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ObjectiveTo investigate the protective efficacy of a pool of denatured membrane protein antigens of Mycoplasma hyopneumoniae(J strain) in the molecular size range 70 to 85 kDa (F3 antigen) in combination with adjuvants for pigs challenged with M hyopneumoniae.

The effects of fuzzy whole cottonseed (WCS) on the performance and health of sheep were examined. Thirty 2-year-old Merino wethers were divided into 3 equal groups and offered maintenance rations for 138 days, with whole wheat grain to WCS ratios of 100:O (diet A), 75:25 (B) and 50:50 (C). Liveweight changes for diets A, B and C were -0.3, +4.4 and +3.0 kg respectively, and were significantly (P<0.05) greater on WCS diets. Wool growth rates were also significantly (P< 0.01) improved by the addition of WCS, with treatment means being 0.65 (diet A), 0.82 (B) and 0.88 mg/cm2.day (C). Digestibility of DM in diet C (677 g/kg) was significantly (P< 0.001) lower than in diets A (782) and B (777 g/kg), perhaps because of increased fibre and oil in the ration. Subclinical anaemia and muscle damage were evident in animals given WCS by days 43 and 127 respectively. Post mortems and histological examination revealed renal haemosiderosis in sheep given WCS, with increased severity at 50% inclusion in the ration. Despite the reduction in digestibility and the subclinical effects on health, at least 25% WCS can be safely included in a wheat-based maintenance ration for wethers and this ration has production advantages over wheat alone. Caution is advised in feeding higher levels of WCS or feeding such a ration for more than 5 months.

An experiment was performed to determine the proportion of roughage required by pregnant and lactating ewes fed wheat-based diets under drought conditions. Five dietary treatments ranging from wheat alone to lucerne hay alone were fed to pregnant and lactating Merino ewes, at levels estimated to give a similar net energy intake per ewe per day. The energy levels fed were altered during the experiment in an attempt to maintain ewe liveweight at a constant level. Wheat alone was unsuitable for lactating ewes, while a diet of 54% hay and 46% wheat (54:46) gave the best milk yields, lamb growth and lamb survival. The mean milk yields of the ewes ranged from 26.5 (SD) 2.5 ml hour-1 for wheat alone to 38.1 2.2 ml hour-1 for the 54:46 diet. Lamb liveweight gains between birth and weaning (at seven weeks) were related to ewe milk yields, with lambs on the wheat alone diet gaining 3.17 kg and those on the 54:46 diet gaining 5.10 kg. Only half of the lambs born to ewes fed wheat alone survived to weaning, compared with 89% of lambs on the 54:46 diet. Analysis of the responses indicated that, for milk yield, the 54:46 diet was near optimum and that lamb growth and survival would be maximized at 60-67% hay.

Lines of medium-wool Peppin Merino sheep selected for resistance (R) or susceptibility (S) to fleece rot and body strike were compared serologically following 4 weekly intradermal inoculations of live I, the predominant bacterial species associated with fleece rot. There was essentially no evidence of fleece rot or body strike in these animals prior to experimentation. In Exp. 1, the 1989-born ewe progeny of the R and S lines were studied (nR = 52; nS = 49). Over 12 weeks, average serum antibody responses against P. aeruginosa were greater in R sheep but the differences were generally non-significant at P = 0.05. The apparent differences in antibody response between R and S lines were largely attributable to the effects of some individual sires in the R line. In a second experiment, the 1990-born ewe progeny of the R and S lines (nR = 75; nS = 76), and the ewe progeny of a line unselected on fleece rot and body strike resistance (F line; nF = 53), were studied. Following inoculation with live I, the mean serum antibody responses of the R and S sheep, which were not different before inoculation, were significantly higher for R sheep for the first 8 weeks of a 10-week observation period. The mean responses of the F line generally fell between the R and S responses. One week after the first inoculation, sire effects in the R line were much greater than for the S and F lines, but thereafter sire effects were similar among lines. Taken together, these results suggest that direct selection for the R or S genotype produced lines of sheep with divergent serological responsiveness following intradermal inoculation with P. aeruginosa; however, in one generation the effects of some individual sires appeared to be largely responsible for these differences.

The relations of the laboratory measurement of cell wall organic matter (CWOM) components and of the in vitro degradability characteristics of CWOM with in vivo digestibility and voluntary intake for high quality white clover were investigated. The voluntary intake, apparent digestibility and apparent rumen retention time of CWOM of white clover harvested at various stages of maturity were measured in rumen-cannulated Merino wether sheep. The in vitro degradability characteristics of CWOM of these diets were also measured. This study has quantified strong predictive relations between structural fibre constituents or degradation parameters and both digestibility and intake for white clover. The CWOM, cellulose and hemicellulose contents and potential degradability of CWOM of the white clover predicted in vivo organic matter digestibility with good precision (r2 = 0.74, 0.67, 0.72 and 0.72 respectively). The voluntary intakes of organic matter and digestible organic matter of the white clover were strongly related to CWOM, cellulose and hemicellulose contents and to the rate of degradation of CWOM in the rumen and the fits of these relations were at least as good as those predicting organic matter digestibility. The predictive equations based on CWOM: OMD (g/kg) = 97.6-0.081 ( 0.012) CWOM OMI (g/kg) = 83-0.085 ( 0.018) CWOM DOMI (g/kg) = 71.4-0.098 ( 0.015) CWOM are recommended because of the ease of analysis of CWOM in the laboratory.

ObjectiveTo report the occurrence of Myxobolus episquamalisin sea mullet, Mugil cephalus L, caught in estuaries in eastern and western Australia.

At the start of a 53 h pre-slaughter fast, 144 steers were subjected to either 0 (controls), 3 or 12 h of road transport to examine the precision of predicting hot carcase weight from liveweight and the effect of transport on liveweight loss and hot carcase weight. The mean rate of liveweight loss declined progressively with fasting, from 2.57 kg/h during the first 5.3 h to 0.71 kg/h during the final 23.6 h. The precision of predicting hot carcase weight from liveweight showed little improvement beyond 5.3 h of fasting. Transport tended to reduce the rate of liveweight loss during the first 24 h of fasting. Hot carcase weight decreased linearly (P < 0.01) with increasing transport length, after an adjustment was made to the same zero-hour liveweight and pre-trial liveweight gain. As a means of improving the precision of predicting hot carcase weight from liveweight, these results question the need for the current practice of fasting cattle overnight before weighing for sale.

Lambs born to ewes fed whole wheat grain were raised and fattened on whole wheat supplemented with varying levels of sodium chloride or elemental sulphur. Liveweights, wheat intakes, feed conversions and carcase weights were measured. Lamb birth weights increased with increasing quantities of energy, and of sodium chloride at high sulphur levels, offered to the ewe during late pregnancy. A weaning weight response to sodium chloride supplementation at high sulphur levels (P < 0.10) was substantially reduced when weaning weight was adjusted for ewe milk production. Lambs were successfully weaned at seven weeks of age to a diet of whole wheat grain. Their subsequent slaughter weights and carcase weights increased with sodium chloride supplementation up to levels of about 1.2 to 1.4 per cent. Little change occurred in the sodium chloride response when slaughter weight was adjusted for weaning weight. The importance of these results in relation to the mineral requirements of lambs fed whole wheat grain is discussed.

This experiment was designed to explore the influence of energy, sodium chloride and elemental sulphur on the productivity of pregnant and lactating ewes fed whole wheat grain diets. A central composite design was used to study the response over five levels of each factor. During the last 42 days of pregnancy, the energy treatments resulted in either maintenance of maternal body weights at about 42 kg, or losses of up to 5.5 kg. Ewe maintenance requirements were about 0.14 MJ ME kg-1 day -1 and their foetal requirement was 1 .I 5 MJ ME kg-1 day-1. Sodium chloride and elemental sulphur supplements had no influence on ewe liveweight change up to lambing, but wool growth increased with sulphur supplements of up to about 0.25 to 0.30 per cent. Energy intake and sodium chloride supplementation increased lamb birth weight. After lambing, ewes that had been offered low energy diets increased their liveweight gain and wheat intake with sulphur supplements whereas these supplements reduced the liveweight gain and wheat intake of ewes offered higher energy. Milk production measured on day 14 of lactation averaged 11 53 g day -1 and was not significantly influenced by treatment. These results are discussed in relation to the metabolism of pregnant and lactating ewes, and in the context of the composite design used.

The effects of increasing rates of lime and ammonium sulphate on French beans were studied on an acid red basaltic soil (pH 4.5-4.8), rich in manganese, on the north coast of New South Wales. Addition of lime resulted in an increased plant yield, a higher soil pH, and a marked reduction in available soil manganese and plant manganese. Applications of 2 or more tons lime per acre corrected manganese toxicity. Ammonium sulphate applications acidified the soil, increased manganese levels in both soil and plant tissue, and increased the frequency of manganese toxicity symptoms at less than 2 tons lime per acre. At pH 4.7-4.8, exchangeable and water-soluble manganese levels were sensitive to slight changes in reaction. Changes in pH between 5.2 and 6.0 caused only slight alterations in manganese levels in soil and plants. Two tons lime per acre reduced the level of manganese in the soil to about half that in the untreated soil, whereas 3 tons lime was necessary to halve the level of manganese in plants. Close linear relationships were found between rates of lime application and pH, between exchangeable and water-soluble manganese, and between both water-soluble and exchangeable soil manganese and plant manganese. Hyperbolic relationships were found between lime and manganese in soil and plants and also between pH and manganese fractions. Toxic levels of manganese in soil and leaves varied seasonally and yearly, and symptoms usually appeared when the manganese content of the first mature leaves was greater than 600 p.p.m. in the winter crop. Symptoms were more closely related to high levels of plant manganese than to soil manganese. The results of this trial indicate that soil and plant analyses are useful for predicting manganese toxicity in acid soils.