bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early reproductive failure of ewes in a hot environment III. The thyroid
Authors: Ryle Margaret 
Published: March 2009

1. A balanced factorial experiment was carried out with 48 Merino ewes. There were two levels of each of the four factors: environmental temperature, thyroxine status, vitamin A intake and progesterone status. Each ewe was killed at 25 days' pregnancy. The thyroid was removed, weighed and examined histologically.2. Thyroid weight in the hot-room animals was significantly decreased by large doses of vitamin A. It was not affected by any of the other treatments.3. With respect to the number of follicles per unit area of cross-section, the following interactions were significant: temperature × vitamin A; temperature × progesterone; temperature × vitamin A × thyroxine. The directions of the effects of vitamin A and of progesterone were reversed by the higher temperature.4. There were no significant effects on nuclear height in the follicular epithelium.5. The frequency of marked ‘scalloping’ at the edge of the colloid was significantly higher among those ewes receiving thyroxine injections than in the remainder. This feature was not significantly affected by any other factor.
Walking trials with cattle II. A comparison of bulls, steers and heifers
Authors: Murray D. M. , Yeates N. T. M. 
Published: March 2009

1. The heat tolerance and walking performance of bulls, steers and heifers exposed to moderate heat stress have been compared, following the method of Yeates & Murray (1966). Hereford cattle aged 14–16 months were used in the experiment. Two speeds of walking were employed and the effect of clipping the coats of both exercised and stationary cattle was studied.2. In the undipped state, at both speeds of exercise (1⅔ and 2⅔ m.p.h.), the heifers performed best followed by the steers and bulls in that order, judged by their ability to preserve normal body temperature.
A study of the effect of supplementing a concentrate diet with roughages of different quality on the performance of Friesian steers. I. Voluntary food intake and food utilization
Authors: McCullough T. A. 
Published: March 2009

SUMMARYConcentrate diets supplemented with 5, 20 and 40% of a high- and a low-quality hay were given ad libitum to British Friesian steers from 9 weeks of age to slaughter. The intake of dry matter and metabolizable energy was studied over weight ranges from 91 to 363 kg live weight. The quality of hay did not significantly affect the drymatter intake at any of the weight ranges studied. From 91 to 182 kg live weight the daily dry-matter intake decreased as the proportion of hay in the diet increased. Over the weight range from 182 to 272 kg live weight, intake was maximum at the 20% level of hay supplementation, while from 272 to 363 kg live weight, intake increased with increasing levels of hay in the diet. The supplementation of high-quality hay significantly increased the intake of metabolizable energy by animals weighing 91–182 kg. Increasing proportions of hay in the diet significantly affected the metabolizable energy intake at all stages of growth studied.At 18 and 36 weeks of age digestibility and N balance studies were carried out. The metabolizable energy expressed as a percentage of the gross energy and the mean retention time of the diets were significantly affected by the age of animal, quality of the hay and the level of hay supplementation. Nitrogen retention was also affected by the age of the animal but not by the quality of the hay.The relationships between the voluntary intake of dry matter and the metabolizable energy of the diet expressed as a percentage of the gross energy, for different stages of growth, are also presented.The change in the digestibility and the mean time of retention of the diets in the digestive tract with age and the effect of this on the point where physical regulation to intake gives way to physiological regulation are discussed.
The sources of assimilate for grain development in tall and short sorghum
Authors: Goldsworthy P. R. 
Published: March 2009

SUMMARYThe dry weight contributed to the grain yield of sorghum by different parts of the plant was measured by removing laminae and by shading the head. A Nigerian tall variety formed more dry weight after heading and had a larger leaf area duration than a short-season, hybrid sorghum, but its grain yield was smaller. Laminae contributed more than 80% of the dry weight formed after heading in the Nigerian sorghum but less than half of this went into the grain. The remainder went into the stem, mainly to replace respiratory losses, or accumulated in the rachis and branches of the head. Top, middle and bottom groups of laminae contributed 42, 22 and 12% respectively to the dry weight of the grain; the remaining 24% was contributed by the sheaths. In the short-season hybrid sorghum over 70% of the dry matter formed after heading was stored in the grain. Only about half of this came from the laminae; assimilation in the head and in the sheaths contributed about equally to the remainder.
The nutritive value of Panicum maximum (Guinea grass): I. Yields and chemical composition related to season and herbage growth stage
Authors: Johnson W. L. , Hardison W. A. , Castillo L. S. 
Published: March 2009

The results of more than fifty estimates1 of herbage yield and ninety-seven analyses of chemical composition are presented in the first of several reports on nutritive evaluation studies of Panicum maximum (guinea grass). Effects of stage of maturity and season are discussed.Herbage yield increased at an increasing rate with maturity, and was depressed by about 40 % in the dry season compared to the wet season. The most significant differences in chemical composition were a decrease in crude protein from 9·8 % to 6·6% and a corresponding increase in crude fibre from 32·1 % to 39·4% as the grass matured from about 2½ weeks to about 2½ months in age. An increased level of nitrogen fertilization resulted in crude protein content being nearly doubled and crude fibre somewhat reduced.
The use of coarsely milled barley straw in finishing diets for young beef cattle
Authors: Forbes T. J. , Raven A. M. , Irwin J. H. D. 
Published: March 2009

SummaryAn experiment was carried out in which young beef cattle were given diets containing different levels of coarsely milled (1 in screen) barley straw. The proportions of straw used were 0, 10, 20, 30, 40 and 50 % and the performance of animals on these diets was compared with that of similar animals on an all concentrate diet. Each diet was given ad libitum to six animals. There was a significant linear decline in live-weight gain with increasing straw intake, the rate of decline being 0·62 ± 0·133 kg per week for each 10 % increase in the level of straw in the diet. The dry matter conversion ratio increased linearly with increasing straw intake, the rate of increase being 0·65 ± 0·186 units for each 10 % increase in straw in the diet. Dry matter intake was significantly (P < 0·001) affected by the proportion of straw in the diet. Although dry matter intake increased to a maximum at a level of 18·8% straw in the diet there was no significant increase in the intake of digestible organic matter (DOMI). There was a significant (P < 0·001) linear decline of 0·19 ± 0·04 kg DOMI with each 10% increase in straw in the diet. There was a significant linear decline in chilled carcase weight to the extent of 5·7 ± 0·096 kg for each 10% increase in straw. The killing-out percentage based on unfasted live weight declined significantly as the percentage of straw in the diet rose from 20 to 30%. However, when the killing-out percentage was calculated on the basis of live weight at slaughter less rumen contents there was no significant difference between treatments.
The estimation of plasma and red cell volumes in pigs
Authors: Anderson D. M. , McDonald I. , Elsley F. W. H. 
Published: March 2009

SummaryPlasma volume, haematocrit, and haemoglobin concentration were measured in 34 sows. Red cell volume and total blood volume were calculated from plasma volume and haematocrit.The method of back extrapolation of the logarith of Evans blue concentration to zero time possibly overestimated plasma volume. Haematocrit was found to be higher and more variable in the initial blood samples in each experiment, than in the blood samples taken 30 and 60 min later.In animals of the same parity, plasma and red cell volumes were closely related to live weight, but the relationship varied between parities.
The concentration of minerals in the blood of genetically diverse groups of sheep: I. Copper concentration at different seasons in Blackface, Cheviot, Welsh Mountain and crossbred sheep at pasture
Authors: Wiener Gerald , Field A. C. , Wood Jean 
Published: March 2009

SUMMARYThe concentration of copper in the blood of more than 300 sheep of a grassland flock was determined on each of five occasions between May 1965 and June 1966. Six breed classes, Scottish Blackface, Cheviot and Welsh Mountain, and the three crosses among these breeds, were involved.Breeds differed significantly in blood copper concentration with the Blackface having consistently the lowest and the Welsh the highest values. Crossbred sheep showed marked heterosis. Their levels were mostly at or near to the concentration of the parental breed with the higher value. Within breeds there was a positive regression of blood copper level on live weight of ewe.Ewes which had produced lambs affected by swayback in 1964 had lower levels of copper in their blood than ewes which had produced normal lambs. The difference was significant and most marked in winter.Ewes which were barren had, subsequently, higher blood copper concentrations than ewes with lambs. Ewes with single lambs had on average slightly higher levels than those with twins (but not significantly so), however, the effect differed among the breeds. Blood copper levels differed significantly on most occasions with the week in which ewes lambed in relation to the date of bleeding. Age of ewe had significant effects on copper concentration only at one bleeding (January 1966).There was an indication that classes low in copper concentration, notably Blackfaces and mothers of swayback lambs, showed a relatively steeper decline in copper levels during the winter than did other sheep.
Flower drop and fruit set in field beans, Vicia faba L.
Authors: Kambal A. E. 
Published: March 2009

SUMMARYThe percentage of the total buds produced that dropped before reaching the mature pod stage was estimated as 86·7% in Baladi, a local strain of field beans, and 93·7% in Giza 1, a variety introduced from Egypt. The drop was appreciable both before and after fertilization. There were indications that both inadequate insect pollination and inter-ovary competition contributed to the reduction of pod yield.Self pollen was detected on the stigma in the bud stage 2–3 days before the flower was open. Estimates of natural cross-fertilization ranged from 35·8 to 42·1%, indicating that self-pollination did not lead to complete self fertilization. Hand manipulation of the flowers increased pod set in most of the cases but the line 1W did not respond to this treatment and proved to be highly autofertile.
Morphological and physio-chemical studies on dwarf Herefords
Authors: Hafez E. S. E. , Ensminger M. E. , Ham W. E. 
Published: March 2009

Thirty-six Hereford dwarfs, ‘comprest’, dwarf-like, and eight controls were available. Body and skin measurements were taken and the types of head abnormalities and cardiovascular activities were recorded. Haematological tests and chemical analysis of blood and hair were carried out.Typical dwarfs showed characteristic head abnormalities with varying degrees either at birth or later in life, possibly as a result of different stages of development at which the defective gene(s) comes into operation. There were progressive changes (qualitative and quantitative) in the expression of dwarf characteristics. Typical dwarfs were chronic bloaters, with pot-shaped belly or with normal belly. Atypical dwarfs were either stunted, showing (miscellaneous) deleterious genes or ‘comprest’ types. The daily live-weight gain of typical dwarfs ranged from 0·71 to 1·69 with an average of 1·26 lb. (controls 1·72 lb.). Body, head, and limb indices in typical dwarfs are similar to those of the ‘comprest’ and the control animals at comparable weights. Volume index was higher in the control than in the typical dwarfs. In the bloater dwarfs the width of the body at the shoulder region was considerably narrower. Skins of the typical dwarfs were thinner. The bloater dwarfs showed a diurnal bloat cycle (in relation to feeding time) as judged by body circumference. The severity of bloat was irregular.There was no significant difference between typical dwarfs and control animals in rectal temperature, pulse rate, blood, specific gravity, prothrombin time, sedimentation rate, red cell count, electrophoretic pattern of serum proteins, serum creatine and creatinine and calcium/phosphorus ratio in hair samples. Typical dwarfs had slower respiration rate, lower blood haemoglobin, haematocrit, and white blood count than did the controls. Post-mortem examination of dwarfs did not show similar causes of death in each case. The heart of the dwarfs was spheroid, showing severe dilation in most cases.
The errors of long-term experiments
Authors: Patterson H.D , Lowe Bridger I. 
Published: March 2009

SUMMARYYield (or other variate) values from crops recurring on the same plots in long-term experiments are subject to correlations known as serial plot correlations. Neglect of these plot correlations can result in loss of efficiency in the estimation of treatment effects and bias in the estimation of error.Serial plot correlations are calculated from 12 experiments on arable crops in England and Wales, for yields 4, 6 or 8 years apart. They are usually positive, with average value 0·2. In one set of experiments the losses in efficiency caused by plot correlations of this magnitude are shown to be small, but some of the biases in the estimates of error are large. Biases in the variances of treatment means can be wholly or partly eliminated by separating two components of error, plot error and plot x year error.
Protein concentrations in colostra from Finnish Landrace × Scottish Blackface ewes during the first week of lactation and in sera from the ewes and their lambs on the third day of lactation
Authors: Halliday R. 
Published: March 2009

SUMMARYTwenty-six Finnish Landrace × Scottish Blackface ewes, mated to a Dorset Horn ram, produced 58 lambs. Protein concentrations in the ewes' colostra during the first week of lactation, and in the ewes' and lambs' sera on the 3rd day after parturition were compared with those in pure-bred Finnish and Blackface sheep. In cross-bred and Blackface lambs the total serum protein and γ-globulin concentrations decreased significantly as litter-size increased. Litter-size had much less effect in Finnish lambs. When litters of the same size were compared, cross-bred lambs tended to have higher concentrations than Blackface lambs, but had much lower concentrations than Finnish lambs. The mean protein concentrations in sera and presuckling colostra from Finnish × Blackface ewes were almost exactly the same as in Finnish ewes, but were considerably lower and higher, respectively, than in Blackface ewes. When suckling began the concentrations in the colostra decreased much faster in Finnish ewes, even when ewes nursing the same number of lambs were compared. Differences in suckling behaviour on the day of birth may therefore partly account for the variations in the amounts of maternal protein obtained by lambs of different breeds.
Use of the quantity/potential relationship to provide a scale of the ability of extractants to remove soil potassium
Authors: Addiscott T. M. 
Published: March 2009

SUMMARYQuantity/potential relationships, between gain and loss of K by the soil and K potential (RT In ακ/⊧αca+Mg) were determined on twenty-seven Rothamsted and Woburn soils. K extracted by neutral N ammonium acetate, by H-resin and 0·5 M sodium bicarbonate (pH 8·5) were also measured.The ability of an extractant to remove soil K is equated to a K potential (derived from the quantity/potential curve) which the soil attains on removing K equal to that taken out by extractant. Mean values for all soils were – 4995 ± 97 cal/equiv for the ammonium acetate, – 6081 ± 88 cal/equiv for the H-resin and – 4336 ±117 cal/equiv for the sodium bicarbonate extractants. For the first and last extractants the ability to remove K was less in rich than in poor soils.Varying the ammonium ion concentration from 0·1 N to 1 N in ammonium acetate/acetic acid mixtures, N in acetate ions, did not greatly affect their ability to remove K.
Studies on goat nutrition Part I. Minimum protein requirement of goats for maintenance-endogenous urinary nitrogen and metabolic faecal nitrogen excretion studies
Authors: Majumdar B. N. 
Published: March 2009

1. EUN and MFN excretions have been determined in goats on a N-low ration and also on a N-free ration. The values obtained were,EUN = 0·052 g./kg. live weight andMFN = 0·41 g./100 g. dry-matter feed intake.2. The values so determined with the two feeding regimens, for both the EUN and MFN agreed very closely.3. The minimum protein requirement of goats for maintenance, as calculated from the EUN value, is 0·65 lb./1000 lb. live weight.4. The formula for calculating the utilizable protein requirement for this species is found to be P = 0·89. W0.734, and is almost identical with the one given by Mitchell.5. The usefulness of the above formula in predicting the EUN of immature goats is discussed.
Effect of humidity and exposure to sun on the pulse rate, respiration rate, rectal temperature and haemoglobin level in different sexes of cattle and buffalo
Authors: Mullick D. N. 
Published: March 2009

Observations in the shed were made for 3 years on groups of cattle and buffaloes of both sexes for pulse rate, respiration rate, rectal temperature and haemoglobin level during the summer months under low and high humid conditions.The average figures for these physiological reactions were always less for buffaloes than for cattle under both dry and humid conditions.Under high humidity conditions cattle cows showed a significant increase in the pulse rate and decrease in rectal temperature whereas respiration rate remained unchanged. In the buffalo cows these physiological reactions showed less change. In both the haemoglobin level was significantly lower during the rainy season.On exposure to direct sun, the buffalo reacted very badly; the Iberia index was 88 for cattle and 61 for buffalo.Because of the smaller variation in the physiological reactions due to increase in humidity at higher temperature in buffaloes (85–93° F.), this species may be considered a better dairy animal than cattle in humid tropical zones if they are protected from direct sun, which can be easily done by altering the time of grazing from day to night.
Cotton crop environment, growth and yield in the Sudan Gezira: II. The causes of variation in yield from year to year
Authors: Jackson J. E. 
Published: March 2009

SUMMARYAt three sites in the Sudan Gezira the variations in seed cotton yields between 1941 and 1961 were due, in the main, to variations in insect pest damage and, at one site only, to a downward trend in soil nitrogen level.At each site seed cotton yield was predetermined by total plant top dry weight before the opening of the first cotton bolls. The cotton crop was sown in August. At Turabi in the northern Gezira and at the Gezira Research Station in the south-central Gezira, variations in plant growth up to early October had little effect on subsequent yield. The yield was determined by growth during October, November and December; the total top dry weight at the end of December was much more important than the pattern of growth by which this weight was attained. At these sites yield was much more closely dependent on the amount of leaf recorded as free from pest and disease damage than on total leaf weight. Damage due to jassid (Empoasca lybica), thrips (Caliothripsspp.) and leaf curl accounted for 69% of the year to year yield variation at Turabi. Damage due to jassid and thrips accounted for 56% of the year-to-year variation at the Gezira Research Station.Severe pest damage was associated with low July plus August rains and high temperatures during the growing season but was not found to be dependent on leaf nitrogen levels.At Hag Abdulla in the southern Gezira, there was a general downward trend in yields over the years as well as variation from year to year consequent on variations in thrips damage. The downward trend inyields was associated with a trend to lower soil nitrate and plant nitrogen levels which resulted in anearlier cessation of leaf growth in recent years than hitherto.Variation in the level of pest attack accounted for 61% of the year-to-year variation in nitrogen response at Turabi, while at Hag Abdulla the response to nitrogen was determined by the deleterious effect of thrips and by a trend to increasing response as natural soil nitrate levels declined.Gezira commercial crop yields were closely correlated with those of the appropriate experimental plots for the years considered (r= 0·859 for the S-type crop, 0·736 for the L-type crop) inspite of some differences in cultural practice. This suggests that the major causes of variation were the same in both cases and that adequate protection against insect pests should do much to prevent the recurrence of seasons of extremely low yield with their serious economic consequences.
Effect of environment on competitive ability of two natural populations of Dactylis glomerata L.
Authors: Eagles C. F. , Williams D. H. 
Published: March 2009

SUMMARYThe competitive ability of two natural populations of Dactylis glomerata, one from Norway and the other from Portugal, was investigated by growing them in monoculture and together in a mixed sward under different temperature and light regimes. At 7 °C and 8 h photoperiod, the performance of the prostrate Norwegian population grown in mixture with the erect Portuguese population was suppressed as compared with its performance in monoculture. However, at 30 °C and 16 h photoperiod, when the growth habits of these two populations were reversed in comparison to those at 7 °C, the dry weight per plant of the erect Norwegian population was significantly greater in the mixed sward than in monoculture. The dry weight per plant of the Portuguese population did not differ significantly in the two types of sward at either temperature. The results are discussed in relation to competition for light.