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Nurses play an important role in the RT of skin and its diseases. This is the third of four articles that attempts to provide a scientific basis for nurses to better understand skin RT patients, skin and its diseases, and acute RT skin reactions and how to care for them to achieve the best outcomes from RT treatments. The first paper outlined the role of the nurse as an integral part of the radiation oncology team and how to conduct an effective patient assessment to ensure the patient’s optimal journey to treatment completion. The second article described the anatomy, physiology, pathology and radiobiology of skin and its diseases. This third article describes the skin RT prescription and plan, especially in relation to volume and dose. The fourth paper will show how the nurse, by applying the knowledge from the previous articles, can predict, explain and care for any side effects that may arise. This knowledge is important for establishing patient expectations, preparing the patient for side effects, and giving scientifically based reasons for complying with care protocols. Hopefully, these articles will help support the nurse to deliver best care to skin RT patients. More prospective research is needed to elucidate the many remaining facets of nursing care for skin RT patients.

Effects of monensin inclusion and cattle subspecies on utilization of bermudagrass hay (13.7% CP, 77.3% NDF, and 38.8% ADF) were evaluated using ruminally cannulated steers (5 Bos taurus indicus [BI] and 5 Bos taurus taurus [BT]; 398 kg BW). Subspecies were concurrently subjected to a 2-period, 2-treatment crossover design. Treatments were 0 (CON) or 200 mg·steer**-1·d**-1 monensin (MON) in 0.91 kg dried distillers’ grains with solubles. Periods were 70 d in length: 20 d of adaptation, 22 d of sample collection, and 28 d for withdrawal of treatment. Steers were group housed during adaptation and moved to individual covered pens for sampling. Hay, ort, and fecal grab samples were collected d 21 through 25 for determination of intake and digestion. Ruminal fluid was collected with a suction strainer 0, 2, 4, 8, and 12 h after feeding on d 42 for pH, VFA, and ruminal NH3–N (RAN) analysis. Additionally, at h 2, ruminal fluid and contents were collected for determination of rate of NH3 production and CH4 production rate. No subspecies × monensin interactions were observed (P greater than or equal to 0.12). Monensin had no effect (P greater than or equal to 0.16) on intake or digestibility parameters. No subspecies effect (P greater than or equal to 0.11) was observed for forage OM intake, total OM intake, or OM digestion. Total digestible OM intake tended to be greater (P = 0.06) for BT steers than for BI steers (14.0 vs. 12.2 g/kg BW). There was an effect of hour after feeding (P less than or equal to 0.01) on pH, total VFA, acetate:propionate ratio, and molar percent acetate and propionate. Total VFA concentration was greater (P = 0.01) in CON steers than in MON steers (66.5 vs. 62.0 mM). Monensin decreased molar percent acetate (P = 0.02) from 72.5 to 71.2% and increased molar percent propionate (P < 0.01) from 16.9 to 18.7%, resulting in a reduced (P < 0.01) acetate:propionate ratio (from 4.34 to 3.85). Although not significantly (P = 0.19), monensin numerically reduced the CH4 production rate by 15.8%. Greater (P = 0.07) CH4 production rate tended to be observed in BI steers than in BT steers (21.4 vs. 16.6 µmol CH4·mL**-1·h**-1, respectively). Monensin had no effect (P greater than or equal to 0.32) on pH, RAN, or rate of NH3 production. A subspecies × hour after feeding interaction was observed for RAN, with BT having greater RAN at h 0 and 4, whereas BI had greater RAN at h 2, 8, and 12. Overall, monensin decreased the acetate:propionate ratio and total VFA concentration but had no effect on forage utilization. Bos taurus indicus steers consumed less digestible OM and had a greater CH4 production rate compared with BT steers, suggesting BT were better able to utilize the available forage resource than BI.

Ruminal fermentation is an inherently inefficient process converting up to 12% of dietary carbon and energy into end products (e.g. CH4) that are largely unusable by the animal. Ruminant nutritionists seek to modify fermentation, specifically by increasing ruminal propionic acid yield, reducing methanogenesis and decreasing ruminal proteolysis and deamination of dietary proteins in order to improve production efficiency. To date, a variety of methods have been investigated in an effort to meet these objectives. Carboxylic polyether compounds, 'ionophores', are an effective means of decreasing enteric CH4 emissions when included in ruminant diets. Although ruminant nutritionists have historically focused on feeding ionophores to increase efficiency and profitability, recent attention has focused on the ability of ionophores to impact global greenhouse gas production. This chapter examines the use of ionophores in cattle diets for the mitigation of enteric CH4 production. Issues like ionophore resistance and the impact of ionophore feeding on human health are also addressed.