bluuebunny/crossref_metadata_2025 huggingface dataset:
Intensive beef production from sorghum grain and sorghum stubble: Effects of methods of processing the grain and the stubble, vitamins A, E and K and selenium supplementation and anthelmintic treatment on rate and efficiency of body weight gain and carcass composition
Authors: Morris J. G. , Pepper Patricia M.
Published: March 2009

The intensive finishing of steers on simple rations of 10% sorghum stubble and 90% sorghum grain plus urea was investigated. Fine grinding of the grain resulted in a lower mean daily intake, but a significantly greater efficiency of conversion of feed to carcass weight gain (P < 0·01) than coarse grinding the grain. Coarse chaffing of the stubble significantly reduced the intake of the stubble in comparison with hammer milling, but had no significant effect on rate of body weight gain, total feed intake or efficiency of feed conversion.

The addition to the ration of either 1 mg of selenium, or 200 mg vitamin E, 200 mg vitamin E and 100 mg vitamin K per day had no significant effect on rate or efficiency of body or carcass weight gain. Seven out of 32 steers which were not injected with 3 million i.u. of vitamin A at the start of the experiment exhibited nyctalopia. None of the 32 steers which received the vitamin A injection had hepatic vitamin A concentrations less than 33 μg/g. Vitamin A injection did not have a significant effect on the rate of body weight gain (mean ±S.E. 1·3 ± 0·03 kg per day), efficiency of feed conversion (10·4 ± 0·16 kg D.M. per kg carcass weight gain), or time to attain slaughter weight (133 ± 3 days). Drenching twice with thiabendazole had no significant effect on rate of body weight gain.
Monogerm sugar-beet seed production experiments
Authors: Longden P. C.
Published: March 2009

Eight experiments investigated how different sowing and harvest dates, plant populations and fertilizers affect yield, germination and size of seed from hybrid monogerm sugar-beet seed crops, grown in situ when raised under barley cover in Lincolnshire, or open sown in Oxfordshire. Weather at seed harvest was wetter than average in 1968, average in 1969, and drier in 1970. Most seed of good quality came from plant populations of 300000 plants/ha sown in early July, given ample P and K fertilizer in the seed bed and 150–200 kg/ha of N in the spring of the second year in Oxfordshire or 200–250 kg/ha N in Lincolnshire. Harvesting in early September on average yielded most seed. Methods used to grow multigerm seed proved suitable also for monogerm seed but the percentage germination was lower for monogerm than multigerm seed.
The yields of wholesale cuts from carcasses of Aberdeen-Angus crosses fattened on grass and in yards
Authors: Harrington G. , Pomeroy R. W.
Published: March 2009

1. Both sides of sixty-eight carcasses of Aberdeen-Angus cross steers and heifers were broken down into wholesale joints by the same butcher using a modification of the London and Home Counties style of cutting. Thirty-four of the cattle were fattened on grass in the summer of 1955 and the other thirty-four in yards during the following winter.

2. Sides of steer carcasses averaged some 50–60 lb. heavier than those of heifers both in summer and winter, and the yard-fattened cattle gave sides averaging 10–20 lb. heavier than those from grassfattened cattle.

3. The cuts along the underline of the animals (brisket and flanks) were increasing in weight at proportionally the greatest rate and the shin and hind-leg cuts at about half this rate, with those along the top of the back intermediate.

4. At a side weight of 300 lb., steers were significantly lighter than heifers in the weight of kidney knob, cod fat, thin flank, forequarter flank, loin and rump, whereas they were significantly heavier than heifers in weight of leg, shin, topside, top rump and the neck cuts (clod and sticking). These differences suggested that at this weight of side, heifers were at a more advanced stage of development than steers.
Estimation of effective infiltration rates in cracked soils
Authors: Pandey R. N. , Pandey R. S.
Published: March 2009

Infiltration is the most important aspect in the hydraulics of surface irrigation, since the design of irrigation systems depends to a large extent upon the infiltration characteristics of the soil. Many workers have contributed to the theoretical understanding of the infiltration phenomenon (Kirkham & Powers, 1972). However, very little work is available on the evaluation of infiltration into cracked soils. Measurement of infiltration into these soils poses a special problem. Depending on the degree of cracking, a fraction of the water added on the soil surface flows down through cracks and goes to waste. The water flowing through the cracks does not contribute to the moisture storage of the soil profile which may subsequently be used by the crops. Also, infiltration rates measured using ring infiltrometers are erroneous. In order to have an efficient design for an irrigation system, realistic estimates of infiltration characteristics for this type of soil are essential. In the present paper an attempt has been made to estimate the effective infiltration rate into such cracked soils. The procedvire suggested has been tested under limited conditions and found useful under field conditions. However, extensive field testing under various soil conditions is necessary before it can be recommended for general use.
Carcass characteristics of young red deer farmed on hill pasture
Authors: Kay R. N. B. , Sharman G. A. M. , Hamilton W. J. , Goodall E. D. , Pennie K. , Coutts A. G. P.
Published: March 2009

Carcass characteristics were studied in young red deer raised on a Scottish hill farm with heather·dominant pasture. Stags slaughtered in September when 15 or 27 months old were very lean, and entire and castrate animals were similar in weight. At 15 months they were barely a half of their expected mature weight. With no pre-slaughter fasting, dressed carcass weight was 49–51% of live weight. A more detailed analysis of carcass conformation was made in a study of entire stags, castrate stags and hinds slaughtered when 15 months old after being held overnight without food or water. The three groups were similar in that their dressed carcasses weighed about 52% of live weight and the content of first class lean meat amounted to 32% of live weight. There was only 4·5% of chemical fat in the empty carcass.

The pH of the meat 36 h post mortem often remained high in the stag groups, relative to a mean value of pH 5·7 found in shot wild stags. This high-pH character was little affected by the severity of stress immediately before slaughter, nor by the availability of food. It seemed to be caused by holding the animals in unfamiliar surroundings for some 16 h before slaughter.
Effect of genotype and position in the ear on carpel and grain growth and mature grain weight of spring barley
Authors: Scott W. R. , Appleyard Margaret , Fellowes Gwynneth , Kirby E. J. M.
Published: March 2009

Grain growth and final weight per grain were measured in 12 genotypes of spring barley, the parents and progeny of two six-row × two-row crosses. Weight of carpels or grains from node 10 on the main shoot ear was measured from shortly after meiosis until grains were at maximum dry weight. Similar measurements were made at representative node positions along the ear of Proctor and of Midas spring barley cultivars.

From about 10 days after anthesis grains grew at a constant rate for about 3 weeks. Amongst genotypes growth rate of the median grain ranged from 1·4 to 2'2 mg/day and there was a very highly significant positive correlation between growth rate and final grain weight. A similar relationship was found among grain positions on the ear. For about 10 days after anthesis growth was exponential and although relative growth rate did not differ between genotypes or grain positions there was a highly significant difference between caryopsis weights during this phase. There were significant correlations between final grain weight and carpel weight at anthesis and between final grain weight and husk weight at anthesis. In the period between meiosis and anthesis growth was exponential and the relative growth rate did not differ between genotypes or node positions on the ear. There were significant differences between carpel weights during this phase. Carpel weight at anthesis and carpel linear dimensions at meiosis were correlated.

These data suggest that the initial size of carpel is an important factor in determining growth rate and potential grain weight. Potential grain size in barley may be determined by physical limitations imposed by the lemma and palea or may be causally related to the size of the carpel. The relative size of the carpel is determined by the time of meiosis and potential size may also be affected by pre-anthesis conditions.
Growth, development and yield of pigeon pea (Cajanus cajan (L.) Millsp.) in the lowland tropics: 4. Effect of sowing depth
Authors: Tayo T. O.
Published: March 2009

The seeds of a dwarf variety of pigeon pea (cv. Cita-1) were sown at 2, 4, 6 or 8 cm depths in three field trials in 1981 and 1982, in order to evaluate the effect of sowing depth on seedling emergence and the subsequent growth, development and yield of the crop.

In all trials, sowing pigeon-pea seeds deeper than 4 cm led to 1–2 days delay in seedling emergence, resulted in only 40–68% seedling emergence, reduced the development of the various growth and yield characters of the plant and significantly reduced seed yield. In two trials, plants from 4 cm sowing performed better than those from 2cm sowing in terms of development of growth and yield characters indicating that shallow sowing of pigeon pea prevents rapid and proper plant establishment.

The results therefore indicate that the optimum sowing depth for pigeon pea is 4 cm under the prevailing lowland humid tropical conditions.
Estimation of fat content of beef carcasses in a commercial classification system
Authors: McIntyre B. L. , Ryan W. J.
Published: March 2009

A total of 25 steer carcasses from a wide range of breeds and carcass weight and fatness were used to examine the relationship between a range of fat thickness measurements and the dissected fat content of beef carcasses. Fat thickness measurements included those on the hot carcass suitable for ‘commercial’ use and others on the cold carcass commonly used in research.

The mean of the measurements of fat thickness from the two sides of the hot carcass between the 12th and 13th ribs (12H) gave the most accurate prediction of carcass fat content (FPCT). The relationship was described by the equation FPCT = 14·61 + 1·85 (12H) (R2 = 0·92; S.E. of prediction of individual FPCT at the mean= ±2·17%).

The mean of four fat thickness measurements made on the quartered surface between the 10th and 11th ribs of the cold carcass was the next most accurate predictor (S.E. = 2·28%) of fat content. Fat thickness measurements made on the hot carcass between the 10th and 11th ribs were the least satisfactory.

Although the hot carcass measurements between the 12th and 13th ribs were made under commercial conditions and included a wide range of types of cattle the prediction of fat content from these measurements had a marginally lower standard error than the prediction based on measurements made under experimental conditions.
The progeny testing of dairy bulls at different levels of production
Authors: Mason I. L. , Robertson Alan
Published: March 2009

1. An analysis has been made of milk records from 13,000 cows bred by artificial insemination in Denmark.

2. The herds were divided into three equal groups on the basis of their average production. The variance of yield within herds increased as the average yield increased, but the coefficient of variation declined slightly. The genetic variance was more than five times as large in the high-yielding herds than in the low, and correspondingly the heritabilities in low, medium and high herds were 0·05, 0·15 and 0·22 respectively. These were estimated from the variation observed between progeny groups of the same 152 bulls at each production level.

3. No evidence was obtained of any sire-herd interaction for yield, either within or between management levels. The true ranking of bulls for breeding value was apparently the same at all levels.

4. The heritability of fat content in the three groups was 0·27, 0·47 and 0·49 respectively, and no evidence of sire-herd interaction was found.

5. The contemporary comparison method of assessing A.I. bulls for yield was found to have the accuracy expected in theory.

6. These results are discussed in relation to those of other workers with which there are some discrepancies. On our results, a policy of choosing bulls on the basis of their daughters' performance in high-yielding herds should be the most satisfactory way of progeny-testing bulls used in artificial insemination.
The progeny testing of dairy bulls: a comparison of special station and field results
Authors: Robertson Alan , Mason I. L.
Published: March 2009

1. A comparison has been made between progeny tests in special stations and those available from field records. The variation between sires in milk yield is much greater at the stations even when they are compared with herds at the same production level.

2. In respect of yield the repeatability of station tests in the field is not good. The regression of field results on station test is only about 0·2 in herds at all production levels. For fat percentage, the regression is 0·5.

3. The tests in special stations (averaging seventeen daughters per bull) were compared with those in high herds (average twenty-seven daughters) in their accuracy of prediction of the performance of bulls in the poorer herds. The field test was slightly (but not significantly) better for both milk yield and fat content.

4. In milk yield, there is undoubtedly some extra variation between progeny groups at the stations which is not repeated in the field. Perhaps the tying of the heifers in distinct daughter groups in the byre may be a cause of this. However, even without this, it is doubted whether the test stations can give as much useful information on the numerical aspects of performance as the field records usually available. It is suggested that the splitting of daughter groups within the byre might increase the accuracy of the special station in the assessment of yield.
Growth of red deer stags under farm conditions
Authors: Hamilton W. J. , Blaxter K. L.
Published: March 2009

The growth in body weight of 91 stags from weaning to 15 months of age and of a smaller number from 15 months to maturity was examined using observations from a farmed stock kept on hill land. Growth rate in winter from 3 months to 10 months of age was proportional to feed allowed and was 35 % greater than for hind calveskept under similar conditions. Growth rate in the subsequent summer was greater for stags than for hinds in sixout of seven instances. After 15 months of age, stags continued to increase in body weight and their weight thus continued to diverge from that of hinds such that at 87 months the average weight of the surviving nine stags was 132 kg and that of the surviving 47 hinds, 78 kg. It is estimated that the equilibrium weight of stags was 154kg.
Sodium transport by lamb proximal colon measured during early postnatal development
Authors: Smith M. W. , James P. S.
Published: March 2009

Proximal colons taken from lambs up to 3 weeks after birth were shown to transport both sodium and chloride from lumen to blood when incubated in vitro.

Sodium transport fell into three phases during postnatal development. The first covered the period from birth to 3 days of age when sodium transport was high and equal to that calculated from measurement of short-circuit current. The second was seen in 5- and 7-day-old lambs where the short-circuit current was low and the net transport of sodium was negligible. The third was seen in 2-3-week-old lambs where sodium transport was high, but the short-circuit current was low.

Chloride absorption by colons taken from 1-day-old lambs appeared to be in exchange for an anion, possibly bicarbonate. Chloride absorption by colons taken from 3-week-old lambs appeared to be electrogenie or coupled directly to the transport of sodium.

A possible explanation for the failure of electrolyte absorption by colons taken from 5- and 7-day-old lambs is discussed.
Inheritance of Seed Shape and Resistance to Ascochyta Blight in Pea (Pisum sativum L.)
Authors: Rastogi K. B. , Saini S. S.
Published: March 2009

To ascertain the inheritance of seed shape and resistance to Ascochyta blight and to incorporate resistance in commercial cultivars, crosses were made between cv. Kinnauri, a round-seeded resistant source and commercially important cvs Bonneville, Lincoln, GC 141, and Selection 18, highly susceptible to disease but wrinkled-seeded. The F1, F2 and F3 data indicated that seed shape and resistance to Ascochyta blight is determined by two independently inherited genes. Round seed and disease resistance are dominant over wrinkled seed and susceptibility. Commercially desirable lines have been selected which combine the resistance gene of Kinnauri with wrinkled seed from susceptible commercial cultivars, and which also possess high pod yields and other desirable characters.
The seasonal distribution of nitrogen fertilizer dressings on pure perennial ryegrass swards
Authors: Reid D.
Published: March 2009

In studies of the seasonal distribution of nitrogen fertilizer dressings on grassland using conventional experimental designs it is usually not possible to separate the true effects of an individual fertilizer dressing on the yield at a particular cut from the residual effects of previous dressings. An experiment is described which was designed to allow separation of the direct and residual effects, with certain restrictions, for a system involving five cuts and five possible fertilizer dressings per season on perennial ryegrass swards. From the results obtained over two harvest years on swards on two adjacent sites equations were derived relating the dry-matter and crude-protein yields of herbage to the rate of nitrogen application at five dressings in the season. Predictions of yield distribution patterns from the equations are compared with observed yields from various sequences of nitrogen dressings included in previous experiments at this Institute. Examples are also given of the prediction of sequences of nitrogen dressings required to obtain certain patterns of yield distribution.
Competitiveness and effectiveness of carbendazim-resistant mutant and indigenous Rhizobiumstrains of chick pea (Cicer arietinutnLinn.) in calcareous soil
Authors: Rai R.
Published: March 2009

Chick pea Rhizobiumstrain RG 4 was treated with 30 /tg/ml of N-nitrosoguanidine and four mutants isolated were resistant to 400 /tg carbendazim/ml. Only two of the mutants (M 1 and M 4) retained the capacity to form nodules. On the basis of number of nodules, their dry weight, nitrogenase activity, triphenyl tetrazolium chloride reductase activity and active iron content of nodules, mutant strains M 1 and M 4 were found to be equally effective for nitrogen fixation both with and without carbendazim (bavistine) and resulted in significantly greater grain yield than the corresponding uninoculated treatments.
Sett weight effects on time of tuber formation and on tuber yield characteristics in water yam (Dioscorea alata L.)
Authors: Onwueme I. C.
Published: March 2009

Setts of water yam (Dioscorea alata) weighing 350, 100, or 20 g were grown in the field. Tuber formation occurred in 50% of the plants at 8, 9·2, and 11 weeks after planting respectively, thus showing delayed tuber formation as sett weight decreased. Leaf area per plant and tuber yield per plant decreased with decreasing sett weight, but the tuber multiplication ratio increased with decreasing sett weight. There was a high coefficient of variation for tuber yield per plant and for leaf area per plant. It is suggested that the delayed tuber formation for small setts may be partly responsible for the low tuber yield per plant observed.
The effect of ground water-level upon productivity and composition of fenland grass
Authors: Eden A. , Alderman G. , Baker C. J. L. , Nicholson H. H. , Firth D. H.
Published: March 2009

1. Studies were made of the effects of varying ground water-levels upon the productivity and composition of Italian Ryegrass grown on a calcareous light peat in the Fenland area. Six cuts were taken throughout the season at 3 to 4-weekly intervals.

2. High ground water-level (approximately 15in. below ground surface) had a very deleterious effect on the total yield of fresh grass and of dry matter. Yields were little more than half of those obtained at medium and low water-levels (24 and 38 in. below ground surface, respectively).

3. High water-level apparently interfered with nitrogen metabolism in the soil, and considerably lower percentages of crude protein were found in the grass growing on the high water-level plots than at the other levels. On the other hand, the percentage of crude fibre remained fairly constant for all levels of ground water.

4. High water-level also had a depressing effect on the percentage of potassium, magnesium and chlorine in the grass. It had no obvious effect upon the calcium and phosphorus levels in the plants. The silica content of the grass rose steadily as the season advanced, this being most marked on the high water-level plots.

5. Physical examination of typical plants showed the effect of the various ground water-levels upon the development of the root systems, with consequent effect upon the chemical composition of the grass.

6. The composition of hay and aftermath showed similar changes to those reported for the green herbage.

7. The findings are discussed in relation to grassdrying policies in Fenland areas.
Red cell electrolyte distribution and its possible significance in zebu cattle
Authors: Sengupta B. P.
Published: March 2009

Two breeds of zebu viz. Hariana and Sahiwal were examined for the possible existence of red cell K+ polymorphism. All the animals examined appeared to be LK type. However, red cell K+ concentration varied rather widely between 7 and 50 m-equiv/1. Within the major LK type three distinct subtypes, tentatively designated as low low (LLK), medium low (MLK) and high low (HLK) were observed. The mean red cell K+ concentration in the various subtypes in the same order were 12·5, 19·5 and 38·0 m-equiv/1 respectively. LLK animals were significantly more frequent in the Sahiwal than in the Hariana breed. The possible genetic basis of the occurrence of these subtypes within the major LK type is discussed.

LLK animals had significantly higher pcv, Hb and RBC, than MLK animals. The WBC and plasma protein values were also higher, though not significantly, in the former group. In addition, animals of the LLK subtype showed consistently lower rectal temperature at comparable levels of respiratory effort under conditions of thermal stress than MLK animals.
Pig-feeding experiment using dried Clostridium residue
Authors: Braude R. , Foot A. S.
Published: March 2009

In an experiment with twenty-four Large White pigs fattened from weaning to bacon weight on a diet containing either 5 or 9% of dried Clostridium residues the latter was found to be an efficient protein supplement.

The authors wish to express their thanks to Dr S. J. Rowland who made all the chemical analyses involved, to the Directors of Commercial Solvents G.B., Ltd., who kindly supplied the product, and to Mr E. Gill, Works Manager of the above Company, for helpful collaboration.
The “restricted” feeding of bacon pigs: A co-ordinated experiment at centres in Great Britain and Ireland
Authors: Shorrock R. W.
Published: March 2009

The results are described of twenty-two experiments carried out on the feeding of bacon pigs at different centres throughout Great Britain, in the course of which nearly 400 pigs were fed according to three different scales of rationing. All the pigs were fed on the same scale until reaching 100 lb. live weight, when they were eating 4 lb. of meal per head per day. From this stage three different levels of feeding were followed; in each case the daily allowance reached a maximum when the pigs were 170 lb. live weight. The amounts being fed were then: 7 lb. 8 oz., 6 lb. 5 oz. and 5 lb. 3 oz. per head per day respectively.
The limited numbers of nodules produced on legumes by different strains of Rhizobium
Authors: Chen H. K.
Published: March 2009

Pot experiments were made with red clover and with soy beans to determine how far the number of nodules developed was a specific character of the strain of Rhizobium supplied.

The number of nodules per gram of root was found to reach a limit specific to each strain. This limiting equilibrium was attained regardless of the size of the root system or the age of plant at which the culture was first supplied, provided enough time were allowed for the limit to be reached.

When two different strains were applied to the root surroundings in succession, the final number of nodules was determined by the limit specific to the strain in contact with the roots while these were making most of their growth. In clover this was the second and in soy beans the first applied strain.
Note on ‘the significance of the pH determination in the evaluation of quality in silages’
Authors: McLean W.
Published: March 2009

It is now generally recognized that the pH of a silage is the best single criterion of its quality. In other words, it is regarded as the best single guide to the type of fermentation that has taken place in the mass in the silo and thus serves to indicate the degree of success achieved in the ensilage process, whatever the crop or its stage of growth. For instance, in the case of silages, made with or without molasses, where the pH is at or below 4·0, the silage would be deemed to be of ‘excellent’ quality, that at 4·0-4·5 would be designated ‘good’, that at 4·5–5·0 only ‘moderate’, and at or above the latter figure the silage would be classified as ‘bad’. To get a complete picture of the chemical changes that have taken place and to assess the feeding value of a silage is quite a different matter and is not the object of the present note.
Effect of nutrition and dose level of PMS on oestrous response and ovulation rate in progestagen-treated non-cyclic Suffolk × Galway ewe lambs
Authors: Keane M. G.
Published: March 2009

March-born non-cyclic Suffolk × Galway ewe lambs were treated with progestagen pessaries while being either fed fresh-cut grass ad libitum, or restricted to 50% of appetite and at pessary removal half of the animals on each nutritional treatment received either 600 i.u. or 300 i.u. PMS. Averaged over both levels of PMS, 97·5% of the lambs showed oestrus when fed ad libitum but only 67·5% of those on restricted feeding responded. When feed intake was not restricted there were no differences due to PMS level but when feed intake was restricted the higher dose level of PMS resulted in a greater percentage showing oestrus and a significantly higher ovulation rate. The dose level of PMS had no effect on the time of oestrous onset but restricted feeding resulted in delayed onset and poor synchronization of oestrus. Duration of oestrus was greatest for lambs fed ad libitum given 600 i.u. PMS and least for those on restricted feeding given 300 i.u. PMS but the difference was not significant. A minority of lambs showed broken oestrous periods.
Effect of some soil amendments on sodium uptake and translocation in dry beans (P. vulgaris L.) in relation to sodium toxicity
Authors: Ayoub Ali T.
Published: March 2009

Bean plants (Phaseolus vulgaris L.) were grown in field plots with the objective of comparing the effect of some soil amendments on sodium uptake and translocation at three levels of salinity in the soil.

Gypsum and wheat straw mulch treatments reduced the translocation of sodium from the roots to the stems and leaves at the higher external sodium level. Incorporation of animal manure with the soil had little effect on translocation at the higher level but may have promoted sodium translocation to the stems at the lower level.

Plant growth and survival were negatively correlated with the sodium content in the plant, particularly with that of the stems.
A model for estimating soil moisture deficits under cereal crops in Britain:2. Performance
Authors: Francis P. E. , Pidgeon J. D.
Published: March 2009

The new model, described in a previous paper (Francis & Pidgeon, 1982), for estimating soil moisture deficits under cereal crops in Britain, was evaluated against experimental neutron probe data for eight test crops. The test crops covered a wide range within Britain of growing-season weather and soil types for both winter and spring cereals. Comparisons were also made with estimates of three other models, those of Ritchie, Rhoades & Richardson (1976), Jensen, Wright & Pratt (1971) and Smith & Douglas (1975).

The new model gives the best fit for six of the eight test crops, with root-mean-square errors (RMSE), taken over the whole season, of less than 10 mm of deficit and having small random bias. RMSE seldom exceeds 10 mm for any section of any season. By contrast, the other three models have whole season RMSE values in the range 10–40 mm. The model of Ritchie et al. (1976) generally overpredicted deficits early in the season and thereafter performed erratically; those of Jensen et al. (1971) and Smith & Douglas (1975) generally underestimated deficits. For two test crops where the new model performed poorly, serious inadequacies in crop growth and/or meteorological input data were identified as the reasons.

A sensitivity analysis for the new model emphasized the importance of the soil variables that were incorporated and the need for rudimentary crop growth information to supplement default assumptions.

It is concluded that the new model, having average RMSE values similar to expected neutron probe measurement errors, offers significant advantages over other models in estimation of soil moisture deficits. The new model could further provide a basis for extension to other crops or to description of the distribution with depth of soil moisture deficit.
The relationship of grain shrivelling to the milling and baking quality of three winter wheat cultivars grown with different rates of nitrogen fertilizer
Authors: Bayles Rosemary A. , Evers A. D. , Thorne Gillian N.
Published: March 2009

It is generally assumed that poorly filled, or shrivelled wheat grain gives poor flour yields on milling, due to low endosperm content. Quality standards therefore often impose minimum limits of specific weight and grain size with the intention of excluding shrivelled samples. Although milling and baking quality are partly genetically determined, certain of their components are strongly influenced by environment. Flour protein, loaf score and alpha-amylase activity may be improved by nitrogen fertilizer (Pushman & Bingham, 1976), although the reaction of other characters is sometimes less favourable. Reduced flour yields and deterioration of flour colour have been reported at high rates of nitrogen fertilizer (Fuller & Stewart, 1968), and grains frequently become smaller and more shrivelled as application rate is increased (Bayles, 1977 c).
A comparison of the yield responses of four grasses to a wide range of nitrogen application rates
Authors: Reid D.
Published: March 2009

The yield results are reported for an experiment in which 21 rates of nitrogen fertilizer were applied on pure-sown swards of four grasses, S. 24 and Barvestra perennial ryegrass, S. 37 cocksfoot and S. 53 meadow fescue. Growth curves fitted to the herbage yield data for each grass in each year are presented. On average the total dry-matter yield curves for the two ryegrasses were similar to one another, but showed a slightly smaller response to nitrogen rates below 300 kg/ha than did S. 23 ryegrass in an earlier experiment, and a more rapid decrease in response at higher rates. S. 37 cocksfoot had a similar dry-matter yield response to the ryegrasses at the low nitrogen rates, but the response decreased more rapidly at nitrogen rates over 250 kg/ha. The dry-matter yield response of S. 53 fescue decreased even more rapidly with nitrogen rates over 200 kg/ha. The mean estimates of the optimal nitrogen rate for each of the four grasses, i.e. the nitrogen rate at which the dry-matter response had decreased to 10 kg/kg N, was 380, 372, 357 and 327 kg N/ha for S. 24, Barvestra, S. 37 and S. 53 respectively, compared with 409 kg/ha for S. 23 ryegrass in the earlier experiment.
The effect of drainage treatments on cereal yields: results from experiments on clay lands
Authors: Armstrong A. C.
Published: March 2009

Crop yield results from three long-term drainage experiments are analysed and show that increases of up to 1 t/ha of winter wheat can be attributed to the effect of drainage. Mole drainage is clearly the preferred treatment on heavy clay soils. There is also a suggestion that drainage permits more efficient utilization of nitrogen.
The effects of growth regulators, seed rates and row spacings on field beans (Vicia faba L.)
Authors: McEwen J.
Published: March 2009

Four growth regulators were tested: N-dimethylaminosuccinamic acid (aminozide); N-pyrrolidinosuccinamic acid (F529); 2-chloroethyldimethyldodecylammonium chloride (JF2579); potassium 2(3-chlorophenylcarbamoyloxy) propionate (JF3072); all shortened stems. JF2579 and JF3072 were phytotoxic and lessened yield. Aminozide and F529 (tested in 1970 only) did not affect yield in 1970 but aminozide increased yield by 28% in 1971. Seed rates and row spacings had small effects on yield which varied with season. Growth regulators did not interact with seed rates or row spacing. Plant density and growth regulators had effects on yield via the number of stems and pods per stem. The effects of season on yield were greater and were caused via 100 grain weight. Speculative hypotheses are suggested to explain the different actions of season and treatments.
A radiographic study of age changes in the skull, mandible and teeth of pigs
Authors: Wenham G. , Fowler V. R.
Published: March 2009

Radiographs were taken, of the medially sectioned half heads and flesh-free mandibles of 32 pigs serially slaughtered between birth and 120 kg live weight. From these radiographs, measurements were taken of the length of the skull, the depth of the cranium, the length and depth of the brain cavity, and five separate measurements of the mandible. Observations were made of the changes in configuration of the skull as a whole including sinuses. The patterns of development and eruption of the deciduous and permanent teeth were examined. It is suggested that the elongation of the mandible and the maxilla necessary to accommodate the full permanent dentition, together with the increasing size of the frontal sinuses, has an important influence on the shape of the skull as a whole. The results are discussed in relation to other published descriptions of the chronological development of the teeth.
Methods of analysing competition with special reference to herbage plants: II. Effects of associate plants
Authors: Hill J.
Published: March 2009

An examination of the role played by associate plants in conditioning the behaviour of a competitor was carried out on a diallel arrangement of five perennial ryegrasa genotypes using regression techniques similar to those devised for the analysis of genotype-environment interactions. By far the largest proportion of the significant genotype x associate interaction could be ascribed to differences between the slopes of the fitted regression lines, with the three long-leaved genotypes (A, C and E)having the highest slopes and hence being the most sensitive to changes in the associate environment. Significant departures from the fitted regression lines occurred, however, but these could be traced solely to genotype C.

Theoretical models capable of identifying those conditions under which 50:50 mixtures may be expected, first, to exceed the average of their component monocultures, and secondly, to surpass the better monoculture, were developed. Applying these models to the present experiment confirms that the performance of the 50:50 mixtures generally exceeds the monoculture average, but rarely surpasses the better monoculture.

The scope of the regression technique was broadened to incorporate the 75:25 and 25: 75 mixtures, thereby revealing that the response of the two strongest competitors (C and E) is frequency dependent. Density dependent effects were also uncovered in this material, with genotype C the strongest competitor, being particularly noteworthy in this respect. The role of this regression technique in the development of new and highly productive mixtures is briefly discussed.
Stocking intensity and pastoral production: I. Changes in the soil and vegetation of a sown pasture grazed by sheep at different stocking rates
Authors: Langlands J. P. , Bennett I. L.
Published: March 2009

A Phalaris tuberosa and Trifolium repens pasture was grazed continuously at stocking rates varying from 2·5 to 37·1 sheep per ha between 1964 and 1969. During this period herbage availability and composition, basal cover, root weight, water infiltration, soil moisture content, bulk density and chemical composition of the soil were measured at intervals.

As stocking rate was increased, herbage availability, root weight, basal cover, soil pore space and the rate of water infiltration declined, and bulk density and the nitrogen and calcium contents of the herbage on offer increased. In periods of below-average rainfall, soil moisture and nitrate levels were greater when herbage was of low availability.

Herbage production was calculated from estimates of herbage consumption and of litter decomposition, and averaged 8·45 t dry matter/ha/year; it was insensitive to changes in stocking rate over the range from 2 to 22 sheep/ha. The ratio, herbage consumption/ pasture production increased by 0'045 per unit increase in stocking rate.
The effects of feeding white clover pellets and red clover hay on teat length, plasma gonadotrophins and pituitary function in wethers
Authors: Saba N. , Symons A. M. , Drane Hilary M.
Published: March 2009

Feeding of white clover or red clover oestrogenic diets to wethers produced increases in teat length but did not affect the basal plasma luteinizing hormone levels or pituitary sensitivity to luteinizing hormone-releasing hormone.
On the relation between milk production and fertility in Kibbutz dairy cattle herds
Authors: Francos G. , Rattner D.
Published: March 2009

Milk production (305 day lactations, 3·5% fat-corrected milk), and lengths of time between calving and conception for 541 heifers and 1127 older cows were examined. These data were collected from 11 herds in collective farms in Israel during two successive years. Herd lactation means ranged from 5046 to 8570 kg for cows and from 5021 to 7250 for heifers; the ranges of time between calving and conception were 89–123 days and 99–141 days, respectively.

A significant correlation was found between the weight of milk given per lactation and the length of the interval between calving and the next conception, with coefficients of 0·298 (cows) and 0·333 (heifers). There was a positive non-linear regression of length of calving to conception interval on production of milk, the regression line becoming steeper, both for cows and heifers, as yield rose.

All herds practised first insemination at the first heat exhibited after 60 days from calving. The results indicate that, when this is done, cows yielding 8000 kg or over per lactation, and heifers yielding 6750 kg or over, will show calving to conception intervals exceeding a mean length of 110 days.
The chemical influence of the duodenal contents on the activity of the antrum and duodenum of sheep
Authors: Mostaghni K. , Howard B. R.
Published: March 2009

The mechanical and eleetromyographic activity of the pyloric antrum and duodenum of sheep has been studied both under resting conditions and while infusing various solutions to alter the chemical composition of the chyme.

Bursts of spike-type electrical activity, synchronized with the depolarization phase of slower potential variations, accompanied duodenal contractions. Both mechanical distension and chemical stimulation of the proximal duodenum influenced the electrical activity and led to changes in the frequency, duration and amplitude of contractions.
The effects of supplementary feeding, pattern of growth and slaughter age on the carcass characteristics of Hereford steers
Authors: Morgan J. H. L.
Published: March 2009

Three groups (1, 2 and 3) of weaned Hereford steers were grazed separately on pasture. Groups 1 and 2 were supplemented with hay and oats during autumn and winter in an attempt to maintain two rates of live-weight gain, namely 0·8 and 0·4 kg/day, respectively. Group 3 was not supplemented and gained at zero and 0·11 kg/day during corresponding periods in the 2 years in which the experiment was repeated (years 1 and 2).

Supplementation ceased at the end of winter (September). Group 1 steers were slaughtered at the end of the growing season (January) when their mean live weight was 420 and 450 kg in years 1 and 2 at 19 months of age. Thereafter, groups 2 and 3 were removed from the plots and grazed together on another pasture at a reduced stocking rate until they attained the slaughter live weights of group 1 when they were slaughtered at 25 and 27 months of age, respectively.

Mean depth of fat cover over the eye muscle at the 10–11th rib in groups 1, 2 and 3 were 8, 6 and 4 mm in year 1, and 12, 5 and 6 mm in year 2, respectively. Group 1 carcasses had shorter skeletal dimensions, contained more fat and graded better than the carcasses of groups 2 and 3. The Longissimus dorsi muscles from group 1 were found to be the most tender in year 1 but no treatment effects were detected in year 2.
Effect of foliage cutting on growth and yield of different rice cultivars under semi-deepwater conditions (0–80 cm)
Authors: Sharma A. R. , De R. N.
Published: March 2009

In 1990 and 1991, four rice cultivars – Utkalprabha, Panidhan, CN573–321–7–1 and Jaladhi–1 were sown in dry soil at the end of May and grown thereafter under semi-deepwater conditions (0–80 cm) at Cuttack, India. These crops were subjected to foliage cutting at the collar of the uppermost leaf on 1 September and/or on 1 October. The amount of foliage cut was greater in 1990 than in 1991 due to a relatively slower rise in water level in the initial stages of the experiments, which resulted in a more vigorous growth of the plants. The tall, rapidly elongating and floating deepwater cultivar Jaladhi–1 yielded the most foliage, followed by the relatively shorter cultivars CN573–321–7–1, Panidhan and Utkalprabha. However, the grain yield of CN573–321–7–1 was greatest and the effect of foliage cutting was least pronounced; whereas Jaladhi–1 gave the lowest grain yield which further decreased significantly when foliage was removed. Cutting in September had no effect on the yield of CN573–321–7–1, Panidhan and Utkalprabha, but the later cut in October had a detrimental effect, particularly when cutting was done a second time. Nevertheless, a single late cutting in October was not found to be harmful to the yield of the tall cultivar CN573–321–7–1 and the long-duration semitall Panidhan. Decrease in grain yield with two cuts of foliage was due to a reduction in the weight and number of grains/panicle as panicles/m2 and 1000-grain weight remained unaffected. The results suggest that foliage could be harvested for feeding cattle from the long-duration, tall and photosensitive rice cultivars without any adverse effect on grain yield under semi-deep lowland conditions.
Proceedings of the Twenty-Fourth Meeting of the AFRC Modellers' Group
Authors: France J.
Published: March 2009

This group, which is concerned with the applications of mathematics to agricultural science, is sponsored by the Agricultural and Food Research Council. It was formed in 1970, and has since met at approximately yearly intervals in London for one-day meetings. The twenty-fourth meeting of the group, chaired by Dr M. A. Scaife of Horticulture Research International, Wellesbourne, was held in the Wellcome Meeting Room at the Royal Society, 6 Carlton House Terrace, London on Friday, 8 October 1993, when the following papers were read.
Strategic milk progesterone testing for the detection of silent oestrus and anovulation in dairy cows
Authors: Williams M. E. , McLeod B. J.
Published: March 2009

Dairy cows were inseminated on the basis of oestrus detection alone (Control, n = 206) or in conjunction with milk progesterone profiles (Experimental, n = 204). Milk samples were taken at 4–5 day intervals to determine oestrous cyclicity and on alternate days (at strategic times) to determine the time of ovulation. Progesterone profiles were consulted routinely as an aid to oestrus detection, and also to identify and aid diagnosis of cows with reproductive disorders. Cycling cows not observed in oestrus were inseminated on the basis of their progesterone profile alone. Animals showing oestrus within 2 days of a progesterone-timed insemination were inseminated again. In Experiments 1 and 2, inseminations were given from Day 42 post partum, but AI was delayed (mean time of 68±1·1 days after calving) in Experiment 3.

The median interval from calving to first insemination was not significantly different between Experimental and Control groups, but the time of conception was earlier (P < 0·05) and the median calving interval shorter (P < 0·05) in progesterone-monitored cows in Expts 1 and 3. In addition, the percentage of cows served within 21 days of the start of the service period was greater (P < 0·05) in Experimental groups in Expts 1 and 2. This was reflected by an increase in the proportion (P < 0·05) of cows pregnant by 85 and 100 days after calving. The frequency with which the interservice interval equated to the length of the oestrous cycle was increased (P < 0·01) by progesterone testing (84·1% and 53·9% in Experimental and Control cows, respectively). Conception rates did not differ significantly between groups, but the number of double inseminations (P < 0·001) and thus the mean number of inseminations/conception (P < 0·01) were greater in progesterone-monitored cows. Conception rate was lower (P < 0·05) in cows that failed to show oestrus, and to the first insemination in double-inseminated cows.

Progesterone testing reduced (by 44–66%, P < 0·01) the number of cows presented for veterinary examination and the mean time of presentation (P < 0·05), and also influenced the diagnosis made.