Comparison of Bovine Mammary Involution and Intramammary Infections Following Intramammary Treatment with Casein Hydrolysate and Other Conventional Treatments at Dry-Off.

Justine E Britten,Kerry A Rood,David J Wilson

doi:10.3390/ani11082360

Abstract

Alternatives to routine antibiotic treatment of dairy cattle during the dry period before their next calving are of interest. This was a preliminary study of whether intramammary infusion of casein hydrolysate, administered alone or combined with standard dry treatment, accelerated the rate of mammary involution early in the dry period. Four treatments were studied in a split udder design. One udder half was assigned a treatment, and the contralateral half was administered dry cow treatment + internal teat sealant as a control. Treatments were casein hydrolysate, casein hydrolysate + dry cow treatment, casein hydrolysate + teat sealant and casein hydrolysate + dry cow treatment + teat sealant. Cows (n = 16) were blocked by a number of intramammary infections per udder half (0 or 1+) and randomized to treatments. Milk production was not different between control or treated udder halves post-calving. A generalized linear mixed model tested for differences between the treatment groups in the concentration of mammary involution indicators in milk: somatic cell count, bovine lactoferrin and bovine serum albumin. At 7 days, dry udder halves treated with casein hydrolysate had higher milk concentrations of lactoferrin than those treated with casein hydrolysate + dry cow treatment, casein hydrolysate + teat sealant and control. At 10 days dry, bovine serum albumin was higher in udder halves treated with casein hydrolysate than in those treated with casein hydrolysate + dry cow treatment, casein hydrolysate + dry cow treatment + teat sealant and control. Post-calving, casein hydrolysate-treated udder halves produced 51% of total milk, unchanged from before dry-off. There were seven total intramammary infections entering the dry period, all caused by coagulase-negative staphylococci. Cure rates (3/7, 43%) were not different among all treatments and control, partly because of the small sample size. Intramammary infusion of casein hydrolysate at the end of lactation may be an alternative or possible adjunct to antibiotic dry cow therapy.

Highlights

The importance of the dry period in dairy cows has long been established within the dairy industry [1,2]
At 10 days dry, bovine serum albumin was higher in udder halves treated with casein hydrolysate than in those treated with casein hydrolysate + dry cow treatment, casein hydrolysate + dry cow treatment + teat sealant and control
The results from this study demonstrate an association between the use of casein hydrolysate and a faster increase in the milk concentration of some markers of mammary involution in comparison with standard industry dry treatment during the early dry period

Summary

Introduction

The importance of the dry period in dairy cows has long been established within the dairy industry [1,2]. Cows may carry existing intramammary infections (IMI) into the dry period that remain present into the lactation and are at an increased risk for acquiring new IMI immediately following cessation of milking [3,4]. Persistent and new IMI following calving have been associated with increased SCC and decreased milk production in the subsequent lactation [5]. The standard practice for mitigating IMI risk at dry-off is the blanket use of intramammary dry cow antibiotic therapy (DCT) [6,7]. Previous studies have demonstrated that blanket use of DCT (BDCT) has been effective in eliminating many existing IMI present at dry-off and preventing new IMI in the early dry period [8,9]. The routine use of DCT has been shown to effectively lower bulk tank milk SCC [10] and nearly eradicate certain pathogens in some countries [11]

Methods

Results

Discussion

Conclusion