---

Control POSILAC P-value

---

NUMBER OF COWS 234 253 Pretreatment period

 Total number of cases

35 55

 % Cows with mastitis

11.1 14.6 0.275

Cases/100 cow-days

0.25 0.36 0.275 Treatment period

 Total number of cases

64 147

 % Cows with mastitis

17.5 29.6 0.001

 Cases/100 cow-days

0.12 0.23 0.002 Distribution over lactation,%

 Pretreatment period

35.4 27.2

 treatment period

64.6 72.8 0.148

---

Figure 1. Differences in mastitis cases per 305 days of lactation as affected by season, parity, herd, lactation and POSILAC

References

1. Bauman, D.E., B.W. McBride, J.L. Burton, and K. Sejrsen. 1994. Somatotropin (bST): International Dairy Federation technical report. Bull. Intl. Dairy Fed. No. 293.

2. FOI. 1993. FDA Freedom of Information Summary. POSILAC(r) (sterile sometribove zinc suspension) for increasing milk production in lactating dairy cows. New Animal Drug Application 140-872. Sponsored by The Agricultural Group of Monsanto Company.

3. National Mastitis Council. Current Concepts of Bovine Mastitis. 1987. 3rd Edition.

4. Technical Manual for POSILAC bovine somatotropin. Revised May 1994. Monsanto Company. pp. 6.1-6.7

5. White et al. 1994. Clinical mastitis in cows treated with sometribove (recombinant bovine somatotropin) and its relationship to milk yield. J. Dairy Sci. 77:2249.