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  • Author or Editor: Walter L. Hurley x
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Objective

To investigate intramammary infections in llamas, identify the pathogens responsible, and determine whether effects of intramammary infection could be detected by use of mastitis indicator tests commonly used for cows.

Design

Observational study.

Animals

100 llamas on 10 farms.

Procedure

Milk samples were evaluated by bacterial culturing and by determination of somatic cell count (SCC), using direct microscopic and automated counting methods, California Mastitis Test score, pH, and N-acetyl-β-d-glucosaminidase activity. Correlation coefficients were determined among the various mastitis indicator tests, and test results were determined for milk from infected and uninfected glands.

Results

Evidence of intramammary infection was evident in 76 of 369 (21%) milk samples, with 54 of 94 (57%) llamas having at least 1 infected gland. Staphylococcus sp other than Staphylococcus aureus were the predominant pathogens. None of the llamas had clinical signs of mastitis, and significant differences were not detected in SCC, California Mastitis Test score, pH, or N-acetyl-β-d-glucosaminidase activity between infected and uninfected samples. California Mastitis Test scores were negative or trace for 307 of 313 (98%) samples, and SCC were low. In contrast, pH and N-acetyl-β-d-glucosaminidase activity of milk from uninfected glands were higher than values reported for milk from uninfected cows, and neither variable was significantly correlated with the number of somatic cells in samples of llama milk.

Clinical Implications

Although intramammary infections develop in llamas, inflammation (mastitis) appears to be rare. Values for mastitis indicator tests used for cows cannot be directly extrapolated to llamas. Subclinical mastitis is apparently not an important problem in llamas in the United States. (J Am Vet Med Assoc 1996;209:1457–1463).

Free access
in Journal of the American Veterinary Medical Association

Objective

To determine whether mammary gland or colostral characteristics at calving could be used to predict colostral immunoglobulin G1 (IgG1) concentration or intramammary infection (IMI) and whether leakage of colostrum affects IgG1 concentration.

Design

Prospective study.

Animals

113 multiparous Holstein cows.

Procedure

Cows were examined within 3 hours of calving, and mammary gland and colostral characteristics, colostral volume, somatic cell count, and concentrations of IgG1, fat, and protein were determined. Bacteriologic culture of mammary secretions was performed approximately 14 and 7 days before calving and at calving. Associations of gland and colostral characteristics with colostral IgG1 concentration, colostral volume, and IMI were examined.

Results

Thick or thin colostrum had higher IgG1 concentration than colostrum of intermediate viscosity. Colostrum from mammary glands that were firm had low IgG1 concentration. Colostral IgG1 concentration was weakly correlated with volume. Intramammary infection was likely to be detected if colostrum contained clots or blood or if the California Mastitis Test (CMT) score was ≥ 2. Somatic cell count was higher for glands with IMI than for uninfected glands, and CMT score was correlated with cell count.

Clinical Implications

Mammary gland and colostral characteristics were of little value in predicting IgG1 concentration. Our findings do not support recommendations that first milking colostrum that is thin (watery) or that is from cows producing large volumes not be fed to dairy calves. Colostral characteristics, particularly CMT score, were of value for predicting IMI. (J Am Vet Med Assoc 1999;214:1817-1823)

Free access
in Journal of the American Veterinary Medical Association