bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reproductive traits of Angus, Criollo and reciprocal crossbred females in the temperate area of Argentina
Authors: Corva P. M. , Villarreal E. L. , Mezzadra C. A. , Melucci L. M. 
Published: September 2010

AbstractReproductive performance of purebred Angus (A) and Criollo (C) cows and crossbred CA and AC cows in the temperate area of Buenos Aires, Argentina, was assessed through the study of reproductive rates, calving date, first insemination date, number of inseminations and weight related variables. The herd was grazed on pastures all year round. Matings were by artificial insemination with visual oestrus detection, from October to December. Heifers first calving was at 3 years of age. All traits were analysed with general linear models including, as corresponded, fixed effects of dam and calf genetic groups, calving year and month, dam physiological status, calving age and first order interactions. Female genetic group adjusted means were used to estimate direct (gl) and maternal (gM) breed differences and heterosis (hl) effects on reproductive traits. Weaning rate was mostly determined by oestrons detection rate. Due to the inhibitory effects of nursing on reproduction, female genetic group effects were significant for suckling cows only: mean oestrous detection rate was higher (P < 0·05) for crossbred cows (AC: 91·2 (s.e. 5-1) %; CA: 88·4 (s.e. 2·9) %) than for A (76·3 (s.e. 2·0) %) and C (49·9 (s.e. 3·3) %); direct breed effects favoured A (glA - g1c = 26·4 (s.e. 3·7) %; P < 0·001) and h1 was 26·7 (s.e. 3·4) % (P < 0·001). When only oestrous-detected cows were considered, direct breed effects were significant only for pregnancy rate fg1A —g1c = 8·5 (s.e. 4·4) %) whereas h1 was significant for pregnancy (8·3 (s.e. 3·8) %), calving (9·3 (s.e. 4·1) %) and weaning (10·1 (s.e. 4·1) %) rates (P < 0·05). Criollo cows calved later than crossbred (≍19 days) and A (≍15 days) cows mainly due to longer post-partum anoestrous. For calving date, direct breed effects favoured A (g1A — g1c = 20·8 (s.e. 5·9) days; P <0·0·001) and h1 was 11·4 (s.e. 2·8) days (P < 0·001). Low reproductive performance in C was not associated with live iveight at the beginning of mating. This genetic group was the latest in showing oestrous behaviour, even when not suckling. Number of inseminations was similar for the four genetic groups. These results sustain the principle of utilizing Fl Criollo-Angus cows to improve beef herd productivity, whereas they do not support the recommendation of using purebred Criollo females under this type of production system.
Efficiency of utilization of absorbed amino acids in growing lambs given forage and forage: barley diets
Authors: MacRae J. C. , Bruce L. A. , Brown D. S. 
Published: September 2010

AbstractThe efficiency of utilization of absorbed essential amino acids (AA) was studied in wether lambs (35 to 40 kg live weight) given dried grass and dried grass: barley pelleted diets over an intake range from maintenance (M) to 2·5 M energy intake. Each animal was prepared with a duodenal and Heal simple (T-shaped) cannulafor the collection of digesta entering and leaving the small intestine and with a catheter into the abomasum for the infusion of digesta phase markers (103Ru phenanthroline and51Cr ethylene diamine tetra acetic acid). The efficiencies of utilization of total AA and individual essential AA (EAA) were calculated from the ratios of the regressions describing AA retention per unit nitrogen (N) intake (assessed using the N retention data obtained in the present study and the AA composition of N retention derived during an accompanying comparative slaughter experiment) and AA absorption per unit N intake. These ratios for total EAA were 0·5 for the grass diet and 0·59 for the grass plus barley diet. Values for individual EAA ranged from 0·32 for threonine in sheep given the grass diet to 0·88 for arginine in sheep given the grass: barley diet. Whilst the ratios for total and individual EAA were generally higher for the grass: barley diet the very wide 95% confidence limits associated with these derived values make any between-diet or between-EAA comparisons equivocal. The data appear to support the introduction by the Agricultural and Food Research Council (1992), of a scaling factor to reduce the high efficiency of utilization of AA used previously.
The effect of increasing the acidity or osmolality of grass silage by the addition of free or partially neutralized lactic acid on silage intake by sheep and upon osmolality and acid-base balance
Authors: Rooke J. A. 
Published: September 2010

AbstractA well fermented grass silage was mixed with 9·3 g lactic acid per kg silage supplied either as the free acid (lactic acid) or partially neutralized to pH 5·2 with sodium hydroxide (sodium lactate) to give three dietary treatments. Treatment with lactic acid reduced silage pH (P < 0·05) from 4·03 to 3·80 and increased (P < 0·01) the amount of sodium hydroxide required to raise silage pH to 6·5 (neutralizing value) from 167 to 261 mmol/kg silage and osmolality (P < 0·01) from 712 to 854 mosmoljkg silage; sodium lactate treatment increased (P < 0·05) silage pH to 4·15 and osmolality (P < 0·01) to 964 mosmoljkg silage but did not change neutralizing value.Wlien fed in a randomized-block design to either six intact lambs or to four rumen fistulated sheep lactic acid treatment reduced (P < 0·05) silage dry matter (DM) intake (g/kg weight0·75) from 34·7 to 27·8 for intact sheep and from 35·5 to 29·9 for fistulated sheep. Intakes of the sodium lactate-treated silage tended to be higher (39·2, intact and 40·1, fistulated sheep, g/kg weight0·75) than the control silage. Silage DM intake was correlated more closely with neutralizing value (r2 = 0·34) than pH (rz = 0·24).Treatment of silage with lactic acid or sodium lactate did not change rumen pH, volatile fatty acid patterns or osmolality. Blood pH, pCO2 and bicarbonate concentrations were not changed by the diets offered and were within normal ranges. Urine acid-base balance was not affected by lactic acid treatment whereas urine pH, and bicarbonate and sodium excretion were (P < 0·01) increased by sodium lactate treatment of the silage.
Responses in carcass composition to divergent selection for components of efficient lean growth rate in pigs
Authors: Cameron N. D. , Curran M. K. 
Published: September 2010

AbstractCarcass composition was measured after six generations of divergent selection for lean growth rate on ad-libitum and restricted feeding, lean food conversion and daily food intake in populations of Large White (LW) and Landrace (LR) pigs. There were 161 half-carcass dissections in LW pigs and for LR pigs, a double sampling procedure combined information from 53 half-carcass and 53 hand joint dissections. The performance test started at 30 kg and finished at 85 kg with ad-libitum feeding and after 84 days with restricted feeding, and pigs were slaughtered at the end of the test.In the LR population, selection for lean growth on restricted feeding increased carcass lean content (605 v. 557 (s.e.d. 19) g/kg), but there were no significant responses in carcass lean content with the selection strategies on adlibitum feeding. Selection for lean food conversion and high lean growth on restricted feeding reduced carcass fat content (201 v. 241 (s.e.d. 14) and 150 v. 218 (s.e.d. 18) g/kg), but selection for high lean growth rate with adlibitum increased carcass fat content (212 v. 185 (s.e.d. 11) g/kg). Responses in carcass composition were not significant with selection on daily food intake.In the LW population, selection for high lean food conversion or low daily food intake increased carcass lean content (539 v. 494 and 543 v. 477 (s.e.d. 11) g/kg) to a greater extent than selection on lean growth rate (509 v. 475 g/kg). Responses in carcass fat content were equal and opposite to those in carcass lean content. Selection on lean growth rate with ad-libitum feeding increased lean tissue growth rate (LTGR) (491 v. 422 (s.e.d. 23) g/day), but there was no change in fat tissue growth rate (FTGR) (206 v. 217 (s.e.d. 15) g/day). In contrast, FTGR was reduced with selection on lean food conversion (169 v. 225 g/day), but LTGR was not significantly increased (520 v. 482 g/day). Selection for lean growth rate with restricted feeding combined the desirable strategies of lean growth rate on adlibitum feeding and lean food conversion, as LTGR was increased (416 v. 359 (s.e.d. 12) g/day) and FTGR decreased (126 v. 156 (s.e.d. 7) g/day). The preferred selection strategy may be lean growth rate on restricted feeding, which simultaneously emphasizes rate and efficiency of lean growth.For ad-libitum fed LW pigs, coheritabilities for growth rate, daily food intake and backfat depth with carcass lean content were negative (-0·12, -0·22 and -0·50 (s.e. 0·05), but positive with carcass subcutaneous fat content (0·22, 0·24 and 0·50), when estimated from six generations of performance test data and carcass dissection data in generations 2, 4 and 6.
A comparison of the welfare of sows in different housing conditions
Authors: Broom D. M. , Mendl M. T. , Zanella A. J. 
Published: September 2010

AbstractTwelve sows in good quality unstrawed stalls, three groups of five sows in strawed pens with individual feeding stalls and sows in a 38-sow group in a strawed yard with an electronic sow feeder were compared during the first four parities. They originated from the same source, were about 9 months of age and in the 7th week of their first pregnancy at the start of the experiment and were kept in adjacent rooms in a building, cared for by the same staff and given the same diets at a rate of 2·2 kg/day per animal. No new animals were added to the groups or stalls during the study and animals returned to the same condition after periods in farrowing and service accommodation. Using a wide range of welfare indicators, it was clear that stall-housed sows had more problems than group-housed sows and that tliese problems were worse in the fourth than in the first pregnancy. By the fourth pregnancy, stall-housed sows spent proportionately 0·14 of time showing activities which were clearly stereotypies and much time on activities which were sometimes stereotyped, i.e. ‘drinking’ and rooting or chewing at pen fittings making a total of proportionately 0·50 of time. Comparable figures for group-housed sows were much lower (0·037 and 0·081 in total). Stall-housed sows were also more aggressive than group-housed by the fourth pregnancy and their body weights were lower. There were no differences using physiological or immunological tests or measures of reproductive output. When the two group-housing systems were compared, sows in the electronic feeder system showed more fighting, especially soon after initial mixing, but fewer total agonistic interactions than sows in groups of five during the first pregnancy. Oral stereotypies were slightly higher in small groups, perhaps because of smaller pen space, than in larger groups but much lower than in stalls. By the fourth pregnancy there were few differences between sows in small and large groups and all seemed to have adapted well to the conditions. Evaluation of welfare in different housing systems requires use of a wide range of measures and of long-term studies.
Utilization of dietary carbohydrates by fish: a comparative study in eel and trout
Authors: García-Gallego M. , Bazoco J. , Suàrez M. D. , Sanz A. 
Published: September 2010

AbstractTo evaluate the ability of the eel to use diets with high carbohydrate content, a comparative study was made by using the rainbow trout, a carnivorous fish, as a reference species. Four isoenergenetic diets (in terms of gross energy) were formulated incorporating different protein/carbohydrate ratios (450/200, 370/300, 290/400 and 210/500 as g/kg dry matter, respectively) and each one was tested in three replicates groups of eels and trout. The data on growth, food conversion and utilization of dietary protein and energy show that the eel has a comparatively greater ability than the rainbow trout for using diets with a high carbohydrate level. Thus it is postulated that higher carbohydrate levels could be used for formulating cheaper diets.
The requirement of the gilthead seabream (Sparus aurata L.) for nicotinic acid
Authors: Morris P. C. , Davies S. J. 
Published: September 2010

AbstractSemi-purified diets were used to determine the nicotinic acid requirement of the gilthead seabream, Sparus aurata. Vitamin losses during food manufacture were minimal resulting in dietary levels which were close to the declared content. Dietary nicotinic acid contents of 52·21 mg/kg and below resulted in sub-optimum growth, reduced food efficiency and poor values for apparent net protein utilization. Diets containing less than 28·67 mg/kg gave a low proportion of carcass lipid concomitant with an elevation in the relative content of carcass moisture. Although gross deficiency symptoms were not observed, a reduced hepatosomatic index and a slightly lower plasma glucose concentration were detected amongst the fish given diets supplemented with nicotinic acid at the level of 25 mg/kg or less. Based upon the results of broken line analysis and data derived by modelling the weight gain of the fish, the nicotinic acid requirement of Sparus aurata fingerlings lies between 63 and 83 mg/kg of diet or 1·57 to 2·07 µg/kg body weight per day.
The influence of animal age and sward height on the herbage intake and grazing behaviour of Charolais cattle
Authors: Cazcarra R. Ferrer , Petit M. 
Published: September 2010

AbstractMature dry cows, 18-month-old heifers and 7-month-old female calves of the Charolais breed (eight animals of each age) were strip-grazed on moderate (15cm) or tall (52 and 32cm) cocksfoot swards over two 15-day experimental periods. The swards were leafy regrowths of 2 (short) and 8 (tall) weeks of age. Herbage intake was estimated by the alkane method, and grazing behaviour was visually recorded.Bite weight was lower, grazing time and biting rate greater, and organic matter in take of grass (OMIG) higher on shorter swards, the latter being related to a higher in vitro digestibility and nitrogen concentration. Average OMIG per kg live weight (M) was 15·2, 19·1 and 17·0 (s.e.d. 0·49)g in cows, heifers and calves respectively. The average allometric coefficient between OMIG and M was 0·88 (similar between swards), and close to that obtained with hay after the grazing trial.Faecal markers suggested a greater selectivity of calves compared with older cattle. Average bite weights (BW) were 310 (s.e. 40), 467 (s.e. 112) and 718 (s.e. 144)mg OM in calves, heifers and cows respectively. The allometric coefficient between BW and M was higher in short swards than in tall ones. Biting rates increased and grazing times tended to decrease with age of cattle.
Relationship between rank order and productive parameters in Verata goats during milking
Authors: Patón D. , Martín L. , Cereijo M. , Rota A. , Rojas A. , Tovar J. 
Published: September 2010

AbstractThe hierarchic behaviour of 71 goats of the Verata breed from two independent flocks on two different farms (no.2 = 34 and no. 2 = 37) was studied during the milking-period of a year. Two statistical procedures: canonical correspondence analysis (CCA) and a log-linear model were used. In the CCA, the total frequencies of each goat in each of the 12 positions at the milking stalls during 210 days of lactation were computed as original variables. Canonical variables were the average values of dairy milk production, proportion of protein and proportion of fat. The first two CCA axes accounted for proportionately 0·72 of the variance. The first axis showed the effect of rank order (V1 = 0·45) and the second axis the variability between animals for the same group of hierarchy (V2 = 0·27). The first position (AC1, = 0·58; AC2 = 0·23) and the last position (AC1 = 0·11; AC2 = 0·26) of the milking stalls were in absolute contributions the most significant in the distribution of the four observed groups of hierarchy, as defined by their frequency of access to the first position. Two parameters were highly correlated with both axes: milk protein content (r1, = - 0·8; r2 = 0·9) and the day milk production (r1 = 0·6; r2 = 0·5). These results showed a direct relationship between rank order and milk production, whereas the variability in each group was best defined by the protein content. The log-linear model showed that goats of lactation numbers one, two and three have a similar behaviour with respect to their locations at the milking stalls, being distributed more randomly (â1, = 0·68 < â2 = 0·7 < â3 = 0·71) than goats of a lactation number four (â4 = 2·95). This effect could be a consequence of two different but related factors: either the animals develop a preference for a particular position over time, or that animals in their fourth lactation showed a more stable behaviour pattern which affected their body condition.
Autumnal timing of photoperiodic manipulation critical via melatonin to winter pelage development in mink
Authors: Valtonen M. , Vakkuri O. , Blomstedt L. 
Published: September 2010

AbstractQuantitive collection of night-time urine every 2nd week was used to elucidate the temporal relationship between changes in melatonin production, weight gain, and priming of the winter pelage under natural light conditions and under a long photoperiod (18L: 6D) imposed at different times in four groups of female mink during autumn. In mink maintained outdoors under the natural photoperiod (group 1), melatonin excretion was 1·80 (s.d. 0·80) ng per night (no. = 3) at the beginning of September, thereafter it began to decrease slowly until November when it was only 0·62 (s.d. 0·32) ng per night. These mink had a normal autumn moult during the first half of October and the winter pelage was mature at the end of November. When mink maintained outdoors were transferred to 18L: 6D on 7 September (group 2), excretion of melatonin decreased promptly, autumn moult was disrupted and winter fur priming delayed. Long photoperiod after mid October (group 3), did not interfere with pelage maturation despite the decrease in melatonin production. Mink implanted with melatonin on 14 July (group 4) showed very high melatonin excretion in early September. In these animals the winter pelage growth was unaffected by the long-day conditions; the pelage matured in mid October. Body weight increased in mink of all groups during autumn. This increase levelled off or a weight loss (group 2) was seen along with the final hair maturation. Activation of hair follicles occurred during a 4 to 6 week period. According to these results, melatonin is the photoperiodic signal to autumnal weight increase and autumn moult but seems not to be necessary for later pelage growth and maturation.
Marker-assisted selection in an outbred poultry breeding nucleus
Authors: van der Beck S. , van Arendonk J. A. M. 
Published: September 2010

AbstractThe value of using a marker for a quantitative trait locus (QTL) affecting a sex-limited trait in an outbred poultry breeding nucleus was studied. Marker and QTL were in linkage equilibrium in the base population. The recombination rate between marker and QTL was 0-05. A closed nucleus with 9000 chickens per generation was deterministically simulated. The genetic model contained polygenes and a QTL linked to a marker. Genetic effects explained proportionately 0·3 of the phenotypic variance before selection. Under selection, polygenic variance reached an equilibrium and QTL variance decreased continuously over time. Cocks were selected in two steps. First the best cocks of each full-sib family were selected (within-family selection) while final selection took place after information on fiill-sibs was available. Hens were selected after they had completed production. The effect of using marker information in estimating breeding values was studied in an ongoing breeding programme. Transmission of marker alleles was always traceable. Cumulative response over five generations increased proportionately by 0·06 to 0·13 if a marker linked to a QTL that explained 0·2 of the genetic variance was used. Cumulative response increased up to 0·28 if the QTL explained 0-8 of the genetic variance. Additional response due to the use of a marker increased with increasing intensity of within-family selection of cocks, increased with increasing variance explained by the QTL and was higher if within-family selection of cocks was carried out after rather than before their sibs had complete records.
Milk production from grass silage diets: effects of high-protein concentrates for lactating heifers and cows on intake, milk production and milk nitrogen fractions
Authors: Sutton J. D. , Aston K. , Beever D. E. , Dhanoa M. S. 
Published: September 2010

AbstractTo examine the effects of increasing the crude protein (CP) content of concentrates at either equal concentrate intake (increasing CP intake) or at reducing concentrate intake (equal CP intake), 44 multiparous Holstein-Friesian cows were allocated to one of five treatments for weeks 4 to 18 of lactation. The treatments were 6 kg dry matter (DM) per day of concentrates containing nominally 200, 300 or 400 g CP per kg DM or 9 or 3 kg DM per day of concentrates containing 200 or 600 g CP per kg DM respectively. In addition 23 first-calf cows (heifers) were offered 5 kg DM per day of concentrates containing 200, 300 or 400 g CP per kg DM. All the animals were offered first-cut perennial ryegrass silagead libitum. Increasing the concentrate CP content at equal intake caused only small and non-significant increases in silage intake by both heifers and cows. It significantly increased yields of milk and milk protein for both groups but whereas the cows responded to both increments of CP, the heifers only responded to the first. The concentrations of total protein, true protein, casein and non-protein nitrogen (NPN) in milk were significantly increased but the concentration of whey protein remained unchanged. Increasing CP concentration while the concentrate ration was reduced enhanced silage intake but had no significant effect on yields of milk or milk solids. The concentrations of total protein, true protein (non-significant), casein and NPN all increased but whey protein was unchanged. Overall the concentrations of casein and NPN were linearly related to the dietary CP concentration. With both concentrate strategies the proportion of true protein in total milk protein decreased and the proportion of NPN increased with increasing dietary CP concentration but the changes, though highly significant, were relatively small. It is concluded that the strategy of reducing the concentrate ration while maintaining concentrate CP intake causes only small reductions in milk solids production but it is dependent for success on supplies of high-quality grass silage to substitute for the concentrates.