bluuebunny/crossref_metadata_2025 huggingface dataset:
Competition between natural populations of Dactylis glomerata
Authors: Eagles C. F. , Williams D. H.
Published: March 2009

The competitive abilities of two natural populations of Dactylis glomeratafrom Norway and Portugal were studied under three controlled environments, 7 °C with an 8 h photoperiod, 20 °C with a 16 h photoperiod, and 30 °C with a 16 h photoperiod. The temperature and daylength treatments affected both the growth habits and the relative competitive abilities of the populations. At 7 °C, 8 h photoperiod the Norwegian population became prostrate and was suppressed in mixed culture compared with its performance in monoculture, and an increased specific leaf area indicated competition for light. At 30 °C, 16 h photoperiod the Norwegian population was more erect than the Portuguese, and more aggressive, with a better performance in mixed culture than in monoculture. The performance of the Portuguese population was not affected significantly either by culture or by environment. At 20 °C, 16 h photoperiod, however, the Portuguese population was suppressed, while the Norwegian population performed better in mixed than in monoculture. This yield increase of the Norwegian population was greater than the decrease of the Portuguese population, and so the mixed culture yielded significantly more than the mean of its component monocultures, whereas at 7 and 30 °C the mixed culture yielded no more than the mean of its monocultures. The physiological basis of these competitive effects is discussed.
Infertile bulls versus steers: III. Carcass characteristics
Authors: Price M. A.
Published: March 2009

The carcass characteristics of a total of 43 infertile bulls were oompared with those of 42 steers from five independent trials. In most cases there was no significant difference between the bulls and the steers for dressing percentage, or fleshing index. Bulls were generally found to have greater hide percentages than steers, the difference being very highly significant (P < 0·001) in one of the trials and significant (P < 0·05) in another. Eye musole area expressed relative to caroass weight was greater in the bulls, the difference being significant (P < 0·05) in three of the trials. The depth of fat over the eye musole and the hind to fore-quarter weight ratio were greater in the steer carcasses. Head weights were found to be significantly greater (P < 0·05) and caul and kidney fat weights less (P < 0·05) in bulls than in steers in the one trial where these parameters could be measured.

Carcass composition was estimated by the three-rib sample joint teohnique in four of the trials, and in these the bulls had a greater percentage of bone and muscle, but a lower peroentage of fat than the steers, the differences being significant in most oases. In the fifth trial composition was estimated by half carcass dissection. This, too, showed bulls to have a greater percentage of bone and muscle and a lower percentage of fat, the differences being highly significant (P < 0·01) and very highly significant (P < 0·001) respectively. On a fat-corrected basis the estimated retail value of the carcasses favoured the bulls by about $20.00 each.

The studies, conducted over a range of nutritional conditions, showed that non-castration favoured muscle growth while suppressing fat deposition, and that this advantage was more pronounced when growth rates were high.
Longevity of ram sperm in various diluents and at different dilution rates
Authors: Schindler H. , Amir D.
Published: March 2009

The effect of various diluents and different dilution rates on the maintenance of motility of ram sperm during storage at 4° C. was tested. Their efficiency was determined by half-life periods and total survival times of the sperm.

A yolk-glycine-citrate diluent maintained sperm motility for a longer period than did yolk—fructose—phosphate, yolk-citrate, cow's milk and ewe's milk, with or without yolk. This diluent has the advantage that the sperm is clearly visible under the microscope, and no sedimentation of any component occurs.

A modified IVT diluent prolonged the total life span of the sperm, but caused a faster motility decline in the first part of the storage period.
The effect of pattern of protein intake and level of energy intake on the performance and nitrogen utilization of the ewe
Authors: Robinson J. J. , Fraser C. , Corse Elizabeth L. , Gill J. C.
Published: March 2009

An experiment was carried out in which each of thirty-six ewes was offered one of six dietary treatments from the 30th to the 140th day of gestation. The treatments supplied two levels of metabolizable energy (ME) intake (128 and 116 kcal/kg W0.75/day) each at three patterns of protein intake, namely equal increments at 22 day intervals, equal decrements at the same intervals and a constant daily intake throughout. The protein intake patterns supplied a mean daily intake of digestible crude protein of 3·74 g/kg W0.75/day. Nitrogen balances were carried out on four ewes from each dietary treatment during the last 10 days of each 22 day period.

Thirteen ewes randomly distributed on all dietary treatments were barren. Mean rate of live-weight gain in the pregnant ewes was 123 g/day compared with 66 g/day in the non-pregnant ewes and was not significantly affected by treatments. Lamb birth weights adjusted to the basis of twins were 3·83, 4·02 and 3·56 kg for the increasing, constant and decreasing patterns of protein intake respectively.

Within patterns of protein intake there were no significant differences in nitrogen retention between pregnant and non-pregnant ewes until after 90 days of gestation. Thereafter retention increased in the pregnant ewes offered the constant and increasing patterns of crude protein and remained constant in the non-pregnant ewes. During the same period the retention of both pregnant and non-pregnant ewes on the decreasing pattern decreased.

The effects of both energy and protein intake on nitrogen retention in early and late pregnancy were assessed by multiple regression analysis. The results are discussed in relation to other recent findings.
The concentration of minerals in the blood of genetically diverse groups of sheep
Authors: Wiener Gerald , Field A. C. , Jolly G. M.
Published: March 2009

Changes in the concentration of copper in the blood of 241 adult ewes bled 4 times over a 12-month period (and 332 ewes over a shorter period) were analysed to examine sources of variation in the changes. Breed, age and swayback history were the most significant of the factors associated with both the amount and rate of decline in copper level from summer through autumn to winter. The number of lambs born, age of ewe, and swayback history were the most significant factors associated with the increase in levels from winter to the following summer.

There was a tendency for the classes of sheep with the relatively higher concentrations of copper in their blood to show less seasonal fluctuation in those levels than classes of sheep with relatively lower concentrations of copper.
The effect of different proportions of hay and fortified rolled barley in the diet on digestible-energy value and urinary-energy excretion by cattle
Authors: Raven A. M.
Published: March 2009

A 6 x 6 Latin Square balance experiment was carried out using six Friesian steers, each of which initially weighed about 304 kg. The six treatments studied were an all-hay diet and five other diets containing 20,40,60,80 and 100 % of rolled barley fortified with mineral and vitamin supplements, accompanied by correspondingly reduced proportions of hay. Each diet was fed at an estimated maintenance level of feeding.

The progressive increase in the proportion of concentrate gave a significantly linear increase (P < 0·001) in both digestible and calculated metabolizable energy. The actual increase in digestible energy was from 2·62Mcal/kg dry matter (59·3% of the gross energy) on the all-hay treatment to 3·42 Mcal/kg dry matter (79·5% of the gross energy) on the all-concentrate treatment. Use of the determined digestible energy values for the all-hay and fortified barley diets to calculate the digestible energy of the four mixed diets gave results in reasonably good agreement with the determined values, the maximum difference being 0·12 Mcal/kg dry matter, which represented 3·83 % of the determined value. The losses of energy in the urine expressed as percentages of the gross energy of the diets showed a small but significantly linear decrease (P < 0·01) with increase in proportion of barley in the diet. The molar proportions of steamvolatile acids in samples of rumen fluid taken from two animals on each treatment indicated that increase in the proportion of concentrate was associated with tendencies for increase in acetic acid, decrease in propionic acid and little change in butyric acid. The mean digestibility of the organic matter was 62·6 % on the all-hay treatment and 81·8 % on the all concentrate treatment. The progressive increase in the proportion of concentrate gave a significantly linear increase (P < 0·001) in digestibility of the organic matter. Although intakes of nitrogen decreased with increase in the proportion of concentrate due to a decrease in the amount of dry matter fed, the weights of nitrogen retained were well maintained and when expressed as percentages of intake showed a significantly linear increase (P < 0·01).
The relationship between diet, the copper and sulphur content of wool, and fibre characteristics
Authors: Kapoor U. R. , Agarwala O. N. , Pachauri V. C. , Nath K. , Narayan S.
Published: March 2009

Thirty-six rams of Chokla breed of about 1–1½12 years of age were randomly divided into six groups and were fed for 4 months on a basal ration of Cynodon dactylon grass or its hay ad libitum. One group acted as the control, while the rations of the remaining groups were respectively supplemented with 250 g of a concentrate mixture, 250 g of lucerne hay, mg CoCl2.6H2O, 10 mg CuSO4.5H2O and 1 mg CoCl2. 6H2O plus 10 mg CuSO4. 5H2O per animal per day. The mean copper, sulphur and cobalt ingestion in the different groups respectively ranged from.1 to 9·7, 475 to 2030 and 0·10 to 0·53 mg per animal per day. The copper, sulphur, fibre diameter, staple length, medullation percentage, crimp per cm and staining grade were not significantly (P > 0·05) affected by the different dietary treatments. The wool copper was strongly correlated with wool sulphur (r = + 0·79) and both were inversely correlated with fibre diameter and medullation percentage. Wool sulphur, but not wool copper, was inversely correlated with staple length. Wool copper, but not wool sulphur, was inversely correlated with the staining grade of canary coloured wool. Staining grade was inversely correlated with fibre diameter as well as crimps per cm. The results suggest that copper plays an intrinsic role in the marshalling of the sulphur component of wool and in the synthetic mechanism of the wool fibre. A suggestion has been made that copper may be playing a biochemical part in the physiological processes causing canary coloration in Indian wools.
Lead contamination of roadside soil and grass in Birmingham, England, in relation to naturally occurring levels
Authors: Davies Brian E. , Holmes Pamela L.
Published: March 2009

Lead was determined in soil and grass from transects across three main roads and one minor road in Birmingham, England. The pattern of enhancement of lead contents was consistent with aerial contamination by lead compounds from motor vehicle exhausts. Data from grass sampled during wet and dry weather suggested that approximately half the lead was present as a removable surface film on the grass blade. Generally, the lead content of the grass was not high enough to affect grazing cattle adversely but the growing of vegetables for human consumption might need regulation. The lead values for contaminated soil, although locally high, were within the normal range for British and American soils and, for comparable traffic volumes, were less than those reported in the U.S.A. Attention is drawn to inter-laboratory differences when reporting analyses of reference rocks and the implications for environmental research.
Studies on mixtures of maize and beans (Phaseolus vulgaris) with particular reference to plant population
Authors: Willey R. W. , Osiru D. S. O.
Published: March 2009

Two experiments are described in which the possible yield benefits of mixing maize and beans were examined under intensive farming conditions. A ‘replacement series’ of pure maize, two-thirds maize/one-third beans, one-third maize/two-thirds beans and pure beans was used at four plant populations. A high level of nitrogen was applied on the maize to eliminate the effects of nitrogen transfer from the beans.

Yields of the mixtures were up to 38% higher than could be achieved by growing the crops separately. It is concluded that this occurred because the mixtures achieved a greater utilization of environmental resources; it is suggested that, because of the marked height differences of the two crops, an increased utilization of light was probably a major contributing factor. The need for high populations in mixtures is indicated, partly because the largest yield increases were achieved at high populations and partly because the mixtures required a higher population pressure to produce their maximum yield.

The maize was found to have the higher relative competitive ability, and this increased with increase in plant population pressure. It is suggested that this was probably due to the shading effect which the maize had on the beans. The effects of a change in relative competitive abilities, or in relative selling prices, on the optimum proportion of two species in a mixture are also considered.
Assessing and predicting environmental response inLolium perenne
Authors: Samuel C. J. A. , Hill J. , Breese E. L. , Davies Alison
Published: March 2009

Recently developed regressional techniques suggest that some of the problems posed by genotype-environment interactions may be solved. These techniques have been applied, therefore, to data from an extensive trial involving perennial ryegrass (Lolium perenne) varieties grown under various treatments at several locations throughout Great Britain. Analysis reveals that the relative performance of the varieties depends mainly upon whether they are grown as spaced plants or swards. Even though the genotype-environment interactions are large, much of their effects could be reduced to an essentially linear scale. These results are considered in the light of the known characteristics of the varieties concerned, whilst the wider implications are also discussed.
The nutrition of the early weaned lamb:I. The influence of protein concentration and feeding level on rate of gain in body weight
Authors: Andrews R. P. , Ørskov E. R.
Published: March 2009

The live-weight gains of male and female lambs were measured during growth from 16 to 40 kg live weight when five cereal-based diets varying in dietary crude protein concentration (from 10 to 20%) were given at three levels in a 5×3×2 factorial design.

Males grew faster than females by about 15% (P < 0·001); this difference increased with age and with the amount of feed given (P < 0·05). Growth rate responded linearly to increase in feeding level (P < 0·001) and curvilinearly to increase in dietary protein concentration (P < 0·01). A significant interaction (P < 0·01) occurred whereby growth increased with higher protein concentrations as feeding level increased.

At the highest feeding level (near ad libitum) the results suggest that the optimum dietary crude protein concentration for growth was about 17·5, 15·0, 12·5 and 12·5% at body weights of 20, 25, 30 and 35 kg respectively. The overall optimum dietary crude protein concentration for growth between 16 and 40 kg body weight was about 17·0, 15·0 and 11·0% when the mean digestible energy intake was 3·0, 2·6 and 2·1 Mcal/day.

The results agree reasonably well with estimates of protein requirements for lambs given by the Agricultural Research Council (1965).
The effect of different extraction procedures on the recovery of cell walls in forage and faeces from cattle and sheep
Authors: Moir K. W.
Published: March 2009

Forages and faeces from 28 digestibility experiments with cattle or sheep were extracted with neutral detergent solution, with and without sodium sulphite, or sequentially extracted with acid-pepsin, ethyl alcohol, diethyl ether and either ammonium oxalate or hot water. Ammonium oxalate was used to extract small amounts of non-protein material not extracted from legumes by hot water. Compared with sequential extraction the average protein-free organic residues after extraction with detergent, with and without sodium sulphite, were significantly lower in legumes and faeces, but not in grasses. The largest differences occurred in faeces from grasses for which the recoveries of cell walls as percentages of the faecal organic matter were found to be 59·2, 62·0 and 66·4 respectively, after extraction with neutral detergent plus sodium sulphite, neutral detergent alone and sequential extraction with various solvents. It was considered that the differences were due to extraction of cell-wall constituents by both detergent and sulphite.
An assessment of the quality of forage from its cell-wall content and amount of cell wall digested
Authors: Moir K. W.
Published: March 2009

Grasses and legumes comprising poor to good quality temperate and tropical species were fed to either cattle or sheep in 36 digestibility experiments. Cell wall in these forages was the ash-free and protein-free residue after sequential extraction with acidpepsin, organic solvents and either water for grasses or ammonium oxalate for legumes. The average amount of cell wall digested per 100 g forage OM was 40·0±0·59 g in grasses and 19·8±1·85 g in legumes. It was considered that within grasses and within legumes the physiology of ruminant digestion, rather than forage quality, was the main determinant of the average amount of cell wall digested and the difference between grasses and legumes was due to interaction of the ruminant digestion process with the physical structure of the cell wall. Of forage factors governing variation about the physiological average, the total cell wall had some effect on the amount of cell wall digested, but the lignin concentration in the cell wall had no effect.

Among grasses and legumes the average, apparently undigested, protein-free non-cell-wall component was 6·2±0·13 g per 100 g forage OM. This component and digestible protein relative to total protein varied among different sets of data. It was concluded that only the component of digestible organic matter which was governed by the relative proportions of cell walls and cellular contents was predictable from chemical composition. It was considered that selection in plant breeding should be based on both digestible cell wall and cell-wall content instead of digestible organic matter.
The potential digestibility of cellulose in grasses and its relationship with chemical and anatomical parameters
Authors: Wilkins R. J.
Published: March 2009

Potential cellulose digestibility, measured by incubation in vitrofor 6 days, decreased during floral development in perennial ryegrass, Wimmera ryegrass, cocksfoot, oat and tall fescue. The rate of decline was slower than for cellulose digestibility measured after incubation in vitro for 2 days only. Morphological fractions ranked in order of descending potential cellulose digestibility – leaf blade, inflorescence, leaf sheath and stem.

Lignin content was determined chemically by the method of Van Soest (1963) and lignified tissue was assessed by staining transverse sections of leaf blades and leaf sheaths with safranin and fast green. Both lignin and lignified tissue increased with maturity. Lignified tissue increased mainly through increase in the number of scleren-chyma cells, but was also affected by the formation of lacunae or cavities between the vascular bundles in leaf blades of cocksfoot and in leaf sheaths of all species studied. For 19 samples of leaf blades and leaf sheaths, potential cellulose digestibility had significant negative correlations with both lignin content (r = -0·862) and lignified tissue (r = -0·905). Limitations to the techniques used to assess lignification and further factors which may affect the relationship between lignification and potential cellulose digestibility are discussed.
Effects of defoliating different zones on the plant in field beans (Vicia faba L.)
Authors: McEwen J.
Published: March 2009

The mean yield of grain of untreated spring field beans was 2750 kg/ha. By the use of differential defoliation, upper and lower limits were set for the photosynthetic contributions of four zones to this yield:

(i) stems and pods 0–300 kg;

(ii) leaves below first flowering node 280–1150 kg;

(iii) leaves on first nine flowering nodes 720–2100 kg;

(iv) leaves above first nine flowering nodes 260–1150 kg.

The evidence suggested that all zones functioned below their full photosynthetic efficiency when other zones were present and that competition between zones for sites to store carbohydrate was a greater limiting factor than mutual shading.
Activity and energy expenditure in laying hens: 2. The energy cost of exercise
Authors: van Kampen M.
Published: March 2009

In capacity studies on adult White Leghorn hens during exercise it was found that the maximum velocity of the bird was 2·4 km/h.

Metabolic rate increased linearly with running speed and, between the speeds of 1 and 2 km/h, was 53–65% higher than the metabolic rate at rest.

The bird moved faster largely by increasing its stride.

The cost of bipedal locomotion for hens, in contrast to men and rhea, is lower than the cost of the quadrupedal locomotion of mammals.
The effect of plant density, date of apical bud removal and leaf removal on the growth and yield of single-harvest Brussels sprouts (Brassica oleraceavar. gemmifera D.C.): III. The components of marketable yield
Authors: Fisher N. M.
Published: March 2009

An analysis of marketable yield of sprouts is suggested in which the components are: number of plants/m3, number of buds/plant, acceptable size fraction, acceptable quality fraction and mean weight per marketable bud.

The number of buds per plant was dependent on date of stopping but was not greatly affected by plant density. This component was not found to limit yield.

Acceptable size fraction was related to the standard deviation of bud size and increased to a maximum at the time of optimum bud size. The maximum acceptable size fraction obtained from field samples could be reliably predicted from measurements of the standard deviation of bud size.

The acceptable quality fraction was of particular importance in later harvested crops and at higher plant densities. It was highly dependent upon cultivar but was little affected by stopping treatment. Unacceptable buds occurred most frequently at the base of the stem and it is argued that the importance of the blemishing diseases responsible for these losses has been increased by the single-pick harvesting technique.

The optimum plant density was related to the expected date of harvest but the practice of delaying maturity by increasing density is limited by the decreased acceptable quality fraction. Crops for harvest in October and November should undoubtedly be stopped both to reduce bud size variation and to stimulate bud growth.
Causes of variation in milk yield and lactation length of Jersey cattle in Western Nigeria
Authors: Adeneye J. A. , Bamiduro T. A.
Published: March 2009

Studies on 59 first four completed lactations of 37 imported Jersey cattle in Western Nigeria showed that their mean lactation length (248·4 days) and average milk yield (1257·4 kg) were inferior to those of their counterparts in other tropical countries. Lactation length following the birth of female calves was longer and milk production greater than those subsequent to male births but the differences were small (P > 0·05). Peak milk production was reached at the third lactation. Influence of season of calving on lactation length was slight; mean milk yield was significantly highest (P < 0·05) among October-December calvers, while the July-December period appeared to be more propitious for milk production. The regression coefficients of lactation length and milk yield on age of dam at calving were negative and unimpressive (P > 0·05), being −2·108 ± 2·661 and −19·106 ± 17·130 respectively. Analysis of variance for weight of milk with lactation length as a covariate revealed that although lactation length was a major (P < 0·001) determinant of milk production, both the period of calving and lactation number had recognizable bearing on milk yield. All interaction effects were trivial (P > 0·05). The period of study was 1968–74.
Absorption and movement of 14C-labelled MH and 2,4-D in onions
Authors: Asif M. I. , Khan A. A.
Published: March 2009

The absorption and movement of 14C-labelled maleic hydrazide (2000 mg/1) and 2,4-D (250 mg/1) were studied in seedlings and mature plants of a local strain of onion (Allium cepa L.) from Kano, Nigeria, in the presence and absence of N (20 mg/1).

Plants absorbed and accumulated considerable amounts of both the chemicals. Addition of N to the treatment solution reduced the absorption of 2,4-D. Also, N reduced the mobility of the chemicals from the roots to the tops which resulted in accumulation of the chemicals in the bulbs.
The performance of Santa Gertrudis, Sahiwal, Brahman and cross-bred animals in the intermediate savannahs of Guyana: 2. Birth weight and preweaning performance
Authors: Harricharan H. , Mahadevan P. , Springer B. G. F.
Published: March 2009

Data collected over a period of 11 years at the Ebini Livestock Station in the intermediate savannahs of Guyana were analysed to determine the effect of breed or cross, sire, sex, year and season of birth of calf, and age and length of calving interval of the dam on weights at birth and at 4, 8 and 12 months of age, in Santa Gertrudis, Sahiwal and Brahman cattle. The heritability of body weights at the different ages was estimated.
The effect of two synthetic steroids on plasma glucose concentration and total entry rate of glucose in sheep
Authors: Ranaweera Anoma , Ford E. J. H.
Published: March 2009

Primed continuous intravenous infusions of tracer amounts of [2·3H]gluscose were used to measure glucose entry rates before and after the administration of triamcinolone acetonide or trienbolone acetate to sheep eating 1200 g/day of chopped hay.

The intramuscular injection of triamcinolone acetonide caused hyperglycaemia with a maximum plasma glucose concentration 24 h after the injection. Twenty-four hours after the injection of 0·5 mg/kg of steroid the mean glucose entry rate rose from 1·44 to 2·14 mg/min/kg. The difference between these means is significant (P < 0·02). Twenty-four hours after injecting 0·05 mg/kg of steroid the mean glucose entry rate had risen from 1·34 to 1·86 mg/min/kg. The difference between these means is significant (P < 0·05). The intramuscular injection of trienbolone acetate (0·5 mg/kg) had no effect on plasma glucose concentration or on glucose entry rate.

These results are compared with the effect of betamethasone and are discussed in relation to the treatment of ketosis in cattle and sheep.
Comparison of methods of extending part lactation records for sire evaluation
Authors: Rao M. K. , Sundaresan D.
Published: March 2009

The first lactation records of 684 Sahiwal, 157 Brown Swiss × Sahiwal (BS × S) and 255 Friesian × Sahiwal (F × S) constituted the data for this study. The 300-day yield was estimated from part lactation yields of 13, 17, 21, 26 and 30 weeks post partum by four methods, namely, regression, ratio, gamma and inverse polynomial functions. The duration of the part record and the method of estimation were evaluated for their reliability in estimating the 300-day yield and sire evaluation.

The correlations between part records and 300-day yield ranged from 0·76 to 0·95, thecorrelations being higher in F × S. The error, absolute error and standard deviation of error weresmaller for ratio and regression methods than for the gamma and inverse polynomial functions. The part records of 30 weeks or more were found to be necessary to estimate 300-day yield within 15% of the actual yield with regression or ratio methods.

The rank correlations and product moment correlations between sire indices calculated with part records and 300-day yield were found to be highly significant. The part records of 17 weeks or more extended by ratio or regression could be used to evaluate sires as accurately as with 300-day yield by increasing the progeny group size by 7–10% in Sahiwal and by about 20% in F × S. Theloss of efficiency in sire evaluation amounted to about 10–15% with part records of 17 weeks or more compared with 300-day yield.
The effect of site and quantity on the extent of absorption of Mg infused into the gastro-intestinal tract of sheep
Authors: Field A. C. , Munro C. S.
Published: March 2009

Balance trials were carried out in which different amounts of Mg (0·44–2·9 g/day) were infused alternatively into the rumen and into the omasum, abomasum or duodenum of sheep consuming a low Mg diet (0·2 g Mg/kg D.M.). Absorption from the region between the infusion sites was measured from the change in urinary excretion and apparent absorption caused by changing the site of infusion.

Absorption was greater from a ruminal than from a comparable duodenal infusion. There was evidence, however, that the absorption mechanism within the stomach area was becoming saturated at the higher infusion rates in that the relationship between the amount absorbed and infused was curvilinear. The proportion of infused Mg which was absorbed from the stomach area fell from 0·61 to 0·14 as the infusion rate increased from 0·44 to 2·80 g/day.

The main site of absorption within the stomach area was the rumen; a small amount was absorbed from the omasum, but none from the abomasum. Positive differences between omasal and duodenal infusions were seen in plasma concentration at the two lowest and in urinary excretion at all infusion rates.

Increasing the amount of Mg infused into the duodenum caused an increase in plasma concentration and a linear increase in absorption.

When the ruminal and duodenal infusions were repeated with the sheep consuming hay, the results were similar but the proportion of infused Mg absorbed was reduced.
Experiments evaluating aqueous ammonia, aqueous urea and a solution of ammonium nitrate and urea as nitrogenous fertilizers for winter wheat
Authors: Widdowson F. V. , Penny A.
Published: March 2009

Six experiments on winter wheat, three in 1974 and three in 1975, evaluated aqueous ammonia, aqueous urea and a solution of ammonium nitrate and urea, using ammonium nitrate granules as the standard. Aqueous ammonia and aqueous urea were injected 8–10 cm deep in bands either 25 or 50 cm apart during April. The ammonium nitrate/urea solution was sprayed and the ammonium nitrate granules were broadcast (a) partly in April and partly in May or (6) wholly in May. All were applied at 50, 75, 100 or 125 kg N/ha. Yields and % N in grain were measured and N removed by grain calculated. In two experiments lodging diminished yield and complicated the comparisons.

Elsewhere, aqueous urea and aqueous ammonia were of similar value, and each gave a larger yield when injected in bands 25 rather than 50 cm apart. Both fertilizers gave yields similar to those from broadcasting the ammonium nitrate granules, but larger yields than from spraying the ammonium nitrate/urea solution. Yields were slightly larger when divided rather than single topdressings were given, but % N in grain and the amounts of N removed were smaller. Yields and % N in the grain were smallest when the ammonium nitrate/urea solution was sprayed. The other three fertilizers were each of greater value judged by N uptake, the ammonium nitrate granules having a slight advantage.
Effects of annual and biennial applications of phosphorus and potassium fertilizer and farmyard manure on yields of potato tubers, on nutrient uptake and on soil properties
Authors: Sharma R. C. , Grewal J. S. , Singh M.
Published: March 2009

A long-term manurial experiment on potatoes was initiated in 1970 on the acidic brown hill soil of Simla to study the effects of fertilizers supplying per hectare: 44 kg P (P44); 44 kg P and 125 K (P44K125) and 88 kg P with 125 kg (P88K125) and of farmyard manure (FYM) supplying 44 kg P/ha applied annually and biennially. The potatoes gave large responses to all the manures. The annual or biennial effects of FYM measured in years of application were as great as that of P and K fertilizer in increasing tuber yield and K uptake by tubers but FYM increased P uptake more than fertilizers did. FYM applied each year gave largest uptake of P. P88 treatment was not better than P44 treatment. The residual effects of the manures on yield were measured in years when the treatments were not applied; the residual effects of FYM were higher than those of fertilizers. Mean residual effects of the treatments on P uptake were 46% and 51% of their annual or biennial effects respectively. About 90% of P added to the soil was not taken up by the crops and was present in the forms of aluminium-bound P, iron-bound P and calcium-bound P in this descending order. The residual effects of the treatments on K uptake were about 84% of their annual or biennial effects. About 60% of K applied to the soil was not taken up by the crops and most was present in exchangeable form. Annual applications of all the manures were better than their biennial applications indicating that residual effects built up from three applications over 6 years were too small to sustain yields.

Soil analyses made 6 years after the start of the experiment showed that FYM was a better source of P than single superphosphate in increasing soil available P. FYM also increased soil exchangeable K more than the K fertilizer did. The highest increase in available P and K in soil was from annual applications of manures. Biennial applications of P as superphosphate or FYM resulted in P accumulating in the soil, while biennial K fertilizer dressings did not increase exchangeable K; however, biennial FYM did increase exchangeable K. Using P alone reduced soil available K. FYM increased pH, organic carbon and total N in soils while P and K fertilizer increased only the pH.
Factors affecting the intake and digestion of roughage by sheep fed maize straw supplemented with maize grain
Authors: Henning Penelope A. , Van Der Linden Yvonne , Mattheyse Mary E. , Nauhaus Wilfried K. , Schwartz Helen M. , Gilchrist Frances M. C.
Published: March 2009

After a preliminary period in which they were all fed maize straw plus a proteinmineral supplement, 18 Merino wethers were divided into six groups and fed straw, proteins and minerals as before, plug pellets containing maize grain so that these constituted 0, 78, 156, 235, 313 and 393 g/kg of the total daily intake.

The diets provided sufficient protein so that NH3and branched-chain volatile fatty acids were not limiting for growth of the fibre-digesting bacteria in the rumen.

The intake of straw, the digestibility of cellulose and hemicellulose, and the mass of cellulose and hemicellulose digested per day declined linearly as the proportion of pellets in the diet increased above 78 g/kg. This decline was not related to the pH of the ruminal contents which was unaffected by the feeding of up to and including 235g pellets/kg diet, and which, with one exception, was only 2–6 pH-hours below pH 6 when more grain was fed.

As the proportion of pellets in the diet increased the number of cellulolytic bacteria in the rumen declined to an extent which correlated well with the decrease in mass of cellulose digested per day. There was no change in the relative proportions of the predominant genera.

There was no decrease in the number of xylanolytic bacteria in the rumen as more pellets were fed, but there was an indication of a change in the predominant genera producing diffusible xylanases.

It is concluded that some factor, in addition to nutrient limitation and pH, may play a role in the decrease in intake and digestion of roughage when starch is fed. It is suggested that starch or sugars derived from it mayper seinhibit the synthesis and/or activity of the rumen cellulases and hemicellulases.
Effects of rate, source and distribution method of nitrogen fertilizer on seed potato production
Authors: Baker A. S. , Yehuda R. Ben , Kafkafi U.
Published: March 2009

Seed potatoes are grown on the high plateaux of northern Israel where it is cool enough for a summer crop. The seed are used for winter production of ware potatoes in southern Israel. Irrigation is essential because of the arid summers. It is customary to apply much of the N fertilizer through the irrigation system in numerous small doses. Total N rates have ranged between 300 and 400 kg/ha. In 1975 various aspects of N, P, K fertilization for seed potato (Solanum tuberosumL., var. Up-To-Date) production were examined. There were no responses to P or K fertilizers so only the N fertilizer responses are reported here.
A histological basis for differences in breast meat yield Between two strains of white turkeys
Authors: Swatland H. J.
Published: March 2009

Two genetic strains of white turkeys were reared together in a large flock under conditions allowing optimal growth from hatching to 20 weeks. Birds of both strains followed similar growth curves with males of both strains growing heavier than females. In one strain, however, the yield of breast meat as a proportion of live weight was greater in both males (287 v. 225 g/kg) and females (276 v. 201 g/kg). When expressed in ratio to breast width, maximum meat depth was greater in the strain which yielded the higher proportion of breast meat. However, with this index of breast plumpness, females scored higher than males in both strains (high yield, 0·45:1·00 v. 0·37:1·00; low yield, 0·33:1·00 v. 0·31:1·00). In the superficial anterior region of the pectoralis muscle in both strains and sexes, there were strong adenosine triphosphatase and weak succinate dehydrogenase reactions in nearly all muscle fibres. Differences in the radial growth of muscle fibres were found between the two strains and, by 20 weeks, birds of the lower yield strain had reached only 0·85 (males) or 0·82 (females) of the mean diameters attained in birds of the higher yielding strain.
Early spring and late autumn response to applied nitrogen in four grasses
Authors: Wilman D. , Mohamed A. A.
Published: March 2009

The regrowth of Aberystwyth S. 23 perennial ryegrass, S. 24 perennial ryegrass, S. 59 red fescue and S. 170 tall fescue was studied in field swards, comparing four levels of applied nitrogen, for 8 weeks following a clearing cut. The clearing cuts were in mid-October, mid-February and mid-March in each of 3 years, different plots being used on each occasion.

The application of N increased the number of leaf primordia, the number of un-emerged leaves, the rate of leaf emergence and death, leaf blade length, width and weight, sheath length, number of leaves per unit area of ground and proportion of green tissue in total yield. The application of N had little effect on the number of leaves per tiller and tended to reduce weight per unit area of leaf blade. The increase in size, weight and number of leaf blades appeared to be major reasons for the positive effect of applied N on yield, previously reported; and the increase in sheath length contributed to the increase in proportion of yield above 4 cm. Rate of leaf extension was not closely related to yield and was more sensitive to temperature than was yield. Changes during regrowth in blade and sheath length helped to explain changes in weight per tiller, previously reported. The effects of improving weather conditions in late winter/early spring were similar to the effects of applied N: larger, heavier leaf blades, longer sheaths, a taller canopy, a lower proportion of dead material, younger leaves. The length of shoot apex per leaf primordium was relatively constant. Leaves continued to emerge, at a slow rate, in the period December–February. S. 170 had the biggest leaves, particularly in May, and the slowest rate of leaf turnover. Rate of leaf extension was increased by applied N more, on average, in the ryegrasses than in the fescues.
Effect of ammonium on anion uptake and trans-root potential in sunflower roots
Authors: Ragab S. M.
Published: March 2009

Studies were made on detopped sunflower plants to see whether the depolarizing effect of NH4on the trans-root potential is the result of increasing H2PO4uptake and to determine the effect of NH4on the flux of NO3and SO4in xylem exudate. Increasing the NH4in the medium increased the H2PO4flux in the exudate, but decreased NO3and SO4fluxes. Ammonium and NO3influenced the uptake of each other but NH4had the greater effect. These NH4effects were attributed wholly or in part to blockage of the root metabolism which may have affected the permeability of root cell membranes. Therefore, the stimulation of H2PO4flux by NH4was probably not attributable to any specific effect of NH4on H2PO4uptake. Enhanced H2PO4and decreased uptake of NO3and SO4reflects toxic effects of NH4on the root metabolism.
A perfused ruminant muscle preparation
Authors: Coward B. Jane , Buttery P. J.
Published: March 2009

A technique was developed for the continuous retrograde perfusion of the muscle of the right crus. The hemidiaphragm was perfused for 3 h with a semi-synthetic medium, containing fresh sheep erythrocytes. The metabolic integrity of the perfused muscle was examined. Visual appearance was satisfactory. Perfusion pressure remained constant throughout the perfusion period. An adequate perfusate flow rate (approximately 8 ml/min) was maintained over the perfusion period. Perfusion pressure and flow rate were proportional. Perfusion was complete as indicated by staining with dye and by latex casts of perfused vessels, but there were indications of heterogeneity of perfusion (the dorsal and ventral ends of the organ). Histological changes following perfusion were minor, and the perfused muscle appeared normal under an electron microscope, with the exception of a loss of cytoplasmic granules. Increases in muscle water content (2·3%) and extracellular space were small. Muscle adenosine triphosphate (ATP) and adenosine diphosphate (ADP) concentrations declined significantly following perfusion but ATP/ADP ratio increased significantly. Muscle glycogen content was maintained only when exogenous insulin was added to the medium; significant losses occurred following perfusion in the absence of insulin. Only 2–3% of tissue glutamate-pyruvate transaminase and glutamate-oxaloacetate transaminase were released into the medium over the perfusion period, but approximately 20% of muscle potassium was lost. Lactate was produced by the perfused sheep hemidiaphragm at a rate higher than those that have been reported for the perfused rat hind-limb, but lower than those reported for perfused rat diaphragm. Ratio of lactate/pyruvate produced by the perfused muscle was also higher than values reported for the rat hind-limb. The perfused muscle actively incorporated labelled amino acids into protein, but estimated protein synthetic rate in the absence of exogenous insulin was only approximately 50% of rates reported for diaphragm musclein vivo. While the isolated, perfused sheep hemidiaphragm shows several deficiencies, it does provide a useful method for the study of ruminant muscle metabolism under carefully controlled conditionsin vitro, and overcomes many of the disadvantages of other techniques that are currently available.
A note on a urine collection system for male pigs
Authors: Colebrook W. F. , Black J. L.
Published: March 2009

A urine collection system suitable for male pigs is described. The system was tested by the recovery from urine of an intravenous infusion of51 chromium as the EDTA complex. Recovery from four pigs was 99·2 ± 1·6%.
Some factors affecting voluntary food intake in buffaloes. 1. Effect of feeding long-chopped and ground roughages
Authors: Taparia A. L. , Sharma V. V.
Published: March 2009

Three experiments each utilizing four buffalo heifers in 4 × 4 latin square designs were conducted over a period of 84 days to estimate the voluntary consumption of eight long-chopped and four ground roughages. Voluntary intake and rate of passage were determined during the last 10 days and digestibility of feed nutrients during the last 6 days of a 21-day experimental period.

The mean daily dry-matter intake (DMI, g/kg W0·75), D.M. digestibility (%) and mean retention time (h) of long and chopped foods were 81·6, 65·7, 75·2; 81·4, 54·2, 60·3; 78·0, 58·6, 66·0; 75·8, 58·5, 66·3; 67·5, 68·1, 87·9; 62·1, 40·9, 73·3; 56·3, 50·6, 70·9 and 55·5, 58·8, 82·4, respectively for maize silage, sorghum stover, dry grass, maize stover, berseem hay, wheat straw, pearl-millet stover and cowpea hay. Appreciable differences were observed between feeds in the digestibility of D.M., organic matter (OM) and crude protein (CP). No consistent pattern in level of intake and either CP or crude fibre (CF) contents of feeds or their D.M. digestibilities was discernible. The relationship between DMI and D.M. digestibility was low (r = 0·29). Higher DMI of feeds tended to be associated with faster rate of passage excepting maize silage and berseem hay. The relationship between D.M. digestibility and mean retention time was low (r = 0·46) and between total digestible nutrient intake and body weight was high (r = 0·79).

The mean daily DMI (g/kg W0·75), D.M. digestibility (%) and mean retention time (h) of ground roughages were 68·7, 51·3, 58·0; 62·9, 38·4, 60·0; 62·4, 40·1, 63·0; 53·1, 66·6, 72·0, respectively for ground maize stover, wheat straw, dry grass and berseem hay. Ground roughages appeared to be utilized less efficiently by buffaloes than longchopped roughages.
Effects of aldicarb and oxamyl in peaty loam soil on potato cyst-nematode, Globodera rostochiensis, and on resistant and susceptible potatoes
Authors: Whitehead A. G. , Tite D. J. , Fraser Janet E. , French Eileen M. , Short L.
Published: March 2009

Potato cyst-nematode, Globodera rostochiensis, was controlled in peaty loam by growing the resistant potato cultivars Cara and Maris Piper, or by incorporating aldicarb or oxamyl granules in the seed bed before planting susceptible cultivars. In heavily infested soils, aldicarb or oxamyl increased tuber yields of susceptible cultivars and Maris Piper but did not increase tuber yields of Cara, which suggests that it is tolerant as well as resistant. Yield responses to oxamyl varied greatly among susceptible cultivars. In the top 20 cm of untreated soil, the nematodes increased twice as much on Bang Edward as on five other susceptible cultivars.
The effect of clipping the coat on various reactions of calves to heat
Authors: Bianca W.
Published: March 2009

Ten calves were exposed for 3 hr. to an atmosphere in which the dry-bulb temperature was 40° C. and the wet-bulb temperature 33° C, (a) with their normal coats, and (b) after their coats had been clipped.

When clipped the calves tolerated the same hot environment better than they did before they were clipped, as evidenced by significant reductions in skin temperature, rectal temperature, respiratory rate and heart rate, as well as by a lessening of various manifestations of distress.

This effect of clipping was thought to be due mainly to an improvement in skin, evaporative cooling.