Assessment and application of new technologies that advance mastitis control, milk quality, and dairy food safety. <p> 1. Development of a non-invasive method for detection of mastitis in prepartum heifers. the goal is to optimize the use of ultrasound to detection infection in a quarter that will facilitate a more targeted approach to intramammary antibiotic treatment and reduce the use of antibiotics in food-producing animals. <p> The expected outputs from this project include both research and outreach products. It is expected that the etiology of mastitis in prepartum heifers will be further elucidated and that the use of ultrasound for detection of mastitis will result in a reduction of mastitis and antibiotic use for the treatment of mastitis. This will be submitted for publication in a peer-reviewed journal. <p> The outreach component will provide dairy producers with an additional tool to detect mastitis and result in a reduction in mastitis and enhancement of dairy farm sustainability.
1. Ultrasound detection of mastitis Intramammary antibiotic treatment of heifers before parturition has been reported to reduce the prevalence of mastitis pathogens in milk in early lactation in several studies. However, in a large multi-university study, the efficacy of the prepartum,intramammary antibiotic therapy differed by location. Although not reported in any of the studies, there is a potential for heifers to develop an intramammary infection when the teat end is opened before parturition or due to improper treatment procedures and the risk for IMM infection increases if all quarters are treated. In addition, the risk for antibiotic residues occurring in milk postpartum is increased with this treatment practice. Avoidance of antibiotic residues in milk is an important focus of the dairy industry. Judicious use of antibiotics, followed by an appropriate milk withholding time and screening for residues are essential aspects of milk quality management for assuring human food safety. It would be prudent to be able to identify specific quarters from heifers that may be infected prior to calving without disrupting the teat end seal of all four quarters. This would allow for targeting antibiotic treatment only in infected quarters, thereby reducing antibiotic use and reducing the risk of antibiotic residues and intramammary infections caused by improper treatment procedures. Ultrasound technology has been an established non-invasive technology in reproductive management, carcass evaluation and for a health assessment in bovines. There has been one paper published using ultrasound to identify infected mammary quarters in dairy cattle and another that identified edema in mammary quarters. The use of ultrasound to identify mastitis would be a novel approach to reducing mastitis in heifers prior to calving.
1. Ultrasound detection of mastitis Intramammary quarters from twenty to thirty heifers will be evaluated by ultrasound at two weeks prior to anticipated calving and aseptic milk samples will be collected to determine infection status. Any quarter determined to be infected with a mastitis pathogen and identified to be infected by ultrasound scanning will be treated with a commercially available lactation cow therapy, as previously described in a study conducted at the University of Connecticut. Briefly, heifers identified with an IMM infection by ultrasound and pathogen analysis will be assigned alternately by identification to one of two treatments at 14 days prior to anticipated calving date. Immediately preceding treatment, quarter samples of mammary secretion will be collected using aseptic techniques for analysis of mastitis pathogens from all heifers. Odd-numbered heifers served as controls and not treated with an antibiotic. Even numbered heifers were infused in each mammary quarter with a commercial lactating cow antibiotic preparation. Following antibiotic infusion for treated heifers and sample collection for control heifers, teats from all animals will be immersed in a barrier teat disinfectant. Following parturition, mammary quarters will be scanned by ultrasound each week for 4 weeks postpartum. Somatic cell counts will be determined in all quarters and intramammary pathogens will be determined at week 1, 2, 3 and 4 postpartum. Intramammary cure of pathogens will be determined and presence of pathogens over 28 days postpartum and milk production over the first 60 days postpartum will be determined.