bluuebunny/crossref_metadata_2025 huggingface dataset:
Learner participation patterns and strategy use in Second Life: an exploratory case study
Authors: Peterson Mark
Published: September 2010

This paper reports on an exploratory case study that investigates the synchronous interaction of intermediate level EFL learners in the 3D virtual world Second Life. The subjects took part in three seventy-minute chat sessions that involved the use of affordances provided by a purpose-built world within this environment. Analysis of the data revealed that the context and tasks appeared to elicit a high degree of participation. The interaction was highly learner–centered, with the majority of messages exchanged between students. The analysis further indicated that the subjects overcame initial difficulties to produce coherent target language output focused on the tasks through collaborative interaction involving the use of five transactional and two interactional discourse management strategies. Transactional strategies identified in the data were the use of split turns, time saving devices, addressivity, upper case and quotation marks. Interactional strategies were the use of politeness and keyboard symbols. The majority of these represented transfers from strategies used in non-computer-based forms of communication. The others were adaptive behaviours appropriate to the online medium. The consistent use of these strategies enabled the subjects to manage their interaction in an effective manner. Learner feedback was largely positive, and indicted that participation appeared to engender high levels of motivation and interest. This paper concludes by identifying areas of potential in future research on the use of 3D virtual worlds in CALL.
The use of the webcam for teaching a foreign language in a desktop videoconferencing environment
Authors: Develotte Christine , Guichon Nicolas , Vincent Caroline
Published: September 2010

This paper explores how language teachers learn to teach with a synchronous multimodal setup (Skype), and it focuses on their use of the webcam during the pedagogical interaction. First, we analyze the ways that French graduate students learning to teach online use the multimodal resources available in a desktop videoconferencing (DVC) environment to monitor pedagogical interactions with intermediate level learners of French in a North-American university. Then, we examine communicational and pedagogical aspects of this process which involves orchestrating different modalities and deploying various regulations for “semio-pedagogical” purposes. We define semio-pedagogical skills as the capacity to mediate a pedagogical interaction by combining or dissociating modalities (written, oral, and/or video) that are adapted to objectives and to the cognitive requisites of the task. We posit that these skills have to become part of the professional repertoire of future teachers, as they will increasingly be required to exploit the multimodal potentialities of online communication in their teaching.

The study draws on screen capture recordings of teacher trainee-student interactions and is completed by semi-directive interviews with teacher trainees (n = 5). It aims (1) to identify the importance of webcamming in the share of the pedagogical range available to teachers and (2) analyze the non verbal dimension of pedagogical communication via DVC.

The outcome of this study is the identification of five degrees of utilization of the webcam medium: there a certain gradation in the way webcamming is used (with a more or less significant use of image) when compared to other modalities. The different uses that are identified vary according to the perceived usefulness of webcamming to monitor teaching and to the teacher trainees’ capacity to manage different workspaces.
The effects of concentrate energy source on the milk production of dairy cows given a grass silage-based diet
Authors: Huhtanen P. , Jaakkola S. , Saarisalo E.
Published: September 2010

Sixteen Finnish Ayrshire cows were used in a four period cyclic change-over experiment to evaluate eight concentrate supplements in a 2 × 2 × 2 factorial arrangement. Two concentrate energy sources (starchy and fibrous) were used, each given with two levels (0 and 180 g/kg on a dry-matter (DM) basis) ofrapeseed meal (RSM) and two levels (0 and 180g/kg on DM basis) of wet distillers' solubles (WDS). The starchy concentrate (S) comprised rolled barley and oats (1:1). For the cows given the fibrous concentrate (F), 600 g/kg of the grain mixture was replaced with a mixture of fibrous by-products. Grass silage was offered ad libitum and the supplements offered at a rate of 9 kg/day (fresh weight).

The cows offered F supplements consumed more silage DM than those offered S supplements (P < 0·01) but the difference in the total DM intake was smaller. The cows given S supplements produced slightly more milk than those given F supplement (26·5 v. 25·9 kg/day) but no differences were observed in the yield of milk constituents between the energy supplements. Replacing starch with fibre in the concentrate had no effect on the apparent digestibility of organic matter but tended to increase that of neutral-detergent fibre.

Including RSM in the supplement increased total DM intake (P<0·05) and led to increases in the yield of milk and milk constituents (P < 0·001 and P < 0·01). Diet apparent digestibility was not affected by RSM supplementation.

There were no significant interactions between concentrate energy source and RSM supplementation. Including WDS in the diet had no effect on food intake. Production responses to WDS supplementation varied with the concentrate energy source. WDS increased (at least P< 0·05) milk yield (1·0 kg/day) and the yields of fat (76 g/day) and protein (48 g/day) when given with the starchy concentrate. With the fibrous concentrate WDS had no effect on milk and protein yield, and decreased fat yield by 52 g/day (P < 0·05). The positive responses in the yields of milk fat and protein to RSM and WDS supplementation were almost additive with the starchy concentrate. Inclusion of WDS in the diet increased the apparent digestibility of organic matter and gross energy.
In vitro produced embryos as a means of achieving pregnancy and improving productivity in beef cows
Authors: Sinclair K. D. , Broadbent P. J. , Dolman D. F.
Published: September 2010

The possibilities of using embryo transfer (ET) with in-vitro produced embryos as an alternative to artificial insemination (Al) for achieving pregnancy in commercial cattle, and improving the number and quality of calves produced were assessed using 157 multiparous, beefX. dairy suckling cows (mainly Hereford × Friesian) in three autumn and three spring-calving herds in Scotland. Within each herd, cows were allocated at random to (i) Al; or ET with in-vitro produced embryos, either (ii) singly (ET(s)), or (Hi) in pairs (ET(t)) to establish pregnancy. In-vitro produced embryos were derived from oocytes recovered from the ovaries of heifers with high-quality carcasses post slaughter. Semen from a single Simmental sire was used for in-vitro embryo -production and for Al across all herds. Following oestrous synchronization, Al cows were inseminated at 48 and 72 h after removal of the synchrony device. ET cows that had a palpatable corpus luteum received either one or two in-vitro produced embryos placed non-surgically in the ipsilateral uterine horn on day 7 after oestrous (oestrus = day 0). Pregnancy rate, calving rate and calving difficulty were monitored for all cows. Calf performance was monitored on the farms of origin from birth to purchase and thereafter at one finishing unit until slaughter. Animals were slaughtered at a prescribed level of body fatness and saleable meat yields determined.

Cows that received one in-vitro produced embryo gave birth to fewer calves than cows that were artificially inseminated or received two embryos (P < 0·01). Gestation length was longer for cows that gave birth to single ET calves (288 days; P < 0·01) than cows that gave birth to Al calves (285 days) or twin ET calves (284 days). Single ET calves were heaviest at birth (P < 0·01) and higher levels of assistance at calving were required for ET calves whether born as singles or twins. ET calves of both birth types grew more quickly (<1·00 kg/day; P<0·05) and produced larger carcasses (297 kg; P < 0·01) with higher yields of saleable meat (2207 kg; P < 0·01) than Al calves (0·92 kg/day; 281·7 kg; 206·3 kg respectively).
Effects of a grazing period on performance of finishing bulls: comparison with an indoor finishing system
Authors: Dufrasne I. , Gielen M. , Limbourg P. , van Eenaeme C. , Istasse L.
Published: September 2010

A comparison was made between two different finishing systems with Belgian Blue bulls. Two groups of bulls were grazed during an initial 140-day period and then finished indoors with concentrates. There were two stocking rates during the grazing period: a medium at six bulls per ha (MGFI) and a high at eight bulls per ha (HGFI). A third group of bulls was finished indoors on a concentrate diet during the whole finishing period (FI). The experiment was repeated over 2 years consecutively. The pasture which was grazed at the medium stocking rate was characterized by a higher sward height (P< 0·01), more refusals (P< 0·001), less Lolium perenne (P< 0·05) and more Trifolium repens (P<0·05) than that grazed at eight bulls per ha. The live-weight gain was 1·15 kg/day during the grazing period for the MGFI bulls and 1·00 kg/day when they were taken indoors. The increase in stocking rate reduced the gain at grass (1·00 kg/day,P< 0·001) and improved the gain indoors (1·24v.1·01 kg/day,P< 0·001). In the groups which were initially grazed when compared with the indoor system, the fattening period was longer (236·0 and 241·0v.186·9 days, P<0·01) and the live-weight gain lower (1·11 and 1·10v.1·44 kg/day,P< 0·001 for MGFI, HGFI and Fl respectively). The dressing proportion was greater also (P< 0·05), and there were higher concentrations of muscles (P< 0·05) and bones (P< 0·05) in the carcass of the bulls which were grazed initially. With these bulls, the lean meat was darker (P<0·05) and lost more water although there were no effects on the myoglobin content or on shear force. The net profit was in favour of the groups which were grazed.
The effect of long photoperiod or bromocryptine treatment on prolactin concentration and fertility in ewe lambs mated at induced oestrus
Authors: Beck N. F. G. , Davies M. C. G. , Davies B.
Published: September 2010

An investigation was conducted into the effects of increasing plasma prolactin concentration with long photoperiod or suppressing it with bromocryptine on the fertility of ewe lambs. One hundred and twenty dim Forest ewe lambs were divided into three groups: group C was kept as a control; group L was exposed to a long photoperiod (16 h light: 8 h dark) and group B was given daily injections of 1 mg bromocryptine from 12 days before until 21 days after mating. All three groups were mated in late November, 30 days after housing, following progestagen/PMSG treatment. Post-mating prolactin concentrations were significantly higher in group L and lower in group B compared with group C (P > 0·05). There was a tendency for pregnancy rate and the number of corpora lutea to be represented by viable foetuses to be lower in group L than in group C (P < 0·05). Furthermore, post-mating progesterone concentration was higher in this group compared with those in group C (P > 0·05). In a second experiment, 100 Welsh Χ Texel ewe lambs were given treatment C or L. Embryo survival tended to be lower and crown rump length, embryo weight and amniotic sac width were reduced at 25 days post mating in the animals given treatment L, compared with those given treatment C (P < 0·05). The combined results of the experiments indicated that fewer corpora lutea were represented by viable embryos or foetuses in group L than in group C (P < 0·05). These results suggest that embryo growth and survival is reduced in animals bred under a long photoperiod.
Effects of clover and milk in the diet of grazed lambs on meat quality
Authors: Vipond J. E. , Marie S. , Hunter E. A.
Published: September 2010

The eating quality of lambs slaughtered at weaning or 8 to 9 weeks later off pastures of diploid grass (D), tetraploid grass (T) and tetraploid grass/white clover (TC) was studied. Samples of lean from grilled chops and roasted leg joints were assessed by members of a group of 36 sensory panellists for texture by rating juiciness and tenderness on an eight-point scale. Lamb and abnormal flavour were assessed in lean and fat samples. Lean from lambs slaughtered off the mother at weaning was significantly more tender than from lambs slaughtered 8 to 9 weeks later (5·8v. 5·0, s.e.d. 0·18; P < 0·001). There was a tendency for lambs slaughtered off TC to be more juicy and tender. Lean from chops was significantly more juicy and tender and of superior flavour to lean from leg and overall acceptability was higher for chops. Acceptability of lamb slaughtered at weaning was higher than of lamb slaughtered 8 to 9 weeks later (5·3v. 4·9, s.e.d. 0·14; P < 0·001).

In further studies a trained sensory panel of 12 judges formed a consensus flavour profile for 10 attributes of lean and five attributes of fat. Univariate analysis revealed only small differences between treatments. Multivariate statistical procedures however identified significant treatment effects that appeared favourable to the flavour of lamb slaughtered off the mother although only around a third of the variation was explained.

Analysis of weight loss on cooking showed less wastage when lambs were slaughtered off the mother (0·209 v. 0·225, s.e.d. 0·0043; P < 0·001) and when grazed on grass/clover (TC)v.grass (D, T) (0·206v. 0·222, 0·223; s.e.d. 0·0053;P < 0·01). Weight loss on cooking was negatively correlated with texture and overall acceptability.

The results obtained provide evidence for enhanced eating quality from production systems involving the sale of lambs off the mother. Incorporation of grazing of clover pastures into production systems showed some small benefits.
The effect of melatonin implants administered from December until April, on plasma prolactin, triiodothyronine and thyroxine concentrations and on the timing of the spring moult in cashmere goats
Authors: Dicks P. , Russel A. J. F. , Lincoln G. A.
Published: September 2010

The effect of melatonin implants administered to cashmere goats in the winter, on plasma prolactin, triiodothyronine (T3) and thyroxine (T4) concentrations and the timing of the spring moult, was studied with the objective of identifying a method of manipulating the timing of the spring moult and increasing fibre harvesting efficiency. The effect of similar melatonin implants on prolactin concentration when administered in the increasing daylength of spring, was also measured.

In the first experiment, using 20 juvenile and 20 adult female cashmere goats, half the animals of each group received continuous release implants of melatonin (18 mg) on 11 December, 1 February and 1 April. In the adult goats the treatment significantly advanced by 7 weeks the time at which peak plasma prolactin concentrations were attained (P< 0·001) and advanced the onset (P< 0·001) of the peak. The treatment also resulted in an advance of the spring moult of cashmere in the adult goats (P< 0·01) and in an earlier initiation (P< 0·01) of the growth of both guard hair and cashmere as judged by histological examination of primary and secondary hair follicles. In the juvenile goats there were no significant effects of melatonin administration on plasma prolactin concentrations, the timing of the moult, or on any of the histological measurements compared with the controls. There were no significant effects on live weight or circulating concentrations of T3 and T4 in either age group. In the second experiment, the administration of one melatonin implant (18 mg) to three adult goats on 1 April caused a significant reduction in plasma prolactin concentrations (P< 0·05) over a period of 3 weeks compared with concentrations observed in four untreated goats.

It is concluded that treatment with melatonin implants is effective in modifying the timing of the seasonal cycle in prolactin secretion in adult cashmere goats and causing corresponding changes in hair follicle activity. However, since the treatment initiated in December caused an advance rather than a delay in the normal spring rise in plasma prolactin concentrations, it is evident that the repeated melatonin implant protocol used in this experiment cannot be used to delay the onset of the spring moult and thus facilitate the harvesting of cashmere.
Estimation of genetic parameters for litter size in Danish Landrace and Yorkshire pigs
Authors: Estany J. , Sorensen D.
Published: September 2010

Variance components for litter size (total number of piglets born) were estimated from Danish purebred Landrace and Yorkshire litters by restricting maximum likelihood. The data were collected from the national Danish breeding programme and consisted of 19 666 litters in Danish Landrace and 29 336 litters in Danish Yorkshire. Four different analyses for litter size were conducted within breed. In the first two, genetic groups were included in the model in order to account for the importation of animals from other countries; in the other two, genetic groups were removed from the model. Within each case, herd-year-type of insemination effects were fitted as fixed (H-fixed models), or herd-year-season-type of insemination effects were fitted as random (H-random models). Estimates of heritability ranged from about 0·11 to 0·14 in Landrace and from 0·10 to 0·11 in Yorkshire. Variance due to herd-year-season-type of insemination ranged from 0·029 to 0·041 of total variance, values somewhat lower than those obtained for non-genetic permanent effects. In order to compare the four models, data were divided into different subsets, and records from one subset were predicted using parameters estimated from the other subset. Both the correlation between observed and predicted values, and the mean squared error of prediction indicated that predictive ability was higher in the case of H-random models. There was no evidence that genetic groups improved the predictive ability for litter size. However, group effects affected inferences about genetic trend, particularly in Landrace, where genetic group composition changed consistently over the years.
The effect of the replacement of grass silage by increasing proportions of urea-treated whole-crop wheat on food intake and apparent digestibility and milk production by dairy cows
Authors: Sutton J. D. , Abdalla A. L. , Phipps R. H. , Cammell S. B. , Humphries D. J.
Published: September 2010

Six Holstein-Friesian cows in mid lactation were used to examine the effects of replacing increasing proportions of grass silage (GS) by whole-crop wheat (WCW) in the diet of lactating dairy cows. Grass silage was a first-cut perennial ryegrass. The WCW was harvested at 645 g dry matter (DM) per kg and was preserved with either 20 (WCW-20) or 40 (WCW-40) kg urea per t DM. The diets were 6 kg DM dairy concentrate daily with one of six forage treatments offered ad libitum. The forage treatments were GS alone, GS with either WCW-20 or WCW-40 in a 2:1 DM ratio, GS with either WCW-20 or WCW-40 in a 1:2 DM ratio, or WCW-40 alone. The experiment consisted of an incomplete change-over design with three 4-week periods. DM intakes were highest with the mixtures (P < 0·05) but milk yield was not significantly affected by the treatments although it tended to be highest with the 1:2 ratio. Milk composition responses were generally small and non-significant, but yields of fat and protein were highest with the mixtures (P < 0·05). The apparent digestibility of DM and organic matter (OM) decreased linearly (P · 0·01) with increasing WCW inclusion but digestible DM and OM intakes were not significantly affected. Apparent digestibility of neutral-detergent fibre tended to be lower with the forage mixtures (quadratic P < 0·20). Apparent digestibility of starch was higher with GS than with diets containing WCW and decreased linearly with diets containing increasing proportions of WCW (P < 0·01). Intakes of starch and digestible starch rose with increasing WCW inclusion but so also did faecal starch output such that 0·75 kg starch per day was excreted on WCW-40 alone. Water intake from food and water excretion in urine decreased linearly with increasing WCW inclusion but water excretion in faeces and milk was not significantly affected by diet. The difference between measured water intake and output (water deficit) increased from 38 kg/day on GS alone to 58 kg/day on WCW-40 alone (linear P < 0·001). The only effects of level of urea treatment were to increase milk urea concentration (P < 0·05). It is concluded that the small size of the milk yield response to the increased forage intake obtained when up to two-thirds of the GS is replaced by WCW is due to the reduced digestibility of the OM and particularly of the starch component resulting from the egestion of whole wheat grains in the faeces.
The effect of environment on behavioural activity, ACTH, (β-endorphin and cortisol in pre-farrowing gilts
Authors: Jarvis S. , Lawrence A. B. , McLean K. A. , Deans L. A. , Chirnside J. , Calvert S. K.
Published: September 2010

This study examined the temporal relationships between behavioural activity and hormones associated with stress in gilts farrowing in two environments. Thirty-one Large White × Landrace gilts with indwelling jugular catheters were blood sampled daily (08.00 and 16.00 h) from 10 days before their expected parturition date (EPD). Five days before EPD they were moved to either a farrowing crate (C) with no bedding, or a pen (P) (2·5 m × 3·0 m) with straw provided and were blood sampled daily at 08.00, 12.00 and 16.00 h. Around 12 h before the onset of farrowing an extension was fitted to the catheter and blood samples were taken remotely at 30-min intervals. The posture of the gilts was recorded using 5-min scan samples over the 24 h pre-farrowing. The proportion of scans standing (an index of activity) was strongly affected by time (P < 0·001) with peak levels at approximately 8 h pre-farrowing in both treatments, and by treatment (0·25 v. 0·33 (s.e.d. 0·03) for C and P gilts respectively; P < 0·05). Plasma cortisol concentrations also increased before farrowing (P < 0·001) reaching a peak at 12 to 6 h pre-farrowing. Crated gilts had higher cortisol concentrations than, penned gilts (overall mean 41·5 v. 30·7 (s.e.d. 3·8) [μg/l for C and P gilts respectively; P < 0·05) at 24 to 12 (P < 0·05), 12 to 6 (P < 0·01) and 6 to 2 (P < 0·05) h pre-farrowing. Plasma ACTH concentration showed a similar pattern to cortisol over the pre-parturient period, peaking at 12 h pre-farrowing in both treatments (time: P < 0·001); crated gilts had significantly higher concentrations of ACTH at 6h pre-farrowing only (P < 0·05). Plasma β-endorphin concentrations also showed a gradual rise (P < 0·001) towards parturition; however no treatment differences were seen. These results suggest that the pituitary-adrenal (PA) axis is stimulated during pre-farrowing activity irrespective of farrowing environment. Crates, without bedding, further stimulate the PA axis over the pre-farrowing period perhaps by preventing nest-building. The rise in Q-endorphin may be involved in an endogenous defence against parturition pain.
Forages in diets for growing pigs 1. Nutrient apparent digestibilities and partition of nutrient digestion in barley-based diets including lucerne and white-clover meal
Authors: Andersson C. , Lindberg J. E.
Published: September 2010

The present study was undertaken to determine the Heal and total tract apparent digestibility and hindgut disappearance of dietary components and energy in a barley-based diet which included either lucerne or white-clover meal (proportionately 0·10 and 0·20). The experiment was conducted as a 5 × 5 change-over design with growing pigs fitted with simple t-shaped cannulas posterior to the ileo-caecal valve. The Heal and total tract apparent digestibilities of organic matter (OM), crude protein, crude fat, nitrogen-free extractives and energy were significantly reduced ivith increasing inclusion of lucerne and white-clover meal in the diet (P < 0·05). The total tract apparent digestibility of total fibre (TF) was significantly reduced with lucerne meal inclusion (P < 0·05), while the Heal apparent digestibility of TF was unaffected by lucerne and white-clover meal inclusion. Hindgut apparent digestibility (proportion of total tract apparent digestibility) of OM and energy was approximately 0·10, 0·70 and 0·70 for barley, lucerne and white-clover meal, respectively.

Both the Heal and total tract apparent digestibility of OM and energy were significantly higher for the control diet compared with lucerne and white-clover meal (P < 0·05). There was also a significantly higher apparent digestibility of OM, TF, crude fibre and energy in the total tract for white-clover meal compared with lucerne meal (P < 0·05). For neutral- and acid-detergent fibre a similar pattern was observed, however the effect was not significant.

The dietary digestible energy content was significantly reduced (F < 0·05), both at the ileum and over the total tract, with increasing inclusion offorage meal.
Effect of extensive feeding on α-tocopherol concentration and oxidative stability of muscle microsomes from Iberian pigs
Authors: Rey A. I. , Lopez-Bote C. J. , Sanz Arias R.
Published: September 2010

The effect of extensive feeding, confinement and diet supplementation with a-tocopheryl acetate (100 mg/kg) on the fatty acid composition and tocopherol concentration of microsome extracts and their susceptibility to oxidation was studied in Iberian pigs. The diet of pigs raised extensively was mostly composed of acorn and grass. The a-tocopherol contents of acorn and grass were 20 and 171 mg/kg dry matter, respectively. Microsomal fatty acid composition showed no differences among groups. Pigs feeding extensively had a higher concentration of a-tocopherol in muscle and microsomes than pigs given mixed diet with the basal level of a-tocopheryl acetate (P < 0·05) but lower values than pigs given supplementary levels (100 mg/kg) (P < 0·05). Microsomal fractions from pigs given mixed diet with a basal level of a-tocopheryl acetate were significantly more susceptible to iron-induced lipid oxidation than extract from pigs given diets containing a supplementary level (P < 0·05). Microsomal extracts from pigs feeding extensively had the lowest oxidation rate (P < 0·05), suggesting that other dietary constituents may play a role in the stabilization of microsomal lipids.
The genetic evaluation of beef sires used for crossing with dairy cows in the UK 2. Genetic parameters and sire merit predictions for calving survey traits
Authors: McGuirk B. J. , Going I. , Gilmour A. R.
Published: September 2010

Genetic parameters were estimated for traits recorded in a calving survey for beef sires used in commercial dairy herds in England and Wales. The five traits included in the survey were calving difficulty score, calf mortality to 48 h after birth, gestation length, and subjectively assessed calf size and conformation. The data file examined included over 88 000 records, on 323 sires of eight beef sire breeds, namely Aberdeen Angus, Belgian Blue, Blonde d'Aquitaine, Charolais, Hereford, Limousin, Piedmontese and Simmental.

Estimates of heritability and genetic and phenotypic correlations were obtained for all traits by REML procedures using a sire model. The effects of cow age, calf sex, year and season of the calving and sire breed were included in the model, together with interactions.

Heritability estimates were 0·09 (s.e. 0·01) for calving difficulty score, 0·32 (s.e. 0·03) for gestation length, 0·02 (s.e. 0·003) for mortality, 0·09 (s.e. 0·01) for calf size and 0·06 (s.e. 0·01) for calf conformation.

Heritability estimates for the scored categorical and binomial (mortality) traits were also obtained using threshold model analysis. As expected, these estimates were higher than the REML estimates; 0·16 (s.e. 0·01) for calving difficulty score, 0·08 (s.e. 0·01) for mortality, 0·14 (s.e. 0·01) for calf size and 0·09 (s.e. 0·01) for calf conformation. Calving difficulty score was strongly correlated genetically with calf size (-0·84), mortality (0·74) and calf conformation (-0·72), and moderately correlated with gestation length (0·26). Calf size and conformation were very highly correlated genetically (0·86), and both were also strongly correlated with mortality (-0·63 and -0·52 respectively). In all cases, the genetic correlations were stronger than the phenotypic correlations.

Sire genetic merit was predicted for all traits and the distribution of these predictions is described. Sire predictions of genetic merit for calving difficulty score on the underlying scale were backtransformed to predict the expected incidence of serious difficulties in future calvings and these predictions are illustrated for the major sire breeds.
Differential response of dairy cows to supplementary light during increasing or decreasing daylength
Authors: Phillips C. J. C. , Lomas C. A. , Arab T. M.
Published: September 2010

Two experiments were conducted to compare the response oflactating cows to supplementary light in their lying area during increasing and decreasing natural daylength. During decreasing daylength, supplementary light in the lying area increased the time cows spent lying down and considerably reduced calculated food intake, milk production, live weight and body condition, so that lights were installed in the feeding area for the last half of the experiment, which partially restored intake and live weight. Plasma cortisol concentrations and milk somatic cell counts were increased by supplementary light in decreasing daylength before, but not after, lights were installed in the feeding passage, suggesting that cows may have been stressed by the difficulties encountered during feeding in the dark. During increasing daylength supplementary light did not affect lying time, had less effect on food intake and no effect on milk production or live weight. There was a small reduction in plasma corticosteroid by the end of the experiment with supplementary light. It is concluded that providing supplementary light only in the lying area of dairy cows will have adverse effects on their production and welfare in decreasing, but not increasing daylength
Factors affecting the intake of grass silage by cattle and prediction of silage intake
Authors: Steen R. W. J. , Gordon F. J. , Dawson L. E. R. , Park R. S. , Mayne C. S. , Agnew R. E. , Kilpatrick D. J. , Porter M. G.
Published: September 2010

A partially balanced change-over design experiment involving 192 beef steers, which were initially 14 months old and 415 kg live weight, was carried out to determine the intakes of 136 silages from commercial farms in Northern Ireland. Each silage was offered ad libitum as the sole food to 10 animals, with eight silages offered in each of 17 periods over 2 years. A standard grass hay was offered to 16 animals in each period to enable period effects on intake to be removed. Detailed chemical and biological compositions of the silages were also determined. The ranges for pH and dry matter (DM), crude protein, ammonia-nitrogen and apparent digestible organic matter (in vivo) concentrations in the silages and silage dry DM intakes were 3·50 to 5·49 (s.d. 0·396); 155 to 413 (s.d. 43·1) g/kg; 79 to 212 (s.d. 24·4) g/kg DM; 45 to 384 (s.d. 63·2) g/kg total nitrogen; 528 to 769 (s.d. 58) g/kg DM and 4·3 to 10·9 (s.d. 1·13) kg/day respectively. Relationships between intake and individual parameters or groups of parameters have been developed using simple and multiple linear regression analysis and partial least-squares analyses. Silage intake was closely related to factors which influence the extent of digestion and rate of passage of the material through the animal, as indicated by the strong relationships (R2 of regressions = 0·28 to 0·50) with in vivo apparent digestibility and rumen degradability and the concentrations of the fibre and nitrogen factors. Intake was poorly correlated with factors such as pH, total acidity, buffering capacity and the concentrations of lactic, acetic and butyric acids (R2 of regressions = zero to 0·11). Near infrared reflectance spectrometry (NIRS) provided the best fit relationship with intake (R2 of relationship = 0·90). The results also indicate that the intake potential of silages can be directly predicted with a high degree of accuracy from the NIRS of both dried and undried samples of silage, provided the appropriate sample preparation and scanning methods are used.
Maize silage, grain sorghum silage and forage sorghum silage in diets with different proportions of concentrate for the finishing of weaner lambs.
Authors: Cilliers J. W. , Cilliers H. J. , Nel W. R. L.
Published: September 2010

The potential of diets, based on maize silage (M), non-bird-resistant grain sorghum silage (NBRGS), bird-resistant grain sorghum silage (BRGS) and forage sorghum silage (FS), in different proportions with concentrate for each silage, was evaluated for the finishing of weaner lambs. On a dry basis the ratios of silage: concentrate were 70: 30, 60:40, 50:50, 40: 60 and 30: 70 respectively for each of the silages. The concentrate mixtures were composed of different quantities of maize meal and soya-bean oilcake meal in order to balance the crude protein contents of the different diets used from weaning to 35 kg live weight and from 35 kg live weight to slaughter at 140 and 110 g/kg respectively.

Better apparent digestibilities of dry matter, crude protein and acid-detergent fibre as well as food conversion to live weight were found for diets with M or NBRGS as roughage sources compared with those with BRGS and FS as roughage sources. At the lower levels of concentrate inclusion in the diets the dressing proportions, carcass grades and food conversion to carcass weight for the diets with M and NBRGS as roughage sources were also better than were those with BRGS and FS as roughage sources. Although higher levels of concentrate inclusion in the diets to a large extent rectified these biological disadvantages of the diets based on BRGS and FS, they will also cause a rise in the price of the diet.
Flushing of mink (Mustela vison): effects on energy metabolism and some blood metabolites
Authors: Fink R. , Tauson A.-H.
Published: September 2010

Energy metabolism during flushing of mink (Mustela vison) in relation to a control group was studied by means of combining pooled data from balance and respiration experiments carried out in 1993 (experiment I) and 1994 (experiment II) and some blood metabolites from experiment II. The experiments, which were divided into six 1-week balance periods, started on 7 February and continued until 22 March. Flushing was performed by restricted feeding in periods 2 and 3 and refeeding in periods 4 and 5. Each balance period included a 24-h measurement of heat production by means of indirect calorimetry in open-air circuit respiration chambers. In experiment II blood samples were taken at weekly intervals and analysed for total triiodothyronine, total thyroxine, free thyroxine, glucose, insulin and fructosamine. Generally, intake of digestible nutrients and energy metabolism measurements within the flushed group were strongly influenced by period (energy supply), whereas they remained stable in the control group and differences between treatment groups over the total experiment were non-significant. The fluctuation in energy status induced by flushing did not involve major changes in body weight. Blood metabolites reflected the food intake by being fairly stable in the control group and decreasing during restriction and increasing during refeeding in the flushed group (P< 0·05). As an effect of flushing the number of corpora lutea increased significantly (P< 0·05).
Use of protein sources alternative to fish meal in diets with amino acids supplementation for the European eel (Anguilla anguilla)
Authors: García-Gallego M. , Akharbach H. , de la Higuera M.
Published: September 2010

This experiment was conducted to test two different protein sources as alternatives to the commonly used fish meal (FM) in the diet of the European eel (Anguilla anguilla). Six experimental diets were tested in three replicated lots of European eels. All diets contained the same protein and energy content (ca, 300 g crude protein per kg dry matter and 18·5 MJ/kg, respectively) but differed in the nature of the protein source: FM was the only protein source in the control diet and was fully or partially (0–5: 0–5) replaced by meat meal (MM) or sunflower meal (SFM) in four other diets; a sixth diet included SFM as the only protein source but was supplemented with several essential amino acids. Food intake, fish growth and several indices of diet and protein utilization were measured. MM clearly was the poorest protein source while SFM could replace, at least 0·5 of the FM with no significant reduction in performance. In addition, the European eel was able to utilize the supplement of essential amino acids. The full-SFM diet was improved significantly when supplemented and results were not statistically different from the control FM-based diet. Overall, a good correlation was found between the results of each diet and the respective essential amino acid index, calculated using as reference the essential amino acid requirements previously defined for another eel species, Anguilla japonica. This index could be used as a reliable measure for an a priori evaluation of alternative protein sources to be included in commercial foods for eels.
Selection for hyaluronic acid production traits: direct and correlated responses in two White Leghorn lines selected for cockerel comb size
Authors: Tufvesson B. , Tufvesson M. , Johansson K. , Wilhelmson M.
Published: September 2010

Hyaluronic acid (HA) is a polysaccharide preferably extracted from cockerel combs and used for medical purposes, mainly eye surgery. One way of increasing the production of HA from cockerels is to increase the size of the combs. The aim of this work was to study comb development and quantify direct and correlated responses for comb size at different ages and comb weight in two lines of White Leghorn selected for comb size at two different ages. Two lines were created, one selected for comb size at 16 weeks of age (CS16) (line E = early comb development) and the other for comb size at 29 weeks of age (CS29) (line A = adult comb size). There were between 500 and 800 birds of each line and generation and the lines had been selected for five generations. Cockerels in line E developed the combs at an earlier age and had smaller 29-week combs compared with the cockerels in line A. Genetic gain for the selection trait in generation five, measured in relation to line means in generation 1, was 58% in line E and 36% in line A. The corresponding correlated response for CS29 and comb weight (CW) in line E was 28% and 25% respectively, while for CS16 and CW in line A it was 46% and 35%. The results indicated that it is possible to increase cockerel comb size at both 16 and 29 weeks of age through selection.
Estimates of genetic parameters for growth traits of Gobra cattle
Authors: Diop M. , Van Vleck L. D.
Published: September 2010

Estimates of (co)variance components and genetic parameters were obtained for birth (no. = 3909), weaning (no. = 3425), yearling (no. = 2763), and final weight (no. = 2142) for Gobra cattle at the Centre de Recherches Zootechniques de Dahra (Senegal), using single trait animal models. Data were analysed by restricted maximum likelihood. Four different animal models were fitted for each trait. Model 1 considered the animal as the only random effect. Model 2 included in addition to the additive direct effect of the animal, the environmental effect due to the dam. Model 3 added the maternal additive genetic effects and allowed a covariance between the direct and maternal genetic effects. Model 4 fitted both maternal genetic and permanent environmental effects. Inclusion of both types of maternal effects (genetic and environmental) provided a better fit for birth and weaning weights than models with one maternal effect only. For yearling and final weights, the improvement was not significant. Important maternal effects werefound for all traits. Estimates of direct heritabilities were substantially higher when maternal effects were ignored. Estimates of direct and maternal heritabilities with model 4 were 0·07 (s.e. 0·03) and 0·04 (s.e. 0·02), 0·20 (s.e. 0·05) and 0·21 (s.e. 0.05), 0·24 (s.e. 0·07) and 0·21 (s.e. 0·06), and 0·14 (s.e. 0·06) and 0.16 (s.e. 0·06) for birth, weaning, yearling and final weights, respectively. Correlations between direct and maternal genetic effects were negative for all traits, and large for weaning and yearling weights with estimates of -0·61 (s.e. 0·33) and -0·50 (s.e. 0·31), respectively. There was a significant positive linear phenotypic trend for weaning and yearling weights. Linear trends for additive direct and maternal breeding values were not significant for any trait except maternal breeding value for yearling weight.
Prediction of the voluntary intake potential of grass silage by sheep and dairy cows from laboratory silage measurements
Authors: Offer N. W. , Percival D. S. , Dewhurst R. J. , Thomas C.
Published: September 2010

Ninety-four silages were made over 5 years from predominantly perennial ryegrass swards using a range of cutting dates (19 May to 18 September), wilting periods (0 to 48 h) and additives (none, acids, inoculants, sugar, sugar + acids, sugar + inoculants). A wide range of silage composition was achieved (CV for dry matter (DM), crude protein (CP), digestible organic matter (DOMD), lactic acid, total volatile fatty acids (VFA) and sugar were 0–2. Silage dry-matter intake (SDMI) was measured for 88 silages using lambs (mean live weight (M) 28 kg) given silage as their sole diet in four incomplete block design experiments using four lambs per silage and a standard hay given every third period for covariance correction. Thirty-four of the silages were also evaluated using early lactation cows (M, 561 kg and milk yield 27 kg/day) with 7 kg/day of concentrate in eight incomplete block change-over experiments each using 12 cows.

Intakes (SDMI mean, range, s.d. glkg M075) were 56, 25 to 84, 13·7 for lambs and 90, 64 to 119, 13·4 for cows. Scaling lamb SDMI by M1'47 accounted best for the effect of lamb weight on intake (mean, range 5·07, 2·43 to 7·68). Silage predictors were grouped as follows: traditional values (BASAL) - DM, CP, organic matter (OM), DOMD,

neutral-detergent fibre (NDF), acid-detergent fibre (ADF), ammonia nitrogen (NH3N), pH, acid hydrolysed ether extract (AHEE); silage fermentation values obtained by high-performance liquid chromatography (HPLC); or by electrometric titration (ET); and near infra-red reflectance spectra (NIRS) obtained on either 100°C dried (NIRSdry) orfreshsamples (NIRSwetl using a vertical transport mechanism and NIRSwet2 using a rotating cup). The most useful predictors within each group were firstly identified by step-wise multiple linear regression and models were then derived by partial least squares.

Standard errors of cross validation (SECV) obtained by the ‘leave one out’ method were for lamb SDMI (g/M1·47) 0·81, 0·81, 0·75, 0·52, 0·82 and 0·56 for BASAL, BASAL + HPLC, BASAL + ET, NIRSdry, NIRSwetl and NIRSwet2 respectively. Corresponding values for cows (g/M0·75) were 7·3, 7·3, 5·9, 5·1, 6·2, and 2·5. Inclusion of fermentation measurements made by ET, but not by HPLC, improved SDMI prediction over that obtainedfromthe BASAL set. However, NIRSdry and NIRSwet2 were the most accurate methods giving values for s.d. (reference population)ISECV of 2·27 and 2·13 for lambs and 2·65 and 5·28 for dairy cows. Use of these methods in advisory silage evaluation should substantially reduce the errors of predicting the intake potential ofgrass silages.
Factors affecting behavioural disturbances in race-horses
Authors: Redbo I. , Redbo-Torstensson P. , Ödberg F. O. , Hedendahl A. , Holm J.
Published: September 2010

The aim of the present study was to identify relations between stereotyped behaviours (cribbing, weaving and box-walking) and wood-chewing in thoroughbred flat-racing horses (TB) and standardbred trotters and the different management, feeding and training factors to which these horses are exposed. This was obtained by inquiries to all the professional trainers of TB and trottinghorses used for racing in Sweden. The usable response rates were 61% for trotters and 72% for TB representing 4597 trotters from 234 stables and 644 TB from 38 stables. A small field study was carried out to control the validity of the main study which gave results similar to those in the main study. There was a large difference between the two horse categories in the occurrence of behavioural disturbances. The TB had significantly more stereotypies than the trotters (P < 0·001) but there were no differences in the occurrence of wood-chewing. There were several differences in external factors between the horse categories, e.g. trotters had more opportunities for social contacts with other horses, they also had more free time outside the stable and they were trained a shorter time per week than the TB. The TB were given larger amounts of concentrate than the trotters. Wood-chewing within each horse category was explained by the amount of roughage (P < 0·05 in trotters and P < 0·001 in TB) together with other factors. Stereotypies in the TB were explained by: amount of concentrate (positive relation), number of horses per trainer (positive relation) and amount of roughage (negative relation).
Maximizing genetic gain for the sire line of a crossbreeding scheme utilizing both purebred and crossbred information
Authors: Bijma P. , van Arendonk J. A. M.
Published: September 2010

A selection index procedure which utilizes both, purebred and crossbred information was developed for the sire line of a three-path crossbreeding scheme in pigs, to predict response to best linear unbiased prediction (BLUP) selection with an animal model. Purebred and crossbred performance were treated as correlated traits. The breeding goal was crossbred performance but methods can be applied to other goals. A hierarchical mating structure was used. Sires were mated to purebred dams to generate replacements and to F^ from the dam line to generate fattening pigs. Generations were discrete, inbreeding was ignored. The selection index included purebred and crossbred phenotypic information of the current generation and estimated breeding values for purebred and crossbred performance of parents and mates of parents from the previous generation. Reduction of genetic variance due to linkage disequilibrium and reduction of selection intensity due to finite population size and due to correlated index values was accounted for. Selection was undertaken until asymptotic responses were reached. The index was used to optimize the number of selected parents per generation and the number of offspring tested per litter, and to make inferences on the value of crossbred information when the breeding goal was crossbred performance. It was optimal to test a maximum number of offspring per litter, mainly due to increased female selection intensities. Maximum response reductions due to linkage disequilibrium and correlated index values were 32% and 29% respectively. Correcting for correlated index values changed ranking of breeding schemes. Benefit of crossbred information was largest when the genetic correlation between purebred and crossbred performance was low. Due to high correlations between index values in that case, the optimum number of selected sires increased considerably when crossbred information was included.