Effects of reseeding with perennial ryegrass, chicory or tyfon in pure stands or mixtures on lamb performance postweaning.

Many producers reseed old pasture (OP) with the objective of improving lamb performance. Old pasture was reseeded with perennial ryegrass plus white clover (RGC), RGC plus chicory (CG), RGC plus tyfon (TG), chicory (C), or tyfon (T) to generate five treatments. In addition, a contiguous block of OP was included in the study for comparative purposes. Lambs (n = 286) were assigned to one of the five treatments plus the section of OP from just after weaning until slaughter. Grazing commenced 45 days after the desiccation of OP for reseeding. All lambs were managed by rotational grazing and drafted for slaughter at a specified target BW. No concentrate supplement was offered during the study. For the RGC, CG, TG, C and T treatments and the OP section, the average herbage NDF concentrations were 524, 473, 402, 352, 256 and 565 (SE 15.4) g/kg DM; total grazing days were 5 213, 4 005, 4 466, 2 262, 3 496 and 3 677 (SE 629.3); BW gain to slaughter was 211, 175, 205, 211, 199 and 203 (SE 9.5) g/day; days to slaughter were 91, 100, 84, 86, 78 and 88 (SE 4.8). Compared to RGC, the C, T, CG and TG treatments had lower herbage NDF concentrations (P < 0.05), and there was no difference (P > 0.05) for BW gain or days to slaughter. Chicory yielded significantly fewer (P < 0.05) grazing days, but tended to give a higher (P < 0.06) carcass weight than RGC. It is concluded that neither reseeding OP with RGC, including either C or T with RGC as a multispecies sward, nor growing pure stands of C or T increased (P < 0.05) lamb BW gain from weaning to slaughter or reduced days to slaughter.

Cobalt supplementation, alone or in combination with vitamin B and selenium: Effects on lamb performance and mineral status.

The effects of supplementing lambs with Co, either alone or in combination with vitamin B and Se, were evaluated over the period from weaning to selection for slaughter. Two hundred and five recently weaned (at 14 wk [SD 0.44] of age), spring-born lambs of various crossbred genotypes were stratified, within genotype, by BW and gender and allocated to 3 groups, which were then allocated at random to one of the following treatments: no supplement (Control), a supplement containing Co only (Co-only), or a supplement containing Co, vitamin B, and Se (VitMin). The concentration of Co in the Co-only supplement was 2.1 mg/mL (as cobalt sulfate); the VitMin supplement contained Co (10 mg/mL, as cobalt acetate), vitamin B (200 µg/mL), and Se (0.25 mg/mL, as sodium selenite). Lambs on the Co-only and VitMin treatments received, every 14 d, 10 and 2.1 mL, respectively, of oral drench. Lambs were managed in a rotational-grazing system from 12 July (swards predominantly ) and selected for slaughter, on the basis of BW, after 45, 73, or 115 d; all remaining lambs were slaughtered on d 157. Supplementation, with Co-only or VitMin, increased BW at slaughter ( < 0.01), ADG ( < 0.001), carcass weight ( < 0.001), dressing percentage ( < 0.001), carcass fat score ( < 0.05), and the proportion selected for slaughter by d 73 ( < 0.05) and 115 ( < 0.01). Relative to the Control, the benefit to ADG from supplementation increased as the season advanced. Therefore, supplementation did not alter ( = 0.82) ADG between d 1 and 45 but increased ADG over the intervals d 45 to 73 ( < 0.01), d 73 to 115 ( < 0.001), and d 115 to 157 ( < 0.001). There was no difference ( > 0.05) between the Co-only and the VitMin treatments for ADG, carcass weight, fat score, or dressing percentage. Supplementation with Co increased liver Co concentration ( < 0.001), and lambs supplemented with VitMin had greater liver Co concentration than lambs supplemented with Co-only ( < 0.05); the concentrations were 0.18, 0.85, and 1.18 µmol/L for the Control, Co-only, and VitMin treatments, respectively. Treatment had no effect ( = 0.65) on the concentration of Se in kidney tissue. It is concluded that supplementation with Co increased lamb performance after weaning, that response to supplementation increased as the grazing season progressed, and that no extra benefit in performance resulted from augmenting supplementary Co with B and Se.

Effects of shearing, forage type and feed value, concentrate feed level, and protein concentration on the performance of housed finishing lambs.

The effects of high and medium feed value grass silage or maize silage (MS), each offered with a range of concentrate feed levels, and ad libitum concentrate on the performance of finishing lambs, which were either shorn or unshorn, were evaluated. Three silages were used: 1 medium feed value (MFV) and 1 high feed value (HFV) grass silage (DM digestibility [DMD] of 71.3% and 74.5%, respectively) and 1 MS (DM and starch concentrations of 30.9% and 35.3% DM, respectively). The 3 silages were offered ad libitum with daily allowances of 0.4, 0.8, or 1.2 kg concentrate per lamb. Two additional treatments were: 1) MS supplemented with 0.4 kg of a low CP (LP) concentrate and 2) concentrate offered ad libitum with 0.5 kg/d of HFV grass silage. These 11 dietary treatments were offered to 264 crossbred Suffolk lambs (initial BW = 39.0 kg), half of which were unshorn and half of which were shorn, for a 54-d finishing period, resulting in 22 treatments. Shearing increased forage DMI (P < 0.001) but did not alter (P > 0.05) carcass weight, carcass gain, or ADG, and there was no interaction with dietary treatment. Reducing CP concentration of the concentrate offered with MS did not alter (P > 0.05) feed intake or lamb performance. Increasing concentrate feed level increased feed DMI and lamb performance (P < 0.001). The linear response in ADG to increased concentrate supplementation was greater (P = 0.012) for MFV than HFV grass silage, and a corresponding difference in carcass gain approached significance (P = 0.075). The linear response was greater for grass silage than for MS for ADG (P < 0.01) and carcass gain (P = 0.019). The response in lamb performance from increased concentrate supplementation was linear for HFV grass silage and MS but quadratic (P < 0.05) for the MFV grass silage, reflecting the large response for this silage when concentrate supplement was increased from 0.4 to 0.8 kg. Relative to the MFV grass silage supplemented with 0.8 kg concentrate, the potential concentrate-sparing effects of the HFV grass silage and MS were 0.16 and 0.32 kg concentrate per lamb daily, respectively. It is concluded that shearing lambs that are housed during finishing reduces the efficiency of the conversion of ME to carcass gain. Maize silage can replace HFV grass silage in the diet of finishing lambs. The total dietary protein concentration for finishing lambs can be reduced to 9% DM without adversely affecting carcass gain.

Effects of silage from maize crops differing in maturity at harvest, grass silage feed value and concentrate feed level on performance of finishing lambs.

The effects of (i) medium and high feed value (MFV and HFV) maize silages and (ii) MFV and HFV grass silages, each in combination with a range of concentrate feed levels, on the performance of finishing lambs were evaluated using 280 Suffolk-X lambs (initial live weight 36.1 kg). The MFV and HFV maize silages represented crops with dry matter (DM) concentrations of 185 and 250 g/kg, respectively, at harvest, and had starch and metabolisable energy (ME) concentrations of 33 and 277 g/kg DM and 9.6 and 11.0 MJ/kg, respectively. HFV and MFV grass silages had DM and ME concentrations of 216 and 294 g/kg and 11.0 and 11.5 MJ/kg DM, respectively. A total of 13 treatments were involved. The four silages were offered ad libitum with daily concentrate supplements of 0.2, 0.5 or 0.8 kg per lamb. A final treatment consisted of concentrate offered ad libitum with 0.5 kg of the HFV grass silage daily. Increasing the feed value of grass silage increased (P < 0.001) forage intake, daily carcass and live weight gains, final live weight and carcass weight. Increasing maize silage feed value tended to increase (P = 0.07) daily carcass gain. Increasing concentrate feed level increased total food and ME intakes, and live weight and carcass gains. There was a significant interaction between silage feed value and the response to concentrate feed level. Relative to the HFV grass silage, the positive linear response to increasing concentrate feed level was greater with lambs offered the MFV grass silage for daily live weight gain (P < 0.001), daily carcass gain (P < 0.01) and final carcass weight (P < 0.01). Relative to the HFV maize silage, there was a greater response to increasing concentrate feed level from lambs offered the MFV maize silage in terms of daily carcass gain (P < 0.05) and daily live weight gain (P = 0.06). Forage type had no significant effect on the response to increased concentrate feed level. Relative to the MFV grass silage supplemented with 0.2 kg concentrate, the potential concentrate-sparing effect of the HFV grass silage, and the MFV and HFV maize silages was 0.41, 0.09 and 0.25 kg daily per lamb, respectively. It is concluded that increasing forage feed value increased forage intake and animal performance, and maize silage can replace MFV grass silage in the diet of finishing lambs as performance was equal to or better (depending on maturity of maize at harvest) than that for MFV grass silage.

Characterization of aluminium-based water treatment residual for potential phosphorus removal in engineered wetlands.

Aluminium-based water treatment residual (Al-WTR) is the most widely generated residual from water treatment facilities worldwide. It is regarded as a by-product of no reuse potential and landfilled. This study assessed Al-WTR as potential phosphate-removing substrate in engineered wetlands. Results indicate specific surface area ranged from 28.0 m(2) g(-1) to 41.4 m(2) g(-1). X-ray Diffraction, Fourier transform infrared and energy-dispersive X-ray spectroscopes all indicate Al-WTR is mainly composed of amorphous aluminium which influences its phosphorus (P) adsorption capacity. The pH and electrical conductivity ranged from 5.9 to 6.0 and 0.104 dS m(-1) to 0.140 dS m(-1) respectively, showing that it should support plant growth. Batch tests showed adsorption maxima of 31.9 mg P g(-1) and significant P removal was achieved in column tests. Overall, results showed that Al-WTR can be used for P removal in engineered wetlands and it carries the benefits of reuse of a by-product that promotes sustainability.

Mushroom poisoning. Case reports and a review of therapy.

Four incidents of mushroom poisoning, representing four of the seven established groups of toxic mushrooms, are presented. These case reports illustrate the range of gastrointestinal and neurological symptoms caused by mushroom poisoning and reflect a nationwide increase in reports of serious poisonings in recent years. Severity of poisonings often parallels the time span between consumption and onset of symptoms, with serious poisonings having longer incubation periods. New therapies for amatoxin poisoning may reduce mortality caused by these poisonings.