bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on the estimation and decomposition of amino sugars in soil
Authors: Bremner J. M. , Shaw K.
Published: March 2009

1. The amounts of amino sugar-N present in acid hydrolysates of six soils with nitrogen contents ranging from 0·17 to 2·82% have been estimated by colorimetric and alkaline decomposition methods.

2. Recovery of amino sugar-N after hydrolysis of chitin or glucosamine was found to be unaffected by the presence of soil during hydrolysis.

3. Substances known to interfere with the methods of amino sugar analysis employed were not detectable in the soil hydrolysates.

4. From the amounts of amino sugar-N liberated by acid hydrolysis it is deduced that 5·10% of the total-nitrogen of the soils examined was in the form of amino sugars.

5. The decomposition of amino sugars in soil has been studied by comparing the rates of decomposition of chitin, glucosamine, casein and yeast nucleic acid when incubated with soil under conditions found to produce rapid nitrification of ammonium sulphate.

6. Glucosamine and chitin are readily decomposed by soil micro-organisms but not so rapidly as casein or yeast nucleic acid.
The performance of heifers got by artificial insemination
Authors: Robertson Alan , Rendel J. M.
Published: March 2009

1. An analysis has been made of the production records of over 1400 heifers got by A.I. bulls at five non-Board centres. The A.I. heifers, when compared with other heifers in the same herd in the same year, showed no significant increase in yield but a significant increase in fat content.

2. The difference in yield between A.I. and contemporary non A.I. heifers was not significantly different in herds at all levels of production. This would suggest that only a small proportion of the differences in yield between the herds in the sample was genetic in origin. In fat percentage, there was some evidence, though not very conclusive, that rather more of the inter-herd variation was genetic.

3. Significant differences were found between the progeny groups by different sires in both milk yield and fat content. The standard deviation of the variation due to the breeding value of the sire was 37 gal. and 0·13% fat respectively.

4. Methods of interpreting progeny tests made under A.I. conditions are discussed theoretically. It is concluded that the comparison with heifer contemporaries in the same herd is most satisfactory for milk yield and the simple average is best for fat content.

5. The relevance of these results to the genetic structure of breeds is discussed. They are in good agreement with the conclusions from pedigree analysis that the genetic differences between the dominant group of herds and the mass of commercial cattle in each breed is not great.
Effects of row width and planting density on growth and yield of two maincrop potato varieties. 1. Plant morphology and dry-matter accumulation
Authors: Ifenkwe O. P. , Allen E. J.
Published: March 2009

Data are reported from three experiments from 1972 to 1974 in which the effects of two row widths (66 and 132 cm) and five planting densities on the growth of two maincrop potato varieties (Désirée and Maris Piper) were studied. The results were consistent over the 3 years and showed that the effects of widening the row width were to reduce the number of axillary branches and their leaves per plant, in Maris Piper L (leaf area index), and early in the season in both varieties dry weights of leaf, stem and underground parts per plant. Row width had no effect on tuber dry weight for most of the season but at the end of sampling, tuber dry weights were greater from 132cm than from 66 cm rows. Increasing planting density reduced number of axillary branches and their leaves per plant, dry weight of leaf, stem, underground parts and tubers per plant, but increased stem length and tuber dry weight per unit area.

Leaf growth of all treatments was rapid during May and high planting densities reached an Lof 3 before the end of this month. L was increased by increased planting density throughout growth, but the lower densities were able to maintain an L of 2–3 formuch of the season. The rapid early increase in L was not associated with any prematuredecline and high rates of tuber dry-matter accumulation were achieved and maintained throughout the season. It is suggested that as the pattern of leaf growth in this environment is coincident with changing light receipts, the environment is almost ideal for the growth of maincrop potatoes.
Uromol as a source of dietary nitrogen for ruminants: metabolic and rumen fermentation studies on buffalo calves
Authors: Malik N. S. , Langar P. N. , Chopra A. K.
Published: March 2009

The nutritive value of uromol, a heated product of urea and molasses, was compared with raw urea–molasses and groundnut meal in three metabolic trials on buffalo calves. The non-protein nitrogen (NPN) as urea or uromol contributed about 65, 48 and 30% of the nitrogen in the experimental concentrate mixtures, replacing partially or completely the groundnut meal of the control diets. The results showed that at 65% nitrogen replacement, the crude fibre and cellulose digestibilities and the nitrogen retention of the uromol diet was similar to that of the control but was significantly (P < 0·05) higher than the urea–molasses diet. At 48% nitrogen replacement the nitrogen retention in the uromol-fed animals was still significantly (P < 0·05) higher than the urea–molasses fed group. At 30% nitrogen replacement, the differences between the control, urea–molasses and uromol groups were not significant.

In vivo rumen studies with the diets containing 50% NPN replacement showed lower but sustained ammonia-N with uromol than the urea–molasses diet. The total volatile fatty acids (TVFA) in rumen fluid, though initially higher in the control and uromol groups, were not significantly different from the urea–molasses group. Abomasal studies with diets containing 65% N as urea or uromol indicated a higher total nitrogen content in the abomasal fluid of the control and uromol-fed animals than the urea-fed animals. The 24 h abomasal passage of total-N/100 g nitrogen consumed was 95·5, 93·5 and 77·9 g in control, uromol and urea groups, respectively. The TCA-precipitatable-N (TCA-N) was also higher in the first two groups. These studies suggest that uromol is safer and has a better feeding value than urea–molasses at high rates of nitrogen replacement.
Effects of progressive feed restriction on the growth and carcass composition of pigs: comparative responses of gilts and castrates
Authors: Fuller M. F. , Livingstone R. M.
Published: March 2009

A barley-based diet, containing 16% protein, was given at average daily rates of 1·2–2·5 kg (16–32 MJ, metabolizable energy (ME)) to 32 female and 32 castrated male pigs during their growth from 25 to 90 kg. At high intakes there was no difference in growth rate between the sexes, but with progressive feed restriction the growth of males was more severely retarded than that of the females. Both sexes achieved their minimum feed conversion ratios at approximately 25 MJ. The reductions of fat thickness with progressive feed restriction were greater by approximately 20% in the females than in the males. The two sexes had the same mean back fat thickness when the gilts had 4·7 MJ more ME per day than the castrates. It was inferred that the energy requirement for maintenance was 15% greater in the males than in the females.
Experiments on the nutrition of the dairy heifer. XI. Further observations on the effect of energy intake on protein utilization
Authors: Broster W. H. , Smith T. , Siviter J. W. , Schuller E. , Broster Valerie J.
Published: March 2009

Five experiments were made to observe the effect on nitrogen (N) utilization by young cattle of supplements of sucrose, glucose monohydrate (dextrose), and maize starch when added to basal diets of concentrates and straw. The supplements provided about 12% of the total intake of air-dry food. Twenty-four yearling Friesian heifers were used in each of two randomized block experiments to measure live-weight gain, and 6, 10 and 10 yearling Friesian steers in three changeover design experiments to measure N retention.

Rates of live-weight gain and N retention were increased by all the supplements amongst which no order of superiority in benefit conferred could be established. The improvement in N retention was associated with a marked reduction in urinary N and a small increase in faecal N with supplemented rations.

The proportions of volatile fatty acids (VFA) in rumen fluid were not affected by starch supplementation. Both sugars, but glucose more than sucrose, decreased the ratio of acetic to propionic acid, measured 2 h after feeding.

Statistically significant multiple linear regression equations were observed between N retained and intakes of N and digestible organic matter (DOM), both as absolute amounts with live weight as a further independent variate, and as intakes/unit metabolic body size. N2and DOM × N as additional variates did not benefit the fit of the equations over the range of intakes studied.
Validation of new systems for protein evaluation in ruminants by testing the effect of urea supplementation on intake and digestibility of straw with or without sodium hydroxide treatment
Authors: Ørskov E. R. , Grubb D. A.
Published: March 2009

Milled barley straw, either untreated or treated with 70 g of NaOH/kg straw was supplemented with four levels of urea, namely 0, 6, 12 or 18 g/kg and fed ad libitum to young sheep. For the untreated straw, dry-matter intakes were (g/day) 423, 451, 441 and 463, while the digestibility of organic matter was 458, 467, 490 and 483 g/kg, respectively. For the treated straw, the intakes of dry matter were 355, 402, 531 and 567 g/day and the digestibility of organic matter was 423, 480, 589 and 628 g/kg respectively.

The different responses to urea supplementation of treated and untreated straw are discussed in relation to a new system of estimating protein requirements for ruminants put forward by the Agricultural Research Council.
Organ development in relation to egg-laying capacity in the fowl
Authors: Hafez E. S. E.
Published: March 2009

Eighty-nine Fayomi pullets were classified into three major classes High, Medium and Low according to the intensity of egg laying. Six birds in each class were slaughtered. The major body organs were dissected and weighed. The number and diameter of the visible oocytes were recorded. The dressing out percentage was obtained. The results were as follows:

1. During the first year of laying, the averagenumber of eggs laid per day was 0·50, 0·42 and 0·24 eggs for the High, Medium and Low classes respectively.

2. There were significant differences in the ovarian weight, length and weight of oviduct, these being highest in the High class.

3. The number of visible oocytes was some 200 in all classes. There were, however, differences between classes in the maturation rate of the oocytes as measured by the differences in the diameter of successive ones.

4. The weight of blood, feathers, head, wings and legs were higher in the Low than in the High; these are all early maturing organs.

5. The weights of the full alimentary canal and the empty gizzard were higher in the High than in the Low, this might be accounted for by a greater appetite and to intake of feed induced by the higher egg production.

6. There were no significant differences in the weight of the circulatory, excretory and respiratory organs which are needed for the physiological welfare of the birds.

7. The dressing out percentage was higher in the Low and Medium than in the High. This may be due to the greater drainage of nutrients required for high egg production.
A study of the distribution of acid and alkaline phosphatase in the genital tract of the Zebu bull (Bos indicus)
Authors: Rollinson D. H. L.
Published: March 2009

The histochemical localization of acid and alkaline glycerophosphatase (phosphomonoesterase) has been determined throughout the reproductive tract in the bull. Sections were incubated in a buffer substrate containing sodium β-glycerophosphate at pH 4·5 and pH 9·4. Duplicate sections were incubated for progressive lengths of time ranging from ½ hr. (alkaline phosphatase) to a maximum of 48 hr. (acid phosphatase).

Evidence of the presence of both enzymes has been obtained in the tissues which compose the reproductive tract. In the case of acid phosphatase the reaction was predominant in the nuclei of the lining epithelial cells. In addition, a positive cellular reaction was found in the distal portions of the epithelium lining the epididymis, the ampulla of the vas deferens and the seminal vesicles. The reaction obtained in the testis appeared to vary with the stage of activity of the tubule.

In the case of alkaline phosphatase the reaction was predominantly shown by the basement membrane and the capillaries throughout the tissues with a cellular reaction in the distal portions of the cells lining the epididymis, the ampulla of the vas deferens and the seminal vesicles. In the seminal vesicles the type ‘A’ cells reacted strongly while the periphery of the osmic staining vacuoles of the type ‘B’ cells also gave a positive reaction. The only activity present in the prostate was in the capillary endothelium. The spermatogenic epithelium showed a positive reaction, but no reaction was given by the interstitial cells.
Note on motility and fertility of colchicine-treated bull and rabbit sperm
Authors: Beatty R. A. , Rowson L. E. A.
Published: March 2009

In 1939, Pinous & Waddington reported tetraploid early cleavage stages of the rabbit after colchicine treatment of fertilized eggs in vitro. Chang (1944) inseminated rabbit does with sperm suspended in 1/1000 colchicine in 0·9% NaCl and noted a few abnormal young in the resulting litters. No chromosome counts were made, but Chang considered the possibility that colchicine had entered the egg and caused polyploidy. Using the same technique as Chang, Swedish workers have claimed the production of two adult triploid rabbits and one adult triploid pig (Häggqvist & Bane, 1950a, b, c, 1951; Melander, 1950, 1951). This Swedish work has been criticized (Beatty, 1951; Beatty & Fischberg, 1950; Becker, 1952–3; Hertwig, 1951; Nachtsheim, 1950; Rostand, 1951; Venge, 1953). Nevertheless, the technique is ingenious and the claim of great interest. The present note records preliminary attempts to extend the technique to cattle and to confirm the results in rabbits.
Seasonal changes in plasma concentrations of proteins, urea, glucose, calcium and phosphorus in sheep grazing a hill pasture and their relationship to changes in body composition
Authors: Sykes A. R. , Field A. C.
Published: March 2009

The seasonal changes in plasma concentrations of albumin, globulin, transferrin, urea, Ca, P and glucose were measured in 59 Scottish Blackface sheep grazing a hill pasture. The sheep were classified according to age and state of permanent incisor dentition into four groups. Sheep were slaughtered at mating (November), mid-lactation (June) and in the late dry period (November), and the changes in plasma constituents related to changes in body composition. A protein-free supplement was offered during late pregnancy.

Another group of sheep was used in the subsequent year to investigate the significance of helminth infections on such pastures.

Plasma albumin concentration fell from 32·0 g/1 in all sheep in early pregnancy to 17·5–19·5 g/1 in late pregnancy and early lactation in 5½- to 6½-year-old animals. Younger animals (2½ year old) maintained higher (23·0 g/1) levels at these latter times. The extent of the decrease in plasma albumin concentration of the groups was related to the loss of N from their soft tissues during the same period.

Plasma volume increased from 2·10 to 2·491 between early pregnancy and midlactation (45 and 66 ml/kg body weight respectively). The increase in volume was considered to account for the reduction in the concentration of plasma globulin which took place during this period.

Plasma urea-N concentrations were extremely low (50—60mg/l) between February and April and had fallen from their highest values (240 mg/1) in August to 150 mg/1 by the following November. It is argued that the fall in albumin concentration which occurred in early pregnancy, coupled with the extremely low urea-N concentration, reflects a very low digestible crude protein intake during most of pregnancy.

Transferrin concentration followed a similar seasonal pattern to urea. The concentration was extremely low in February (2·2–2·4 g/1), highest in August (3·45 g/1) and had fallen by November (3·0 g/1). The value of transferrin as a nutritional index is discussed.

Regular dosing with anthelminthic of sheep on these pastures had a beneficial effect on plasma albumin concentrations, particularly during critical nutritional periods, namely late pregnancy and lactation.

Plasma glucose, Ca and P concentrations were of no value in monitoring the nutritional status of the animal with respect to these nutrients.
Animal and dietary variation in the absorption and metabolism of phosphorus by sheep
Authors: Field A. C. , Woolliams J. A. , Dingwall R. A. , Munro C. S.
Published: March 2009

In Expt 1 the efficiency of absorption of phosphorus in feedingstuffs was compared within four sets of 18-month-old, chimaera-derived triplets; 12 feedingstuffs were evaluated in four balance trials with 32P. Seven diets consisted of a P-rich ingredient mixed with a low-P basic diet and five of hay or pelleted dried grass or lucerne. The P ingredients tested were the protein-rich meals, rape, soya-bean, maize gluten, fishmeal and rice bran, and the cereals, barley and wheat.

Sets of triplets absorbed dietary P with different (P < 0·001) efficiencies; the mean values were 0·72, 0·63, 0·76 and 0·79. The availability of P differed (P < 0·001) between diets, highest values being seen with the fishmeal (0·80), barley (0·78) and wheat diets (0·78) and the lowest with rice bran (0·63) and a perennial ryegrass hay (0·64). There was no evidence for an age effect on efficiency of absorption.

Endogenous faecal excretion was positively related to intake (P < 0·001) and negatively related to efficiency of absorption of dietary P. Plasma concentration was positively related (P < 0·001) to both intake and, between sets, to the efficiency of absorption.

Significant urinary excretion of P generally occurred when the efficiency of absorption was greater than 0·70. Two members of a set which absorbed P with high efficiency and excreted low volumes of urine died from urethral obstruction caused by calculi.

In Expt 2 an estimate of the variation in the concentration of P in plasma of 48 ewes on a barley-based diet was assessed and the values for three of the chimaera sets fell within the top quartile.

Safety factors were calculated from the animal and plant variations in the efficiency of absorption of dietary P and used to determine dietary allowances for different classes of sheep.
Nodule development and nitrogen fixation in cultivars of Phaseolus vulgaris L. as influenced by planting density
Authors: Graham P. H. , Rosas J. C.
Published: March 2009

Three cultivars of P. vulgaris, tested 39 and 69 days after planting, differed in the extent to which nitrogen (C2H2) fixation and nodule development were affected by plant density.

At the 39-day harvest the climbing cultivar P590 declined in fixation from 15·1 μmol C2H4 produced/plant/h at 8·5 plants/m2, to only 4·2 μmol C2H4 produced/plant/h at 41·5 plants/m2; while the prostrate P498 showed consistently high fixation from 8·5 to 41·5 plants/m2. Variation in nitrogen fixation could be explained largely by change in nodule weight, though specific nodule activity (SNA) was affected, particularly in the cultivar P590. Since the percentage soluble carbohydrate in nodules of two varieties increased at certain planting densities while SNA decreased, some nodule dysfunction is possible.

Density changes affected leaf, root and stem development in all cultivars, leaves on the lower nodes being most severely affected.

At the 69-day harvest two varieties were advanced in filling the pods and showed poor nodulation and limited fixation, even at the widest plant spacings, while nodulation and nitrogen (C2H2) fixation in the third variety, which had just flowered, showed optima similar to the earlier harvest.
Using Suffolk sheep for improving lamb production from sub-tropical Egyptian sheep:1. Reproductive performance
Authors: Aboul-Naga A. M.
Published: March 2009

The present study deals with the reproductive performance of an imported Suffolk flock and the cross-bred ewes resulting from upgrading the local Ossimi sheep with the Suffolk. A total of 1738 ewe records were available for the study.

No significant difference was found between Suffolk and Ossimi ewes in conception rate or proportion of multiple births. However, the Ossimi ewes (mated to Suffolk rams) weaned 25 more lambs per 100 ewes lambing than the imported ewes. The cross-bred ewes were of better reproductive performance than both pure-breds. The best Suffolk cross-bred ewes were those of 40–49 % Suffolk breeding. They weaned 21 more lambs per 100 ewes run with the rams than the local ewes. Reproductive performance of the cross-bred ewes declined with increasing Suffolk genotype above this proportion.

Under the prevailing sub-tropical conditions, the Suffolk ewes have an anoestrous period of 200 days from late January to late July or August; the local ewes showed oestrous activity throughout the year, but with some irregularity.
The use of rainfall, temperature, and actual transpiration in some crop-weather investigations
Authors: Buck S. F.
Published: March 2009

This paper reports various investigations of the effects of meteorological factors on the yields of crops in England and Wales. The investigations were undertaken primarily with the objects of seeing (a) whether variations in temperature had any direct effect on yields, and (b) whether Penman's concept of actual transpiration gave a better measure of the overall effect of rainfall than the use of a multiple regression on variates representing total rainfall and its distribution.

The effect of temperature and its seasonal distribution on the yields of wheat on various plots of the classical wheat experiment on Broadbalk field at Rothamsted was studied in conjunction with rainfall and its seasonal distribution, using the regression method devised by Fisher. Variations in temperature were found to show no effects on the final yields.

The relationship between actual transpiration and yield was investigated for the Broadbalk field and for sugar beet and potatoes, using average yields determined by sampling methods, for various districts in England and Wales. For sugar-beet virus yellows infection, and for potatoes blight attack, were also taken into account.

No relationship between actual transpiration and wheat yields on Broadbalk field was found, but sugar beet and potatoes both showed a positive association between actual transpiration and yield except for sugar beet in the Spalding area, where there is a high-water table. Actual transpiration was in general more effective than a regression on total rainfall and its distribution accounting for variations in yield. As might be expected virus yellows and blight also account for a good deal of the variation in yield.
The utilization of food by sheep and cattle
Authors: Blaxter K. L. , Wainman F. W.
Published: March 2009

1. The utilization of the energy of the same ration by sheep and by cattle was measured using three steers and three sheep in twenty-one and twentyfour experiments, respectively. Five different amounts of the ration were given to each steer and six different amounts to each sheep.

2. No differences of any magnitude were found in the percentage losses of dietary energy in faeces, in urine or as methane if comparisons were made at comparable nutritional levels. Faecal energy losses increased and urine energy losses and methane production fell with increase in feeding level, the feeding level being defined as the ratio of food intake to that required to attain an energy retention of zero.

3. The net availability of metabolizable energy for maintenance was the same in both species at 80·4%. The net availability of energy for the production of fat was 53·5 ± 1·4 in sheep and 51·4 ± 2·6 in cattle.

4. The results are discussed in relation to the effect of the amount of food given on the utilization of its energy. It is pointed out that net energy per unit of food declines with increasing intake, due firstly to a decline in digestibility and secondly to the fact that oxidative processes operative at and below maintenance are more efficient processes than is the synthesis of fat.
Studies of the response of the anoestrous ewe treated with progesterone and pregnant mare serum
Authors: McDonald M. F.
Published: March 2009

1. An experiment was conducted to study the effects of progesterone and pregnant mare serum (p.m.s.) on incidence of oestrus, macroscopic changes in the ovaries, histological appearance of the genital tract, the vaginal smear and cervical mucus of New Zealand Romney Marsh ewes in deep anoestrus. Ten animals served as controls, thirty-five received progesterone daily for 4–12 days and ten were given p.m.s. alone. The remaining fifteen ewes were treated with progesterone for 4–6 days followed by p.m.s.

2. In ewes treated with progesterone alone, neither ovulation nor oestrus resulted. After p.m.s. alone six animals ovulated, while injection with both hormones caused ovulation in all 15 ewes and one was in oestrus.

3. Sections cut from the mid-region of the fallopian tube, uterine horn and cervix were examined. Histological responses to progesterone and p.m.s. were found in all positions of the tract and were greatest in the ewes which had ovulated.

4. In the ewes which ovulated a sequence of macroscopic and microscopic changes occurred in the vagina and these seemed similar to those associated with ovulation during the oestrous cycle.

5. Crystallization patterns in cervical mucus were seen in some ewes of all groups. Accompanying ovulation the phenomenon was seen for several days but was absent during most of the luteal period. When no follicles ruptured cervical mucus patterns often persisted. In most cases the presence and absence of arborization was presumably related to follicular oestrogen and progesterone from an induced corpus luteum and was in similar time relationship to that normally accompanying ovulation in the oestrous cycle. Some inconsistency in the response of cervical mucus following hormone treatment was noted.

6. No evidence was found that hormone treatment had initiated a regular cycle of ovarian activity.
Magnesium in forage plants I. Magnesium contents of different species and strains as affected by season and soil treatment
Authors: Todd J. R.
Published: March 2009

1. Individual herbage species were grown in pots and their magnesium contents studied throughout the growing season. The effects of treatments with sulphate of ammonia, superphosphate and calcined magnesite were also investigated.

2. Of the grasses studied timothy was consistently the lowest in magnesium content, the rye-grasses and cocksfoot being appreciably higher and similar. The clover species had higher magnesium contents than the grasses, especially in the spring.

3. The magnesium contents of the grass species were lowest in spring and showed a marked increase as the season advanced. The corresponding increases in clover magnesium content were considerably smaller.

4. The effects of sulphate of ammonia and superphosphate were slight increases in magnesium contents, but the calcined magnesite resulted in major increases in magnesium contents of both grasses and clovers.
Studies on the efficiency of mating in the sheep I. The effect of paddock size and number of rams
Authors: Lindsay D. R. , Robinson T. J.
Published: March 2009

A factorial experiment is described in which seventy-two spayed crossbred ewes were used in four successive tests at intervals of 15 days in a study of factors affecting the detection of oestrus. Variates introduced in each test were: (a) number of rams to eighteen ewes (one or three); (b) size of mating paddock (17 acres or ⅕ acre); (c) dose of oestrogen (oestradiol benzoate, ODB: 10·0, 15·6, 24·4 μg.).

All ewes were primed with progesterone for 12 days prior to ODB injection and joining. The number of ewes detected in oestrus and the mean number of ewes served per ram were recorded.

In the four successive tests, thirty-two, fortyseven, forty-six and forty-one ewes were served (P < 0·05). Three rams working together detected ninety-eight ewes in oestrus while rams working individually detected sixty-eight (P < 0·001). Size of mating paddock had no significant effect (17 acres, 89; Jacre, 77).

The mean number of ewes marked per ram when used singly was indistinguishable from the mean number when rams were in groups of three (8·5 and 9·3). This resulted in multiple coverage of oestrous ewes when group joined (average 2·3 rams per ewe).
Some effects of seed size and spacing on the yield and grading of two maincrop potato varieties: II. Bulking rate
Authors: Wurr D. C. E.
Published: March 2009

Data are presented from two experiments which examined the effect of three seed sizes and three within-row spacings on the bulking rate of graded potatoes from the two early mainorop varieties Pentland Crown and Maris Piper.

There were significant linear and quadratic regressions of yield on time and there were significant effects of all main treatments on the bulking rate of the crop. Differences in yield between the levels of each treatment depended upon the time of harvest and the size of tubers considered.
The effect of supplementary and fertilizer sulphur on voluntary intake, digestibility, retention time in the rumen, and site of digestion of pangola grass in sheep
Authors: Rees M. C. , Minson D. J. , Smith F. W.
Published: March 2009

Pangola grass grown with and without sulphur fertilizer was cut as a 7-week regrowth to measure voluntary intake and digestibility by sheep. To determine the extent of a simple sulphur deficiency half the sheep on each feed were supplemented with 0·6 gsulphur daily. Retention time of feed in the reticulo-rumen and proportion of feed digested anterior to the duodenum was also determined.

Sulphur fertilizer increased the sulphur content of the pasture from 0·09 to 0·15%, voluntary intake of dry matter from 44·4 to 64·1 g/kg W0·75/day and dry-matter digestibility from 55·2 to 60·2%. Sulphur fertilizer reduced the retention time in the reticulo-rumen by 16% and increased the extent of dry-matter digestion before the duodenum from 13 to 34%.

Feeding a sulphur supplement increased dry-matter digestibility of the low sulphur feed to that found with sulphur fertilized pangola grass but only accounted for 63% of the difference in voluntary intake.

It was concluded that fertilizer sulphur leads to large increases in both voluntary intake and digestibility of sulphur deficient grass and that the improvement in nutritive value may be more than can be achieved by feeding a sulphur supplement.
Observations on the effect of environmental temperature and environment at moult on the heat production and energy requirements of hens and cockerels of a White Leghorn strain
Authors: O'Neill S. J. B. , Jackson N.
Published: March 2009

The heat production of hens and cockerels of a White Leghorn strain (‘H & N’) was measured after acclimation to environmental temperatures of 16, 23, 27 and 33 °C. No difference in fasting heat production was found between 16 and 23 °C for well-feathered hens in the first few months after moult though there were substantial reductions at 27 °C and above. Both hens and cockerels showed a trend of increasing net availability of metabolizable energy with increasing environmental temperature though this was non-significant. There were significant reductions between 16 and 27 °C in the metabolizable energy requirements for maintenance for both sexes.

Results are also given for the heat production of laying hens exposed to short daylight periods and high or low environmental temperatures. Although the mean fasting heat production of the high-temperature group was greater, the difference was not statistically significant.
Adaptive significance of red cell potassium types in buffaloes
Authors: Sengupta B. P.
Published: March 2009

The possible adaptive significance of the occurrence of HK and LK red-cell types in Murrah buffaloes was investigated. Judged by haematological indices and thermorespiratory responses under conditions of moderate thermal stress, LK animals appeared to have a greater adaptive potential than HK animals in a hot arid environment. Dry matter percentage, packed cell volume (pcv), haemoglobin concentration (Hb), red blood corpuscles (RBC) and plasma protein values were significantly higher in LK-type animals. In addition, under identical conditions of thermal stress the LK animals exhibited significantly less rise in rectal temperature and respiratory rate than the HK animals.
Interactions between genotype and density on the yield components of Zea mays: I. Production of dry matter by the shoot
Authors: Voldeng H. D. , Blackman G. E.
Published: March 2009

The interacting effects of genotype and density on the yield of dry matter by mature shoots were examined at Oxford, England. There were six hybrids, either pure dent or flint × dent crosses, together with two open-pollinated flint varieties of very early maturity. Over a range of 15 densities (5·0–30·8 plants/m2) for all the genotypes the relationship between the yield of the shoot and density can be adequately described by the reciprocal equation 1/w = A + Bp, where w = weight per plant, p = number of plants per unit area and A and B are constants for any particular set of conditions. Values of both 1/B (asymptotic yields) and 1/A (weight per plant at very low densities) were dependent upon the genotype. In a regression analysis between 1/w and p, the variance of 1/w was over 40 times as great at high as at low densities and a weighted analysis was necessary. Some hybrids approached maximal yields at 5 plants/m2, whereas others required a density of 10–15 plants/m2. The possible reasons for these interactions are discussed and improvements in experimental design suggested.
Composition of beef carcasses: III. The reliability and use of visual assessment
Authors: Harries J. M. , Pomeroy R. W. , Williams D. R.
Published: March 2009

The technique of visual appraisal of intact sides of beef was used on most of the carcasses previously described in Parts I and II of this series. Tests of discrimination and consistency were carried out for each of the judges taking part, and their assessments were compared with the results of subsequent dissection of the carcasses.

It was found that visual appraisal of the subcutaneous fat content of a carcass was very good, especially with the aid of photographic standards, though a curious tendency to match the standards consistently to carcasses of a higher proportion of fat than those used for the photographs themselves was apparent. This did not materially affect the use that can be made of visual judgements in predicting fat content and it was found that expert judgement alone is capable of predictive accuracy roughly equal to that obtained from simple measurements, though not as good as that obtained by partial dissection, as described in Part II. Equations are given for the prediction of carcass composition, using visual appraisal in combination with other variables.

The appraisal of conformation was not so successful; reasons for this are advanced, and suggestions made for future improvement.
Utilization of berseem hay by ruminants
Authors: Sharma V. V. , Murdia P. C.
Published: March 2009

Four young females of four ruminant species, namely cow, buffalo, sheep and goat were used to study the utilization of sun-cured berseem hay (20·6% CP) fed in long form during a 28-day experimental period. Voluntary intake of hay was estimated during the last 10 days and digestibility of feed nutrients and nitrogen balance during the last 6 days.

The digestibility coefficients of dry matter (D.M.), organic matter (OM), crude protein (CP), crude fibre (CF), ether extract (EE) and nitrogen-free extract were higher for sheep and goat than for cow and buffalo but such differences were significant for D.M., OM and CP only. The daily D.M. intake was 3·56, 3·17, 0·92 and 0·63 kg/animal and 82·5, 81·2, 70·4 and 65·1 g/kg W0.75 in buffalo, cow, sheep and goat, respectively, but intake of total digestible nutrients (TDN) relative to metabolic body size was similar for all species.

Buffalo was superior to the other three species and cow to sheep and goat in ability to retain nitrogen. Berseem hay fed ad libitum supported a daily gain of 742, 500, 71 and 31 g in young female buffaloes, cows, sheep and goats, respectively. Digestible CP values of 13·33, 13·47, 15·38 and 15·01% and TDN values of 59·8, 57·6, 70·4 and 77·6% were obtained for cow, buffalo, sheep and goat, respectively.
A method of including urea in whole grains
Authors: Ørskov E. R. , Smart R. , Mehrez A. Z.
Published: March 2009

A method of including urea into whole grains is described. The whole grains were found to absorb completely a saturated solution of urea.

The method gave the different cereals examined (barley, oats, wheat and maize) a homogeneouis distribution of urea and increased the voluntary intake of whole grains by lambs. The evolution of NH3in the rumen liquor was slightly slower when urea was absorbed into the grains than when it was included as urea crystals. The N content in the urea-treated grain was not changed after 6 months of storage.
The relation between animal gain and stocking rate: Derivation of the relation from the results of grazing trials
Authors: Jones R. J. , Sandland R. L.
Published: March 2009

Several models have been proposed in the literature relating gain per animal (Ya) and stocking rate (x) from grazing experiments. Results from an experiment in which tropical pasture species were grazed continuously by beef cattle at a number of stocking rates (Jones, 1974) were used to examine this relation. A simple linear model of the form y = a − bxfitted the data well. Production per hectare (Yh) was related to stocking rate by yh = ax − bx2.

Stocking rate for maximum gain per hectare (the optimum stocking rate) on each pasture could be calculated from the linear regression by a/2b.

Data from a number of stocking rate experiments in tropical and temperate environments were examined to see if this relation held for a wider range of stocking rates and pasture types. Results were expressed on a common basis by calculating the optimum stocking rate and relating ratios of gain to ratios of stocking rate relative to that at the optimum.

For gain per animal, the overall relation obtained: Ya = l·999–0·999x (r = –0·992; P < 0·001; n = 114) did not differ significantly from the expected linear relation: y = 2−x. Linearity was established over the range 0·18–2·0 times the optimum stocking rate. At rates greater than twice the optimum, animal gain was negative. When expressed as gain per hectare (Yh) the quadratic equation Yh = 2x − x2 gave a good fit to the data over this range.

It is suggested that, since the relation between production per animal and stocking rate (animals/ha) remains linear over a wide range of stocking rates, two rates of stocking (with replication) may be adequate for grazing experiments and these would not have to span the optimum stocking rate in order to predict gain at the optimum stocking rate.
Effectiveness of some mechanical, thermal and chemical laboratory treatments on the drying rates of leaves and stem internodes of grass
Authors: Harris C. E. , Thaine R. , Sarisalo H. I. Marjatta
Published: March 2009

Drying rates of stem internodes of S. 24 perennial ryegrass and S. 37 cocksfoot, some with leaf sheaths and laminae attached, were measured in controlled conditions of air speed, temperature and relative humidity after exposure for 60 sec to dry heat, steam, steam containing petroleum ether vapour, and petroleum ether vapour only. The last treatment was most effective in increasing the drying rate, but a similar effect was obtained by splitting the stem internodes longitudinally or by removing from the larger plant fragments (internodes with leaf) the leaf sheaths and laminae. Observations on leaves with a scanning electron microscope confirmed that the steam and petroleum treatments acted on the surface waxes thus reducing the cuticular resistance to water loss. The presence of internal tissue resistance was demonstrated by anaerobic treatment of ryegrass leaves and stem internodes to disrupt cell protoplasts. The ensuing increase in drying rate was clearest in stems which have a low surface area to volume ratio. The results suggest that the combination of both mechanical damage and thermal or chemical surface treatment could form the basis for more effective methods of increasing the drying rate in the field of crops cut for conservation.
Changes in growth habit of pigeon-peas (Cajanus cajan (L.) Millsp.) due to late sowing
Authors: Dahiya B. S. , Brar J. S. , Kaul J. N.
Published: March 2009

The habit of growth of pigeon-pea cultivars was greatly affected by environmental changes. The effect was greatest in the highest yielding cultivar, Pant A2, for the characters plant width, number of pods/main branch, number of pods/plant, grain yield and plant weight. In the late-sown crop the ‘vegetative sink’ was affected more than the ‘generative sink’. T21 was the outstanding yielder under late-sown conditions. It is suggested that a rotation of mungbean–pigeon pea–wheat can be grown in 1 year, with profitable returns.
The effect of quantity, source and time of application of nitrogen fertilizers on the yield and quality of Andropogon gayanus at Shika, Nigeria
Authors: Haggar R. J.
Published: March 2009

Experiments made at Shika, Nigeria, over a period of 3 years showed that the drymatter response of Andropogon gayanus to applied N was curvilinear over the range 0–896 kg N/ha, with maximum yields being obtained at an application rate of about 500 kg N/ha. However, the highest return of dry matter per unit of fertilizer applied (14·4 kg D.M./kg N) occurred at 28 kg N/ha and there was only a modest increase in crude-protein content as N was increased, reaching a maximum of 10·5% at the highest level of N. Also, at both high and intermediate levels of N, A. gayanus was replaced by less desirable grasses.

May, the beginning of the rainy season, was found to be the most efficient time to apply N, although reasonable dry-matter responses were obtained by applying N in the dry season. ‘Nitro-chalk’ and calcium nitrate were more efficient sources of N than urea, sodium nitrate and, in the long term, ammonium sulphate.
An analysis of factors contributing to the determination of saturation capacity in some tropical soil types (With One text-figure.)
Authors: Turner P. E.
Published: March 2009

The limitations of the “constant” saturation capacity as a factor in the characterisation of types of soils, rather than individual soils, are discussed. An attempt has been made to overcome these limitations by distinguishing between the contributions made to saturation capacity by the organic and inorganic colloidal components of three widely different tropical soil types.

1. Numerical evidence is given which shows that saturation capacity is very closely related to the content of clay and organic matter of soil (irrespective of the proportions in which they are present), but not to the fine silt fraction. Nevertheless, the correlation between saturation capacity and (a) organic matter, and (b) clay, is significantly greater for the tropical type containing the smallest amounts of these components than for the type containing the largest amounts.
Development, structure and seasonal change in the fleeces of unimproved Scottish Blackface sheep from the Hebrides
Authors: Ryder M. L.
Published: March 2009

Details are given of the fleece and other characteristics of three rams and three ewes of a strain that has lived feral on the island of Boreray in the St Kilda group since 1930.

The animals are horned and short-tailed, the rams are about 60 cm high at the withers and weigh about 45 kg at maturity, while the ewes weigh between 25 and 30 kg and are 55 cm high. The ewes reached their maximum weight after 1 year, but the rams increased in weight during the 3 years under observation.

The fleeces were shorter and finer than those of the modern Blackface, tending to have kemps rather than hairy heterotype fibres. The fleece weight was 1·25 kg, staple length ranged from 75 to 150 mm and mean fibre diameters ranged from 23 to 32 μm.

Variable fleece casting occurred although no more than about 80% of both the primary and secondary follicles became inactive during the winter. Unlike other primitive breeds studied there was a relatively narrow peak of follicle inactivity in midwinter, although in the ewes this tended to occur later in the winter, as observed in improved breeds.

There was a subsidiary small peak of follicle inactivity in August corresponding to the primitive shedding of the summer coat. Maximum fibre medullation occurred in June, and there was a second smaller peak in September.

As in other primitive breeds a relatively high proportion of follicles lacked fibres at birth, but this retardation of development was no longer evident by 14 days when the usual peak in medullation occurred. More fibre shedding was observed at 56 days than in the modern Blackface. The fibre type arrays were of Plateau P1 type.
The clearance rate of rumen liquid and rumen fermentation pattern in sheep receiving forage diets
Authors: Thomas P. C. , Hodgson J. C.
Published: March 2009

An experiment was carried out to study the composition of the mixture of rumen short-chain fatty acids and the clearance rate of the rumen liquid phase in sheep given diets of dried grass, high-nitrogen hay, low-nitrogen hay and barley straw. Differences between diets in clearance rate were not significant (P > 0·05) and differences between diets in the composition of the mixture of rumen acids were small. There were substantial variations in clearance rate between individual sheep but this was not associated with variations in the pattern of fermentation and the correlation between the proportion of propionic acid and the clearance rate in the rumen was low (r = –0·23).

In a second experiment sheep receiving a moderate-quality hay were given intravenous injections of atropine sulphate which resulted in significant increases in rumen volume (P < 0·01) and significant reductions in ruminal clearance rate (P < 0·05). These were accompanied by significant increases in the numbers of protozoa (P < 0·05) and bacteria (P < 0·05) in the rumen but the composition of the mixture of rumen short-chain fatty acids was unchanged.

It is concluded that there is little possibility through alteration of ruminal clearance rate, for manipulation of rumen fermentation pattern in sheep receiving diets of moderate- or poor-quality forages.