bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of faecal organisms from sheep for the in vitro determination of digestibility
Authors: El Shaer H. M. , Omed H. M. , Chamberlain A. G. , Axford R. F. E. 
Published: March 2009

SummaryA method is described in which a liquid suspension of sheep faeces is used as an inoculum in the in vitro determination of digestibility of feedingstuffs for ruminants. The modified method was applied to 21 samples of grass, ten of lucerne, and a variety of other food materials. The results correlated closely (r = 0·98) with the in vivo digestibilities, and the relationship between in vitro and in vivo digestibilities was represented by the equation: in vivo digestibility = in vitro digestibility × 1·003.
Calcium metabolism in red deer (Cervus elaphus) offered herbages during antlerogenesis: kinetic and stable balance studies
Authors: Muir P. D. , Sykes A. R. , Barrell G. K. 
Published: March 2009

SummaryKinetic studies of Ca metabolism, using 45CaCl32, were carried out on two mature red deer stags during the period of maximum rate of Ca deposition in the antlers. They were offered green-feed oats to provide energy for maintenance; the diet provided approximately 42mg Ca/kg W per day.Ca appeared to be irreversibly lost from the circulation into the antlers and could be treated for kinetic purposes in the same way as loss of Ca from the body in milk. The size of the rapidly exchangeable Ca pool in the body, excluding the antlers, was 0·21 g/kg W, similar to estimates for lactating cattle. Rates of Ca deposition in the antlers of the two stags, calculated from the model of Ca metabolism, were 58·4 and 38·6 mg Ca/kg W per day. Net endogenous loss was 6–7 mg Ca/kg W per day, much lower than estimates available for other ruminant species. Only 25–40% of Ca requirement or 11–24 mg Ca/kg W per day was derived from the diet, suggesting that the availability of Ca in greenfeed oats is much lower than current estimates for forages. Bones removed on completion of the experiment showed evidence of considerable skeletal demineralization.In other stags subjected to stable Ca balances at the same stage of antler growth, while consuming ryegrass-white clover forage, 60–80% of Ca requirement was derived from the diet, with calculated rates of true absorption of 32–46 mg Ca/kg W per day. These rates of Ca absorption are low compared with values observed in other ruminants at times of high Ca demand such as during lactation.
Leaching of salts as affected by the method of water application and atmospheric evaporativity under shallow and saline water-table conditions
Authors: Minhas P. S. , Khosla B. K. 
Published: March 2009

SummaryField studies on leaching a highly saline sandy loam soil having a shallow groundwater table showed that application of 150 mm water in two equal parts at 10 days interval had no distinct advantage over a single application of the whole amount. On the contrary, the surface-accumulated salts were displaced to a lesser extent and the salt peak remained at a shallower depth under split application, particularly during periods of high atmospheric evaporativity when the leached salts tended to move upward between successive water applications. A soil mulch created by shallow tillage reduced evaporation losses and curtailed upward movement of salts, resulting in nearly 10% increase in leaching efficiency. Significantly a small quantity of water (0·41 cm leaching water per unit soil depth) sufficed for 70% chloride removal, indicating that under the prevailing conditions a larger fraction of the pores contributed to the leaching process. A compact layer, having a bulk density of 1·69 g/cm3, at the soil surface, also appeared to be related to the higher leaching efficiency by maintaining a preponderance of unsaturated flow.
Ruminal degradation characteristics of some African rangeland grasses
Authors: O'Reagain P. J. , Goetsch B. C. , Owen-Smith R. N. 
Published: March 2009

SUMMARYThe seasonal rate and extent of dry matter (DM) and neutral detergent fibre (NDF) degradation of the African sourveld grassesAlloteropsis semialata, Andropogon appendiculatus, Cynodon dactylon, Elionurus muticus, Eragrostis plana, Harpochloa falx, Heteropogon contortus, Hyparrhenia hirta, Microchloa caffra, Themeda triandraandTristachya leucothrixin the rumen were measured using the nylon bag technique at the Döhne Agricultural Development Institute, South Africa, in 1993. The size of the soluble fraction (SF) was markedly different (P< 0·05) between species, being largest inA. semialata(22·6%) and smallest inE. plana(13%). Over all species, the mean SF was highest (P< 0·01) in spring (21·6%) and lowest in winter (11·8%). Species differed (P< 0·05) in the size of the potentially digestible fraction (PDF), withH. contortusandT. leucothrixhaving the largest (71%) andM. caffrathe smallest (53%) PDF. Mean PDF declined (P< 0·01) from spring (77·3%) through to winter (55·8 %). The rate of DM degradation (kd) in the rumen also differed (P< 0·01) between species, withC. dactylonandA. semialatahaving the fastest (0·054) andE. planaandA. appendiculatusthe slowest (0·039) degradation rates. Mean kdvalues were lower (P< 0·05) in winter (0·039) than in the other seasons (0·048).Neutral detergent soluble (NDS) content was highest inA. semialata(29%) and lowest inE. plana(21·5%). Species similarly varied in the amount of potentially digestible cell wall (PDCW), withE. planahaving the highest (57%) andC. dactylonthe lowest (45·1%) PDCW content. Mean PDCW content was highest in spring (59·5 %) and lowest in winter (44·6%). Cell wall degradation (kc) rates were fastest (0·04) inC. dactylonand slowest inM. caffra(0·03). Overall, kcdeclined from spring (0·039) through to winter (0·029). In general,A. semialata, T. triandraandH. hirtaappeared to have the most favourable, andE. plana, A. appendiculatusandM. caffrathe least favourable, ruminal degradation characteristics. These differences suggest that species composition is likely to have a major impact on potential animal production on these low quality grasslands.
Estimating nutrient content of animal slurries using electrical conductivity
Authors: Stevens R. J. , O'bric C. J. , Carton O. T. 
Published: March 2009

SUMMARYElectrical conductivity was evaluated for estimating the nutrient content of cattle and pig slurries. Slurry samples were collected in 1991 from the storage tanks of 48 cattle and 10 pig units on commercial farms in Ireland. Samples were analysed for NH4+and total concentrations of Na, K, Ca, Mg and P. Electrical conductivity (EC) was measured on raw slurries (ECraw) and on slurries diluted by 10 with water (ECdilute). Relationships between EC and nutrient content were examined by correlation and linear regression analyses.In both slurry types, NH4+was the dominant cation with K+second in importance on a molar basis. Within each slurry type, the concentration of each of these cations was significantly correlated with EC. Using ECdilutegave more accurate predictions of concentrations than ECraw, but even ECrawwas a better predictor than dry matter (DM) content. The linear relationships between NH4+or K+and ECdiluteexplained > 82% of the variance within each slurry type. The P content in slurries was related better to DM than to EC. Since EC measurement could be by cheap, robust meters, its potential for on-farm use deserves further investigation.
Environmental control of lentil (Lens culinaris) crop development
Authors: McKenzie B. A. , Hill G. D. 
Published: March 2009

SUMMARYThe lentil (Lens culinaris Medik.) cultivars Titore and Olympic were sown at Canterbury, New Zealand, on eight dates, from April to November in 1984 and in May and August in 1985. Of the four important physiological growth stages (sowing to emergence (S–E), emergence to flowering (E–F), flowering to physiological maturity (F–Pm) and physiological maturity to harvest (Pm–H)), the duration of all except E–F depended upon accumulated thermal time above 2 °C. The mean accumulated thermal times for E–F, F–Pm, Pm–H were 116, 565 and 293 °C days, respectively. Stage E–F required from 1165 °C days for an April sowing to 509 °C days for a November sowing. There was a highly significant positive relationship (r2 = 0·99) between the rate of development during E–F and mean temperature. Photoperiod also affected development rate.Neither of the two cultivars studied had a vernalization requirement for the induction of flowering. In both years, the development rate during E–F was highly dependent upon photoperiod-corrected temperature. The relationships presented show that development of lentil crops in Canterbury can be accurately predicted using accumulated temperature and photoperiod-corrected temperature.
Seed-bed cultivations and sugar-beet seedling emergence
Authors: Gummerson R. J. 
Published: March 2009

SummaryExperiments are described in which a range of seed beds was created in each of 5 years. The weather in these years produced wet, dry and capping seed-bed conditions. The time course of sugar-beet seedling emergence on each seed bed was recorded each year and the differences were considered in terms of soil physical characteristics: much of the year-to-year variation was accounted for by considering thermal time above 3 °C. The differences in emergence between seed beds were large only when conditions were dry, but in all years it was advantageous to level the seed bed in autumn or winter. Seed beds with a dense soil below the seed and fine aggregates above gave the most suitable conditions for rapid and successful emergence.
Protein and energy retention by growing rabbits offered diets with increasing proportions of fibre
Authors: Partridge G. G. , Garthwaite P. H. , Findlay M. 
Published: March 2009

SummaryNinety-six young rabbits (48 males, 48 females) each weighing 08 kg were offered one of six diets to appetite (n = 8 per treatment) or at one of four restricted feeding levels (n = 2 per treatment). All animals were culled at ca. 2 kg body weight and carcass analysis was carried out. Nutrient retention was estimated by the comparative slaughter technique.Five of the experimental diets (A–E) were formulated to contain increasing concentrations of a poor-quality grassmeal (0, 100, 300, 500 and 700 g/kg, respectively), the remainder of the diet consisting predominantly of ground oats and soya-bean meal. A sixth diet (F) was based on a common laboratory rabbit diet (SGI). All diets contained similar digestible crude protein (DCP): digestible energy (DE) ratios of ca. 13·1 g DCP/MJ DE. Acid detergent fibre concentrations in diets A–F were 146, 158, 213, 264, 321 and 180 g/kg dry matter (D.M.), respectively.When feeding to appetite, growth rates were depressed at the highest inclusions of grassmeal (diets D and E). Growth rates (GR) and voluntary food intakes (VFI) for diets A–F were: GR (g/day): 40, 41, 43, 36, 30 and 40; VFI (g D.M./day): 93, 103, 120, 137, 159 and 111, respectively. The depression in growth rate on diets D and E was associated with a reduction in total daily DCP and DE intake. The data suggested that, when the DE content of the diet falls below 10·5 MJ/kg D.M., the young rabbit is unable to compensate further by increasing daily VFI. Males grew significantly faster than females (40 cf. 37 g/day) and females had fatter carcasses at slaughter (301 cf. 274 g fat/kg carcass D.M.).Relationships between daily N and energy intake and their retention in the body of the growing rabbit were calculated using data from both restricted and ad libitum-fed animals. Daily energy retention (ER, kJ) was related to daily DE intake (DEI, kJ) by the equation: ER = –227 + 6 x DEI (b ranged from 0·407 to 0·502, according to diet).The estimated maintenance energy requirement of the growing rabbit ranged from 351 to 434 kJDE/kg0·75 per day and the average value across all diets was 377 kJ DE/kg0·75 per day.Daily N retention (NR, g) was related to daily digestible nitrogen intake (DNI, g) by the equation: NR = –0·398 + 6 x DNI (b ranged from 0·589 to 0·667, according to diet).The estimated N requirement for maintenance ranged between 0·464 and 0·525 g DN/kg0·75 per day and the average value across all diets was 0·497 g DN/kg0·75 per day.
Phosphorus homoeostasis in growing calves
Authors: Challa J. , Braithwaite G. D. , Dhanoa M. S. 
Published: March 2009

SummaryThe mechanisms by which phosphorus homoeostasis is achieved in growing calves in response to changes in P supply ranging from deficient to excess were investigated in three studies in which additional P was given in the diet, infused into the abomasum, or infused directly into the blood.Whereas the rate of P absorption was directly related to P supplied, the efficiency of absorption of P differed according to the supply. Thus, the absorption efficiency was low from the P-deficient basal diets, increased with P supplementation until the supply was sufficient to meet requirements and then decreased at higher rates of P supply, possibly as a result of homoeostatic control.The serum P concentration, which was directly related to the rate of P absorption, appeared to determine the rates of P retention, salivary P secretion and urinary P excretion. Urinary P excretion was negligible at P intakes below those needed to supply requirements, and any additional P absorbed was partitioned between retention and salivary P secretion in the ratio 0–88:1, these two processes continuing to have equal priority for absorbed P until retention reached a maximum, approximately equal to the postulated growth requirement. Only when the growth requirement for P had been met, did urinary P excretion occur, increasing progressively as the serum P concentration exceeded the renal threshold.The endogenous faecal loss of P increased in direct relation to salivary P secretion and hence to the rate of P supply, the increase occurring even in P-deficient animals. This finding supports the claim that the inevitable endogenous faecal loss of P is not maintained at the constant rate expected at zero P intake until all requirements are met, as assumed by the Agricultural Research Council (1980) in their calculations of P requirements, but varies in direct relation to the P intake needed to supply a particular requirement. Indeed, these results suggest that the ARC (1980) recommendations for P, particularly for growing animals, are too low.Finally, these studies show that bone resorption, salivary P secretion, P absorption and urinary P excretion all play a part in P homoeostasis in the growing ruminating calf, and that the relative importance of each of these processes depends upon the P status of the calf.
Modelling the fate of nitrogen in crop and soil in the years following application of 15N-labelled fertilizer to winter wheat
Authors: Bradbury N. J. , Whitmore A. P. , Hart P. B. S. , Jenkinson D. S. 
Published: March 2009

SUMMARYA computer model is presented that describes the flow of nitrogen between crop and soil on the field scale. The model has a compartmental structure and runs on a weekly time-step. Nitrogen enters via atmospheric deposition and by application of fertilizer or organic manures, and is lost through denitrification, leaching, volatilization and removal in the crop at harvest. Organic nitrogen is contained within three of the model compartments – crop residues (including plant material dying off through the growing season), soil microbial biomass and humus. Inorganic nitrogen is held in two pools as NH4+ or NO3-. Nitrogen flows in and out of these inorganic pools as a result of mineralization, immobilization, nitrification, leaching, denitrification and plant uptake. The model requires a description of the soil and the meteorological records for the site – mean weekly air temperature, weekly rainfall and weekly evapotranspiration. The model is designed to be used in a ‘carry forward’ mode – one year's run providing the input for the next, and so on. The model also allows the addition of 15N as labelled fertilizer, and follows its progress through crop and soil. Data from a Rothamsted field experiment in which the fate of a single pulse of labelled N was followed over several years were used to set the model parameters. The model, thus tuned, was then tested against other data from this and two contrasting sites in south-east England. Over a period of 4 years, the root mean square (R.M.S.) difference between modelled and measured quantities of labelled N remaining in the soil of all three sites was c. 7·5 kg N/ha, on average. The root mean square error in the measurements was c. 2·5 kg/ha. Similarly, the R.M.S. difference between modelled and measured recovery of labelled N by the crop was 0·6, compared with 0·3 kg/ha in the measurements themselves.
Comparison of Texel-and Suffolk-sired lambs out of Finnish Landrace × Dorset Horn ewes under grazing conditions
Authors: Latif M. G. A. , Owen E. 
Published: March 2009

SUMMARYTwo hundred and ten Finn–Dorset ewes were mated to ten rams, five Suffolks and five Texels, in 2 years, to evaluate Texel rams as fat lamb sires. Three hundred and ninetyseven lambs were born and used in the study until the 6th week of age, after which 155 lambs were available for the rest of the experiment. From 6 weeks of age they were grazed with their dams and weighed weekly until slaughtered at 30 kg (females) or 36 kg (males) live weight. Carcasses were assessed by the Meat and Livestock Commission and a random sample of 16 left sides were fully dissected.Fertility and prolificacy of the ewes were 95 and 190% respectively, and were not affected by sire breed. Texel-sired lambs did not differ from Suffolk in birth weight, weight at 6 weeks, growth rate from 6 weeks to slaughter, overall growth rate or age at slaughter. Except for growth rate from birth to 6 weeks, sex difference was significant (P < 0·05) in all growth estimates.No significant breed or sex difference was found in dressing percentages or carcass weight for age. Mean dressing percentage was 47·4 ± 3·48 and 47·5 ± 3·78 for Texel and Suffolk crosses, respectively. Texel cross carcasses had significantly (P < 0·05) lower fat scores and males did not differ from females. Texel cross carcasses had significantly (P < 0·05) higher lean and bone percentages, but significantly (P < 0·01) lower total fat percentage.Apart from demonstrating the capacity to produce leaner lambs compared with Suffolk, the results suggest that Texel sires offer the possibility of producing heavier carcasses without excess fat production.
Effects of laboratory germination, soil temperature and moisture content on the emergence of spring wheat
Authors: Khah E. M. , Ellis R. H. , Roberts E. H. 
Published: March 2009

SummaryIn field investigations in a sandy-loam soil, probit percentage seedling emergence of commercial and aged seed lots of spring wheat (Triticum aestivum L., cv. Timmo) was a positive linear function of probit percentage laboratory germination and mean soil temperature and a negative linear function of percentage soil moisture content over the ranges 12·1–15·5% moisture content and 7·0–11·0 °C. In a laboratory investigation using the same soil a similar form of relationship was observed in six lots over a range of constant soil moisture contents between 10 and 18% and at constant soil temperatures of 8 and 20 °C. In all cases there was no interaction between any of these determinants of seedling emergence.Linear relationships between the mean rate of seedling emergence in the field (i.e. reciprocal of mean emergence time) and probit percentage laboratory germination and mean soil temperature were shown, but there was no obvious effect of mean scil moisture content between 12·1 and 15·5% on rate of field emergence. Seed lots of different percentage laboratory germination had the same base tsmperature for emergence (1·9 °C): differences between seed lots in mean emergence rate were due to different thermal time (day-degree) requirements for emergence; the thermal times required were a function of probit percentage germination in a standard laboratory test. The implications of these results in providing better advice on sowing rates are discussed.
Effects of ova transfer on the birthcoats of lambs
Authors: Burns Marca 
Published: March 2009

SUMMARYBirthcoat samples from Lincoln and Welsh Mountain lambs born in an ova transfer experiment (Weiner & Slee, 1965) were examined to determine the fibre type arrays and any effect of ova transfer on manifestation of the prenatal check or the base (Dry, 1965).In the Lincoln breed arrays were Truncated Ravine or Truncated Valley thus showing central checking. Pre-curly tip fibres were mainly confined to central primary follicles. Post-natal medullation was plentiful, especially in peak curly-tips, but kemp was absent. In the Welsh lambs all identifiable arrays were either Plateau or Saddle, with the lateral primary fibres more checked than the centrals. Pre-curly tip fibres occupied almost all the primary follicles, with only a few curly-tips in primary laterals. Post-natal medullation was strongest in pre-curly tips and their successors.The effect of ova transfer was to decrease the manifestation of check in Lincoln-in-Welsh and increase it in Welsh-in-Lincoln, without affecting the base. Although this, in each case, changed the check of the lamb in the direction of that of the foster breed, it is suggested that this may not be due to any influence of maternal check on foetal check. The effect on pre-natal check may be due to foetal size, and in particular skin expansion, during a short period immediately following completion of primary follicle initiation. As compared to their respective controls, the Welsh transfer lambs had a higher S/P ratio at birth, whilst that of the transferred Lincolns was reduced.If increased prenatal fibre check is associated with increased foetal growth rate at the relevant period, it may also be correlated with increased lamb size at birth and therefore have been favoured in selection for meat production, at least in some breeds.
An investigation into copper deficiency in cattle in the Southern Pennines. II. Response to copper supplementation
Authors: Thornton I. , Kershaw G. F. , Davies M. K. 
Published: March 2009

SUMMARYCopper supplementation within the molybdenum-rich areas, on an exploratory basis in 1967 and in controlled trials in 1968, showed mean live-weight responses of 10–70% in dairy followers representing mean herd increases due to copper of 30–70 lb per animal over a 6-month grazing period. With few exceptions control stock showed no clinical symptoms of hypocuprosis.
The effect of ewe body condition at lambing on the performance of ewes and their lambs at pasture
Authors: Gibb M. J. , Treache T. T. 
Published: March 2009

SUMMARYEwes in body condition scores of 2·4 (thin) or 3·2 (fat) on a 5-point scale and suckling twin lambs were grazed at two stocking rates for the first 16 weeks of lactation. Paddocks were grazed for periods of 2 weeks at densities of 80 and 160 ewes/ha in weeks 1–8 and then 70 and 140 ewes/ha in weeks 9/16 of lactation.Intakes of herbage by ewes were not significantly affected by body condition. Estimation of milk yield by weekly measurement of secretion rates over 4 h failed to demonstrate significant differences due to body condition except in weeks 9, 11 and 12, although there was a tendency throughout for fat ewes to produce more milk. However, the daily growth rates of the lambs during the first 8 weeks and the overall live-weight gains were significantly higher for lambs suckled by fat ewes than for those suckled by thin ewes. Intake of herbage by lambs was not affected by the body condition of the ewes.Herbage intakes, milk yields and lamb growth rates were all significantly higher at the low stocking density than at the high stocking density.