TY - JOUR
AU - Tao, S.
AB - Abstract Mammary biopsy (MB) collection is a necessary and valuable approach for studies in mammary gland biology, but it is not known if repeated MB impair performance of the lactating cow. Our objective was to examine the effect of multiple MB during lactation on udder health, DMI, and milk yield of dairy cattle. Sixty-four multiparous, mid-lactation Holstein cows were enrolled in a trial and 32 cows were randomly selected for repeated MB. The MB and non-MB cows had similar parity (2.6 ± 0.9, P = 0.13) and DIM (96.5 ± 56.3 d, P = 0.13) at enrollment. All animals were housed in the same barn and fed the same diet. Cows were milked three times a day and milk yield was recorded at each milking. Milk composition was measured weekly and DMI was recorded daily. Three MB were performed per cow: at enrollment and at 3 and 5 mo post-enrollment. The first and third MB were taken from the left rear quarter whereas the second MB was from the right rear quarter. The experimental procedures were approved by the Institutional Animal Care and Use Committee of the University of Georgia. Before MB, cows were mildly sedated through i.v. injection of xylazine HCL (20 µg/kg of BW). Briefly, the MB was performed using a rotating stainless steel cannula with a retractable blade at the cutting edge connected with a cordless drill. After sanitation with iodine and ethanol, an incision was made through the skin and connective tissue in the middle of the quarter and a core of mammary tissue (0.75 to 1 g) was extracted. The incision was closed using stainless wound clips and sprayed with an antiseptic dressing to avoid infection. After MB, udder health, wound healing of incisions, and appearance of blood in milk were visually examined at each milking. All bloody milk was discarded and blood was cleared from milk 3.86 ± 2.0 d after MB. During the experiment, four MB quarters and 14 non-MB quarters were diagnosed and treated for clinical mastitis. Compared with non-MB cows, MB cows had similar (P > 0.1) DMI, milk yield and percentage of fat, lactose, protein, solids-not-fat, and somatic cell score. In conclusion, mid- to late-lactation cows recover rapidly from MB and repeated MB have no impact on DMI, milk yield and composition, and udder health of lactating dairy cows. PDF This content is only available as a PDF. American Society of Animal Science © American Society of Animal Science 2016
TI - 0842 Repeated mammary tissue collections during lactation have no impact on cow performance
JF - Journal of Animal Science
DO - 10.2527/jam2016-0842
DA - 2016-10-01
UR - https://www.deepdyve.com/lp/oxford-university-press/0842-repeated-mammary-tissue-collections-during-lactation-have-no-1ASVaUsvgo
SP - 405
EP - 405
VL - 94
IS - suppl_5
DP - DeepDyve
ER -