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A small-plot experiment was conducted in south-west Ireland to investigate (i) the effects of pre-closing regrowth interval and closing date on dry-matter (DM) yield and sward structural and composition characteristics, during the autumn–winter and spring opening periods, and (ii) subsequent carryover effects. The study used a randomized block design with a factorial arrangement of treatments (4 closing dates × 2 opening dates) with a split plot (two pre-closing regrowth intervals). The long pre-closing (LPC) interval began on 9 August, and the short pre-closing interval (SPC) started on 15 September. The autumn closing dates were as follows: 1 October (CD1), 15 October (CD2), 1 November (CD3) and 14 November (CD4). Plots were defoliated again on 1 February (EOD) or 1 March (LOD). On the LPC treatment, herbage yield increased from CD1 (2463 kg DM ha−1) to CD3 (3185 kg DM ha−1). On the SPC treatment, herbage yield was similar for CD3 and CD4, indicating a ceiling in herbage accumulation. For each 1-d delay in closing date between CD1 and CD4, the opening herbage yield was reduced by 10 kg DM ha−1. Herbage quality decreased as the closing date was delayed; DMD and CP decreased by 0·06 and 12 g kg DM−1, respectively, between CD1 and CD4. The EOD resulted in increased leaf and decreased dead proportions over the LOD treatments. A balance between autumn CD and spring OD needs to be achieved to ensure a sufficient supply of high-quality grass in spring.

The objective of this study was to compare the milk production, dry matter intake, and energy partitioning of autumn-calving Holstein-Friesian cows offered a high or low amount of concentrate using 1 of 2 feeding strategies. One hundred and eight autumn-calving Holstein-Friesian cows were blocked based on milk production data from wk 3 and 4 of lactation, and were divided into low-, medium-, and high-milk yield subgroups. Cows were randomly assigned to 1 of 4 treatments (n=27) in a 2×2 factorial design. Treatment factors were concentrate feeding amount, high concentrate=7.0 (Hi) or low concentrate=4.0kg of DM/cow per day (Lo), and concentrate feeding strategy, flat rate (FR) or group-fed to yield (GFY). In the GFY treatments, cows were allocated concentrate based on their milk yield in the third and fourth weeks of lactation. The lowest-yielding cows (n=9) received 5.3 and 2.3kg of DM of concentrate on the Hi and Lo treatments respectively, the highest-yielding cows (n=9) received 8.7 and 5.7kg of DM of concentrate on the Hi and Lo treatments respectively, and the average yield cows received the same amount of concentrate as the corresponding FR group (i.e., 7.0 and 4.0kg of DM of concentrate on the Hi and Lo treatments, respectively). The proportion of forage in the diet was 63% of total dry matter intake (TDMI) for the Hi treatment and 75% of TDMI for the Lo treatment. No significant interaction was noted between concentrate feeding amount and concentrate feeding strategy for dry matter intake or milk yield. Cows on the Hi treatment had a higher TDMI (18.7±0.36kg/cow per day) compared with cows on the Lo treatment (15.8±0.36kg/cow per day). The milk yield of cows offered the Hi treatment was 1.3kg/cow per day higher than the milk yield of cows on the Lo treatment (23.8±0.31kg/cow per day). Milk solids yield was 0.10kg/cow per day higher on the Hi treatment than on the Lo treatment (1.83±0.03kg of DM/cow per day). Cows on the Hi treatment had an estimated net energy demand of 18.0±0.38 UFL (unite fourragere lait)/cow per day and a net energy intake of 17.6±0.33 UFL/cow per day during the experimental period. Cows on the Lo treatment had an energy demand of 16.8±0.38 UFL/cow per day and an energy intake of 14.9±0.33 UFL/cow per day. No significant difference in TDMI, milk yield, milk solids yield, or energy balance was observed between the FR and GFY treatments. By increasing the total amount of concentrate offered, cows had higher TDMI and energy intake, which resulted in increased milk production and reduced negative energy balance and body condition score loss.

PERMANENT interstitial implants with radon-222 and gold-198 seeds are of special value in cancer therapy because they are easier to carry out, cause less discomfort to the patient, and are safer than removable implants. In removable applications, afterloading technics greatly reduce the radiation hazard (1) or even eliminate it altogether (2), but in permanent implants they are of only limited help. The only solution to the radiation exposure problem in permanent implants appears to be the use of lowenergy gamma emitters. Their value in reducing radiation hazard was first pointed out by Harper and his associates in 1958 (3), who suggested radioisotope solutions, especially cesium 131 and palladium 103, either for injection into applicators or for direct injection into tumors. On the other hand, we believe these low-energy radioisotopes can be made more effective by encapsulating them in the form of seeds similar to the commonly employed radon222 and gold-198 seeds. In our experience with many different te...

The use of soft x-ray-emitting radioisotopes in cancer therapy offers many potential advantages. Sixty-day iodine 125 and 9.7-day cesium 131 are particularly promising because of their “un-contaminated” monoenergetic x-ray emission of approximately 30 keV. Numerous advantages accrue as a result of the ease of shielding the 30 keV x rays, coupled with their useful range in tissue. Soft x-ray “seeds” containing I125 and Cs131 have been fabricated for use in brachytherapy. Dosimetry studies have shown that standard distribution rules normally used for radium or radon implants will apply equally well to implants of these “seeds” with the added advantages of more rapid fall-off beyond the implant. The tissue dose distribution in the first 1.5 cm from such a “seed” was found to be comparable to that from radium, while at distances beyond 5 cm the fall-off was significantly greater due to increased tissue absorption. Experience gained from their use in animal studies has demonstrated their ease of handling and p...