Aggressive behavior of sows at parturition

Sows, especially primiparous, may show aggressive behavior at parturition against their own piglets, resulting in wounding or death of the piglets. Frequency, environmental influences and heritability of aggressive behavior were studied in two data sets. The first (923 first litters) was collected at an experimental farm and the other (925 first litters) came from a pig breeding organization. Frequency of aggressiveness ranged, depending on its definition, from 7 to 12%. Fixed effects of year, season and feeding level of the gilt during the rearing period did not affect the frequency of aggressiveness. A regression of aggression on postpartum sow weight was found, suggesting that low weight at first farrowing might predispose sows to aggressive behavior. Coefficients for backfat and litter size were positive but nonsignificant. Heritability of aggressiveness on the underlying normal scale, estimated from the paternal half-sib component of variance, averaged .12 for the first data set, and .25 for data set II. Estimates from daughter-dam regression were .49 and .87 for the two data sets, respectively. A simulation study indicated that this difference might be due to maternal effects. A simple application would be to select boars and gilts from non-aggressive sows only. Response to selection would be rather slow if the frequency of aggressive behavior is low. At frequencies that are too high from an economic point of view, estimation of breeding values, combining own performance and(or) data from relatives, is required.     

Nervous tissue lesions caused by elaphostrongylosis in wild Swedish moose

During the first 5 months of 1985, 35 moose were obtained for necropsy at the National Veterinary Institute, Uppsala, Sweden. 17 (49 %) of these cases were found to be infected with Elaphostrongylus sp. The nematodes were found in the epidural space of the spinal cord and brain, around and in the sciatic nerves and in muscle fasciae. Predilection sites appeared to be near cauda equina and the fasciae of the thoracic, gracilis and sartorius muscles.Most of the infected animals were calves. Both sexes were equally represented. Pathological changes found were characterized by focal haemorrhages and oedema. The changes were present in the muscle fasciae and in the leptomeninges of the brain and spinal cord. Beside infiltrates of mainly lymphocytes and plasma cells, adult nematodes, larvae and eggs were observed.Cases with mild gliosis in the cerebrum and degenerative changes of peripheral nerve roots affecting the epi- and perineurium were also found. In one case the inflammatory changes reached the endoneurium of a sciatic nerve bundle and in another case into a ganglion.Inflammatory reactions against the parasite were mainly directed towards eggs. In loose connective tissue close to nerve tissue in the central nervous system larvae were found close to eggs and remains of eggs indicating that eggs may hatch at this site.This investigation shows that natural infections with Elaphostrongylus sp. occur in wild moose and may produce pathological changes in large peripheral nerves and in the central nervous system.     

Sweden beyond oil: nuclear commitments and solar options

The project "Energy and Society," sponsored by the Swedish Secretariat for Futures Studies, has studied different indigenous energy sources as alternatives to imported oil in Sweden. One alternative is nuclear energy, antoer is renewable energy. Large uncertainties are associated with both alternatives today. The main characteristics of an energy policy for the rest of the century that does not foreclose either of these options have been identified. Such a policy will have to be based on an understanding of similarities and differences between the alternatives. A nuclear and a solar energy system have been outlined as a basis for an analysis of technical, economic, and institutional issues.     

Effects on performance and carcass composition of turning beef cattle out to pasture early in the spring

Abstract The effects of turning beef cattle out to pasture earlier in the spring than is conventional in Northern Ireland on performance until slaughter in late summer were examined. Thirty‐eight steers, which were initially 525 kg live weight (LW), were divided into blocks of two according to breed type, previous plane of nutrition and LW and were allocated to two treatments at random within each block. Steers on Treatment 1 were turned out to pasture on 14 March and grazed a permanent perennial ryegrass‐based pasture with a mean sward surface height of 8·4 (s.e. ± 0·36) cm until Treatment 2 steers were turned out on 2 May. Thereafter, all steers grazed as a single group until slaughter at the same estimated carcass fat content, which occurred between June and September. Between the two turnout dates, steers on Treatment 2 were given grass silage ad libitum. For the early and late turnout treatments, respectively, LW gains between the two turnout dates were 1·5 and 0·7 kg d^?1, carcass gains from 14 March until slaughter (mean 143 d) were 0·69 and 0·53 (s.e. ± 0·022) kg d^?1, and carcass weights were 370 and 347 (s.e. ± 2·7) kg. It is concluded that, under the conditions of this experiment, turning beef cattle out to pasture in early spring may offer economic benefits in beef production in situations in which this is practicable.     

Transgenic sugar beet tolerant to glyphosate

Phenology (i.e. the influence of environment on ontogeny) is the most important single factor influencing crop adaptation. The timing of flowering is particularly important since it largely determines when annual cereal, pulse and oilseed crops will subsequently be ripe for harvest. Two environmental factors are of overriding importance in the induction of flowering – photoperiod (daylength) and temperature. In seeking to predict times from sowing to flowering, f, it has proved profitable to analyse photothermal responses in terms of the rate of progress from sowing to flowering, 1/f. This paper summarises the advantages of a model based on rates rather than the traditional approach based on f. Over a wide range of photothermal regimes, the model involves just six coefficients, all of which (and their derivatives) have clearly defined biological meaning. Of paramount importance too is that the coefficients are not affected by the environment; they are genetic characters which determine phenotypic responses to the environment in a quantitative and predictable way.     

Quantitative genotyping to estimate genetic contributions to pooled samples and genetic merit of the contributing entities

Abstract

Genotyping required to track family membership in aquaculture breeding programs is reduced dramatically by estimating the contributions of different families to pooled samples of tissue. This approach is relevant to widely differing scenarios involving animals, plants, and microbes. For the family membership scenario, SNP markers are genotyped for the contributing families' parents, and quantitatively genotyped to estimate allele frequencies within the mixed-family pooled tissue. Results are used to infer proportional contributions of the different families to the pool. Different computational strategies were tested for bias and sampling error. A correlation of 99% between estimated and true genetic contributions was achieved using 20 (50) randomly chosen SNPs at a standard error of allele frequency estimates of 0.01 (0.02). Optimal grouping of families and choice of markers further increases performance markedly. Trait means and distributions of families can be quite accurately estimated by tissue sampling across the range of trait values.     

The influence of grass and maize silage quality on apparent diet digestibility, metabolizable energy concentration and intake of finishing beef cattle

The effects of offering a range of grass silages and mixtures of grass and maize silages on the intake of beef cattle were studied. Four grass silages (GS1, GS2, GS3 and GS4) were used. Grass silage 1 was ensiled from a second regrowth in mid‐late September and treated with an inoculant additive. Grass silages 2, 3 and 4 were ensiled, without additive, from a primary regrowth harvested in early July, late May and mid‐June respectively. Wilting periods were 8, 30, 36 and 36 h for GS1, GS2, GS3 and GS4 respectively. Grass silages 1, 2 and 3 were precision chopped and ensiled in bunker silos, while GS4 was ensiled in round bales. The DM content (g kg^?1) and starch concentration (g kg^?1 DM) of the three maize silages (MS1, MS2 and MS3) used were 256 and 128, 256 and 184, and 402 and 328 for MS1, MS2 and MS3 respectively. Seventy‐two Charolais and Limousin cross‐bred steers were used in a changeover design with two 4‐week periods. The study consisted of sixteen treatments incorporating the four grass silages fed alone and with the three maize silages arranged as a 4 × 4 factorial design. The grass silage and maize silage mixtures were offered in a ratio of 0·60:0·40 (DM basis) once daily using individual Calan gates. All silages were offered ad libitum with 3 kg per head per day of a concentrate supplement. Dry matter and metabolizable energy (ME) intakes were highest with diets based on grass silage GS4 compared with diets containing the other grass silages. Metabolizable energy intakes of diets containing no maize silage, and those based on MS1 and MS2, were similar (P > 0·05) but lower than that of diets containing MS3. Only limited increases were found in DM and ME intakes with the inclusion of maize silage in grass silage‐based diets while offering high‐quality grass silage (assessed in terms of DM content, and fibre and N concentrations) promoted high voluntary intakes.     

A monitoring study to assess the acute mortality effects of indoxacarb on honey bees (Apis mellifera L.) in flowering apple orchards

To evaluate the effect of the indoxacarb 300 g kg(-1) WG, Steward 30WDG, on the honey bee (Apis mellifera L.) in apple orchards, a monitoring study was conducted in Dutch apple orchards in April/May 2004. Before apple flowering began, two honey bee colonies were placed in each orchard to investigate honey bee mortality. Each hive was provided with a Münster dead bee trap to collect dead honey bees. The numbers of dead bees found in these Münster dead traps were counted every 3-4 days for about 2 weeks before and after the period of the insecticide treatment. In nine flowering orchards no indoxacarb was applied during the flowering period, which served as control sites. In 30 flowering orchards indoxacarb was sprayed by the fruit growers according to local practice at 170-260 g formulated product ha(-1) (51-78 g AI ha(-1)). In the control orchards the average mortality was 8 honey bees colony(-1) day(-1). The average daily honey bee mortality before and after indoxacarb application was 8 and 10 honey bees colony(-1) day(-1) respectively. At one test site, indoxacarb was mixed with other plant protection products plus plant nutrients, and in this orchard a slight but biologically non-significant increase in acute honey bee mortality was recorded. It was concluded that the application of indoxacarb caused no effects on honey bee mortality, and that the number of dead honey bees counted in the Münster traps in the orchard treated with indoxacarb was comparable with those determined in control orchards.