bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sexual behaviour and reproductive performance of ewe lambs at and after puberty
Authors: Edey T. N. , Kilgour R. , Bremner Kaye 
Published: March 2009

SUMMARYObservations were made on mating behaviour and reproductive performance during the puberal period in 61 well-grown Perendale (Cheviot × Romney) ewe lambs. In four animals, the first oestrus (as indicated by raddle marks) was not accompanied by ovulation, and three other lambs, though marked by the rams, were not inseminated.The behavioural responses to a ram, of ewe lambs experiencing oestrus for the first and second times, showed many signs of inadequacy by comparison with those of mature ewes. Individual ewe lambs and mature ewes in oestrus were exposed to a ram in a pen for 3 h, and their responses were ranked on a scale of 1 (full adult response) to 5 (weak response). Of mature ewes 95% scored 1, compared with only 27% of ewe lambs. Across the lambs 59% scored 3 or more, indicating failure of some aspects of the courtship sequences which are required to sustain and reinforce the ram's interest. In a paddock-mating system many lambs showed a strong tendency to disassociate themselves from the rams after each courtship and mating sequence. Consequently there was little evidence of harem formation. Fifty-six per cent of services came in the first 2 h of oestrus, only 14% after the 6th hour and none after the 11th hour.Duration of the first oestrus in lambs was 18·4 h compared with 29·3 h in mature ewes. Mating the 61 ewe lambs over the first three cycles after puberty resulted in 38 of them being pregnant with 46 foetuses at autopsy in mid to late pregnancy. The success rate did not differ between cycles.
A note on drought-resistance in the lucerne plant
Authors: Wilman David 
Published: March 2009

1. Lucerne was grown in a glasshouse under different moisture regimes in order to determine the effect of soil moisture content at the time of defoliating on subsequent yield.2. Drought conditions were found to reduce yield in the short-term, particularly in conditions in which demand for water was high, but the crop subsequently recovered when supplied with ample moisture. Defoliation during a drought period showed no long-term effect on yield.This work was carried out as part of the programme of crop-husbandry experimentation at the University of Cambridge School of Agriculture, and the author welcomes this opportunity of thanking Mr F. Hanley, Reader in Crop Husbandry, for advice and suggestions.
The post-natal development of the follicle population in English Romney Lambs
Authors: Wildman A. B. 
Published: March 2009

The follicle ratio S/P and the fibre ratio Sf/Pf have been determined for various post-natal ages of English Romney lambs in six lamb crops.A maximum site-sampling error has been determined for use in assessing the degree of significance of differences in values of the ratio S/P determined from successive skin samples from individual lambs. Variations encountered in these Romney lambs in the level of their follicle and fibre ratios, in their rates of change and in the degree of their association with live-weight changes show that rigid conclusions based on data from one lamb crop only are not justified. An intensive study of birth and 8-day old samples has shown that follicles may regress in the early post-natal life of the lamb.Not all follicle anlagen are initiated before birth and the ‘ceiling value’ of the adult ratio Sf/Pf is not necessarily determined or set pre-natally except in the sense of there being a genetic maximum which may or may not be attained. Low restricted follicle and fibre ratios at birth may increase rapidly postnatally and high ratios at birth may increase little, if at all, post-natally. The follicle and fibre ratio may increase even between the ages of 6 and 12 months.
The effect of the increased dietary volatile fatty acids on the morphological and physiological development of lambs with particular reference to the rumen
Authors: Rickard M. D. , Ternouth J. H. 
Published: March 2009

Acetic acid, propionic acid, and butyric acid were fed to lambs at a level of 4% of ration over the period of 3-8 weeks of age. The effects of this on weight gains and rumen development were measured.Separate pathways are involved in the metabolism of C3and C4V.F.A. in the rumen wall, and the enzyme systems involved can adapt to high levels of each acid in the diet. The adaptation is longstanding.The groups of lambs supplemented with propionic acid showed greater weight gains than the other groups.Propionic acid in some way increases the efficiency of V.F.A. utilization by the animal, possibly by reducing the heat increment, and/or reducing loss of energy as ketone bodies in the urine.At 9-12 weeks a higher efficiency of food utilization in the acetic acid group was observed.The stimulatory effect of acetic and propionic acids on papilla numbers was observed at 8 weeks.Some observations were made on histological sections of rumen papilla at 8, 12 and 16 weeks and their relationship to the diet.
The protein and energy nutrition of the pig. V. The effect of varying the protein and energy levels in the ‘finishing diets’ of heavy pigs
Authors: Robinson D. W. 
Published: March 2009

1. A feeding trial was carried out using fortyeight Large White pigs, individually fed in a Danish type piggery. Six different diets prepared at two levels of digestible energy and three levels of crude protein were fed to eight replicates consisting of four hogs and four gilts per replicate. A record was maintained of the weekly live-weight gain and food was given at a defined restricted level in relation to the live weight. Carcass quality was assessed by complete dissection into visible lean, fat and bone etc.2. Of the main effects, energy, supply was without significant effect upon growth, food conversion efficiency (FCE) or any carcass characteristics except body length which was increased with a high energy level. The protein level in the diet had a significant effect upon the percentage of carcass lean and the killing-out percentage, the higher levels of protein increasing both these measurements significantly. Gilts were significantly superior to hogs in every carcass measurement although hogs grew significantly faster.
The utilization of Hyparrhenia veld for the nutrition of cattle in the dry season I. The effects of nitrogen fertilizers and mowing régimes on herbage yields
Authors: Smith C. A. 
Published: March 2009

1. The potential herbage yield of Hyparrhenia veld under mowing and fertilizer managements was measured, as a part of the work to study the utilization of the natural grassland for the feeding of cattle in the dry season.2. The uninterrupted seasonal pattern of herbage growth results in a relatively large yield of stemmy, low-quality fodder at the end of the growing season.3. Cutting at simulated ‘silage’ and ‘hay’ stages of growth reduced herbage yields compared with one, end-of-season harvest, but because of increased leanness, the regrowth herbage had a higher crude-protein content.4. The seasonal crude-protein yield was unaffected by mowing treatments, and a reduction in herbage yield was counterbalanced by an increase in percentage crude protein.5. The use of nitrogenous fertilizers resulted in a large increase in both herbage yield and percentage crude protein. The calculated nitrogen recovery was approximately 40%.6. There were no harmful effects on either veld vigour or botanical composition after 4 years of mowing and fertilizer treatments. The nitrogen fertilizer treatments alone showed a transient residual effect.7. The practical bearing of the results is discussed briefly. Only a low-quality fodder can, in practice, be harvested from the natural grassland, unless nitrogen fertilizers are used.
Work on improvement of saline-alkali land on the University Farm, Khartoum, 1956–59
Authors: Worrall G. A. 
Published: March 2009

Over the 3 years of the experiment the salt in the top 2 ft. of the soil was reduced by almost a half of the original amount, and nearly all this was removed in the first season. The movement was downwards, and there was little evidence of any upward movement; flushing was not very effective in removing salt from the soil. The type of cultivation affected the amount of salt removed, deep subsoiling being most successful with over 50% removal, but irrigation without any cultivation removed 29%. The penetration of irrigation water was very restricted in the first waterings, but became increasingly deeper as the experiment continued.Crop yields showed a steady improvement from season to season, the final average of about 1500 lb. per feddan being above the average for the district. The various treatments did not appear to have much effect on the yields, and the general improvement in yields is attributed to the reduction of salt content and to the deeper water penetration, chiefly the latter. The detrimental effect of the dry north winds was more apparent than the effects of the different treatments.
The effect of different nitrogenous fertilizers, applied as solids or solutions, on the yield and nitrate-N content of established grass and newly sown ryegrass
Authors: Nowakowski T. Z. 
Published: March 2009

Experiments on permanent grass and newly sown Italian ryegrass compared ammonium hydroxide solution, with ammonium sulphate, ammonium nitrate, calcium nitrate and urea, applied at 56 and 112 lb. N/acre as solids, and also when dissolved in water to give a final N content of 5 %. Ammonium hydroxide solution containing 5% N damaged established grass severely and did not increase drymatter yields; when applied to the seed-bed before sowing Italian ryegrass, ammonium hydroxide solution did not affect germination but yields were lower than with other N fertilizers.On permanent grass all fertilizers significantly increased dry-matter yields and N uptake at both cuts. The form of N fertilizer did not significantly affect dry-matter yields or N uptake of grass of the first cut. The method of application (i.e. solid or liquid) did not affect dry-matter yields, except that ammonium nitrate in solution gave a significantly higher yield than did the solid form at the second cut; the grass had higher N content with solid forms than with solutions. The grass took up more N from solid forms than from solutions except with ammonium nitrate at the second cut. Delaying the N application by 20 days decreased dry-matter yields considerably and increased the N content of the grass.
The maintenance requirements of beef steers and the relationship of maintenance needs and total fattening requirements
Authors: Luitingh H. C. 
Published: March 2009

Although considerable work has been done on basal metabolism and maintenance requirements of animals, maintenance needs in relation to total feed requirements for production have not received much attention in South Africa. Most workers have investigated production requirements, whilst the part of the total needs of the fattening of steers used for maintenance, has received very little attention.This capital cost or ‘overhead’ expense is an item which constitutes a large proportion of the animals' fattening ration. In South Africa, only a small percentage of cattle is marketed under 4 or 5 years old. The maintenance cost of these animals must be considerable and the nett efficiency of beef production very low. As only the amount of a ration in excess of the maintenance requirements can be utilized for production, it follows that a level of nutrition well above the requirements for maintenance will facilitate a more efficient production system by narrowing the ratio between the part of the ration used for maintenance and that used for production. It is well known that differences in the efficiency of production between steers can only be due to the difference in the level of feed intake above maintenance needs—hence probably the strong correlation between rate of gain and efficiency of feed utilization. Apart from the actual determination of maintenance needs the object of this investigation was to determine the relationship between maintenance requirements and the total feed intake of beef steers when fed on fattening rations containing different ratios of concentrates to roughage.
Early reproductive failure of ewes in a hot environment I. Ovulation rate and embryonic mortality
Authors: Ryle Margaret 
Published: March 2009

1. Twenty-four Merino ewes acclimatized to a hot environment were compared with twenty-four kept at normal temperatures, with respect to ovulation rate and embryonic loss by 25 days' pregnancy. Possible modifying effects of the three subsidiary factors, thyroxine level, vitamin A intake and progesterone level, were sought. The design of the experiment was a balanced factorial one.2. While the differences between the hot-room and yard groups as a whole were not significant, in the former there were fewer ovulations, a smaller proportion of the potential embryos actually began to develop and, of these, a larger proportion had died by 25 days' pregnancy. Consequently only thirteen hot-room ewes contained live embryos compared to twenty in the yard; the total numbers of live embryos were fourteen and twenty-seven, respectively.3. Of the subsidiary factors only thyroxine produced any marked effect. Both in the hot-room and in the yard the proportion of potential embryos developing and the proportion of actual embryos surviving at 25 days' pregnancy were greater where thyroxine injections were given. There appeared, however, to be no effect on ovulation rate. There was a significant increase in the proportion of hot-room ewes with live embryos due to thyroxine. Grouping hot-room and yard ewes together, thyroxine injections were associated with a significant increase in the proportion of potential embryos developing and in the proportion of actual embryos surviving; also, consequently, in the proportion of ewes with live embryos.4. The results are discussed in relation to published work on the effects of high temperatures on reproduction.
Studies on the production of beef from zebu cattle in East Africa III. The value of feeding a phosphatic supplement
Authors: Lampkin G. H. , Howard D. A. , Burdin M. L. 
Published: March 2009

1. Three experiments are described in which dicalcium phosphate was fed as a phosphatic supplement to beef-type zebu cows and weaner calves grazing at Muguga in the Kenya Highlands.2. The treatment caused an increase in the level of inorganic phosphate in the bloods only during times of drought, when it also caused an improvement in the condition of the cows. A slight beneficial effect on fertility was noted throughout the experiment.3. Evidence was found that other nutritional factors were causing considerable variation and it is suggested that more attention should be given to improving the general level of nutrition of cattle during dry seasons.
Reproductive performance of New Zealand Romney sheep grazed on red clover (Trifolium pratense) pastures
Authors: Ch'ang T. S. 
Published: March 2009

The reproductive performance of 253 female Romney sheep of different ages has been studied from 1958 to 1960. Comparisons of the reproductive performance were made between ewes grazed on red clover pastures and ewes grazed on perennial rye-grass and white clover swards. The red clovers were oestrogenic during all periods of utilization.The ingestion of oestrogenic red clovers caused the ewe lambs to accept the male before the start of the normal breeding season. No corpus luteum was found in the ovary of these lambs thus induced into oestrus. The subsequent reproductive performance of these ewe lambs at 2 years of age was not affected. The oestrus per se or the regularity of oestrus of the young (1½-year-old) or the aged (5½-year-old) ewes was not affected by the diet of oestrogenic red clover.The ingestion of oestrogenic red clover did not affect the reproductive performance of the young ewes at 2 years of age, but did cause a protracted lambing season and a reduced level of lambing performance in the aged ewes at 6 years of age. No endometrial cyst was found in the aged ewes. It was suggested that the reduced level of reproductive performance of the aged ewes could have resulted from an unfavourable environment within the ewe, for the process of fertilization or implantation of the fertilized ova during the breeding season.
The time of ovulation and efficiency of fertilization following progesterone and pregnant mare serum treatment in the cyclic ewe
Authors: Robinson T. J. 
Published: March 2009

A factorial experiment designed to determine the time of ovulation relative to oestrus and to the cessation of progesterone treatment in cyclic maiden ewes, and subsequent fertilization of ova, is described. Seventy-two ewes were used. Factors were: (a) type of service (natural v. A.I with fresh undiluted semen v. A.I. with semen diluted 1:1 with heated cows' milk); (b) frequency of progesterone (daily v. every 2 days); (c) post progesterone withdrawal treatment (500 i.u. PMS v. no PMS); (d) week of treatment (3 successive weeks); and (e) days within weeks (2 successive days). Insemination was carried out on the third day after cessation of progesterone without reference to the results of teasing with vasectomized rams.Progesterone (20 mg.) administered every 2 days was as effective as 10 mg. administered daily for suppression of ovulation. PMS resulted in a highly significant increase (P < 0·001) in the numbers of ewes which ovulated and which exhibited oestrus after progesterone, and in the number of fertile ewes (P < 0·05).There was a considerable spread of time of onset of oestrus and of ovulation. This was unaffected by any treatment. Most ewes were served 24–96 hr. (peak 48–84 hr.) and ovulated 48–108 hr. (peak 72–108) after cessation of progesterone. The time relationships of oestrus, ovulation and ovum transport appeared normal.
Observations on the age of shedding of the deciduous and the eruption of the permanent anterior teeth in a herd of Friesian cattle
Authors: Andrews A. H. , Green D. A. , Harrop A. E. 
Published: March 2009

SUMMARYObservations on the time of development of the permanent anterior teeth in a herd of Friesian female cattle (heifers + cows) are described. The animals were examined at approximately monthly intervals. A modified longitudinal survey method was employed. A table is presented of the maximum and minimum (i.e. the range), mean and median ages for the stages of development for each permanent pair of teeth. The stages were defined as: one of permanent pair present and/or one/both temporary teeth absent, both permanent teeth emerging, ¼ up, ½ up, ¾ up and fully up. A large amount of variation was found in the ages for each stage of development in individual animals. Tables are included for the time taken for a pair of permanent teeth to pass from first to complete emergence, the time a pair of teeth were fully up before any further development was observed and the time taken between a tooth being at one stage in one pair of teeth to the same stage in the succeeding pair of teeth.
The effect on bacon pig backfat iodine number and calorific value of feeding barley or maize based diets to give different growth rates
Authors: Lawrence T. L. J. 
Published: March 2009

SUMMARYIn an experiment involving sixty Large White pigs fed maize or barley based diets either ad libitum (AL) or to one of two restricted scales (R1 and R2), between 55 and 86 kg live weight, there were no significant cereal × feeding interactions for growth rate and the mean growth rates for the main effects were 0·62, 0·63, 0·81, 0·73 and 0·35 kg/day for the maize, barley, AL, R1 and R2 treatments respectively. There were no significant cereal × feeding treatment interactions for iodine number or calorific value of carcass backfat and the only significant differences between the main effects were those of lower iodine numbers for the barley (cf. maize) and the AT. (cf. R1) treatments.
The voluntary intake and digestibility of oat straw by pregnant beef cows as influenced by urea and phosphorus supplementation contained in molassed sugar-beet pulp
Authors: Fishwick G. , Fraser J. , Hemingway R. G. , Parkins J. J. , Ritchie N. S. 
Published: March 2009

SUMMARYPregnant beef heifers allowedad libitumaccess to oat straw were given 2·7 kg molassed sugar-beet pulp alone or with additional dicalcium phosphate or urea or a combination of both materials in a Latin square design involving four feeding periods each of 21 days. Supplementation with urea to increase the total daily intake of digestible crude protein from about 130 to 290 g/day increased straw consumption by 20%. This increased the total intake of metabolizable energy from about 13 to 15 Meal/day. Increasing the total intake of phosphorus from about 6 to about 17 g P/day did not increase straw intake or digestibility or the total intake of metabolizable energy in either the presence or absence of additional urea.Supplementation with urea increased the concentration of urea and glucose in the blood plasma and the concentration of ammonia in the rumen liquor, but did not increase the concentrations or alter the proportions of rumen volatile fatty acids. Addition of urea tended to increase the digestibility of the dry matter and crude fibre of the straw. Phosphorus supplementation increased the concentration of phosphorus in the blood plasma.
Ear development in spring wheat
Authors: Kirby E. J. M. 
Published: March 2009

SUMMARYData from experiments with spring wheat, variety Kolibri, were used to examine size gradients within the mature ear in relation to ear development. The greatest number of grains and florets per spikelet, and the heaviest grains, occurred in the lower-mid part of the ear. Within the spikelets in this region grain 2 > grain 1 > grain 3.It is proposed that the timing and period of ear development and the number of spikelets can be described quantitatively in terms of (1) the rate of leaf initiation, (2) the number of leaves, (3) the rate of spikelet initiation and (4) the total number of primordia. Both leaf and spikelet initiation proceeded at more or less constant rates, but spikelet initiation was about three times as fast as leaf initiation. Differentiation of the spikelet primordia started at about the time the terminal spikelet was initiated, occurring first in the spikelets in lower-mid part of the ear. The rate of floret initiation was lower than that of spikelet initiation, but did not differ between spikelets. A maximum of nine florets per spikelet was formed and then, in all spikelets, some of the last-formed primordia died, leaving two to four potentially fertile florets.Morphologically, primordia in the lower-mid part of the ear were always the most advanced. The more rapid development of the terminal primordia tended to synchronize events such as meiosis and anthesis, thus shortening the development period of the later formed florets. Changes in meristem size were such that both length and diameter were the greatest when the primordia of the lower-mid part of the ear were initiated.The statistical model to describe primordium initiation and ear size is compared with other models describing primordium initiation rates. The analysis of ear development in quantitative terms is discussed in relation to analyses of ear development by morphological stages. A correlation between grain size and time of floret initiation is demonstrated and the significance of the size changes in the meristem is discussed.