The influence of the level of dry-matter intake and the dry-matter concentration in the diet on the water consumption of dairy cows in early lactation was investigated for a 2-month period from early August to early October. The importance of the various components of weather on voluntary water intake was also examined. The cows used in the experiment either grazed pasture alone, or were offered pasture and pasture hay supplements. Mean voluntary water intake increased by 2-30 kg per cow per day for every additional kg dry matter consumed and also increased by 0-053 kg per cow per day for each g/kg increase in dry matter concentration. Of the climatic factors, rainfall had the greatest single influence on the daily fluctuations in voluntary water intake and this was negative. Intake was also negatively related to minimum temperature, relative humidity and wind, and positively related to sunshine and evaporation. Although maximum temperature per se had no apparent influence on intake, it showed a positive relationship after the removal of the effects of rainfall. A model for the prediction of total water consumption is: Total water consumption (kg per cow per day) = 11-34 + 4-63 dry-matter intake (kg per cow per day) -0-036 dry-matter concentration (g/kg) + 0-84 mean temperature (°C). This can only be used to predict the water requirements of lactating dairy cows in different environments.

The effects of stocking rate and nitrogen (N) fertilizer on the productivity of irrigated perennial pasture grazed by dairy cows was studied for 2 years at Kyabram, Victoria. There were ten treatments: five stocking rates ranging from 4.4 to 8.6 cows ha-l at both 0 and 224 kg N ha-1 year-1 . Although weeds did not invade the pasture, increases in stocking rate resulted in reduced daily pasture growth, and this was related to the level of residual pasture after grazing. Annual pasture production in both years declined by 0.394 t DM ha-1 for every additional cow per ha. The levels of the herbage minerals, N, P, K, Ca, Mg and Na were adequate from an animal health point of view at all stocking rates, at least in the short term. The response to N fertilizer declined from 17 to 3 kg DM kg-1 N applied, as stocking rate increased from 4.4 to 8.6 cows ha-1, and it appeared that this response was due mainly to an increase in the growth of the grasses. Apart from the stocking rate responses, which are specific to the Kyabram environment, a number of relations were found, which showed how residual pasture after grazing, pasture allocation and pasture utilization at a single grazing, influenced pasture intake. Providing allowances are made for pasture type and the level to which any particular pasture type can be grazed, these relations could be expected to give a reasonable assessment of pasture intake in other environments.

The relation between the stocking rate of dairy cows and their production from irrigated perennial pasture, with and without nitrogen (N) fertilizer, was studied over 2 years at Kyabram, Victoria. Pastures were rotationally grazed at stocking rates ranging from 4.4 to 8.6 cows ha-1. In each year, N treatments were topdressed four times at a rate of 56 kg N ha-1. For every additional cow per ha, production per ha decreased by 260 and 329 kg of milk, 12.3 and 15.5 kg of butterfat, and 10.7 and 14.5 kg of protein for years 1 and 2, respectively. In year one, the highest production of milk and butterfat (17,900 and 847 kg ha-1, respectively) was from cows stocked at 8.6 cows ha-1, and for protein (597 kg ha-1) from 7.6 cows ha-1. In year 2, production per ha of all milk products maximized and then declined. Maximum production of milk and butterfat (14,180 and 675 kg ha-1, respectively) was at 6.6 cows ha-1, and protein (508 kg ha-1) at 5.9 cows ha-1. Increasing stocking rate also reduced the liveweight of cows at all times. Topdressing with N fertilizer had no effect on total milk or butterfat production per cow, but consistently increased protein production. The range in response increased from 2 to 7 kg protein per cow at 4.4 and 8.6 cows ha-1, respectively. Application of N fertilizer increased liveweight per cow, with greater increases occurring at high stocking rates. In year 2, the efficiency of butterfat production over the whole year was 29.9, 29.3 and 37.0 kg of DM (pasture and supplements) per kg of butterfat produced for 4.4, 6.6 and 8.6 cows ha-1, respectively.

During summer in the Goulburn Valley, two herds of Jersey- Friesian crossbred cows were used to study the effects of restricted access to drinking water. There were three treatments applied to two herds-(1) free access, (2) 20 min. access before each milking, and (3) 20 min. access before the night milking only. One herd was individually penned and had free access to shade while the other was grazed with no access to shade. Both herds were fed irrigated perennial pasture containing 24.5% dry matter. Maximum air temperature averaged 33.7�C. Over the whole experiment, restricting the access of dairy cows to drinking water did not significantly reduce mean milk yield (mean 12.6 kg/cow day-1) or mean liveweight of cows (mean 41 1 kg) in either herd. However, during the first 4 days of treatment, mean milk yield and mean liveweight were lower (P < 0.05) for cows on a once-a-day access than for those on either free or twice-daily access. In the pen experiment, intake of drinking water averaged 67,45 and 49 l/cow day-1 for treatments 1, 2 and 3, respectively; dry matter intake was unaffected by treatment (mean 15.6 kg/cow day-1). Because of the modifying influence of shade on the environment of the penned cows, there was no significant effects of climate on their water intake. It was concluded that farmers need not supply drinking water to dairy cows in all paddocks.

We have attempted to reproduce differences in low resolution nuclear magnetic resonance (NMR) T2 spin-spin relaxation times between homeopathically potentised and unpotentised Nitric acid (nit-ac) solutions previously reported by Conte, et al. Using similar instrumentation and experimental protocols, we have shown that it is likely that Conte's original results are attributable to experimental artifact originating in the glassware used for the manufacture of the NMR tubes.