Abstract #M85
Section: Animal Health (posters)
Session: Animal Health II
Format: Poster
Day/Time: Monday 7:30 AM–9:30 AM
Location: Exhibit Hall A
Session: Animal Health II
Format: Poster
Day/Time: Monday 7:30 AM–9:30 AM
Location: Exhibit Hall A
# M85
Association of subclinical hypocalcemia and teat canal diameter after milking in dairy cattle.
A. A. Barragan*1, L. da Costa2, S. Bas2, A. Della Libera3, E. Hovingh1, S. Rassler1, M. A. Ostach1, F. da Costa4, 1Department of Veterinary and Biomedical Sciences, Penn State University, University Park, PA, 2Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, OH, 3Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brazil, 4Olentangy Liberty High School, Powell, OH.
Key Words: dairy cattle, hypocalcemia, teat canal diameter
Association of subclinical hypocalcemia and teat canal diameter after milking in dairy cattle.
A. A. Barragan*1, L. da Costa2, S. Bas2, A. Della Libera3, E. Hovingh1, S. Rassler1, M. A. Ostach1, F. da Costa4, 1Department of Veterinary and Biomedical Sciences, Penn State University, University Park, PA, 2Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, OH, 3Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brazil, 4Olentangy Liberty High School, Powell, OH.
Hypocalcemia (clinical and subclinical) is a metabolic condition that affects more than 50% of dairy cows within 48 h of parturition. Hypocalcemia has been associated with increased risk of retained placenta, metritis, mastitis, and displaced abomasum. It has also been proposed that this condition negatively affects the closure of the teat canal, thereby increasing the risk of new intramammary infections. The objective of this study was to evaluate the association of subclinical hypocalcemia (HYPO; < 8.0 mg/dL serum Ca) and teat canal diameter after milking in postpartum dairy cows. Twenty-five dairy cows from 2 commercial dairy farms were enrolled in this study. Immediately after the morning milking (T1), and 30 min later (T2), ultrasonography (US) of each teat was performed using a 7.5-MHz linear transducer. Blood samples were collected via coccygeal venipuncture at T2 to assess circulating Ca concentration. US images were analyzed with an image-processing program to determine the diameter in millimeters (mm) of the teat canal at the mid-point between the teat end and Furstenberg’s rosette at T1 and T2. The measurements were read blindly 3 times by 3 different individuals. The data were analyzed using ANOVA by the MIXED procedure of SAS. The proportion of cows with HYPO in this study was 20% (5/25). For all cows, the teat canal diameter at T1 tended to be larger compared with T2 (T1 = 3.42 ± 0.12 mm; T2 = 3.19 ± 0.11 mm; P = 0.09). There was no difference in teat canal diameter at T1 between normocalcemic (NORMO; ≥8.0 mg/dL serum Ca) and HYPO cows (HYPO = 3.27 ± 0.12 mm; NORMO = 3.58 ± 0.20 mm; P = 0.17). However, HYPO cows had larger teat canal diameter at T2 compared with NORMO cows (HYPO = 3.54 ± 0.19 mm; NORMO = 2.84 ± 0.20 mm; P = 0.002). The preliminary results from this study suggest that subclinical hypocalcemia may affect the proper closure of the teat canal after milking, an important udder defense mechanism against mastitis pathogens, highlighting the importance of effective prevention of this metabolic disease in dairy operations.
Key Words: dairy cattle, hypocalcemia, teat canal diameter
