Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10980516 | Journal of Dairy Science | 2013 | 7 Pages |
Abstract
The effect of an intramammary infection (IMI) at calving on the milk yield of heifers during their first 200 d in milk (DIM) was estimated by comparing monozygotic twins, where one member had a naturally occurring IMI detected at the first milking after calving and the other twin did not. Data collected weekly over a full lactation for 29 twin pairs were used to estimate the effects of a peri-calving Streptococcus uberis IMI on milk yield and composition. Data for 19 twin pairs were used to estimate the effects of pericalving coagulase-negative staphylococci (CNS) IMI. A heifer with a Strep. uberis IMI produced 200Â kg (7%) less milk during the first 200 d of lactation compared with her uninfected twin, with significant differences evident throughout the 200-d period. Similar milk losses were recorded for heifers that developed CM or remained subclinical. An elevated milk SCC for infected heifers was only apparent for the first month (d 2-30), although SCC tended to remain high during the second (d 31-60) and third (d 61-90) months. Milk protein concentrations were greater in the Strep. uberis-infected twin over the 200-d period, whereas fat and lactose concentrations showed little change. An IMI caused by Strep. uberis was associated with a lower milk yield, whereas an IMI by CNS was not, despite CNS-infected twins having a higher SCC than their uninfected twin for the first 30 d of lactation.
Related Topics
Life Sciences
Agricultural and Biological Sciences
Animal Science and Zoology
Authors
L.J. Pearson, J.H. Williamson, S.-A. Turner, S.J. Lacy-Hulbert, J.E. Hillerton,