Step 1: Understanding the Concept:
Mastitis is the inflammation of the mammary gland, primarily caused by bacterial pathogens.
Environmental mastitis is caused by pathogens (such as *Escherichia coli*, *Klebsiella* spp., and *Streptococcus uberis*) that reside in the cow's environment (bedding, soil, manure) rather than spreading directly from cow to cow during milking.
Control relies on comprehensive, system-wide herd management.
Step 2: Detailed Explanation:
Let us evaluate the importance of each listed strategy for controlling environmental mastitis:
- (A) Dry cow management and therapy: The dry period is a high-risk time for environmental mastitis pathogens to invade the mammary gland, particularly during the early dry period and just prior to calving.
Proper dry cow therapy (using long-acting intramammary antibiotics and internal teat sealants) combined with clean, dry housing is essential to prevent new infections.
- (B) Monitoring udder health status: Regular testing using the California Mastitis Test (CMT), Somatic Cell Count (SCC) monitoring, and clinical examination helps identify subclinical mastitis and track the incidence of environmental infections in the herd.
- (C) Periodic review of the udder health management program: Environmental challenges change with the seasons, bedding materials, and hygiene practices.
An annual or bi-annual review of milking protocols, housing hygiene, and vaccine strategies ensures the control program remains effective.
- (D) Good record keeping: Keeping accurate records of clinical mastitis cases, treatment efficacy, SCC history, and culture results is critical to identify trends, evaluate the success of interventions, and make informed culling decisions.
Since all four strategies are essential components of an effective mastitis control program, (A), (B), (C), and (D) are all correct.
Step 3: Final Answer:
The correct option is (D).