the between-animal differences in acidosis susceptibility. All of the animals received the 2 diets ad libitum as total mixed ration according to a crossover design of two 4-wk periods. Mean daily DMI was similar between the 2 diets but the variability was higher for the HI than for the LO diet. Goats produced more milk when fed the HI diet compared with the LO diet but with a lower fat:protein ratio (0.81 vs. 0.99). They ate more rapidly the HI than the LO diet but stopped eating sooner after the afternoon feed allowance, and spent less time chewing. The increase in concentrate percentage modified rumen parameters: the pH and acetate:propionate ratio decreased and total VFA, ammonia, and soluble carbohydrate concentrations increased. Hematocrit, plasma NEFA, and blood K and Ca concentrations decreased but glycemia and uremia increased. Other parameters were not modified: milk fat content, blood pH, and bicarbonate and Na concentrations. A large between-animal variability was detected for all the measured parameters, especially for feeding behavior, with important consequences on rumen and blood parameters. This work confirmed the effects of a high percentage of concentrate on feeding behavior, rumen and blood parameters, and milk production, and some known relationships such as the positive link between rumen pH and chewing index. It also pointed out other relationships between parameters seldom measured at the same time, such as rumen redox potential or blood pH and chewing index, or the negative link between blood and rumen pH. When the animals spent a lot of time chewing, they probably produced a lot of saliva that buffered the rumen pH and prevented them from suffering from subacute ruminal acidosis. However, they used part of their blood bicarbonates reserve, which might have induced metabolic acidosis, as rumen and blood pH were inversely related. This could explain why some animals suffer from acidosis and others do not in a herd receiving the same diet, and why some animals seem to suffer more from subacute ruminal acidosis and others from metabolic acidosis.

The use of a multivariate analysis to study between-goat variability in feeding behavior and associated rumen pH patterns.

This study examined feeding patterns and their relation to rumen pH. The measured variables were the cumulative time spent chewing (eating or ruminating) and the mean rumen pH, per 20-min intervals (46 intervals altogether). A total of 333 feeding patterns, defined as time-series of measurements for 1 animal and 1 given day during 15 h and 20 min following the afternoon feeding, were collected from 12 stall-housed dairy goats fed a total mixed ration twice daily. The first objective of this study was to analyze the within-day variability of feeding behavior to characterize different feeding patterns. The second objective was to analyze, for each goat, the between-day variability of its feeding behavior. The third objective was to study the influence of feeding behavior on rumen pH. A multivariate method (principal component analysis) was performed on the time spent eating or ruminating during each of the 46 intervals. The factor score plots generated by the principal component analysis highlighted the evolution in time of chewing activities. They also were used to determine 4 different types of feeding behavior in the extreme patterns of the first 2 axes. These feeding patterns were associated with different rumen pH patterns in goats with the same total dry matter intake and mean rumen pH. Some goats had a major eating period immediately after feeding, followed by a period of rumination; this pattern was associated with a marked decrease in rumen pH and a pH nadir below 6.0. Other goats performed alternate periods of eating and ruminating throughout the studied period. The latter feeding pattern was associated with a shorter total duration of rumination, but a more stable rumen pH than the feeding pattern described previously. Feeding pattern was quite constant between days for some goats, but highly variable for others. However, the continuum observed between these 4 groups shows that many intermediate types of behavior can be observed. In conclusion, characterizing animals according to their feeding behavior by using a principal component analysis may provide information on the animal's predisposition to rumen acidosis.

Modeling of off-feed periods caused by subacute acidosis in intensive lactating ruminants: application to goats.

Off-feed periods caused by subacute rumen acidosis are often observed in intensive ruminant production systems but appear in an unpredictable manner. The objectives of this paper were first, to study the influence of spontaneous off-feed periods due to bouts of acidosis on milk composition and on some rumen and blood parameters and second, to model the day-to-day variations in rumen pH, dry matter intake (DMI), and milk production during these bouts of acidosis. Twenty-five spontaneous off-feed periods were detected in an experiment performed in 18 mid-lactating goats fed a high concentrate diet over 11 wk. Dry matter intake, milk production, and rumen pH were measured daily during the experiment, which allowed us to model the day-to-day evolution of these 3 parameters during spontaneous bouts of acidosis. Bouts started with a very rapid pH decrease (1 d) followed by several days of relatively high rumen pH (>6.5) before recovery of preacidosis values. The pH decrease was followed by a decrease in DMI, reaching a nadir around 2 d after the start of the episode, and a milk yield decrease, reaching a nadir 3 d after the beginning of the episode. The high rumen pH was caused by the relatively small decrease in daily chewing time during the decrease in DMI. Therefore, chewing time per unit of DMI increased, which probably increased the buffer supply per unit of DMI. Dry matter intake and milk yield needed around 20 d to recover to preacidosis values. Energy balance also decreased during DMI and milk yield decreases but recovered more rapidly than DMI and milk yield. However, energy balance cumulated from the start of the bout of acidosis remained negative for more than 10 d. Milk composition and rumen and blood parameters were not measured daily and therefore could not be used in the modeling process. However, during off-feed periods, milk fat and protein contents were negatively correlated with DMI, whereas milk lactose content was positively correlated with DMI. Low DMI was also linked to low blood pH, bicarbonates, and low rumen volatile fatty acids but high levels of plasma nonesterified fatty acids. This indicates that rumen fermentation was reduced and body reserves were mobilized during bouts of acidosis. This analysis showed that spontaneous bouts of acidosis in intensively reared dairy ruminants can have a great influence on animal production and health over at least 3 wk, and can thus represent an important economic loss.

Meta-analysis of the influence of Saccharomyces cerevisiae supplementation on ruminal parameters and milk production of ruminants.

The effects of yeast supplementation on intake, production, and rumen fermentation characteristics have been widely studied, but results are inconsistent between different studies. A quantitative meta-analysis was applied to 110 papers, 157 experiments, and 376 treatments dealing with yeast supplementation in ruminants. The objective was first to highlight the major quantitative effects of live yeast supplementation on intake, rumen fermentation, and milk production, and second, to identify major differences in experimental conditions between studies that can affect the response to treatment. Some of these experimental conditions are referred to as interfering factors. Yeast supplementation increased rumen pH (+0.03 on average) and rumen volatile fatty acid concentration (+2.17 mM on average), tended to decrease rumen lactic acid concentration (-0.9 mM on average), and had no influence on acetate-to-propionate ratio. Total-tract organic matter digestibility was also increased by yeast supplementation (+0.8% on average). Yeast supplementation increased dry matter intake (DMI; +0.44 g/kg of body weight; BW), milk yield (+1.2 g/kg of BW), and tended to increase milk fat content (+0.05%), but had no influence on milk protein content. Dose effects of yeast supplementation, expressed as log(10) [1+(cfu per 100 kg of BW)], globally confirmed the qualitative effects observed in the first analysis. The positive effect of yeast supplementation on rumen pH increased with the percentage of concentrate in the diet and with the DMI level. It was negatively correlated with the level of dietary neutral detergent fiber (NDF). The positive effect of yeast supplementation on rumen volatile fatty acid concentration increased with DMI and crude protein levels. The positive effect of yeast supplementation on organic matter digestibility increased with the percentage of concentrate and NDF in the diet. The negative effect of yeast supplementation on lactic acid concentration tended to decrease when the DMI level and the percentage of concentrate in the diet increased. The effects of interfering factors were globally similar when either dose effect or qualitative effect of yeast was taken into account. Although rumen fermentation efficiency per se was not measured, these results suggest an improvement in rumen fermentation by yeast supplementation. This effect could, however, be modulated by several different factors such as DMI, percentage of concentrate or NDF in the diet, or species.

Effect of concentrate percentage on ruminal pH and time-budget in dairy goats.

The aim of this study was to compare rumen pH and time-budget in eight mid-lactation goats receiving two diets in a cross-over design (low-concentrate diet (L): 30% and high-concentrate diet (H): 60% concentrate). Feeding H increased daily intake (4.3 ± 0.08% v. 4.7 ± 0.08% of body weight for L and H, respectively) and daily milk production (3.01 ± 0.130 v. 3.50 ± 0.130 kg/day of 3.5% fat-corrected milk for L and H, respectively). It decreased milk fat and inverted the fat-to-protein ratio (1.07 ± 0.054 v. 0.94 ± 0.054 for L and H, respectively). As suggested by the percentage of time spent with rumen pH below 6.0 (23.4 ± 6.60% v. 39.9 ± 5.88% for L and H, respectively), H was more acidogenic than L. When offered H instead of L, goats spent less time eating (298 ± 17.5 v. 265 ± 17.5 min for L and H, respectively) and ruminating (521 ± 21.0 v. 421 ± 21.0 min for L and H, respectively) but more time resting (352 ± 27.1 v. 459 ± 21.1 min for L and H, respectively) over a 24-h period. They also tended to spend more time drinking (20 ± 2.9 v. 25 ± 2.9 min for L and H, respectively; P = 0.08) when offered H rather than L. These differences in activities were mainly observed during the first hours following feeding. When offered H, goats adapted their feeding behaviour around the feedings, which allowed them to limit the physiological disturbances potentially inducible by H and to increase milk production, without experiencing too much acidosis.

Clinical evaluation of a nutraceutical, carprofen and meloxicam for the treatment of dogs with osteoarthritis.

The efficacy, tolerance and ease of administration of a nutraceutical, carprofen or meloxicam were evaluated in a prospective, double-blind study on 71 dogs with osteoarthritis. The client-owned dogs were randomly assigned to one of the three treatments or to a placebo control group. The influence of osteoarthritis on the dogs' gait was described by comparing the ground reaction forces of the arthritic dogs and 10 normal dogs. Before the treatments began, and 30 and 60 days later, measurements were made of haematological and biochemical variables and of the ground reaction forces of the arthritic limb, and subjective assessments were made by the owners and by the orthopaedic surgeons. Changes in the ground reaction forces were specific to the arthritic joint, and were significantly improved by carprofen and meloxicam but not by the nutraceutical; the values returned to normal only with meloxicam. The orthopaedic surgeons assessed that there had been an improvement with carprofen and meloxicam, but the owners considered that there had been an improvement only with meloxicam. The blood and faecal analyses did not reveal any changes. The treatments were well tolerated, except for a case of hepatopathy in a dog treated with carprofen.

Neutrophilic airway inflammation in horses with heaves is characterized by a Th2-type cytokine profile.

Heaves in horses shares many similarities with human asthma, including lower airway inflammation, reversible airway obstruction, and bronchial hyperresponsiveness. Extrinsic asthma is an allergic response to environmental allergens and a similar immunologic mechanism may be implicated in heaves. It is now recognized that a Th2 subset of CD4+ lymphocytes is associated with allergic diseases such as atopic asthma. The purpose of this study was to determine whether airway inflammation in heaves is associated with a pattern of expression of cytokine suggestive of a Th2 type response. The expression of mRNA, encoding interleukin (IL)-4, IL-5, and interferon gamma (IFN-gamma) was measured in bronchoalveolar cells from seven horses with heaves and five control horses, using in situ hybridization and radiolabeled equine-specific cRNA probes coding for these cytokines. Bronchoalveolar cells of horses with heaves had an increased expression of IL-4 (p = 0.01) and IL-5 (p = 0.02) mRNA and a decreased expression of INF-gamma (p = 0.01) compared with control horses. Here we show that inflammatory cells in lungs from horses with heaves display a Th2-type cytokine profile that is consistent with the hypothesis that heaves is an allergic condition with similarity to human asthma.

Pansteatitis in a free-ranging red-tailed hawk (Buteo jamaicensis).

A free-ranging juvenile female red-tailed hawk (Buteo jamaicensis) that was unable to fly was admitted to a rehabilitation center and died 1 day later. Hematology and serum chemistry abnormalities included moderate regenerative anemia, elevated creatine kinase, and hyperphosphatemia. Necropsy revealed a generalized steatitis, and histology showed a necrotizing and granulomatous pansteatitis with intralesional pigment compatible with ceroid. There was also moderate diffuse myodegeneration, mild multifocal cardiomyopathy, and mild multifocal hepatic necrosis. These changes and lesions resemble those caused by vitamin E deficiency in mammals and fish-eating birds.

Atypical sporadic lymphosarcoma in a 7-month-old Holstein heifer.

A 7-month-old calf with a firm, diffuse infiltration of the left hind limb with sciatic nerve motor deficit was presented. The cytology indicated a malignant, round cell tumor and at necropsy, tissues were positive to a Kappa-lambda immunohistochemistry test. The final diagnosis was sporadic bovine leukosis, juvenile form.

Focal symmetrical encephalomalacia in a 6-month-old Dorset sheep.

Neurological examination of a sheep that had acute onset of recumbency and mental depression indicated a diffuse symmetrical thalamocortical lesion. Cerebrospinal fluid analysis suggested a degenerative central nervous system disease. Thiamin administration resulted in partial and temporary improvement. Brain histological lesions were typical of focal symmetrical encephalomalacia.

Influence of vulvar hygiene on cytology of vaginal smears after sham artificial insemination in sows.

The description of vaginal cytology in the sow in relation to artificial insemination (AI) has never been reported. Poor vulvar hygiene is frequently imputed as a cause for the development of endometritis after AI and could thus enhance the inflammatory response of the genital tract. The goal of this study was to use cytology as an objective tool to evaluate the vulvar hygiene during sham AI. Sixty-eight sows were matched according to their parity and week of mating and divided into 2 groups: treatment sows (CVS) had their vulva cleaned with a 1:2000 Hibitane solution and control sows (SVS) had theirs soiled with feces. Both groups of sows were inseminated twice with saline following this vulvar treatment, once at detection of estrus and a 2nd time 24 hours later. Vestibular smears were taken before each AI, and vaginal smears were taken after each AI from the material present on the insemination spirette. Cytological smears were described by the predominant type of cells, namely epithelial, neutrophil, or no predominance. Results showed no significant differences between the 2 groups and no evolution in the predominance of neutrophils from the 1st to the 2nd AI (P > 0.05). The pooled results from the 2 groups showed an increase in cellularity from the 1st to the 2nd AI (P > 0.05). Neither the cellularity nor predominant cell type in vestibular or vaginal smears from estrus sows are predictors of vulvar hygiene during sham AI (P > 0.05).

Diagnosis of ruptured urinary bladder in a foal by the identification of calcium carbonate crystals in the peritoneal fluid.

A 3-day-old Quarter Horse colt was examined because of signs of severe depression, discomfort, and abdominal straining. The foal seemed disoriented, and the abdomen was tense and distended ventrally. The differential diagnoses included ruptured urinary bladder, retained meconium, septicemia/bacteremia, and neonatal maladjustment syndrome. Serum biochemical analysis revealed marked hyponatremia, hypochloremia, and moderate hyperkalemia, as well as mildly high urea, creatinine, and phosphorus concentrations. The primary differential diagnosis at this time was ruptured urinary bladder. Abdominocentesis was performed to confirm this diagnosis. Microscopic examination of abdominal fluid revealed calcium carbonate crystals, which originated from the urine of the foal. Biochemical analysis also confirmed the diagnosis of ruptured urinary bladder, because the ratio of peritoneal fluid creatinine to serum creatinine was 2.8:1. The foal died before surgical correction could be attempted.

Multicenter evaluation of the hemodynamic effects of bisoprolol in patients with mild to moderate hypertension.

Twenty-six patients with mild-to-moderate essential hypertension participated in a 6-week outpatient, multicenter, randomized, double-blind, placebo-controlled two-way crossover study to assess the hemodynamic effects of bisoprolol (20 mg QD) at steady state. Hemodynamic assessments included sitting blood pressure, heart rate, and left-ventricular ejection fraction by radionuclide ventriculography after 7 days of bisoprolol or placebo at trough (24 h post-dose) and peak (3 h post-dose) values. The group adjusted mean ejection fraction was not significantly different in patients receiving bisoprolol compared with the placebo group at either peak or trough measurements; in fact, means in patients taking bisoprolol were slightly higher than in the placebo group. No symptomatic hypotension was documented. Blood pressure, measured 24 hours after dosing, was significantly lower in those receiving bisoprolol when compared with the placebo group, by 7.7 mm Hg and 9 mm Hg for diastolic and systolic blood pressure, respectively. Similarly, mean values of heart rate were 10 beats/min lower in the bisoprolol patients than in the placebo group. Only headache and insomnia occurred as adverse events. Bisoprolol (20 mg QD) effectively lowered blood pressure over a 24-hour period without significantly reducing ejection fraction or causing adverse clinical or biochemical events.

Real-time intravascular ultrasound imaging in humans.

The capability of obtaining cross-sectional, high resolution images of arteries with the use of ultrasound catheters has recently been demonstrated in animal studies. In this study the in vivo feasibility of intravascular ultrasound imaging in humans was evaluated. In 26 patients who had undergone diagnostic cardiac catheterization or iliofemoral arteriography, 1 of 3 different models of 20-MHz ultrasound catheters was advanced retrograde, into the iliac arteries and aorta or anterograde into the femoral arteries and real-time cross-sectional images of the arteries were obtained in all. In 10, the iliac arteries were normal and appeared circular and pulsatile with a 3-layered wall and crisply defined lumens. In 7 patients with nonobstructive plaques, the plaque was easily identified in the ultrasound image as a linear, bright, adynamic echo-dense structure. In 4 with obstructive disease in the iliac artery, the arterial lumen appeared irregular, bordered by a thickened, nonpulsatile wall. Variable grades of atheromatous abnormalities in the wall could be visualized. In all 5 patients with arteriographic evidence of obstructive disease of the femoral artery, intravascular ultrasound displayed reduced lumens and irregular borders with protruding high-intensity echoes in the wall. In all patients, the arterial lumen and the normal or abnormal wall were well visualized in the ultrasound images. There were no complications. This study thus demonstrates the feasibility of intravascular ultrasound imaging of arterial circulation in humans. With further improvements in catheter design and image quality, this imaging approach is likely to have a number of potential applications in the assessment of peripheral and coronary arterial diseases and in guiding interventional therapeutic procedures.

Immunohistochemical detection of intermediate filament proteins in formalin fixed normal and neoplastic canine tissues.

Normal and well differentiated neoplastic canine tissues were immunohistochemically stained for keratin, vimentin and desmin intermediate filament proteins using commercially available monoclonal antibodies. Keratin was detected in 56 of 57 carcinomas, vimentin in 59 of 62 sarcomas and desmin in three of four muscle cell tumors. Most normal and neoplastic tissues expressed only one type of intermediate filament; exceptions were one hemangiosarcoma and one pulmonary carcinoma in which there was coexpression of vimentin and keratin proteins. Since immunohistochemical detection of intermediate filaments has tissue-specific distribution in the majority of well differentiated canine neoplasms, these stains may be useful in the differential diagnosis of anaplastic canine tumors. However, the monoclonal antibodies to cytokeratin which were tested in this study failed to detect intermediate filaments in liver, pancreas and salivary glands which suggests that these antibodies may also be unable to detect epithelial tumors derived from these tissues. In addition, in nine neoplasms, the normal tissues adjacent to neoplastic cells failed to stain for the intermediate filament normally expressed. When this occurs, evaluation of intermediate filament expression is invalid for the determination of tissue of origin of the neoplastic cells.

Clinical and noninvasive hemodynamic results after aortic balloon valvuloplasty for aortic stenosis.

Balloon valvuloplasty has been shown to be an effective treatment for adults with aortic stenosis, typically providing a 50 to 80% increase in aortic valve area and marked improvement in exertional dyspnea, angina and syncope. However, the duration of this hemodynamic and clinical improvement is uncertain. Forty-two patients were followed for 10.2 +/- 0.5 months. Balloon valvuloplasty caused dramatic immediate reduction in the number of patients with moderate or severe dyspnea (80 to 14%), moderate or severe angina (39 to 2%) and syncope (30 to 2%). Furthermore, this improvement in symptoms continued for the duration of the follow-up period in most patients. Echocardiographic aortic valve mean gradient and area determined at 3-month intervals, however, showed a trend toward or return to prevalvuloplasty levels by 9 months' follow-up in 13 of 25 patients (52%), whereas 12 of 25 patients showed no deterioration in their hemodynamic parameters. This trend toward restenosis was accompanied by symptomatic deterioration in 5 of 13 patients (38%). This tendency toward restenosis in greater than 50% of patients by 9 months underscores the need for further technical improvements if balloon valvuloplasty is to be widely applied. Even with these limitations, however, balloon valvuloplasty seems to provide a significant improvement in actuarial survival compared with the natural history of elderly patients with severe aortic stenosis.

Treatment of cardiogenic shock by emergency aortic balloon valvuloplasty.

We used aortic balloon valvuloplasty to successfully treat two patients who had cardiogenic shock associated with calcific aortic stenosis. In both patients, the resulting reduction in mean aortic valve gradient and increase in calculated aortic valve area allowed prompt discontinuation of treatment with pressors and a return to near normal renal function. Both patients were discharged within 10 days after valvuloplasty and showed significant, long-lasting clinical improvement. Aortic balloon valvuloplasty can reverse cardiogenic shock associated with calcific aortic stenosis.

Mechanism of aortic balloon valvuloplasty: fracture of valvular calcific deposits.

Balloon valvuloplasty has been shown to acutely reduce the hemodynamic and symptomatic severity of calcific aortic stenosis. The mechanism by which this improvement is accomplished is not known. At necropsy, three patients who died after hemodynamically successful aortic balloon valvuloplasty were found to have aortic valve calcific deposits fractured at one or more sites. These findings suggest that fracture of leaflet calcium represents the basis for successful aortic balloon valvuloplasty.