The effects of delays between restraint and sampling on some blood parameters in sheep

Twenty three non pregnant, non lactating aged Merino and Border Leicester ewes were subject to four jugular venipunctures one hour apart (times 0, 1, 2 and 3). Four different delay intervals of 12.5, 64.0, 128.0 and 252.9 seconds between catching and sampling (delays 1, 2, 3 and 4) were used on each sheep in a random manner. Estimates were made of packed cell volumes (PCVs), plasma and erythrocyte sodium and potassium concentrations. The mean PCV at time 0 of 35.4 per cent was significantly higher than the levels of 33.1, 31.8 and 32.2 per cent at times 1, 2 and 3 respectively. There was no significant difference between the means at times 1, 2 and 3. The mean plasma potassium concentrations at time 0 of 4.37 mmol/l was significantly higher than the levels of 4.16 and 4.14 mmol/l at times 1 and 3 respectively. Delays had no significant effects on the means of any of the parameters studied. The findings strongly suggest that sheep become excited by initial handling but not by subsequent venipunctures and that a delay between catching and sampling of between 12.5 and 252.9 second has no effect on the blood constituents studied.     

Presumptive 1/29 autosomal translocation in Australian cattle.

A cytogenetical study was made of 9 descendants of a Charolais bull, heterozygous for a presumptive 1/29 translocation, three of the dams of some of these descendants, and three unrelated bulls which were mated to some of the descendants. Photographic karyotypes of Giemsa stained and C-banded chromosomes were prepared for each animal. The dams of the progeny showed no chromosomal abnormalities indicating that translocations were inherited from the sire. Three daughters of the Charolais bull and two of his grand daughters were heterozygous for the translocation, with a modal chromosomal number of 59, while the remaining three daughters and their progeny possessed normal karyotypes. No phenotypic abnormalities were observed in the animals examined. Measurements of the arms of the chromosomes suggested that the translocation chromosome (a large submetacentric) contained chromosomes 1 and 29. The submetacentric translocation chromosome had a single C-band, the two submetacentric X chromosomes showed no C-bands and each acrocentric autosome had a single C-band. All cattle heterozygous for the translocation showed normal fertility.     

Limitations of salivary and blood cortisol determinations in pigs

Blood and saliva samples were taken from groups of pigs maintained in intensive conditions. Multiple samples were taken from two unrestrained pregnant sows fitted with jugular cannulae. Single samples were taken from groups (mixed gilts and entire males; 70–90 kg) which were lightly exercised (7) or restrained (12). The rate of salivary secretion was low and collection of adequate samples took 5 min; in a number of pigs no saliva could be obtained.In order to stimulate salivary secretion, pigs (70–80 kg) were injected with pilocarpine nitrate (25 mg, subcutaneous) which produced a copious flow of saliva persisting for at least 15 min.Resting sows had higher mean levels of cortisol in plasma, ultrafiltrate and saliva than the other groups, which did not differ from each other. Within the pilocarpine group, males had a higher ultrafiltrate level of cortisol than females. In most instances salivary cortisol was significantly greater than ultrafiltrate cortisol.Ultrafiltrate and plasma cortisol were highly correlated (r=0.883) but this correlation was low in the presence of pilocarpine (r=0.260). Salivary cortisol was poorly correlated with either plasma (r=0.167) or ultrafiltrate cortisol (r=0.278) and the correlation with plasma was even lower following the administration of pilocarpine (r=0.086).It was concluded that salivary estimates of cortisol in the pig were not usefully correlated with levels of ultrafiltrate (free) cortisol.     

Objective measures of welfare in farming environments

Welfare in farm animals is both difficult to define and measure. Definitions of welfare and the indicators of welfare which can be scientifically measured are discussed. These indicators are health, productivity, physiological and biochemical changes, and behavioural patterns; they can often be correlated from a husbandry system to give a good indication of the welfare status of the animals in the system. Most of the research work in this area has been done in the intensive pig and poultry industries, although the correlation of biochemical measures with husbandry procedures used in sheep and cattle has begun. It is difficult at this stage to develop a simple stress test that would take all the variables into account, but a change of any of the indicators will suggest further investigation is required. The most obvious to monitor is behaviour, as even a slight change can indicate a change in welfare status.     

The molecular identification and genetic diversity of economically important wireworm species (Coleoptera: Elateridae) in Canada

Click beetle larvae (wireworms) are significant crop pests in Europe and North America. In Canada, there are ~30 economically important species which are morphologically difficult to identify, but for which sequence data are lacking. Accurate knowledge of damage-causing species and the population genetics and phylogeography of elaterids will provide insight into their sustainable management. Here, we use interspecific variation in mitochondrial 16S rRNA as a robust method of identification, consider the intra- and interspecific genetic variation of some important Canadian wireworm pests and assess the genetic structure and isolation by distance for a re-emerging major pest species, Hypnoidus bicolor Eschscholtz. Wireworms were sampled from Canada and the USA, identified as morphospecies, and sequenced at the 16S rRNA region (294–442 bp). Within some species unusually high intraspecific genetic distances between samples suggested the possibility of cryptic wireworm species or misidentifications, though this was <1 % for most species. Phylogenetic analyses gave some indication of the likely identity of these ambiguous samples. There was a significant correlation between genetic and geographic distance and significant genetic structuring within and between H. bicolor populations, which appeared to be composed of two species comprising several haplotypes. These data provide a starting point for determining the distribution of damage-causing species throughout Canada. The inclusion of data from other nuclear and mitochondrial loci, and use of sequence data from known adult samples, would further aid identification and relationships of wireworm species.