bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of underfeeding for 6 months during pregnancy and lactation on blood constituents, milk yield and body weight of dairy cows
Authors: Roberts C. J. , Reid I. M. , Dew Sally M. , Stark A. J. , Baird G. D. , Collins R. , Mather Denise 
Published: March 2009

SummaryLong-term undernutritional stress is often a feature of sheep and beef cattle production, but has only become a major feature of dairy cattle husbandry in the United Kingdom in recent winters when food was short and expensive. An experiment was carried out to study the effects of long-term underfeeding during pregnancy and early lactation on some blood constituents, milk yield and composition and body weight of dairy cattle. Two groups of cattle were fed at 60 and 40% of the estimated requirements for maintenance and pregnancy or lactation for 13 weeks before and 13 weeks after calving, and one group was fed at the maintenance level only for the same period. A control group was fed at 100% of estimated requirements for this period. All groups were subsequently fed at the control level for a further 24 weeks.The experiment showed that cows undergoing long-term nutritional deprivation were able to maintain concentrations of blood constituents within narrow limits; the concentrations of such constituents as glucose or non-esterifled fatty acid did not reflect energy deficit or surplus. The animals remained clinically healthy during the underfeeding and recovery periods. The results suggest that debility occurring under field conditions in association with reduced food supply may be due to a multiplicity of factors or to severe imbalance of specific nutrients, rather than to energy or protein deficit alone.There was a difference in efficiency of utilization of energy of 19% between cows in the most severely underfed groups which maintained lactation and those which were not able to maintain lactation. There was evidence that this difference in efficiency was detectable within a few weeks of the start of the period of reduced nutrition. Animals which were less affected in the early stages of food deprivation were also those which maintained the advantage through the deprivation and recovery periods.
Some varietal differences in factors affecting nutritive value and in recovery after cutting in Lolium multiflorum
Authors: Wilman D. , Omaliko C. P. E. 
Published: March 2009

SummaryFour varieties of Italian ryegrass (Lolium multiflorum), which have been found to differ in voluntary intake by livestock at the same level of digestibility, were examined in the year of sowing and in the two subsequent years in a field experiment. Eight dates of first harvest during May–June in the years after the year of sowing were compared. During May–June in these years the proportion of leaf in the crop was closely related to the stage of development of the crop relative to heading date, whereas yield and digestibility were more closely related to calendar date. As a result the later-heading varieties, S. 22 and Sabalan, had a higher proportion of leaf than the earlier-heading varieties, RvP and Tetila Tetrone, at a given yield and digestibility and this may at least partly account for higher intake in the former varieties. In addition, in Sabalan, the proportion of green leaf relative to dead was particularly high and the proportion of cell wall particularly low. The surface area per unit dry weight of leaf blade was much higher than that of ‘stem’, which may contribute to shorter retention time in the reticulo-rumen. Surface area per unit weight of both leaf blade and ‘stem’ declined with delay in date of first harvest.The yield of RvP relative to the other varieties was modest at the first harvest in the years after the year of sowing and high at subsequent harvests, in accord with National Institute of Agricultural Botany results. The high yield of RvP relative to the other varieties after the first harvest appeared to be associated with a relatively large number of tillers with their shoot apex below cutting height at the time of first harvest. It seemed that most of these tillers had emerged during the few weeks before that harvest. The proportion of tillers with their shoot apex below rather than above cutting height at the time of first harvest was higher in all four varieties than casual observation would suggest and the proportion remained rather high throughout May and June. The rapid rate of turnover of tillers in Italian ryegrass was confirmed.
Studies on reproduction in prolific ewes:8. The concentrations and rates of accretion of amino acids in the foetuses
Authors: Robinson J. J. , McDonald I. , Brown D. S. , Fraser C. 
Published: March 2009

SUMMARYData are presented for the amino acid contents of 64 litters of Suffolk × (Finnish Landrace × Dorset Horn) foetuses varying in gestational age from 90 to 145 days and in litter size from one to five. The concentrations of glycine, cystine, arginine, proline and hydroxyproline in foetal dry matter increased with age, those for threonine, serine, glutamic acid, valine and methionine remained fairly constant while those for aspartic acid, phenylalanine, histidine and lysine tended to decrease. The most pronounced of these age effects were for cystine and hydroxyproline which increased in concentrations by 60 and 100% respectively over the final 2 months of foetal life. The rates of accretion of the individual amino acids are discussed in relation to estimates of the amounts that may be supplied by microbial protein.
A comparison of leaf and ear development in barley cultivars as affected by nitrogen supply
Authors: Dale J. E. , Wilson R. G. 
Published: March 2009

SummaryTwenty-one two-row and 19 six-row barley cultivars, originating from the major barley growing areas, were compared in a duplicated experiment conducted under controlled environment conditions. Plants were grown in sand and supplied nitrate at two concentrations.Number of leaves on the mainstem and leaf emergence rate both varied widely but there were no consistent differences between two- and six-row cultivars. The low nitrogen treatment led to significant reductions in number of leaves and emergence rates. As a result of these opposing effects the time of appearance of the flag leaf was not affected by treatment. The number of leaves unfolded was a linear function of time where nitrogen was supplied at high concentration but for plants supplied with low nitrogen, appearance of the third and fourth leaves was considerably delayed. Cultivars producing fewer leaves on the mainstem also showed faster leaf emergence and both these factors contributed to the earliness of a cultivar.Low nitrogen treatments reduced number of spikelets per ear in both two-row and six-row barleys; this treatment also reduced the number of grain filled, although mean grain weight was not affected. Faster leaf emergence rates were associated with fewer spikelets per ear in both nitrogen treatments.Since they are based on a relatively large number of cultivars it is likely that these results are general for barley. The importance of further detailed examination of apical development is indicated.
Effect of fertilizer nitrogen on drought resistance inCoffea arabicaL.
Authors: Tesha A. J. , Kumar D. 
Published: March 2009

SummaryWhen coffee trees have a good supply of nitrogen they are less affected by drought. Explanation and evidence are presented. Trees treated with extra nitrogen contained more adenosine triphosphate, aqueous protein and ‘bound water’.Such N-rich trees exhibited lower transpiration rates than trees relatively poor in N when water supply was limiting. They had lower stomatal density and water saturation deficit values. Leaves maintained higher chlorophyll and turgidity. The conclusion is that nitrogen increases the drought-resisting capacity of coffee trees. This aspect was clearly reflected in yield, as nitrogen-rich trees produced more coffee beans.
The effect of dietary intake of calcium and dry matter on the absorption and excretion of calcium and phosphorus by growing lambs
Authors: Field A. C. , Woolliams J. A. , Dingwall R. A. 
Published: March 2009

SUMMARYThe isotope dilution technique was used to measure endogenous faecal excretion and absorption of dietary Ca and P by growing lambs. Groups of four lambs were given 0·8 or 1·2 kg/day of a pelleted barley and soya-bean diet containing 4·2 g P/kg D.M. and supplemented to contain 1·79, 3·52 or 4·67 g Ca/kg D.M.At the lowest dietary concentration of Ca, absorption of Ca was insufficient to meet the Ca required for deposition in the newly formed bone matrix of the skeleton; retention was 0·39, 1·16 and 1·12 g/day with increasing dietary Ca concentration. The proportion of dietary Ca absorbed decreased (P < 0·001) with increasing Ca intake, ranging from 0·85 to 0·44. Endogenous faecal excretion of Ca was independent of the absorption of dietary Ca, but increased (P < 0·05) from 17·2 at the lower to 21·1 mg/kg live weight/day at the higher D.M. intake. Plasma concentration of Ca was higher for the female (2·51) than the male (2·33 mmol/1) lambs and increased linearly (P < 0·001) with dietary concentration of Ca from 2·31 to 2·52 mmol/l.The retention of P increased with Ca and D.M. intake. On the other hand, the proportion of dietary P absorbed (0·85) was independent of Ca intake and hence of P retention. Increases in P retention were reflected by decreases in urinary P, but not in endogenous faecal excretion. Endogenous faecal excretion of P increased with D.M. or P intake from 17·9 at the lower to 33·5 mg/kg live weight/day at the higher intake.The results are discussed in relation to dietary allowances of Ca and the mechanism of P homoeostasis.
The usefulness and limitations of estimating the number of genes in a barley breeding programme
Authors: Powell W. , Caligari P. D. S. , Jinks J. L. 
Published: March 2009

SUMMARYRandom inbred lines produced by doubled haploidy and single seed descent have been used to estimate the number of genes or more correctly effective factors (k) controlling quantitative characters in barley. Estimates of k obtained by various biometrical methods are generally an underestimate since the effective factor may be considered a unit only in a temporary sense. In the past, estimates of k have been used to predict the range of inbreds extractable from a cross. Alternative and efficient methods are now available to predict the number of inbreds expected to exceed any given standard. Under these circumstances the need to estimate the number of genes is questionable.
Allometric changes during growth in rabbits
Authors: Deltoro J. , Lopez Ana M. 
Published: March 2009

SUMMARYDifferential growth from 1 to 20 weeks of age was studied on 320 rabbits from two lines (New Zealand White and California) and both sexes by means of the allometric equation log y = log a + b log x. Regression lines were fitted to the evolution of organs (blood, skin, thymus, heart–lungs, liver, kidneys and alimentary tract), carcass, tissues (bone, lean and fat) and anatomic components (head, breast and ribs, loin, abdominal wall, fore and hind legs) relative to empty body weight; stomach, caecum and intestines relative to alimentary tract; bone and lean groups relative to total bone and lean and fat depots relative to total fat.The convenience for a correct description of relative growth of determining both the quantitative growth, in order to apply the allometric equation only to the real growth period of each component, and the possible existence of allometric changes, is discussed.The results for each component are presented and discussed. There were no significant differences due to line, and sex had a significant influence (P < 0·001) only on the relative growths of total fat, lean content in the loin and hypodermic fat. All the components, with the exception only of thymus, presented a change in their allometric coefficients. These changes for most components, except fat depots, were concentrated in a small interval of time (4–8 weeks of age) between weaning and the inflexion point of the body weight growth curve.
Water relations of winter wheat: 2. Soil water relations
Authors: Gregory P. J. , McGowan M. , Biscoe P. V. 
Published: March 2009

SummaryVolumetric soil water content and soil water potential were measured beneath a winter wheat crop during the 1975 growing season. Almost no rain fell between mid-May and mid-July and the soil dried continuously until the potential was less than – 20 bars to a depth of 80 cm. Evaporation was separated from drainage by denning an ‘effective rooting depth’ at which the hydraulic gradient was zero.Rates of water uptake per unit length of root (inflow) were calculated for the whole soil profile and for individual soil layers. Generally, inflow decreased throughout the period of measurement from a maximum of 2·5 × 10–3 to a minimum of 0·66 × 10–3 ml water/cm root/day. Values in individual layers were frequently higher than the mean inflow and the importance of a few deep roots in taking up water during a dry season is emphasized. A similar correlation between inflow and soil water potential was found to apply for the 0–30 cm and 30–60 cm layers during the period of continual soil drying. This relationship represents the maximum inflow measured at a given soil water potential; actual inflow at any particular time depends upon the interrelationship of atmospheric demand, soil water potential and the distribution of root length in the soil.
Studies in grazing management IV. A comparison of close-folding and rotational grazing dairy cows on intensively fertilized pasture
Authors: Holmes W. , Waite R. , Fergusson D. L. , MacLusky D. S. 
Published: March 2009

1. In continuation of experiments made in 1949 (Holmes et al. 1950) an experiment was carried out from 7 May until 23 September 1950, to compare close-folding and rotational grazing of cows on pastures which were liberally treated with nitrogenous fertilizer. With close-folding the cows were moved daily to an area of fresh pasture calculated to supply the day's feed requirements; the rate of stocking for the day ranged from thirty to sixty-five cows per acre. With rotational grazing the cows were stocked on pasture at the rate of seven to eight cows per acre and moved from one pasture to the other at intervals of 3–4 days. Two uniform groups of six Ayrshire cows were used in a double reversal layout with four periods each of 5 weeks. The same pastures as in 1949—a permanent pasture and a cocksfoot ley—suitably divided by electric fences were used. No supplementary feeding was given.2. The average yield per acre from close-folding was 241 cow-days, 732 gal. of milk and 320 lb. live-weight gain—equivalent to 632 lb. digestible crude protein and 4316 lb. starch equivalent. Rotational grazing on similar adjoining paddocks gave 181 cow-days, 557 gal. of milk and 285 lb. liveweight gain per acre, equivalent to 486 lb. digestible crude protein and 3371 lb. starch equivalent.3. The average daily milk yield per cow was 29·5 lb. for one group and 30·2 lb. for the other. For close-folding it was 29·6 lb. and for rotational grazing it was 30·1 lb., none of the differences being significant. Nor were any differences in the average live weight of the groups or in their live-weight gains significant.4. The increased production per acre from closefolding compared with rotational grazing—amounting to 20–40%—could be related to the increased efficiency with which the available pasture was consumed.5. Close-folding had no harmful effect on the pastures. Although the season was exceptionally wet, poaching occurred only in the gates and alleyways. 6. The frequent applications of nitrogenous fertilizer throughout the season maintained regular production of good herbage. In June and July, however, despite the fertilizer applied, the crudeprotein content dropped on some paddocks to 13% of the dry matter, a figure barely sufficient to maintain high milk yields.7. Comparison of the production per acre in 1950 with that in 1949 where close-folding was used, showed an increase of 34% in starch equivalent utilized on the permanent pasture. For each extra cwt. ‘Nitro-Chalk’ applied in 1950 over that in 1949, 190 lb. starch equivalent were produced. On the cocksfoot the response to additional nitrogen was reduced because of potash deficiency induced by cropping for grass-drying in 1948.8. The factors affecting the increased production from close-folding and the fertilizer requirements of pasture are discussed.
The fate of soluble mucin in the gastro-intestinal tract of sheep
Authors: Hecker J. F. 
Published: March 2009

SummaryExperiments were done to determine the fate of soluble mucins in the gastrointestinal tract of sheep. Incubation of a soluble mucin with liquor from large intestinal contents resulted in loss of mucin. Some of this loss was due to soluble enzymes. The loss of mucin was less when incubation was with rumen liquor and variable when with ileal liquor.The mean amounts of nitrogen in a soluble mucin fraction which was soluble in trichloroacetic acid (T.C.A.-soluble mucin) were 2·5, 7·3 and 20·0 mg per 100 ml in rumen caecal and faecal liquors respectively. These amounts were only a small proportion of the total soluble nitrogen in these fluids.Amounts of T.C.A.-soluble mucin, measured by sugar content, were greatest in contents from the small intestine. When the amounts of T.C.A.-soluble mucin were compared with the amounts of lignin in the samples, there was an increase between the abomasum and the first part of the small intestine and then a decrease to the caecum. Amounts relative to lignin were low in other parts of the gastro-intestinal tract.The greatest ratio of fucose to rhamnose in T.C.A.-soluble mucin from gastro-intestinal liquors was in ileal liquor. The presence of the two methyl pentoses, fucose and rhamnose, indicates that the T.C.A.-soluble mucin is derived from mucus and bacteria.
Variation in the birthcoats of Wiltshire lambs, and its relation to casting of the adult fleece
Authors: Ryder M. L. 
Published: March 2009

SummaryFour of five ‘hairy’ Wiltshire lambs had fibre type arrays (as defined by Dry, 1965) of Plateau (P0 and P1) type, whereas in five ‘woolly’ lambs there was only one Plateau (P3) array, the arrays of the remaining lambs being Ravine or Saddle. In terms of Dry's theory that the severity of pre-natal check determines persistence of wool growth in adults, it appears that the amount of checking in these Saddle and Ravine arrays was insufficient to prevent the casting of the adult coat.
The behaviour of nitrogenous materials buried in the soil II. The solubilization of nitrogen under full aeration for long periods
Authors: Barnes T. W. 
Published: March 2009

Soil was maintained in a moist condition with as complete aeration as possible, for periods up to 89 weeks, either alone or after the addition of straw, ground-up mustard plants, ground-up tare plants, or ammonium sulphate. The nitrogen which existed as nitrate, ammonia, or other materials soluble in cold water, as compounds only soluble in hot water, or as substances only soluble in dilute HCl, was determined at intervals during this period. In general, little change took place after 11 weeks apart from a very slow and very slight increase in the nitrate produced, except after the addition of straw. Ammonia was reduced to a trace in all cases. The whole of the nitrogen soluble in cold water became converted into nitrate or ammonia in less than 11 weeks, except in the case of the admixture with straw. With straw there was far less accumulation of nitrate than when no addition was made, and this prevention of the formation of nitrate continued to the end of the experiment (89 weeks). The less soluble nitrogenous material (i.e. that only soluble in hot water or in HCl) was hardly affected by the long incubation.The added nitrogen was entirely recovered after the end of the experiment, except where ammonium sulphate was used. In this case there was an apparent disappearance of 30% of the added nitrogen.
An examination of sample joint dissection and specific gravity techniques for assessing the carcass composition of steers slaughtered in commercial abattoirs
Authors: Ledger H. P. , Gilliver B. , Robb J. M. 
Published: March 2009

SummaryThe relationships between joint and carcass specific gravities and composition are examined and the prediction efficiency of equations relating these parameters tabulated. The problems of assessing carcass composition in large abattoirs are indicated. The use of the tenth rib sample joint in conjunction with a specific gravity estimation technique is recommended.
The effect of body-weight loss on the composition of Brahman cross and Africander cross steers: II. Dissected components of the dressed carcass
Authors: Seebeck R. M. 
Published: March 2009

SummaryComparative slaughter was used to assess the effects of body-weight loss on Brahman cross (BX) and Africander cross (AX) steers of the F3generation with respect to gross dissected carcass composition and the distribution of these components over the dressed carcass. Animals were slaughtered at design body weights of 325, 341, 358, 374 and 390 kg, some while during positive body-weight growth (Group A), and others during weight loss from 390 kg at a rate of approximately 0–5 kg/day (Group B).Gross composition was similar in the two breeds, irrespective of the body-weight loss treatment. Body-weight loss resulted in muscle and fat approximately reversing the path of development, while bone and fascia and tendon remained approximately constant. No evidence of proportionally early loss of fat and later loss of muscle was found. Of the fat components, kidney and channel fat showed the highest relative loss. The distribution of muscle was different between the breeds, the most statistically significant differences being that AX had heavier muscles around the spinal column and lighter shin muscles, at the same total muscle weight. Bone weight distribution differences also occurred, with AX tending to have lighter leg bones, at the same total bono weight. A breed difference in intermuscular fat distribution meant that the AX animals were earlier developing in the forequarter and later developing in the hind quarter in respect to its intermuscular fat, than the BX animals.Body-weight loss affected muscle-weight distribution, the most marked effect being that the relative proportion of abdominal muscles fell during body-weight loss. Boneweight distribution was affected to a minor extent, the effects mainly being in the leg bones rather than the axial skeleton. The distribution of neither fascia and tendons nor subcutaneous fat was affected by the body-weight loss treatment, but the distribution of intermuscular fat was affected.
The effects of single injections of progesterone on oestrous cycle length in ewes
Authors: Dixon I. W. , Thwaites C. J. 
Published: March 2009

SummaryTwo hundred and forty mature Merino ewes were used in a factorial experiment to investigate the effects of single injections of either 0, 40, 80 or 160 mg progesterone on the length of the subsequent oestrous cycle. Equal numbers of ewes (15 per group) received subcutaneous and intramuscular injections, and equal numbers were treated either on the day of oestrus or the following day.Oestrous cycle length was significantly reduced in all treated groups, with a minimum cycle length of 7–10 days following treatment with 80 or 160 mg progesterone. Neither route of administration nor day of treatment significantly affected the response. The conception rate achieved by treated ewes at the first post-treatment oestrus did not differ significantly from that in comparable controls.The results suggest that a single massive dose of progesterone on the day of oestrus is an effective means of shortening the oestrous cycle of the ewe without loss of fertility.