bluuebunny/crossref_metadata_2025 huggingface dataset:
Components of yield in field beans, Vicia faba L.
Authors: Kambal A. E.
Published: March 2009

The components of yield were studied in a local strain of field beans (Baladi) and two Egyptian varieties (Rebaya 40 and Giza 1). Although no significant differences between varieties were detected in yield per plant, there were differences in components of yield. The Egyptian varieties produced heavier seeds but less pods and seeds than the local strain. The higherpod number in Baladi resulted from a capacity to produce more pods per stem rather than from anability to produce more stems per plant.

Correlations between yield and other plant characters and between components of yield were computed. The path-coefficient analysis was employed to partition the correlation coefficients and to compare the relative importance of the primary yield components in predicting yield. Pods per plant showed the highest correlation with yield and selection for high yield can be based on it. Seed weight was negatively associated with pod number and seeds per pod but the r values were too low to be of predictive value. Multiple correlations indicated that 95–98% of the variability in yield was accounted for by the components pod number, seeds per pod and seed weight.
Some measurements of evaporation in a field of barley
Authors: Grant D. R.
Published: March 2009

A project has been initiated to study the growth of barley under conditions of partial drought. The method of producing the drought and comparisons of measurements of evaporation using lysimeters and neutron moisture meters are discussed. Good agreement was obtained between the lysimeter and neutron probes in the lysimeter tank and in the field.

In the plots subjected to drought the evaporation was reduced by approximately the amount of rain prevented from falling on the plots and, as a result, the reduction in soil moisture deficit was quite small.

Estimates of internal diffusion resistance are made throughout a full season.
An Example of A Method of Statistical Analysis of a Grazing Experiment
Authors: Conniffe D. , Browne D. , Walshe M. J.
Published: March 2009

Conniffe, Browne & Walshe (1970) proposed a form of experimental design and statistical analysis for grazing experiments. The original paper did not include any example of the analysis on real data. This note presents such an example and makes some comments on the statistical validity of the method of analysis.
Growth in sheep. I. The chemical composition of the body
Authors: Searle T. W. , Graham N. McC. , O'Callaghan M.
Published: March 2009

Fifteen sheep were fedad libitumfrom 2 days to 27 months of age, and another 15 sheep were each fed exactly half the average amount consumed by the first group, age for age. The body composition of each sheep (water, fat, protein, energy) was estimated from tritiated water space on 13 occasions during this period.

To describe the course of growth in individual sheep in terms of the relationships between the various body components and body weight, a model was set up in which 4 phases of growth were distinguished, viz. the milk-feeding phase, the period of rumen development, and a prefattening followed by a fattening ruminant phase. Each phase was represented by a linear equation.

Except for phase 1, mean composition within each phase differed significantly between well-fed animals and those which had been given a restricted diet. Individual animals differed in the body weight at which the final phase commenced; the average weight wasca.31 kg. Fat storage was zero or negative during the main period of rumen development; otherwise the fat and therefore energy content of weight gain increased from phase to phase. The protein and water content of gain was high in phases 1 and 2 and decreased subsequently.

Calculations based on data in the literature indicated that, in phase 4, the composition of weight loss was the same as that of weight gain. It is also suggested that the body weight at which this fattening phase commences is related to mature weight, with animals of large ultimate size starting to fatten at heavier body weights than those of small ultimate size.

The application of the results to the determination of nutrient requirements is discussed.
A glutathione deficiency in the red cells of certain Merino sheep
Authors: Tucker Elizabeth M. , Kilgour L.
Published: March 2009

Red cell GSH concentrations were measured in 83 pure-bred and 65 cross-bred Tasmanian Merino sheep. A bimodal distribution was found; 40% of sheep had mean GSH values of 27·3 ± 1·2 mg and 60% had 92·2 ± 1·5 mg/100 ml red cells. Family data are limited, but they suggest that this difference is under genetic control, the gene for low GSH levels being dominant to that for high. Unlike GSH-low type Finnish Landrace sheep, GSH-low type Merino sheep do not have lower than normal red cell sodium and potassium concentrations.
Water and fertility management of rice varieties under low atmospheric evaporative demand
Authors: Pande H. K. , Singh Panjab
Published: March 2009

Four soil moisture and two nitrogen levels were combined in eight treatments to study moisture and nitrogen effects on Dular (June–September crop) and Patnai-23 (June–November crop) varieties of rice. Both the varieties when grown under natural precipitation yielded significantly less than at other moisture levels. Whereas there were no significant differences amongst the three treatments of submergence (15–10 cm), cyclic submergence (15–0 cm) and cyclic wetting-drying (saturation to field capacity) for Dular rice, the former two treatments proved better than the latter for Patnai-23 rice. Dular responded to the treatments of cyclic wetting-drying in a way similar to that of submergence because the crop completed its life cycle during the period of low evaporative demand. Among the levels of nitrogen, 40 kg N/ha proved optimum for Dular rice and 6O kg N/ha for Patnai-23 rice. The increase in yield of grain was associated with increase in the number of panicles, number of spikelets/panicle and percentage of ripened spikelets. The concentration of N, P, Fe and Mn in the plant was maximum under submergence followed by cyclic submergence, cyclic wetting-drying and natural precipitation. Higher levels of nitrogen increased only N and P contents in the plant.
Matric suctions to which soils in South Central England drain
Authors: Webster R. , Beckett P. H. T.
Published: March 2009

In a survey of soils in South Central England matric suctions were measured frequently during 1962 and 1963. Results for the period October to May are given for sites lying above the influence of the regional ground water table and show the matric suctions to which the soils drain. Sandy soils drain within 2 or 3 days to a definite field capacity at about 50 mbar suction. Loams and clay loams, though from profile appearance regarded as freely drained, take up to about 1 week to drain to a fairly constant suction of 40–50 mbar, which can also be regarded as field capacity. However, suctions prevailing during this time are less – about 20 mbar. The prevailing suctions in clay soils are about 10 mbar in the topsoil (13 cm) and – 10 mbar in the subsoil (38 cm). These soils drain slowly but steadily when rain ceases and no definite field capacity is evident. For the sandy soils, loams and clay loams, the matric suctions characterize the upper limit of the available water capacity (AWC) of the soil. The values are less than almost all previous estimates or assumed values. For the clays the upper limit of AWC remains best estimated by field sampling at the time of interest.
An examination of Fairfield Smith's law of environmental variation
Authors: Pearce S. C.
Published: March 2009

Fairfield Smith's law relating the error of a field experiment to the size of its plots is well established by observation and in general use, but it appears to have no theoretical basis. It is here shown by computer simulation that it could arise in many ways as a good approximation, provided the range of plot sizes considered is not unreasonably large.
Activity and energy expenditure in laying hens: 3. The energy cost of eating and posture
Authors: Van Kampen M.
Published: March 2009

The influence of standing, spontaneous activity and eating on heat production was determined.

The extra heat production of standing is negatively correlated with the length of standing period. In a short standing period of 30 min the associated activity, pecking against the respirometer wall and fluffing the feathers, was high and the heat production was increased by 25% compared with that during sitting. After standing for 1½ h spontaneous activity was very low and the difference in heat production between the standing and sitting bird was reduced by 9%.

During eating the heat production increased by an average of 37% (range 11–68%); this was due mainly to the act of eatingper seand not to the work of digestion.

The mean energy cost of eating was calculated to be 143 J/kg0·75/min spent eating.
Growth rate and its effect on empty body weight, carcass weight and dissected carcass composition of sheep
Authors: Murray D. M. , Slezacek Olga
Published: March 2009

The effect of three different growth rates from 15 to 40 kg live weight on the body composition of lambs was studied. The treatments were: High (H) ad-libitum feed intake, Low (L) restricted feed intake and High–Maintenance–High (HMH) ad-libitum feed intake from 15 to 25 kg followed by a 50-day period during which live weight was maintained constant, which in turn was followed by ad-libitum feeding. The animals were individually penned and fed a pelleted lucerne chaff-cereal grain mixture. Two animals were killed at the start of the experiment (15 kg) and the remaining 27 animals (nine in each treatment) were killed at common live weights of 25, 30, 35 and 40 kg. Analyses of covariance were used to compare linear regression equations representing results from each treatment using the logarithmic transformation of the allometric equation, y = axb.

Animals in the H and L treatments had a mean growth rate from 15 kg until slaughter of 0·23 and 0·09 kg/day, respectively. From a live weight of 15 to 25 kg, the HMH group grew at a similar rate as the H group, viz. 0·22 and 0·21 kg/day, respectively. After the 50-day period of maintenance of live weight, the HMH animals killed at 30, 35 and 40 kg showed a marked compensatory growth response to ad-libitum feeding. These HMH animals had a mean growth rate of 0·37 kg/day compared with 0·26 kg/day for H animals over identical live-weight ranges.

Empty body weight (EBW) formed a similar proportion of full body weight (FBW) in all three treatments. As a proportion of FBW, hot carcass weight (HCW) was similar in the H and L treatments, while at the 35 and 40 kg slaughter weights HCW was less in the HMH than in the H treatment. HCW also formed a lower proportion of EBW at the 35 and 40 kg slaughter weights in the HMH, than in both the H and L treatments. In the L treatment, HCW formed a greater proportion of EBW than in the H treatment, indicating a greater offal component of EBW in the H animals.

The results of carcass dissection studies showed that, at the same dissected side weight (DSW), the amount of muscle, bone, connective tissue and total side fat (TSF) was similar in the three treatments. Although no differences were found between treatments in TSF, there were significant treatment effects on both the subcutaneous and inter-muscular fat depots. Animals in the H treatment had more and less, respectively, subcutaneous and intermuscular fat than the L animals. The amount of intermuscular fat was also greater in the HMH than in the H treatment.
Dynamics of seedling emergence of opaque-2 and analogous normal maize in cold tests and effect of fungicide seed treatment on their cold tolerance
Authors: Gupta D. , Kovács I.
Published: March 2009

Six opaque·2 (O2) inbred lines and the single, three-way and double-cross hybrids derived from them were compared for emergence at low temperatures with their analogous normal inbred lines and hybrids. The results demonstrate that there is an increasing difference in emergence between the o2 and the normal forms with an increase in the period of incubation, the o2 types being inferior, in general, to the normal.

A treatment of seeds with fungicides like Quinolate V4X, TMTD–Lindan and Vitavax 75W before sowing improved the cold tolerance of both the o2 and normal analogues, but the o2 forms remained far below the level of the normal.
The effect of inbreeding and cross-breeding on dairy traits in cattle
Authors: Galal E. S. E. , Aboustate T. M. , Afifi Y. A.
Published: March 2009

A total of 886 cows of two herds belonging to the Ministry of Agriculture, Egypt, were used in this study to investigate the effects of inbreeding and cross-breeding on dairy traits. The first herd consisted of the native breed Domiatty (D), Shorthorn (S) and different grades between them while the second of Jersey (J) and its different crosses with D. There were 1027 lactations from the first herd and 460 from the second. Inbreeding coefficient (F) averaged 0·06 in the first herd and 0·08 in the second, both ranging from 0·00 to 0·30. The range was partitioned into three classes: the first with 0·0 ≤ F ≤ 0·1, the second 0·1 ≤ F ≤ 0·2 and the third F ≥ 0·2. Traits studied were first and second lactation 305-day milk yields, age at first calving, first calving interval and first dry period.

Inbreeding had no statistically significant effect on any of the traits except dry period in the first herd. Inbreeding was not associated with decrease in yield when F ≤ 0·2 in the first herd, while there was consistent decrease with inbreeding in the second herd. No clear trend could be observed on the effect of inbreeding on any of the other traits in the first herd whereas in the second the rise in inbreeding was always associated with greater age at first calving, with wider calving interval and with longer dry period.
Effect of sublethal treatments with the insect growth regulator, Altozar, ZR-512, on blood constituents of Bombyx mori L. in relation to silk yield
Authors: Rawash I. A. , Gaaboub I. A. , Mostafa S. M.
Published: March 2009

Concentrations of larval blood protein and blood lipid and density of blood in relation to the silk yield of Bombyx mori L. were estimated under the action of sublethal treatments (to give 0·0% kill of larvae) with the insect growth regulator Altozar, ZR-512.

Results indicated that there was an inverse correlation between Altozar dosage and both weights of larvae and of the resulting cocoons, larval blood-protein and blood-lipid concentrations and density of blood. The decline in these attributes compared with the controls may indicate that a considerable proportion of the inhibitory effect of the growth regulator compound occurred during the development from larva to pupa.

Considering the relationship between larval blood-protein or blood-lipid concentrations and wet weight of the resulting cocoons under the sublethal dosages of Altozar used, the present results confirm our findings concerning the strong relationship between the larval protein content and silk formation. There was a positive increase in the mean wet weight of the resulting cocoons as the protein and lipid concentrations increased.

These experiments suggest that the sole source for the synthesis of silk protein is the protein present in the haemlymph of silkworms and dependent on the larval diet.
Combining ability in early Indian cauliflower
Authors: Lal G. , Swarup V. , Chatterjee S. S.
Published: March 2009

Six early maturing inbreds from maturity group I of Indian cauliflowers were selected and diallol crosses were made to study the combining ability of inbreds and identify the desirable parent(s) for hybridization. Seven characters, i.e. curd weight, curd size index, maturity, plant height, number of leaves, leaf size index and plant spread were studied both in F1and F2generations. Though the estimates of both general and specific combining ability variances were highly significant for all the characters, the magnitudes of general combining ability variances were higher than that of specific combining ability variances. The performance of the inbreds was in general associated with their general combining ability effects. The inbred 103 was found to be best combiner for all the characters and the cross 105 x 108 showed maximum yield potential.
Oxidation and metabolism of linoleic acid in fed and fasted sheep
Authors: Lindsay D. B. , Leat W. M. F.
Published: March 2009

Using continuous infusion techniques the entry rate of linoleic acid and its contribution to carbon dioxide production has been studied in fed and fasted sheep. The entry rate of linoleic acid in fasted sheep (0·052 mg/min/kg) was considerably less than that of stearic acid (0·432 mg/min/kg), and the percentage of total carbon dioxide production derived from the oxidation of linoleic acid (0·4%) was also markedly less than that from stearic acid (10·13%).

On starvation there was a preferential mobilization of palmitic, stearic and oleic acids relative to linoleic acid.

The infused14C-labelled linoleic acid was initially incorporated into plasma phospholipids, with maximal radioactivity at about 1 day post-infusion, and subsequently into plasma cholesteryl esters with a maximum at 2 days post-infusion. The incorporation of14C-labelled stearic acid into plasma phospholipids was only 25–30% that of linoleic acid, with negligible incorporation into cholesteryl esters.

Possible explanations for ruminant animals being able to exist on a very low intake of linoleic acid are discussed. In essence, there is a discrimination against the use of linoleic acid as an energy source, but the mechanisms involved do not appear to be unique to ruminant animals.
Sugar beet bolting in the root crop
Authors: Lisa J. M.
Published: March 2009

Sugar beet bolting in the root crop was studied during nine growing seasons, under the extreme climatic conditions in which the autumn-sown crop grows in Southern Spain.

Bolting is positively correlated with the number of days with minimum air temperatures ranging from 2 to 8 °C or with the number of days with mean temperatures between 8 °C and 13 °C.

The occurrence of bolting is also affected by rainfall distribution in so far as it determines the date of seedling emergence.
Effect of inhibition of flowering on improvement of cane yield and juice quality under Coimbatore conditions
Authors: Singh Sudama , Reddy M. Sanjiva
Published: March 2009

The effects of paraquat (l, 1'-dimethyl-4, 4'-dipyridylium dichloride or Gramoxone) and diquat (l,1'-ethylene-2, 2'-dipyridylium dichloride or Reglone) on inhibition of flowering and the effect of such an inhibition on improvement of cane yield and juice quality in late maturing sugarcane varieties Co. 853 (early-season flowering) and Co. 419 (mid-late season flowering) planted in February were studied under field conditions at Coimbatore (latitude 11° N). In Co. 419, the spray of paraquat @ 0·35 kg a.i./ha and diquat @ 0·45 kg a.i./ha (diluted in 3000 1 of water) in two equal doses at 3–4 day intervals during the 1st and 2nd week of August suppressed the flowering almost completely, while in Co. 853 flowering could not be checked successfully by chemical spray. Flowering in Co. 853 could be checked only when the spindle leaves were cut continuously from 15 July to 12 August at 4–5 day intervals. In Co. 419, cutting leaf spindles at any day between 1 August and 12 August prevented flowering totally.

The sprayed non-flowered crop of Co. 419 gave 13·84–15·69 t/ha more cane yield in February and 16·14–18·07 t/ha in April, whereas sugar yield increased by 1·16 t/ha in February and 3·56 t/ha in April compared with the control flowered crop. There was practically no difference in paraquat and diquat sprays. Suppression of flowering by defoliation in Co. 853 also increased the cane and sugar yield in and after February.
A note on leaf removal in hybrid maize
Authors: Singh R. P. , Nair K. P. P. , Sharma K. C.
Published: March 2009

The effects of differing degrees of leaf removal was studied in maize at different stages of growth and in varying plant densities. In control (untreated) plants significantly lower grain yield/unit area at the higher density (90000 plants/ha) was associated with greater barrenness, percentage of lodging and time taken for silking. Increase in plant density from 60000 to 90000 plants/ha led to a reduction in length and diameter of the ear and in weight of 1000 grains. Delay in the time of leaf removal from the tasselling stage until 10 days later increased yield, number of ears, ear length, diameter and test weight and decreased percentage of barrenness and lodging.

Leaf removal adversely affected yield and yield components (number of ears, percentage of lodging, ear size and test weight of 1000 grains). Complete leaf removal at tasselling time delayed silking and reduced lodging.
Developmental characteristics of grass varieties in relation to their herbage production
Authors: Davies I.
Published: March 2009

The length and weight per unit length of individual internodes of mature reproductive tillers of S. 24 and S. 23 perennial ryegrass and S. 345 and S. 143 cocksfoot were examined under three manurial treatments. At the lower level of nitrogen application successive internodes generally increased in length from the base upward. With additional nitrogen there was an increased proportion of tillers in which internodes near the base of the stem were longer than those immediately above them; lateheading tillers were most affected.

Nitrogen increased the weight per unit length of upper internodes of all four varieties; the effect was most marked in S. 23 ryegrass. In the two ryegrasses, nitrogen reduced the weight per unit length of the basal internode.

At maturity the upper internodes had lower dry-matter digestibility values than the lower. Nitrogen reduced the dry-matter digestibility of upper and lower internodes.

The results are discussed in relation to selection criteria in variety synthesis.
A model for the simulation of the fate of nitrogen in farm wastes on land application
Authors: Bhat K. K. S. , Flowers T. H. , O'Callaghan J. R.
Published: March 2009

A model for predicting the various transformations undergone in the soil by nitrogen applied in farm wastes, in response to variations in soil and climatic factors, is presented. The soil is divided into layers and a simple mass balance model is used to describe the movement and redistribution of water within the soil profile, as a function of rainfall, evapotranspiration and soil moisture characteristics.

Ammonification of native and applied organic N is assumed to follow first-order reaction kinetics and nitrification and denitrification are treated as zero-order reactions. The rates or rate constants for all three reactions were related separately to soil temperature, moisture content and pH.

Uptake of nitrogen by a grass crop, dry-matter production, removal of dry matter and N through harvests, addition to soil of C and N through dead plant material and stubble and the consequent immobilization of mineral N are allowed for. Some of the predictions of the model are compared with the results of a lysimeter experiment.
The relationship between response to N and P fertilizers and soil N and P
Authors: Singh B. R. , Uriyo A. P.
Published: March 2009

The magnitude of response to fertilizer-N and fertilizer-P decreased with increasing amounts of total soil-N and available soil-P, respectively. Attempts have been made to group the soils into N- and P-fertility classes based on the magnitude of response to applied fertilizers on soils of different fertility with respect to these two nutrient elements.
Seasonal variations in physico-biochemical determinants of buffalo (Bos bubalis) semen and their relation to fertility
Authors: Chaudhary K. C. , Gangwar P. C.
Published: March 2009

Semen from eight Murrah buffalo bulls was collected and analysed for physical and biochemical determinants throughout the year. Depending upon the climatic conditions, the whole year was divided into four periods. The mean values of volume, density, mass motility and sperm concentration was 1·64 + 0·060 ml, 2·48±0·032 (3-point scale), 2·65±0·069 (5-point scale) and 1185 ±19·2 million/ml, respectively. The mean values of alkaline and acid phosphatases were 1238±47·4 and 1244±54·5 King-Armstrong units (KAU)/100 ml of seminal plasma. Average figures for citric acid, calcium, phosphorus, total nitrogen and non-protein nitrogen (NPN) were 507 + 14·1, 53·0±l·2, 121±4·9, 649±12·8 and 116±2·0 mg/100 ml of seminal plasma. Periods of the year had significant effect on volume, alkaline and acid phosphatases, citric acid and NPN (P< 0·01). Different correlations of physical and biochemical determinants are discussed. Of all the determinants only weight of the bull, sperm concentration and NPN were found to be positively correlated with fertility while phosphorus was negatively correlated.
The influence of some seed potato production techniques on basic tuber characteristics
Authors: Wurr D. C. E. , Barnes A.
Published: March 2009

The effects of the planting density of the seed potato crop, the date on which it was defoliated and the time at which it was lifted, on the weight, shape and number of eyes on progeny tubers in a given size grade, were small and were unlikely to be of practical importance.

Size grade was both closely and linearly related to the number of eyes on a tuber and seemed to be a perfectly adequate practical method of grading seed tubers according to their number of eyes.
Influence of time, pH, temperature, organic matter and exchangeable cations on the adsorption of oxamyl on illites and kaolinites
Authors: Bansal O. P. , Bansal Vijay
Published: March 2009

The adsorption of oxamyl under various conditions of time, pH, temperature, organic matter and exchangeable cations on illites and kaolinites was examined. The first order reaction indicated diffusion-controlled adsorption, maximum adsorption occurring at pH 6–5 which is near the pK value of oxamyl. Exchangeable cation in the order Na > H > Ca, organic matterand increasing temperature decreased adsorption. Adsorption isotherms and the molecular structure of oxamyl point to a reaction mechanism for oxamyl association with acid- and base-saturatedclays which involve either protonation or co-ordination of exchangeable clay cations to the carbonyl of the amide structure.
Beef carcass conformation and some relationships with carcass composition and muscle dimensions
Authors: Colomer-Rocher F. , Bass J. J. , Johnson D. L.
Published: March 2009

Carcasses of 129 steers from ten different sire breeds including dairy breeds, traditional British beef breeds and continental breeds were classified according to the shape of the tuber ischii-tuber calcis profiles of their hindquarter using a 7·point conformation scale. Conformation class was found to be related to both commercial and dissected carcass composition as well as the dimensions of seven hindquarter muscles. At the same carcass weight and fatness the muscle content of the hindquarter increased by 0·56 kg and the bone decreased by 0·13 kg linearly per unit increase in conformation class; the corresponding increase in the muscle-to-bone ratio was 0·07. The general trend for muscle dimensions was that the convex carcasses had shorter and thicker muscles than concave carcasses. A simple method of assessing carcass conformation based on three fundamental profiles of the hindquarter, from which the seven conformation classes were derived, permitted the grouping of carcasses according to their composition. Nevertheless the accuracy of the method may be improved with further investigation.
Edge and neighbour effects in cereal yield trials
Authors: Austin R. B. , Blackwell R. D.
Published: March 2009

In two field experiments with winter wheat varieties, the grain yields per unit area calculated from entire plots 4·2 × 1·18 m were 25% greater than the yields of the centre row. This occurred mainly because the outer rows in the plots yielded 62% more than the centre row. When the yields were calculated on the basis of a plot width of 1·53 m (the distance from path centre to path centre across the long axis of a plot), it was estimated that they were 4% less than the yields of the centre rows. In the most extreme case when a short variety in a plot of this size was bordered by neighbours 70 cm taller, its yield, relative to that of the tall variety, was underestimated by 10–12%.

A separate experiment showed that the greater yield from plants at the edges of plots was associated mainly with more ears.
Circadian variation in the apparent digetibility of diets measured at the terminal ileum in pigs
Authors: Livingstone R. M. , Baird Barbara A. , Atkinson T. , Crofts R. M. J.
Published: March 2009

Circadian variation in the apparent digestibility of diets having different physical characteristics was measured in samples taken from the terminal ileum using simple cannulae and marker ratios. Six pigs were used in three latin squares involving three iso-nitrogenous diets (30 g N/kg D.M.). Diet A was based on barley, weatings, soyabean meal and fish meal, diet B included barley, weatings and oats and diet C was purified. The allocation of diet provided 100 g D.M./kg Weg0·75/24 h and in each latin square a different pattern of feed intake was used; diets were given at intervals of either 1 or 12 h, or ad libitum.

Differences in the digestibility of the diets were consistently distinguished by the technique. The circadian variation in digestibility was related to the type of diet and could be modified by changing the number and distribution of feeds per day. The results show that an understanding of the variation associated with different diets and feeding methods is necessary for optimizing the strategy for sampling from the terminal ileum.
Sorghum-pigeonpea intercropping and the effects of plant population density
Authors: Natarajan M. , Willey R. W.
Published: March 2009

The use of growth resources is examined in an intercropping combination of early sorghum (82 days) and later-maturing pigeonpea (173 days) in a row arrangement of 2 sorghum: 1 pigeonpea.

Prior to sorghum harvest, light interception by the intercrop combination was almost as high as sole sorghum. After sorghum harvest, light interception by the remaining pigeonpea was very poor and it is suggested that pigeonpea yield could be increased with higher plant population density and better plant distribution. Soil water measurements indicated that this would increase the amount of water being transpired through the crop but would not increase the total evapotranspiration demand. Higher nutrient concentrations in the intercrop pigeonpea compared with sole pigeonpea during this post-sorghum period suggested that yield of intercrop pigeonpea was not limited by nutrient stress, though the total uptake of nutrients by both crops was much greater from intercropping than sole cropping.
Investigation of the effect of supplementary zinc on growth rate of beef cattle on farms in N. Scotland
Authors: Price J. , Humphries W. R.
Published: March 2009

Trials were conducted on 21 farms to examine the influence of supplementary zinc on growth rate of 978 beef cattle maintained on winter rations typical of N.E. Scotland.

The concentration of zinc in the normal farm rations ranged from 13·3 to 32·1 mg/kg D.M. and half of the animals on trial on each farm received supplements providing an additional 60 mg Zn/kg D.M. Before supplementation, the farm mean plasma zinc concentrations varied from 0·73 to l·10mg Zn/l; these levels were not elevated by zinc supplementation.

The differences in mean daily weight gain between zinc-supplemented and control cattle on individual farms during 100–140 days on trial ranged from –0·14 to +0·22 kg/day and were not related to plasma zinc concentration before supplementation or to the zinc content of the basal rations. The mean daily weight gain of heifers receiving supplementary zinc was significantly greater (P< 0·02) than that of the controls by 0·05 kg/day during the first 60–80 days only. Bulls and steers showed no response to supplementary zinc.
Periodic regression in long-term agricultural experiments
Authors: Roberts E. A.
Published: March 2009

Evans & Roberts (1979) considered that loworder polynomials such as mean, linear and quadratic were adequate to describe the trends that occur in treatment contrasts in long-term agricultural experiments. This conclusion was based on experience with experiments on levels of fertilizers and rates of stocking on similar pastures. In such experiments, the marked seasonal pattern in the data disappears when comparisons between treatments are followed. However, further experience with experiments comparing cultivars has shown that some comparisons still show a seasonal pattern. Such patterns may be accounted for by periodic regression (Bliss, 1970).
Acclimatization of calves to a hot dry environment
Authors: Bianca W.
Published: March 2009

1. Three calves were individually exposed in a climatic room to an environment of 45° C. dry-bulb and 28° C. wet-bulb temperature for 21 successive days up to 5 hr. each day.

2. In the 21-day period, mostly during the first half of it, the following changes in the physiological reactions of the animals were observed: progressive reductions in rectal temperature, in heart rate and in respiratory rate with a change of breathing from a laboured to a less laboured type.

3. It was suggested that a decrease in metabolic heat production might play a part in the observed acclimatization.
The efficiency of food utilization for egg production by pullets and yearling hens
Authors: Bolton W.
Published: March 2009

1. The efficiency of food conversion by pullets and yearlings fed on high- and low-energy diets has been determined.

2. Egg production was slightly higher by birds fed the low-energy diet for both pullets and yearling hens; pullets laid more eggs than yearling hens.

3. For each age, the gross food intake was greater for birds fed the low-energy diet; the consumptions of digestible protein, non-protein digestible energy and metabolizable energy were the same for both diets and both ages of bird.

4. The food cost per dozen eggs was slightly greater in the yearling year when the cost of rearing the pullets was ignored, and about the same when it was included.

5. The efficiency of utilization of digestible energy and protein showed only a slight decrease from the pullet to the yearling year.

6. The variation in the composition and digestibility of eighteen consecutive mixes of the highenergy diet and twenty-five of the low-energy diet was: crude protein 2%, non-protein digestible energy 5% and metabolizable energy 0·4 kg. cal./g. The digestibility of the crude protein and oil was 87%, for both diets; carbohydrates were 81% digestible in the high-energy diet and 59% in the low-energy diet.
The histology of the bovine muzzle
Authors: Mackie A. M. , Nisbet A. Myfanwy
Published: March 2009

1. The structure of the muzzle of the cow, its blood supply and the histochemistry of its glands have been studied.

2. The nasolabial glands are multilobular compound tubulo-acinar glands similar in structure to salivary glands. They secrete a watery mucincontaining fluid. It is suggested that they may be sweat gland homologues.

3. Arterio-venous anastomoses are present in the muzzle. Their possible function is discussed.

4. Although this investigation has shown how much the muzzle differs from the rest of the integument no particular function can be ascribed to it on the basis of the findings described.
Studies on zinc deficiency symptoms in some common crops of Gujarat (India)
Authors: Nair G. G. K. , Mehta B. V.
Published: March 2009

1. Symptoms of zinc deficiency and toxicity have been studied in guar, brinjal, maize, tobacco and Mosambi (Mozambique) using a sand-culture technique.

2. In zinc-deficient guar plants, depressed vegetative growth and smaller leaves than normal ones were found. Only few flower buds were seen, and there was abscission of leaves at the time of flowering.

3. Chlorosis followed by necrosis and finally the drying up of leaves was the most characteristic deficiency symptom in the case of brinjal; growth was stunted and flowers failed to set fruits.

4. In the newer leaves of maize, intermittent light yellow bands were formed just parallel to the midrib.

5. In the lower leaves of tobacco, chlorosis followed by necrosis was observed; growth was stunted and leaves were small in size.

6. In Mosambi (Mozambique), whitish yellow patches in between the veins were observed; leaves were small, pointed and quite unhealthy.

7. There was an increase in zinc uptake with increased rates of application of zinc.

8. Crude protein increased with increasing zinc supply up to levels beyond the optimum for growth.
The effect of leaf rust on the growth and chemical composition of oats and ryecorn
Authors: Greenall A. F.
Published: March 2009

Leaf-rust infection of severity 3–4 on the modified Cobb scale reduced the dry-matter yield of Dun oat leafage by 30% and N.I.A.B. ryecorn by 23%. The reduction in root growth of ryecorn was similar to that of the aerial parts.

The dry-matter percentage of the green forage was significantly increased in two of the three experiments. Palatability reduction due to leaf rust is suggested from field observations.

With Dun oats leaf-rust infection increased the percentage of crude protein (C.P.) by a fifth, of ash by a tenth and decreased that of crude fibre (C.F.) by an eighth, and of nitrogen-free extract (N.F.E.) by a nineteenth. With ryecorn, rust increased the percentage of c.p. by a fourteenth, of ash by a fifth, and decreased that of N.F.E. by a twentieth.

The decreased forage yield caused by rust is in accord with the results of experiments of other research workers and with field observation. The effect of rust on proximate constituents was interpreted as an improvement to feed value. This agrees with the results of most reported experiments but conflicts with the field evidence.

The hypothesis that leaf rust affects forage composition mainly by reducing the physiological age of cereals is proposed.
Nitrate fluctuations in tropical soils
Authors: Greenland D. J.
Published: March 2009

The soil nitrate content has been determined at fortnightly intervals on bare fallow plots and on plots under crops and natural vegetation in the forest and savannah regions of Ghana. Nitrifiable nitrogen, ammonium and soil moisture contents have also been determined. It has been found that the changes in nitrate content are related to changes in the content of nitrifiable nitrogen. During the dry season, a partial sterilization of the soil occurs and consequently the content of nitrifiable nitrogen rises. This nitrifiable nitrogen is slowly converted to nitrate in the dry season and rapidly converted once the rains commence. Nitrate is then lost from the soil by leaching and denitrification. Under bare fallow conditions leaching is the most important cause of nitrate loss, but it is probable that denitrification makes some contribution on cropped soils and those under permanent vegetation. There is no indication of microbial nitrate absorption under a crop. This is presumably due to the rapidity with which nitrate is lost by leaching and denitrification, and to the greater quantity of organic matter required in these free-draining tropical soils than in most temperate ones to produce an equivalent absorption of nitrate. The high levels of nitrate and nitrifiable nitrogen which are found under natural forest probably represent an equilibrium level typical of a cycle in which nitrogen fixation and nitrification as well as nitrate losses proceed very rapidly. Natural savannah grassland suppresses nitrogen mineralization in the field almost entirely, but the nitrifiable nitrogen content is at times high, in spite of the very high carbon/nitrogen ratio of the soil of over 20. This confirms the view that little nitrate absorption takes place in spite of the presence of what might be considered excess carbonaceous material. The suppression of mineralization under grass is considered due to an excretion of the plant roots which is toxic to the nitrification process. The failure of organic matter to build up in these savannah soils, although mineralization is suppressed, is most probably associated with their low general fertility.
A note on the chemical composition of fish meals used in a hatchability experiment
Authors: Carpenter K. J.
Published: March 2009

Coles (1957) has reported the results of a hatchability trial in which four pens of hens each received 10% of a different sample offish meal (A–D) in their diet as the only experimental variable. There was a high level of egg production in each pen, but differences in hatchability as indicated in Table 1. The pen with lowest hatchability received fish meal D, which was darker in colour than the others. It was suggested that this might indicate a scorching of the meal with heat damage, and that in turn this might be responsible for the lower hatchability. The meals have now been analysed to investigate this point.
Endogenous faecal loss of calcium by ruminants
Authors: Braithwaite G. D.
Published: March 2009

A re-examination of the results from 374 sheep used in previovis studies of calcium metabolism show there is a highly significant linear relationship between endogenous faecal loss of Oa and food intake, endogenous loss increasing by about 0·64 mg/day/kg body weight for each 1 g/day/kg body weight increase in food intake. This loss was unaltered by Ca intake or by pregnancy and lactation but was slightly higher in young animals than in adult animals given the same Ca intake on a body-weight basis. It is suggested that a variable factor for endogenous Ca loss, based upon some measure of level of feeding, should be introduced into rationing schemes.
The influence of plant raising conditions on the head weight of crisp lettuce at maturity
Authors: Wurr D. C. E. , Fellows Jane R.
Published: March 2009

Two experiments investigated the effects of raising crisp lettuce seedlings under different environmental conditions prior to transplanting, on transplant size and weight and head weight at maturity.

The use of tungsten lighting for 4 h after the end of a 12 h period of fluorescent and tungsten lighting increased transplant size and weight and the weight of heads at maturity compared with fluorescent and tungsten lighting only. Glasshouse-raised transplants were larger than those raised under artificial lighting but gave heads of similar weight to transplants which had supplementary tungsten lighting for 2 weeks. Both these treatments gave significantly heavier heads than a drilled crop or plants raised without supplementary tungsten lighting. Increasing the number of weeks of the supplementary lighting treatment tended to increase the coefficient of variation (c.v.) of head weight. Nevertheless the drilled crop had a higher c.v. of head weight than any transplanted treatment.

The variety Pennlake produced pointed (‘coned’) heads when grown in the open and its leaves were shorter and broader than those of plants grown in polyethylene tunnels, which did not show ‘coning’. It is suggested that ‘coning’ occurs primarily as a result of either lower mean temperatures or a lower amplitude of temperature when grown in the open. It occurred most frequently with glasshouse-raised plants indicating that a higher raising temperature may also contribute to the problem.
The indirect determination of energy retention in farm animals: I. The development of method
Authors: Blaxter K. L. , Rook J. A. F.
Published: March 2009

1. Methods of estimating water retention in the body of cattle are discussed, and it is shown that methods based on determinations of the initial and final body-water content are of low accuracy and are not suitable for the indirect estimation of fat balance over a period of 24 days.

2. Analyses of tissues from young and adult cattle showed that with the exception of serum, brain, skin and bone, water content of the tissues may be predicted from the following equation:

Water(g./100g.)= 0·292 Na(mg./100g.)+ 0·147 K(mg./100g.).

This equation shows that 1 m.equiv. of the Na of tissues is associated with more water than is 1 m.equiv. of the K.

3. No differences between cattle aged from less than 1 week to more than 5 years were observed in the relationship between water and Na and K content.

4. The equation applied also to the contents of the digestive tract, other than those of the abomasum which gave low results, ascribed to the presence of a high concentration of H+ions.

5. Analyses of whole foetuses for Na, K and H2O showed that their water content could be predicted accurately. The same was true of amniotic fluid, but the water content of allantoic fluid was underestimated by 50%.

6. It was shown that despite the anomalous behaviour of brain, serum, skin and bone, accurate predictions of the water content of the animal could be made from simultaneous determinations of Na and K retentions, providing a correction was made for the storage of bound Na in bone.

7. Data are presented which indicate that the equations apply equally well to the tissues of the sheep.
The indirect determination of energy retention in farm animals: II. Studies on the validity of the method
Authors: Blaxter K. L. , Rook J. A. F.
Published: March 2009

1. A series of simultaneous determinations of the Na, K, N, C, ash, H2O and energy retentions of calves have been made in order to test the validity of a method of estimating energy retention without recourse to respiration chamber technique. The experiments involved 72 days' calorimetric observation with six animals. A further series of fourteen experiments with sheep involving 58 days' calorimetric observation were made but are not reported in detail

2. It was found that, with calves, water retention could be estimated by an indirect method from Na, K and ash metabolism without significant systematic error. The standard deviations attached to the indirect estimates appeared to be invariant with length of period. Thus, by increasing the length of the period the accuracy of the mean daily estimate of water retention could be considerably increased.

3. With calves, energy retention measured indirectly from body-weight gain and the gain of ash, protein and water did not differ significantly from that determined calorimetrically by the C and N balance technique. The standard deviation of the mean daily difference fell with increasing length of period, being ± 407 Cal./24 hr. in an experiment lasting 8 days. It was calculated that experiments with four calves lasting 24 days would give results of the same precision as that obtained in a single calorimetric trial.

4. The use of the ratio calorie retention/protein retention could permit the calculation of energy retention from the N metabolism of the animal. It is suggested that this method, if developed to take into account the effect of nutritional plane on the ratio, could have considerable practical value.

5. It was found that cutaneous losses of K by the sheep in its skin secretions (suint) make it impossible to interpret the difference between the intake and faecal and urinary losses of K as a body gain of K and express it in terms of water. The method is not therefore suitable for the sheep.

6. The difficulties involved in the application of the method to adult cattle are pointed out, particularly those that stem from the high K content of most of the foods they eat. A very high analytical accuracy is necessary if the estimates of Na and K retention are to have the necessary precision.
Crop compatibility and spatial arrangement in sorghum-based intercropping systems
Authors: Waghmare A. B. , Krishnan T. K. , Singh S. P.
Published: March 2009

Field experiments on crop compatibility and spatial arrangements in sorghum were conducted at the Indian Agricultural Research Institute, New Delhi in irrigated conditions in 1976 and 1978. Grain yield of sorghum increased when grown in association with the legumes greengram, groundnut, grain and fodder cow peas and soya bean, compared with sole sorghum. Planting of sorghum in paired rows (30:90 cm) with two rows of intercrop in the 90 cm space produced maximum yields of sorghum and intercrops.