Dual-Energy X-Ray Absorptiometry and Force-Plate Analysis of Gait in Dogs With Healed Femora After Leg-Lengthening Plate Fixation

Dual-energy x-ray absorptiometry was used to measure bone mineral density of four regions in healed femora of nine dogs after fracture fixation with a leg-lengthening plate. Six to 85 months (mean, 46 months) after surgery, the bone mineral density of healed femora was not significantly different from the contralateral uninjured femora ( P >.05; power = 0.8 at Δ= 15%). Radio-lucencies around the proximal screws, apparently associated with screw loosening, were seen on radiographic views of the healed femora of three dogs. In one of these dogs, one screw in the proximal metaphysis had broken. Force-plate analysis of gait was also performed on dogs at the time of bone mineral density measurement. Peak vertical force was decreased in the pelvic limb with the healed fracture compared with the contralateral unoperated limb ( P < 0.05). Clinically apparent lameness in three dogs did not appear to be associated with altered bone mineral density and may have been caused by hip osteoarthritis, a nondisplaced hairline diaphyseal fracture, and screw loosening in conjunction with extensive post-traumatic soft tissue injury.     

The duration of lot-feeding of sheep before sea transport

Adult wethers (n = 750) were lot-fed for 13 days, 8 days or 3 days before a simulated voyage lasting 18 days to examine whether the period of lot-feeding affected the proportion of sheep that ate pelleted feed and their body weight change during simulated shipping. There was no significant difference in the proportion of non-feeders between treatment groups on days 7 and 14 of the voyage. Body weights were not significantly different between the treatment groups on days 14 and 18 of the voyage. Overall body weight loss, from the farm to the end of simulated shipping, was 4.08 kg (+/- 0.28, s.e.m.), 4.58 kg (+/- 0.28) and 4.51 kg (+/- 0.28) in sheep lot-fed for 13 days, 8 days and 3 days, respectively, and was not significantly different between treatments. It was concluded that lot-feeding for 13 days conferred no advantage in body weight or numbers of non-feeders compared with shorter periods in this study.     

A novel approach to Striga and Orobanche control using synthetic germination stimulants

A series of synthetic germination stimulants for the plant parasites Striga and Orobanche has been prepared. These compounds, analogues of the natural Striga germination stimulant, strigol (I), (Cook et al., 1966, 1972) cause signiticant germination of Striga hermonthica (Del.) Benth. seed at concentrations as low as 10^?9 M, and an even greater activity against species of Orobanche has been demonstrated. Initial outdoor box trials of the compounds against Striga asiatica (L.) O. Ktze. in Hyderabad, India, have shown a reduction of up to 65% of the seed after a single treatment of the soil 6 weeks before the planting of the sorghum host.     

Genetic analysis of resistance to Puccinia striiformis in the wheat differential cultivars Heines VII, Heines Peko and Strubes Dickkopf

One major gene for resistance to isolate WYR 85-22 of race 6E0 of Puccinia striiformis was identified by genetic analysis of the differential cultivars Heines Peko, Strubes Dickkopf and Heines VII. This gene was different from Yr2 Yr6 already identified in Heines Peko ( Yr2 Yr6 ) and Heines VII ( Yr2 ), was allelic in the three cultivars and also to a gene expressed in the other differentials Reichersberg 42 ( Yr7 ) and Clement ( Yr9 ). In Heines Peko, Strubes Dickkopf and Heines VII, a minor gene was also postulated, which, it is proposed, gave only a low level of resistance by itself but strengthened the expression of the major gene when the latter was homozygous or heterozygous. The genetics of the resistance was analysed using six resistance classes and applying multidimensional analyses. The number of resistance genes was hypothesized using data from F3 families from crosses between the three differentials and the cultivar Heines Kolben, which is susceptible to this race.     

Aeromonas hydrophila B-haemolysin: purification and examination of its role in virulence in 0-group channel catfish, Ictalurus punctatus (Rafinesque)

Abstract. A single step procedure for purification of B-haemolysin from Aeromonas hydrophila is described which recovered 94% of the haemolytic activity with a sixfold increase in specific activity. Toxicity of haemolysin in 0-group channel catfish was 0–6 mg of purified protein per gram offish. Of six strains of A. hydrophila evaluated for differential toxin production and virulence in 0-group channel catfish, three B-haemolysin-deficient strains were virulent while three B-haemolysin-producing strains were avirulent.     

Use of differently enriched rotifers,Brachionus plicatilis,during larviculture of haddock,Melanogrammus aeglefinus: effects on early growth,survival and body lipid composition

We evaluated the effects of enriched rotifers on growth, survival and on the lipid composition of haddock larvae. The treatments tested were (1) AlgaMac 2000^®, (2) AquaGrow^® Advantage and (3) Pavlova sp. paste and AlgaMac 2000^®. The treatments did not influence larval growth rate throughout the experimental period (P = 0.70). Larvae from all treatments grew approximately 8% of their dry weight per day between 1 and 29 days post hatch (dph). Treatment 3 resulted in the best survival, estimated to be 3 on a scale from 0 to 5, whereas for the two other groups the survival estimates were 0 and 2. Rotifers from treatment 1 had low sterol concentrations, high eicosapentaenoic acid/arachidonic acid ratio and their feeding resulted in high larval mortality. Rotifers enriched with Pavlova sp. had the lowest proportions of the sum of saturated fatty acids, docosahexaenoic acid and sum of ω3 and the highest proportions of the sum of monounsaturated fatty acids (ΣMUFA). This was partially reflected in larvae from treatment 3 in that they had the highest proportions of ΣMUFA and the lowest proportions of Σω3 (P < 0.0001 for both analyses). In addition, these larvae had the highest and lowest ΣC₂₀ and ΣC₂₂ polyunsaturated fatty acids (PUFA) respectively (P < 0.0001 for both analyses). We suggest that more research with ω3 and ω6 PUFA can lead to improvements in the rearing of haddock larvae produced in hatcheries.     

Inhibition of germination of sporangia of Peronospora hyoscyami by cation deprivation: the effects of substrate and chelating agents

Germination of sporangia of Peronospora hyoscyami de Bary (tobacco blue mould) was affected by the germination substrate. Washed sporangia germinated freely in water on glass slides, but failed to germinate on agarose. Germination was reduced on detached tobacco leaves, being lower on cv. Hicks Q46 than on cv. ZZ100. Inhibition of germination by agarose was reversed by the addition to the inoculum of an extract obtained by centrifuging a suspension of non-living, powdered torula yeast Candida utilis (Hennenberg) Lodder & van Rij. Yeast extract also improved germination in vivo. The siderophore rhodotorulic acid, the chelating agents ferric and sodium citrate, and riboflavin combined with calcium and magnesium salts, also stimulated germination of sporangia on agarose. The chelating agent ethylenediaminetetraacetic acid (EDTA) inhibited germination on glass slides. Inhibition by EDTA was partially reversed by the addition of ferric salts. The inhibition of germination by agarose and stimulation by additives may have been due to effects on the availability of cations to sporangia of P. hyoscyami. The reduction in germination on tobacco leaves may have involved a similar mechanism.