The effects of yeast feed supplementation on turkey performance and pathogen colonization in a transport stress/Escherichia coli challenge.

A commercial yeast culture feed supplement (YC; Celmanax SCP, Vi-COR, Mason City, IA) was provided to turkeys throughout a 16-wk grow-out to determine if it would prevent the effects of stress on production and pathogen colonization. The YC was provided either continuously at 100 g/t (YC-CS) or intermittently during times of stress at 200 g/t (YC-IS). Birds were stressed with an environmental challenge of Escherichia coli and by transporting them in a vehicle for 3 h after which they were penned in new social groups, without feed or water, for an additional 9 h. Turkeys were transported and challenged at 6, 12, and 16 wk of age to model the movement of birds within a 3-stage housing system. The YC-IS was provided only for the first week after hatch and for a 1-wk period encompassing each challenge. At wk 7 and 9, a decrease in BW of challenged birds was prevented by YC-IS but not YC-CS. There were no significant differences in BW due to either challenge or YC during wk 11 and 13. At wk 16, the challenge decreased BW, but there was no improvement in either of the YC treatments. Overall feed conversion ratio (FCR) was increased by transport/E. coli (P < 0.0001). The YC-CS improved FCR of challenged birds by 21 points, whereas YC-IS improved FCR by 36 points and this effect was significant (P = 0.013). The YC-CS tended to decrease both Salmonella and Campylobacter isolation from the ceca of stressed birds (P > 0.05). The YC-IS also tended to decrease Salmonella isolation (P > 0.05) with no effect on Campylobacter isolation. These data suggest that the practice of transporting turkeys decreases performance and that YC-IS may be more effective than YC-CS for alleviating the effects of this stressor on feed efficiency.

Effects of supplementation with yeast culture and enzymatically hydrolyzed yeast on performance of early lactation dairy cattle.

One hundred fifty multiparous cows were balanced to 1 of 3 treatments (2 pens/trt) according to previous lactation 305-d mature equivalent yield to evaluate supplementation with yeast culture (YC; A-Max, Vi-COR, Mason, IA) and YC plus enzymatically hydrolyzed yeast (YC+EHY; Celmanax, Vi-COR) on production performance in dairy cattle. Cows entered pens at calving and remained through 14 wk postpartum. Treatment assignment to pens was random throughout the barn. Pens were identical in layout and each contained an exit alley to eliminate feed and animal mixing. The 3 treatments were control: nonsupplemented; YC: control diet with YC (56 g/d); and YC+EHY: control diet plus YC and EHY (28 g/d). Mean pen dry matter intake was similar across treatments. Cows supplemented with YC and YC+EHY produced more milk, fat-corrected milk, and energy-corrected milk than control cows (1.4 and 1.6, 1.6 and 1.8, 1.7 and 1.9 kg, respectively). Treatments YC and YC+EHY did not differ. Milk fat and lactose percentages were not affected by treatment. Milk protein percentage was higher for cows supplemented with YC+EHY than for those on YC and control treatments (2.98, 2.93, and 2.91%, respectively) with control and YC-supplemented cows not being different from each other. Differences in fat and protein yields were primarily reflective of milk yield. Treatment had no effect on milk urea nitrogen. No differences in the incidence of metabolic health were observed; however, cases of clinical mastitis for YC+EHY were less than half those for control and YC during wk 8 to 14 on trial. Somatic cell count was higher for cows fed control and YC diets compared with YC+EHY, primarily during wk 8 to 14 on trial. Supplementation of early lactation cows with YC improved milk production performance; furthermore, EHY supplementation improved milk protein percentage and mammary gland health.

The economic benefit for family/general medicine practices employing physician assistants.

OBJECTIVE: To measure the economic benefit of a family/general medicine physician assistant (PA) practice. STUDY DESIGN: Qualitative description of a model PA practice in a family/general medicine practice office setting, and comparison of the financial productivity of a PA practice with that of a non-PA (physician-only) practice. METHODS: The study site was a family/general medicine practice office in southwestern Pennsylvania. The description of PA practice was obtained through direct observation and semistructured interviews during site visits in 1998. Comparison of site practice characteristics with published national statistics was performed to confirm the site's usefulness as a model practice. Data used for PA productivity analyses were obtained from site visits, interviews, office billing records, office appointment logs, and national organizations. RESULTS: The PA in the model practice had a same-task substitution ratio of 0.86 compared with the supervising physician. The PA was economically beneficial for the practice, with a compensation-to-production ratio of 0.36. Compared with a practice employing a full-time physician, the annual financial differential of a practice employing a full-time PA was $52,592. Sensitivity analyses illustrated the economic benefit of a PA practice in a variety of theoretical family/general medicine practice office settings. CONCLUSIONS: Family/general medicine PAs are of significant economic benefit to practices that employ them.