bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of short-term feeding of clenbuterol on nitrogen retention, performance and meat quality in finishing pigs
Authors: De Schrijver R. , Fremaut D. , Broeck M. Van Den 
Published: March 2009

SUMMARYAn experiment using 30 Belgian landrace finishing pigs was carried out, in 1989, at the University of Leuven, Belgium, to examine the effect of clenbuterol in the diet (1 mg/kg) on the repartitioning of nutrients and body composition. Clenbuterol was administered for 20 days preceding the week before slaughter. Fifteen animals were fed a diet containing the β-agonist, and 15 other animals served as negative controls. Weight gain, feed conversion and N utilization improved during β-agonist treatment. Removal of clenbuterol from the diet rapidly increased blood urea concentrations, indicating immediate, less efficient, N utilization. In the week before slaughter, the animals did not lose the extra weight gained in the period of clenbuterol feeding. Backfat thickness at slaughter was reduced by 15% in the animals fed clenbuterol. Dressing percentage and post mortem pH decline, colour and water-holding capacity in ham and the longissimus dorsi were not affected by dietary treatment. Clenbuterol was not detected in renal fat and the longissimus dorsi at slaughter.
Morphology of perennial ryegrass (Lolium perenne) plants in pastures under intensive sheep grazing
Authors: Brock J. L. , Fletcher R. H. 
Published: March 2009

SUMMARYThe morphology of independent plants of perennial ryegrass (Lolium perenneL.) in mixed swards under intensive sheep grazing was studied at Palmerston North, New Zealand in 1988/89. Intact plants of two cultivars, ‘Grasslands Nui’ and ‘Grasslands Ariki’, were sampled from pastures under rotational grazing, set stocking, and a combination of both systems, every 2 months for 16 months, by taking turves (250 × 250 mm) and washing out the plants. Characters measured for each plant were: number of flower heads, leaves and tillers; basal stem and internode stolon length; flower head, leaf blade, leaf sheath and stolon dry weight (DW). Additional pasture data on tiller density and dispersion and herbage DW to ground level were also collected.Perennial rye grass exhibited a strong clonal growth pattern similar to that of white clover (Trifolium repensL.) but with a better balance between growth at the apex and death of old basal stem. Release of branch stolons to form new plants was regular, which maintained population stability. Formation of internode (I) stolon appeared to be a response of heavily shaded tillers for survival by elevation of the growing point to a more favourable position. The total DW of ryegrass stolon in pastures was greater than that of the companion white clover.There was little seasonal variation in number of tillers or basal (B) stem length per plant. During the reproductive period (late spring/early summer) plants were heavier and had more leaves and internode stolon than at other times of the year. Grazing management had little effect on plant structure, but plants under rotational grazing had 75% greater DW, less basal stem and reduced probability of internode stolon formation than plants under set stocking. Nui plants had heavier but fewer tillers than Ariki did, resulting in little difference in plant DW. Ariki had fewer single-tiller plants and a higher proportion of multiple-tiller (> 7) plants than Nui had. The structure of the populations was not affected by season, management or cultivar and remained stable throughout the year, with a log-normal distribution of plant size. Because of the uniformity of plant structure, plant density in pastures paralleled tiller density, averaging 1900, 3360 and 2330 plants/m2for rotationally grazed, set stocked and combined grazing treatments respectively.In view of the strong influence that grazing management can have on ryegrass performance and persistence in pastures, the lack of response at the level of plant and population structure to grazing management suggests that some other level of organization within the ecology of the pasture is of greater importance.
Evaluation of multipurpose tree germplasm: the use of gas production and rumen degradation characteristics
Authors: Siaw D. E. K. A. , Osuji P. O. , Nsahlai I. V. 
Published: March 2009

SUMMARYThe rumen degradation and gas production characteristics (methane, carbon dioxide) of leaves of 20 accessions of multipurpose trees (MPTs) from six genera: Acacia, Cajanus, Chamaecytisus (L. fil.) Link, Erythrina, Leucaena and Sesbania and some poisonous plants were investigated in vitro and in sacco in rumen fistulated cows fed on a diet of grass hay ad libitum supplemented with cotton seed cake. The degradation constants (i.e. the soluble fraction (a), the slowly degradable fraction (b) and the rate of degradation (c) and the potential degradability (a + b) (PD)) were calculated. The gas production constants were estimated following the equation: Volume = bg(1—e-cgt) where bg is gas production and cg is the rate of gas production. Between and within genus comparisons of degradability and gas production constants were done.The soluble fraction (a) was significantly higher for Sesbania (59) (P < 0·05) than the other genera, which had values between 45·18 and 40·38 units. There were no significant differences in the slowly degradable fraction (b) between genera. Sesbania was degraded significantly faster (P < 0·05) than either Acacia, Leucaena or Cajanus. Similarly, the potential degradability was significantly higher (P < 0·05) for Sesbania (92·7) than for the other genera. Acacia was the least degradable genus.Degradation characteristics were similar between species within the genera Acacia, Erythrina and Leucaena. However, within the Leucaena genus, L. revoluta had the highest soluble fraction (50·02) and the cross L. leucocephala × L. diversifolia had the lowest (29·24). L. leucocephala had the highest slowly degradable fraction (57·32) and L. revoluta had the lowest (42·37). L. leucocephala × L. pallida had the highest rate of degradability (0·0626) and L. pallida had the lowest (0·0221). L. leucocephala had the highest potential degradability (92·23) and the cross L. pallida × L. diversifolia the lowest (84–81).Between the genera, more gas was produced from Sesbania than from any other genus. The effect of genus was significant (P <0·0003). On the other hand, the rate of gas production (cg) was higher with the genus Chamaecytisus than with any other genera (P < 0·0001). Although the two methods used agree in the position of a forage of a high degradability like Sesbania, they fail to agree on the relative positions of the forages of lower degradabilities. For some genera, drying of the tree foliage reduced the volume of gas produced, but increased the rate of gas production.
Soil inorganic-N and nitrate leaching on organic farms
Authors: Watson C. A. , Fowlerf S. M. , Wilman D. 
Published: March 2009

SUMMARYOn two organic farms, nitrate-N and ammonium-N in the surface layers of the soil of representative fields were recorded for 2 years. Nitrate-N was also determined in different soil layers down to 120 cm at the beginning, middle and end of two winters and at intervals after ploughing three fields, to seek evidence of leaching.Nitrate-N and ammonium-N were both consistently low in the surface layers of fields in ley. Nitrate-N accumulated in arable soils on some occasions when there was little or no crop uptake of N, after ploughing, and after very heavy applications of manure.There was some evidence of nitrate leaching in all five fields which were deep-sampled. In four cases, the loss by leaching appeared to be < 25 kg N/ha per winter. In the other case, in which a 4-year ley was ploughed on 5 October, the loss by leaching appeared to be c. 70 kg N/ha. Ploughing in winter, rather than early autumn, might have reduced the nitrate leached, but the drilling of the next crop might have been delayed.The nitrate concentration of water draining from recently ploughed sandy soil in Shropshire was high, but it would have been diluted by water draining from unploughed fields.
Phenotypic stability of oats measured with different stability analyses
Authors: Peltonen-Sainio P. , Moore K. , Pehu E. 
Published: March 2009

SUMMARYThe phenotypic stability of seven Finnish and Nordic oat cultivars and 12 breeding lines developed at the Hankkija Plant Breeding Institute, Finland, was studied using the Finlay–Wilkinson regression method, Eberhart–Russell stability analysis, principal component analysis (PCA) with biplot presentation, canonical variate analysis (CVA) and Procrustes analysis. Comparison of stability analyses was based on four dissimilar growing seasons. In addition to the measurement of phenotypic stability of grain yield, the performance of 12 morpho-physiological traits was evaluated, including maturity class and structure of canopy and plant stand.The different stability analyses examined produced uniform results and ranked the cultivars and breeding lines without major disagreements. Lines with exceptionally stable yield performance over the different growing seasons were identified. In general, there was an association of high yielding ability with poor stability. However, some cultivars deviated from this tendency and showed high grain yield production and average stability of yield performance.
Fate of35S-labelled urine sulphate in urine affected areas of pasture soil under field conditions
Authors: Williams P. H. , Haynes R. J. 
Published: March 2009

SUMMARYThe fate of35S-labelled sheep urine sulphate in the soil and its plant uptake were measured in field experiments over a 12 month period in 1990/91 in Canterbury, New Zealand. Urine was applied in either summer or winter. After the summer application, there was a marked increase in pasture growth and S uptake which lasted for a period ofc.90 days. Plant uptake of applied35S was very rapid andc.11% was recovered in the pasture herbage within 65 days of application. By the end of the experiment,c.80% had been recovered in the herbage. A portion of applied35S was incorporated into soil organic forms mainly as C-bonded S. After 86 days, 30% of the applied 35S was in the C-bonded form but during the rest of the experiment this declined to 17% as the35S was remineralized and absorbed by the growing pasture plants.Following the winter urine application, the increase in pasture dry matter production and32S uptake was much less marked than that for the summer application. Twenty five percent of the applied35S was recovered in pasture herbage within 65 days and this increased to 70% by the end of the experiment. Some of the applied S was incorporated into soil organic forms and, by 83 days, 20% of the applied35S was present in C-bonded form. Through mineralization this declined to 7% by the end of the experiment. Over the initial 41 days of the experiment,c.25% of the35S was lost due to leaching.
Measurement of soil mineral nitrogen to predict the response of winter wheat to fertilizer nitrogen after applications of organic manures or after ploughed-out grass
Authors: Shepherd M. A. 
Published: March 2009

SUMMARYIn the autumns of 1985, 1986 and 1987, a total of 84 fields in England and Wales, which had received a recent dressing of organic manure or had recently been ploughed out of grass, was sampled to 90 cm depth to measure soil mineral nitrogen (Nmini.e. NH4-N and N03-N). Amounts of Nminvaried widely between sites, indicating the difficulty in estimating soil supply following ploughing grass or manure application although type of manure and Nminwere related. Soils contained much inorganic nitrogen where manures containing a large proportion of readily available N (pig slurry or poultry manure) had been applied. Where manures containing straw were applied, Nminwas greater in the second year after application than the first. The relationship between Nminand response of winter wheat to fertilizer was measured on 62 of the 84 sites sampled; there was no simple relationship between Nminand response to N. For fields just ploughed out of grass, the relationship was particularly poor. However, for fields with a history of arable cropping, there was no response to N fertilizer when Nminwas > 300 kg/ha N in either autumn or spring. Below this amount, response to fertilizer N varied considerably even for sites with similar amounts of Nmin. Nminmeasurements are of value in identifying soils containing sufficiently large N residues to allow fertilizer applications to be reduced, or even omitted, with confidence. Where residues are smaller, models need to be developed which take into account other factors, such as mineralization of organic nitrogen reserves, which modify nitrogen supply.
Growth responses in red deer calves and hinds grazing red clover, chicory or perennial ryegrass/white clover swards during lactation
Authors: Niezen J. H. , Barry T. N. , Hodgson J. , Wilson P. R. , Ataja A. M. , Parker W. J. , Holmes C. W. 
Published: March 2009

SUMMARYTwo experiments were conducted at the Massey University Deer Unit, New Zealand in 1990 and 1991 to evaluate the performance of lactating red deer hinds and their calves grazing conventional perennial ryegrass-based pastures, red clover or chicory. In both experiments, hind and calf performance was evaluated from 1 month post-parturition over a 2½ month summer period to weaning at 3½ months of age.In Expt 1, hinds and calves were grazed on low (5·4 kg dry matter (DM)/hd/day), medium (10·8) or high (16·4) allowances of red clover, or on a medium allowance of a conventional ryegrass/white clover sward (9·9 DM/hd/day). In Expt 2, hinds and calves grazed equal DM allowances (12 kg DM/hd/day) of perennial ryegrass/white clover, chicory or red clover.Red clover generally had higher organic matter digestibility (OMD) and higher total N than ryegrass/white clover, and when grazed at equal DM allowances, promoted higher voluntary food intake in the hinds, increased calf growth (430v.330 g/day) and increased hind liveweight change. Although decreasing the red clover allowance in Expt 1 slightly but non-significantly decreased hind voluntary food intake and decreased both calf and hind liveweight change, all low red clover values were still consistently higher than all ryegrass/white clover values (P < 0·05). In Expt 2, chicory was of higher OMD and ash content than red clover but N content was lower and similar to ryegrass/white clover. Chicory promoted lower levels of calf liveweight change than red clover but higher than ryegrass/white clover. Hind liveweight change on chicory was lower than on red clover and was similar to ryegrass/white clover. It was concluded that red clover offers potential as a special purpose forage for deer production and that further experimental work is needed with chicory.
Quantitative carbon distribution in clonal plants of white clover (Trifolium repens): source-sink relationships during undisturbed growth
Authors: Chapman D. F. , Robson M. J. , Snaydon R. W. 
Published: March 2009

SUMMARYThe assimilation and distribution of carbon in laterally spreading white clover plants was quantified in a controlled environment using CO2exchange rate measurements and14C as a tracer. Plants were restricted to three mature leaves on the main stolon apex, and the movement of14C from these leaves (and one immature, but carbon-exporting, leaf) to meristematic zones throughout the plant was determined by detailed plant dissection.Sinks throughout the plant drew small to moderate proportions (typically 1–8%) of the14C exported by all mature leaves. The three mature leaves displayed similar export patterns, and no specific source-sink relationships involving any of these leaves were observed. However,14C exported by the developing leaf moved predominantly to the main stolon apex, and to adjacent young stolon tissue. Estimated respiratory losses over 24 h accounted for 40–49% of the 14C fixed. Of the total amount of C exported by all four leaves and utilized in new growth or reserve storage, 22% moved to the main stolon apex, 16% to stolon tissue of the main stolon, 34% to adventitious roots on the main stolon (most of which was utilized in older, nodulated roots) and 29% to branches. The apex received the greatest amount of C/unit weight, reflecting its high sink activity, its proximity to the source leaves and, possibly, apical dominance. Subtending leaves provided 46–51% of the C utilized by young branches. Older branches continued to import significant quantities of C from parent stolon leaves despite having their own C sources, though parental support for branches was seen to decrease as branches aged, when the quantity of C they imported was expressed as a function of their weight.Relative sink strength and distance between sources and sinks contributed to the observed patterns of C distribution. No apparent restriction on C movement was imposed by the vascular architecture of stolons.
An evaluation of the minirhizotron technique for estimating root distribution in potatoes
Authors: Parker C. J. , Carr M. K. V. , Jarvis N. J. , Puplampu B. O. , Lee V. H. 
Published: March 2009

SUMMARYThe minirhizotron technique was evaluated for estimating root length density in potatoes (Solanum tuberosum‘Record’) by comparing observations in angled 45° glass tubes with corresponding root length densities obtained by (a) destructive core sampling, and from (b) counts of root tips on the soil face of excavated trenches. Measurements were made in a field experiment in Bedfordshire, UK, in 1985, with shallow and deep cultivation as variables, and in a glasshouse trial.Only at depths below 0·3 m did root lengths observed with minirhizotrons reflect at all closely those estimated from core sampling and even then there was a tendency to overestimate root density. In the surface cultivated layers, where 80–90% of the total root length was present, results from minirhizotrons were unreliable, probably because of poor soil–tube contact and, in soils which shrink on drying, preferential root growth at the interface between the soil and the glass.Minirhizotrons can provide a realistic estimate of the rate of root growth of potatoes with depth over time when compared with maximum depths of water extraction, but appear to be unreliable for providing a quantitative measure of total root length density.
Simplified rotational grazing management of dairy cows: effects of rates of stocking and concentrate
Authors: Hoden A. , Peyraud J. L. , Muller A. , Delaby L. , Faverdin P. , Peccatte J. R. , Fargetton M. 
Published: March 2009

SUMMARYAn experiment was carried out in Normandy between 1986 and 1988 over c. 6 months in each year, using a simplified rotational grazing technique (two paddocks in spring, four in autumn) with a total of 162 high-yielding cows (mean milk yield of 30·0 kg/day at turn-out). Three stocking rates, designated control (C: 2·3 cows/ha over the total area of the system), moderate (M: 2·6 cows/ha = 115% of C) and high (H: 3·0 cows/ha = 130% of C), were compared at two rates of concentrate supplement, 3·7 kg/cow per day and 0·5 kg/cow per day. Individual milk yield differed by a non-significant 5% between the extreme stocking rates (21·3 v. 20·3 kg fat-corrected milk (FCM) for treatments C and H, respectively). Milk production/ha was 23% greater in the H treatment (9816 v. 7970 kg FCM for H and C, respectively). Concentrate supplementation led, on average, to a 9% milk yield improvement (21·8 v. 20·0 kg FCM for high and low rates, respectively), i.e. a mean efficiency of 0·6 kg FCM/kg supplement. This response tended to be greater in the higher-yielding cows and for the high stocking rate. The sward measurements contributed to a better understanding of herbage utilization by the cows.
Grouping and complete diet composition in relation to parity and potential yield in dairy cows
Authors: Kroll O. , Owen J. B. , Whitaker C. J. 
Published: March 2009

SummaryThree experiments, involving a total of 294 Israeli Holstein cows, were carried out to study aspects of the grouping of cows in relation to timing of changes and the type of complete diet given. In Expt 1, 40 cows were changed from a high energy diet to a medium energy diet either at 60 or at 180 days post calving. The results indicated a larger reduction in milk and FCM yield following the later than the earlier change of diet.Experiment 2 involved 64 cows subjected to two treatments, one involving a ‘uniform’ diet (25:75 forage to concentrate D.M. ratio) and the other a ‘step’ treatment where the same diet as in treatment 1 was given for approximately 74 days and then changed to a diet of 35:65 forage to concentrate ratio. The results showed that it is not necessary to adopt different feeding systems according to the potential yield of the cow and that cows could be given rather lower energy diets within the range offered without loss of efficiency.In Expt 3, involving 190 cows, the cows were divided into one of two feeding treatments, ‘uniform’ and ‘step’ similar to Expt 2 and the effect of potential yield and parity was considered. The results emphasized the importance of potential yield rather than feeding system in relation to yield. The results showed a shorter period from calving to conception for the ‘uniform’ treatment.A strategy for efficient cow feeding is outlined.
The use of random F3 families for cross prediction in spring barley
Authors: Thomas W. T. B. 
Published: March 2009

SummaryRandom F3 families from six crosses typical of those being made in a spring barley breeding programme at the Scottish Crop Research Institute were used to rank the crosses on the basis of their predicted probabilities of exceeding a given standard for a number of characters. The predicted rankings were then compared with the observed rankings of the crosses based on observations of random inbred lines from the same crosses. The agreement between predicted and observed rankings was very good for single characters and good for bivariate combinations of the characters. The agreement for the bivariate combination of height and single plant yield was exact and the combination also appeared to be capable of accurately ranking crosses on the basis of height and plot yield.The practical considerations of using such a cross prediction technique in a cereal breeding programme are discussed. Results from this experiment suggest that single plant measurement could be replaced by measurements on progeny rows, thereby saving considerably on labour. Predictions could just be made on the most important characters in the breeder's model for the early identification of the best crosses but this is still an advance on the approach of making many crosses and assessing relatively few selections from each cross in yield trials.