bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of different stocking rates on the weight gain of Ankole steers on natural grassland in Western Uganda
Authors: Thornton D. D. , Harrington G. N. 
Published: March 2009

SUMMARYStocking rates of 3, 6 and 9 acres per 2- to 3-year old steer on Acacia-Cymbopogonj Themeda complex pasture in Ankole, Uganda, demonstrated that 3 acres per head gave significantly lower individual live-weight gains, but that there was little difference between 6 and 9 acres over a 6-year period. Although cattle grazed at 3 acres averaged only 175 lb per head per annum, compared with 207 lb at 6 acres per head, the income was Sh. 34 per acre compared to only Sh. 20–50 at 6 acres per head. At 9 acres/head the return was Sh. 13–50 an acre.A comparison of a 2 paddock/1 herd system with continuous grazing revealed no differences in production, despite the heavier capital investment involved in the former system. Growth rates at all three stocking rates were similar for most of the year, but in the dry season when all the cattle lost weight those stocked at 3 acres per head suffered the greatest losses (50–60 lb) and those at 9 acres per head the least (20–30 lb).
Some preliminary observations on the nature of factors influencing the excretion of non-dietary faecal nitrogen by ruminant animals
Authors: Mason V. C. 
Published: March 2009

SUMMARY1. When roughage rations of medium to high quality were given to steers and aduit sheep, the excretion of non-dietary faecal nitrogen was positively related to the intake of truly digestible dry matter. In these experiments no significant relationships were noted between non-dietary faecal nitrogen excretion and the intake of either truly digestible nitrogen or truly indigestible dry matter.2. When concentrate rations containing 1.6–3.2% nitrogen were given to lambs weighing 19–27 kg the excretion of non-dietary faecal nitrogen was positively and significantly related to the intake of both truly digestible dry matter and truly indigestible dry matter, but not related to the amount of truly digestible nitrogen consumed.3. Grinding and pelleting a grass ration for steers resulted in an increase in the excretion of non-dietary faecal nitrogen and bacterial + endogenous debris nitrogen, of 28 and 30% respectively, compared with the chopped material.4. It is concluded that these responses reflect the dominating influence of nitrogen of microbial residues from the rumen and hind-gut on the excretion of bacterial + endogenous debris nitrogen and non-dietary faecal nitrogen.
Early reproductive failure of ewes in a hot environment IV. The ovary
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 ovaries were removed, weighed and examined histologically.2. There were no significant treatment effects on ovarian weight, corpus luteum diameter, lutein cell frequency, lutein cell nuclear diameter, the number of Graafian follicles exceeding 0·9 or 1·9 mm. diameter, or mean follicle diameter. The results suggest that with more animals heat might prove to depress ovarian weight and vitamin A to increase ovarian weight, corpus luteum diameter and the number of large follicles.3. There were no significant differences between the mean values for those ewes with live embryos and those with dead ones with respect to any of the above indices.4. The results support the conclusion that variations in embryonic viability due to the experimental treatments were not mediated primarily through variations in ovarian hormone secretion.
An evaluation of naturally occurring fixed ammonium in soils
Authors: Freney J. R. 
Published: March 2009

1.Fixed ammonium could be completely recovered from clay minerals by leaching small amounts of clay with large volumes of salt solutions (containing the cations but not K+, Rb+, or Cs+), but no clay fixed ammonium could be found in soils when analysed by this technique.2. It is suggested that ammonium fixation is largely a laboratory phenomenon caused by the use of extractants containing potassium ions which trap exchangeable ammonium, or the use of reagents which decompose organic nitrogen compounds.
Seed Ripening in grasses
Authors: Stoddart J. L. 
Published: March 2009

1. Floret samples of S321 perennial rye-grass (Lolium perenne L.), S215 meadow fescue (Festuca pratensis L.) and S352 timothy (Phleum pratense L.) were taken at 3-day intervals from inflorescence emergence to seed harvest. These were analysed for total chlorophyll content, chlorophyll a: chlorophyll b ratio and total anthocyanin content.2. All varieties showed qualitatively similar patterns of total chlorophyll content. At emergence chlorophyll first increased on exposure to light and then fell as anther formation progressed. After fertilization a rapid increase in floret chlorophyll content coincided with early seed formation due to pigmentation of the expanding seed epidermis. Polymerization of carbohydrates to form endosperm starch resulting in increasing dry-matter content caused a concomitant fall in total chlorophyll when assessed on this basis. The final stages of seed maturation were accompanied by a further gradual decline to a very low level.
Extremity skin temperature in British and Zebu cross cattle
Authors: Johnson K. G. , Webster M. E. D. 
Published: March 2009

1. Extremity skin temperature changes in British and Zebu cross cattle examined in moderate thermal environments followed a thermoregulatory pattern similar to that describedby Whittow (1962). At low environmental temperatures, ear and lower leg skin temperatures were usually only slightly above air temperature. At a variable time after air temperatures began to rise or the animals were fed, extremity skin temperatures increased suddenly to near trunk skin temperature.2. In eight of the ten pairs of animals studied in rising ambient temperatures and during feeding after fasting for 36–72 hr, increases in ear temperature were measured in the British animal before similar changes occurred in its Zebu counterpart. Changes in lower leg skin temperature followed a similar pattern.Trunk skin temperatures and respiratory frequencies were significant higher in British cross animals than in Zebu cross animals of similar thermal history. The mean rectal temperature of both British and Zebu cattle was 38·5 °C.
The effect of constant long daily photoperiod upon the onset of puberty in ewes
Authors: Smith I. D. 
Published: March 2009

The effect upon the onset of reproductive activity of exposure of ewe lambs of three British breeds (Border Leicester, Southdown, Suffolk) to constant long daylight hours (16 h light/8 h dark) was studied.Oestrus, ovulation and conception were depressed but not inhibited; however, only the incidence of conception was significantly less than in the control group. Athough the treatment retarded the onset of oestrous activity, the age at first oestrus was still within the normal age range for puberty.
A comparison of grazing systems for dairy herd replacements
Authors: Leaver J. D. 
Published: March 2009

SUMMARYAn experimental and a conventional grazing system for 7- and 19-month-old dairy replacements were compared during 136 days of the grazing season. In the experimental system A, 24 calves were rotationally grazed around paddocks followed by 24 pregnant heifers which ate the herbage residue left by the calves. The conventional system B consisted of 24 calves and 24 pregnant heifers maintained at the same overall stocking rate as in system A, but the calves and heifers grazed in completely separate rotations. Half the calves on each system were drenched with an anthelmintic at weekly intervals from mid-July onwards to estimate within systems the effect of gastrointestinal worms on live-weight gain.
Body composition studies with the milk-fed lamb. II. The effect of the age of the lamb and the protein content of the diet on the chemical composition of the body and its organs
Authors: Jagusch K. T. , Norton B. W. , Walker D. M. 
Published: March 2009

SUMMARYEighteen male cross-bred lambs (aged 2–5 days) in two equal groups were given artificial milk diets of either low- or high-protein content; subgroups of three lambs were slaughtered after 2, 4 and 6 weeks on experiment. The composition of the change in empty body weight (E.B.W.), and the chemical composition of the change in weight of the separate compartments and organs, were determined by the comparative slaughter method.Lambs given the high-protein diet made significant gains in weight and in all chemical components in all periods. The composition of their E.B.W. was closely related to E.B.W. regardless of age. Lambs given the low-protein diet made only small gains in weight in 6 weeks, of which 76% was fat. The chemical composition of their E.B.W. was closely related to E.B.W. within each age group. The net gain of protein of these lambs in 6 weeks represented only 1% of the total weight gain, and over 50% of the protein gain was in wool. The skin and blood lost protein during the first 2 weeks, and failed to recover this loss during the remaining 4 weeks. Other organs lost protein initially but recovered this loss between 2 and 6 weeks.It was concluded that the initial loss of protein represented the labile protein reserves of the lamb, and the subsequent recovery was an adaptation to the low-protein diet. Furthermore, the results with both diets indicated that the skin and blood were the most inefficient of the organs in the body in utilizing the available N during a period of protein deficiency, or during a period of abundance in the dietary supply of N.
A comparison of the effects of anhydrous ammonia and a solid ammonium nitrate fertilizer on herbage production from a pure perennial ryegrass sward
Authors: Reid D. , Castle M. E. 
Published: March 2009

SUMMARYIn a 2-year experiment anhydrous ammonia (82% N) and an ammonium nitrate fertilizer (34·5% N) were applied at three annual rates—100, 200 and 300 lb N/acre (112, 224 and 336 kg/ha)—on an S.24 perennial ryegrass sward. At each rate the two fertilizers were applied either as a single dressing in the spring or as five equal split dressings over the season. Total yields of herbage dry matter and of crude protein were determined by cutting the herbage at approximately the same stage of growth five times each year. On the basis of total yield and seasonal distribution of yield anhydrous ammonia was best applied as a single dressing in the spring, whereas ammonium nitrate was best applied as five equal split dressings over the season. However, in both years anhydrous ammonia applied as a single dressing gave smaller yields and a poorer seasonal distribution of production than did ammonium nitrate applied as five equal split dressings. The factors contributing to the lower yield level with anhydrous ammonia applications are discussed. It is concluded that anhydrous ammonia has no marked advantages over ammonium nitrate as a nitrogen fertilizer for intensively managed grassland.
Increasing litter size in three breeds of sheep by superovulation
Authors: Newton J. E. , Betts J. E. , Large R. V. 
Published: March 2009

SUMMARYEwes of three breeds, Devon Longwool, Kerry Hill and Welsh Mountain were injected with different levels of Pregnant Mare Serum Gonadotrophin (PMSG) for 3 consecutive years. Within the levels of PMSG examined (0–1500 i.u.) the highest mean litter size was obtained at 1000 i.u. for the Devon Longwool (2·10) and the Welsh Mountain (2·33), and at 1500 i.u. for the Kerry Hill (2·41). This represented a response of 0·66, 1·28 and 0·56 extra lambs born for the Devon Longwool, Welsh Mountain and Kerry Hill breeds, as untreated ewes of these breeds produced 1·44, 1·05 and 1·85 lambs/litter. The lambing percentage attained was, however, lower than the response in litter size indicated, due to the incidence of barren ewes and of lamb mortality.Though the Devon ewes were heavier than the Kerry's, twin lambs out of the latter were bigger than twins from the Devon's. The relationships of body weight and of natural fertility to optimum dosage of PMSG are considered. There is discussion of the maximum litter size and minimum birth weight compatible with the production of viable lambs.
The interaction between nitrogen and water in The growth of Grass Swards: I. Methods and dry matter results
Authors: D'Aoust M. J. , Tayler R. S. 
Published: March 2009

SummaryAn experiment examined the interaction between nitrogen and irrigation on a sward of Lolium multiflorum (Italian ryegrass). Between rates of 100 and 200 units of nitrogen per acre, the response to nitrogen over the whole season was not increased by irrigation. Positive and negative interactions occurring in different periods cancelled each other out. Between rates of 200 and 400 units of nitrogen per acre, irrigation substantially increased the response to nitrogen, negative interactions being small relative to positive interactions. The results suggest that the moisture status of the upper few inches of the soil is an important factor in determining response to applied nitrogen. Response to nitrogen was increased when irrigation improved the moisture status of this zone.
Seasonal oestrogenic activity of various legumes
Authors: Newton J. E. , Betts J. E. 
Published: March 2009

SUMMARYOestrogenic activity was recorded by teat length extension in wether lambs grazing red clover S. 123 in September and October 1965 and between 21 April and the end of October 1966. The number of lambs born alive to ewes grazing red clover (S. 123) for the 2 weeks prior to mating and for 4 weeks after mating was reduced. Oestrogenic activity was also recorded in wether lambs on lucerne var. Eynsford and on white clover S. 100 from mid-June to mid-October 1966.Oestrogenic activity was confirmed in red clover, but not in lucerne, by mouse bioassay. Slight oestrogenic activity was shown in one white clover sample only.
Sodium and potassium relationships in sugar beet
Authors: Draycott A. P. , Marsh J. A. P. , Tinker P. B. H. 
Published: March 2009

SUMMARYThree field experiments with sugar beet grown on a light calcareous soil tested a wide range of amounts of sodium and potassium fertilizer with either magnesium or nitrogen. Both sodium and potassium increased sugar yield and there was a large negative interaction between them. Magnesium also increased sugar yield, but the larger dressing of nitrogen decreased it. Sodium, potassium and nitrogen fertilizers also affected the concentration of impurities in the root juice at harvest.Plant samples were also analysed in August when the crop usually contains most sodium. Sodium fertilizer greatly increased the sodium and decreased the potassium concentration in the dry matter of the tops but the composition of the roots changed little. Potassium dressings slightly increased potassium in the tops but did not affect the root composition.Exchangeable sodium in the top soil of plots given sodium fertilizer decreased rapidly early in the season, but increased again from August, probably because sodium was taken up rapidly early in the summer and returned later in dead leaves. Soil potassium decreased throughout the season on plots where potassium was applied, but did not change on plots without potassium fertilizer; this is explained by fixation and release from non-exchangeable forms.On this soil there was no reason to regard sodium in its effect on yield, other than as a replacement for potassium, but its behaviour in the soil and effect on the composition of the plant was quite different.
Protein and lysine levels in practical rations
Authors: Braude R. , Lerman P. 
Published: March 2009

SUMMARYA co-ordinated trial has been carried out at twenty-one centres to obtain information on the following problems: does the addition of synthetic lysine to a ‘standard’ ration, widely recommended and used in this country, beneficially influence the performance of growing pigs, and is the effect influenced by whether the source of supplementary protein is white fish meal or soya bean meal ?In comparison with a ration providing levels of crude protein and lysine recommended in the A.R.C. ‘Nutrient Requirements of Pigs’, the ‘standard’ ration which contained less crude protein and total lysine, produced slightly lower performance, but about the same profit. The performance on the ‘standard’ ration could be improved by the addition of synthetic lysine, but such supplementation would not be profitable unless the cost of synthetic lysine was less than 21s./kg.The response to added synthetic lysine was similar on rations in which the source of supplementary protein was either white fish meal or soya bean meal.
Field experiments comparing ammonium sulphate, ammonium nitrate, calcium nitrate and urea combine-drilled with spring barley
Authors: Devine J. R. , Holmes M. R. J. 
Published: March 2009

1. Twenty-one experiments were carried out in various parts of England and Scotland in 1959–61 comparing two or more of the nitrogen sources ammonium sulphate, ammonium nitrate, calcium nitrate and urea, combine-drilled in compound fertilizers for spring barley.2. Ammonium sulphate and ammonium nitrate combine-drilled at rates from 35 to 105 lb./acre of nitrogen checked early growth slightly in some of the experiments, with no important difference between the two sources, which also gave similar grain yields.3. Calcium nitrate and urea combine-drilled at 45 lb./acre of nitrogen had no large effect on early growth, while at 70 and 90 lb./acre both fertilizers seriously delayed brairding and reduced the plant population in many of the experiments, especially in eastern England. They gave lower yields than ammonium sulphate and ammonium nitrate in many of the experiments in which early growth was affected, and gave lower mean yields at all rates of application.4. In eleven of the experiments, broadcast applications of two or more of the four nitrogen fertilizers were compared. All sources gave similar mean yields.5. There was a slightly smaller yield from combine drilling than from broadcasting ammonium sulphate and ammonium nitrate, and a markedly smaller yield from calcium nitrate and urea.
The artificial rearing of lambs on cold reconstituted whole milk and on milk substitute
Authors: Large R. V. , Penning P. D. 
Published: March 2009

1. Two experiments with 52 lambs are described investigating the use of reconstituted cold milk for rearing lambs and comparing full cream dried milk with a milk substitute.2. The use of cold milk resulted in high growth rates and few health problems.3. Satisfactory food conversion efficiencies were obtained by feeding of cold reconstituted whole milk and cold milk substitute.4. During the first 3 weeks of rearing, the growth rates and food conversion efficiencies on the milk substitute were similar to those obtained on the full cream milk.
Long-term effects of fertilizers on herbage production: I. Yields and botanical composition
Authors: Heddle R. G. 
Published: March 2009

In a factorial experiment on a mixed grass/clover sward, continued over 13 years, D.M. yields were strongly affected by N and K, which showed a marked interaction. P had very little effect on yield. There was evidence of a depressing effect on yield of continued application of KC1 at low rates of N input: this is thought to be due to excess Cl. It may be associated with the effect of Cl on clover growth, since it did not occur in predominantly grassy swards heavily dressed with N, in spite of high Cl content in the herbage.The botanical composition of the herbage was strongly affected by the fertilizer treatments.
Long-term effects of fertilizers on herbage production: II. Chemical composition
Authors: Heddle R. G. , Crooks P. 
Published: March 2009

The effects of Nitro-chalk, superphosphate and potassium fertilizers on the chemical composition of grassland herbage and the removal of major plant nutrients have been traced over 14 years.Without fertilizer N, but with adequate K, clover supplied a yearly average of up to 87 lb Nsol;acre. With an annual application of 348 lb N and adequate K, 237 lb of N was recovered annually.Without applied P, herbage P concentration fell with time especially under heavy N treatment. When P was applied, herbage P concentration did not fall, irrespective of N treatment: K depressed P concentration irrespective of P application. Maximum removal of P occurred with annual applications of 348 lb N, 43 lb P and 280 lb K: at these rates gain and loss of P approximately balanced.Herbage K concentration was greatly increased by K fertilizer. It was reduced by N when no K was applied but applying K counteracted this effect. Removal of K slightly exceeded the 280 lb of K applied when 348 lb N was also applied.
The influence of nutritional level in early pregnancy of the ewe
Authors: Coop I. E. , Clark V. R. 
Published: March 2009

SummaryA series of three large-scale field trials, involving 3500 ewes over a 3-year-period, was conducted to study the effect of restricted nutrition of breeding ewes in early pregnancy. Control or non-restricted ewes were fed at approximately maintenance level and restricted ewes at approximately half-maintenance. The majority of ewes fell into two categories—those 2–3 weeks pregnant at the time restriction was commenced and those 5–7 weeks pregnant. Restriction was applied for from 5 to 8 weeks, live-weight differences of approximately 10 1b were achieved.Differences in performance in individual trials were invariably very small, and nonsignificant. The main effect of restricted nutrition over all trials was to decrease twinning by 0·5% and decrease the number of barren ewes by 0·8%. These differences are considered to be negligible. Only one statistically significant effect was observed within one of the trials—this was a depression in twinning in ewes 18–24 days pregnant at the time of applying the treatment, but this effect could not be confirmed in the other two trials. However, the fleece grown was affected by treatment—the fleece weight being depressed by approximately ½ lb, and grade reduced slightly.It is concluded that restricted nutrition at the level and time applied has no effect on reproductive performances of ewes and therefore the practice of restriction in early pregnancy to conserve feed for late pregnancy is a sound policy.
Transgressive segregation for frost resistance in hexaploid oats (Avena spp.)
Authors: Jenkins G. 
Published: March 2009

SummaryResults are presented from freezing tests on five varieties of winter oats from diverse origins, on their crosses in the F1and F2generations and on selected F3lines from six of the crosses.Analysis of the F1results indicated that frost resistance was mainly determined by recessive genes, additive in their effect, but in the F2experiment there was evidence of non-allelic gene interaction. Significant general combining ability (GCA) effects were obtained in both the F1and F2experiments but specific combining ability (SCA) effects were significant only in the F2crosses. The variety Novosadsky II displayed consistently high general combining ability.Tests on F3lines derived from selected F2plants revealed considerable transgression for frost resistance in all six crosses studied. The results are discussed in relation to breeding for improved frost resistance in oats.
Length of tongue in a honey bee in relation to the pollination of red clover
Authors: Hawkins R. P. 
Published: March 2009

SummaryRed clover florets are generally longer than a honey bee's tongue. Original data are submitted showing that honey bees can reach to a depth of 7 mm into the corolla tube of a red clover floret. The importance of this figure is discussed in relation to breeding bees with longer tongues and the breeding of red clover with shorter corolla tubes. Breeding a variety of red clover with more nectar so that honey bees can reach it is considered to be the best solution and would produce an increase in yield of both seed and honey.