Lameness is a painful and debilitating condition that affects dairy cows worldwide. The aim of this study was to determine the plasma concentration of norepinephrine, β-endorphin, and substance P in dairy cows with lameness and different mobility scores (MS). A total of 100 Friesian and Jersey cows with lameness (parity range: 1–6; weight: 400–500 kg; milk yield: 22–28 L a day, and lactation stage less than 230 days) were selected. Animals were selected and grouped according to MS (MS 0–3; n = 25), and plasma concentration of norepinephrine, substance P, and β-endorphin was measured using ELISA. Cows with MS 3 had higher plasma concentrations of norepinephrine and substance P and lower plasma concentrations of β-endorphins when compared to MS 0 cows. Variations in plasma concentration of norepinephrine, substance P, and β-endorphin could be associated with intense pain states in dairy cows with lameness, but are insufficient to differentiate these states from the mildest pain states. Further studies are necessary in order to evaluate the potential use of these biomarkers in the detection of chronic bovine painful conditions.

OBJECTIVE To evaluate IM injection of oxytetracycline as an experimental model to induce pain and assess the analgesic efficacy of flunixin meglumine (FM) in dairy cows. ANIMALS 15 healthy nonlactating Jersey (n = 10) and Holstein (5) cows. PROCEDURES In the first of 2 experiments, 5 Jerseys were administered oxytetracycline (10 mg/kg, IM), divided between the right side of the neck and left hind limb. The left side of the neck and right hind limb received sham injections. Cows were also randomly assigned to receive FM (2.2 mg/kg, IV; n = 3) or an equal volume of saline (0.9% NaCl) solution (0.044 mL/kg, IV; control; 2) once daily for 5 days. The mechanical nociceptive threshold (MNT) was measured before oxytetracycline administration and at predetermined times after each injection of the assigned treatment. Experiment 2 was similar to experiment 1 except it involved 5 Jerseys and 5 Holsteins, oxytetracycline was injected only in a hind limb, and the assigned treatment was administered for 10 days. RESULTS For both experiments, mean MNT for the oxytetracycline injection site was consistently less than that for the sham injection site in the hind limbs, and mean MNT at the hind limb oxytetracycline injection site for FM-treated cows was greater than that for control cows beginning on day 3. CONCLUSIONS AND CLINICAL RELEVANCE IM injection of oxytetracycline in a hind limb reliably induced signs of pain in dairy cows and, with validation, might be useful as an experimental model for assessing pain mitigation strategies in cattle.

Foot-and-mouth disease (FMD) and vesicular stomatitis (VS) cause such similar clinical signs and lesions that laboratory tests are required to distinguish between infections caused by each virus. Using mouse anti-foot-and-mouth disease virus (FMDV) 3B monoclonal or polyclonal anti-vesicular stomatitis virus-New Jersey (VSV-NJ) antibodies and recombinant FMDV 3ABC or VSV-NJ glycoprotein (G) antigens coated to MagPlex beads, competitive Luminex immunoassays (cLIAs) were developed for FMDV and VSV-NJ, respectively. The cLIAs successfully detected antibodies to FMDV 3ABC and VSV-NJ G in sera from infected animals. The diagnostic sensitivity and specificity were 93% and 98%, respectively for FMDV and 93% and 95.4%, respectively for VSV-NJ. These cLIAs are potential alternatives for competitive enzyme-linked immunosorbent assays (cELISAs) and provide the opportunity for multiplexing to reduce time and the amount of serum required for testing.

Objective-To identify risk factors associated with Cryptosporidium parvum infection in dairy calves. Animals-108 case animals and 283 control animals. Procedures-Case animals were calves infected with C parvum, and controls were infected with Cryptosporidium bovis (n = 67) or calves not infected with Cryptosporidium spp. Fecal samples were tested via the flotation concentration method for Cryptosporidium spp. Samples were genotyped by sequencing of the 18s rRNA gene. Associations between host, management, geographic, and meteorologic factors and Cryptosporidium genotype were assessed. Results-Younger calves and calves housed in a cow barn were more likely to be infected with both genotypes. Herd size and hay bedding were associated with an increased risk of infection with C parvum, and Jersey breed was a risk factor for C bovis infection. Compared with a flat surface, a steeper slope was significantly associated with a decreased likelihood of infection with both genotypes, and precipitation influenced the risk of C parvum infection only. Conclusions and Clinical Relevance-Risk factors for calf infection with C parvum differed from those for infection with C bovis. Results may be useful to help design measures that reduce animal exposure and decrease public health risk and economic losses associated with C parvum infection in cattle.

To study volemia and renal function in cattle with acute rumen lactic acidosis (RLA) five Jersey (J) (Bos taurus) and five Gir (G) (Bos indicus) steers were used. Blood, urine and ruminal fluid samples were collected throughout 24h after RLA induction. Higher levels of hipovolemia (p < 0.00001), and total rumen volume (p < 0.05), lower glomerular filtration (p < 0.003) and urinary volume (p < 0.05) were detected in the G steers. Nevertheless, these steers excreted more efficiently H+(p < 0.0001); although higher urinary D-lactate fractional excretion was seen in the G steers similar amounts of D-lactate were excreted by both breeds throughout the trial. Lower urinary levels of L-lactate were excreted by G steers. The higher the urinary pH, the lower the D-lactate fractional excretion in both breeds. | A volemia e a função renal de bovinos com acidose láctica ruminal (ALR) foram estudadas em cinco garrotes Jersey (J) (Bos taurus) e cinco Gir (G) (Bos indicus). Amostras de sangue, urina e conteúdo ruminal foram coletadas durante 24h após a indução experimental da ALR. Os bovinos G apresentaram maior grau de hipovolemia (p < 0,00001) e volume ruminal (p ; 0,47) na excreção total diária deste isômero; garrotes G excretaram menor quantidade de lactato-L na urina (p < 0,05). Independente da raça, quanto menor foi o pH urinário maior a porcentagem de excreção fracionada urinária de lactato total e de lactato-D (r = - 0,69).

A volemia e a função renal de bovinos com acidose láctica ruminal (ALR) foram estudadas em cinco garrotes Jersey (J) (Bos taurus) e cinco Gir (G) (Bos indicus). Amostras de sangue, urina e conteúdo ruminal foram coletadas durante 24h após a indução experimental da ALR. Os bovinos G apresentaram maior grau de hipovolemia (p < 0,00001) e volume ruminal (p ; 0,47) na excreção total diária deste isômero; garrotes G excretaram menor quantidade de lactato-L na urina (p < 0,05). Independente da raça, quanto menor foi o pH urinário maior a porcentagem de excreção fracionada urinária de lactato total e de lactato-D (r = - 0,69).