bluuebunny/crossref_metadata_2025 huggingface dataset:
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.
Estimating the heritability of butterfat production
Authors: Searle S. R.
Published: March 2009

Part of the variation among butterfat yields in dairy cows arises from genetic differences among the animals. The proportion which this bears to the total variance is known as heritability. In the ‘narrow’ sense it is defined (Lush, 1940), as the proportion of the total variance that is due to additive gene effects; the ‘broad’ sense definition includes genetic variation arising from non-additive gene effects as well as that due to additive effects. Since related animals have a proportion of their genes in common the covariance among their production records can be used for estimating genetic variation and hence heritability. This paper discusses three groups of related animals most frequently used for this purpose, twins, daughter-dam pairs and paternal half-sibs, and presents the results of analysing production records of artificially bred heifers in New Zealand, including evidence of the magnitude of the sampling errors of the heritability estimates.
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

Observations 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

In 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

Pregnant 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

Data 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.
The effects of season and age of stand on the nutritive value of heather (Calluna vulgaris, L. Hull) to sheep
Authors: Milne J. A.
Published: March 2009

In two experiments frozen heather (Calluna vulgaris, L. Hull), which contained 85–90% of the current season's shoots, was offeredad libitumto castrated male sheep. In one experiment, heather harvested in July, September, November and March was offered to six sheep per harvest, D.M. digestibility fell from 55.9% in July to 41.9% in March, with the greatest decline occurring after flower development in August. There were no significant changes with season in voluntary intakes, which were low, ranging from 29 to 39 g D.M./kg W0.75/day. Apart from the July harvest, intakes of digestible D.M. were insufficient to maintain the sheep. The apparent digestibility of N(14·3–42·2%) and plasma urea N values (5–6 mg/100 ml) were low and undigested N of dietary origin in the faeces was high (25–45%). Sheep offered the September, November and March harvests were in considerable negative apparent balances of N and it was calculated that the sheep were in a negative balance of truly digested N. In a second ex-periment, heather harvested in August from pioneer, building and mature stands was offered to six sheep per harvest. There were no significant differences between stands in voluntary intake and digestibility.
An effect of soil ingestion on the utilization of dietary copper by sheep
Authors: Suttle N. F. , Alloway B. J. , Thornton I.
Published: March 2009

To test the hypothesis that the ingestion of Mo-rich soils by ruminants might adversely affect Cu metabolism, four groups of initially hypocupraemic ewes were repleted with a Cu-supplemented diet either soil-free or containing 10% of one of three soils of low, medium and high Mo content. The three soils were equally effective in inhibiting the response in plasma Cu and probably reduced the availability of Cu by more than 50%. The ingestion of certain soils produced increases in urinary Mo and Zn concentrations, indicating that the Mo and Zn ingested in soil can be biologically available: however, these Cu antagonists were probably released in insufficient quantities to have contributed greatly to the observed interference with Cu metabolism. Soil ingestion may be involved in the aetiology of hypocuprosis in cattle and swayback in sheep, since it commonly constitutes 10% of the D.M. intake of animals grazing winter pasture.
Effect of variations in dietary protein and of supplements of cod-liver oil on energy digestion and microbial synthesis in the rumen of sheep fed hay and concentrates
Authors: Sutton J. D. , Smith R. H. , McAllan A. B. , Storry J. E. , Corse D. A.
Published: March 2009

Estimates have been made of the amount of energy fermented and the amounts of microbial protein and total fatty acids synthesized in the rumen of sheep given various rations of hay and concentrates. The sheep had re-entrant cannulas in the proximal duodenum. The amount of protein synthesized was calculated from the flow of RNA-N at the duodenum. The change in the amount of total fatty acids between the food and the proximal duodenum was also measured.

In Expt 1, six sheep were given a low-protein basal diet and the same diet supplemented with a vegetable protein concentrate with or without tannin treatment. Some 72% of the digestible energy was apparently digested in the rumen and an estimated 150–170 g microbial protein were synthesized per kg organic matter apparently digested in the rumen. Differences due to the dietary treatments in the amount of energy digested and the amount of microbial protein synthesized were small and non-significant.

In Expt 2, the effect of a supplement of 20 g/day of cod-liver oil (CLO) on digestion of a mixed diet of hay and concentrates was examined in five sheep. Despite a marked fall in the ratio of acetic acid to propionic acid in the rumen volatile fatty acids when CLO was added, there were no clear differences in the amount of energy fermented in the rumen, which averaged 64% of the digestible energy, or in the efficiency of microbial protein synthesis, which averaged 200 g/kg organic matter apparently digested in the rumen. On the basal diet an increase of 6·7 g total fatty acid/day occurred in the stomach. This was presumably synthesized in the rumen. However when CLO was added to the diet, a decrease of 4·1 g total fatty acid/day was measured.
The growth responses to weather of simulated vegetative swards of a single genotype ofLolium perenne
Authors: Thomas Henry
Published: March 2009

The influence of ambient weather conditions on the regrowth and morphology of a perennial ryegrass sward, over the period May–October 1972, was assessed by following the performance in the field of a succession of vegetative, single genotype, simulated swards previously grown under standard conditions. Crop growth rates estimated from largely non-destructive measurements of growth components (leaf extension, leaf weight/length ratio, tillering rate and tiller density) agreed with, and were more precise than, rates determined from harvests; the components having the greatest influence on growth rate were leaf extension and leaf weight/length ratio. Leaf extension and appearance were closely dependent on temperature; leaf weight/length was only slightly affected by the weather. The growth rates of total above ground parts, especially of herbage above the cutting height, were largely determined by temperature and initial leaf-area index, and insensitive to insolation. At higher temperatures, a greater proportion of assimilates was partitioned into herbage growth.
The utilization of maize silage for intensive beef production: II. The effect of urea on silage fermentation and on the voluntary intake and performance of young cattle fed maize silage-based diets
Authors: Thomas C. , Wilson R. F. , Wilkins R. J. , Wilkinson J. M.
Published: March 2009

Maize was cut at 22·6, 27·0 and 41·6% dry matter and ensiled in 4 kg quantities in polythene bags without additive or after the addition of urea at 0·5, 1·0, 1·5 and 2·0% of the crop dry-matter content. Silos were opened at intervals up to 96 days. Maize of 23·4% dry-matter content was ensiled in 10 t butyl rubber silos without additive or after the addition of urea at 1·0% or fishmeal at 4·0% of the crop dry-matter content.

Silages from the polythene bag silos were all well preserved. pH values increased and total acid content fell with increasing maturity of the crop. Addition of urea had little effect on these values. Only with the most mature crop did ammonia content increase markedly with increasing level of urea addition. All silages from the butyl rubber silos were well preserved with low pH values and similar total acid contents.

Silages from the butyl rubber silos were used to measure voluntary, intake live-weight gain and efficiency of utilization of young beef cattle. The diets fed were silage without nitrogen supplement or supplemented with urea or fishmeal, added at ensiling, at feeding or included in a concentrate feed. One third of the total dry-matter intake of all cattle was provided by a pelleted concentrate feed consisting of equal quantities of dried grass and rolled barley.

The increase in nitrogen content brought about by the addition of urea or fishmeal did not affect total dry-matter or organic-matter intake but was associated with 25% increase in nitrogen consumed. Live-weight gain on all treatments with added nitrogen was 20% higher than for the unsupplemented silage. This improvement in growth rate was accompanied by significant increases in efficiency of utilization of dietary dry matter and organic matter but efficiency of nitrogen utilization was reduced. The results indicate that neither the source nor site of addition of supplementary nitrogen significantly affect live-weight gain, dry-matter intake, organic-matter intake or utilization of dry matter or organic matter. They also demonstrate that urea can be used effectively to provide supplementary nitrogen to young cattle fed a maize silage-based ration.
Emergence of seedlings from different depths following high temperature stress
Authors: Onwueme I. C. , Adegoroye S. A.
Published: March 2009

Seeds of Amaranthus, melon, cowpea and tomato were planted in moist soil at 1, 4 or 7·5 cm depth and subjected to a heat stress of 45 °C for 10 h on the day of sowing (day 0), 1 day after sowing or 2 days after sowing. Seedling emergence was retarded by heat stress, the most drastic retardation being due to heat stress on day 1 for cowpea and tomato, day 2 for melon, and day 0 for Amaranthus. Emergence also decreased with increasing depth of sowing. The interaction of depth and heat stress was also significant in all cases, such that the delay in emergence due to heat stress tended to be greater with increasing depth of sowing. The agronomic significance of the results is discussed.
The exploitation of polyploidy in sugar-beet breeding
Authors: Hornsey K. G.
Published: March 2009

Tetraploid lines were produced from colchicine treatments of European multigerm diploid material, and seeded in polycross plots. The same lines were crossed with European multigerm diploids to give anisoploid varieties, and also used as pollinators of American male-sterile diploids to yield monogerm and multigerm triploid varieties. Bigerm triploids were obtained from male-sterile hybrids heterozygous for the monogerm character, using European multigerm O-types in the grandparental generation. Double-cross monogerm triploids were obtained by crossing male-sterile diploids with non-equivalent O-types to provide male-sterile hybrids, and pollinating these with outbred tetraploids.

Results from 35 root-yield trials showed that the sugar yields of the anisoploids and triploids were similar to those of contemporary commercial varieties, but that outbred tetraploids were slightly, and inbred tetraploids considerably, less productive. Changes induced in characters other than root weight by chromosome-doubling of diploid material were sometimes important, but not consistent in magnitude or direction. It is suggested that these changes result from selection and random drift rather than the ploidy change.

A seed-yield trial demonstrated advantages of using hybrid seed-parents for triploid seed production. Problems of seed quality are discussed with particular reference to triploid varieties.

It is concluded that the main importance of multigerm anisoploid varieties was in their combination of good sugar yield with near-monogerm fruit clusters at a time when commercial monogerm varieties were deficient in yield; the chief value of triploidy lay in its application to the short-term improvement of genetic monogerm varieties. The development of monogerm anisoploids is considered unlikely; but some advantages of deriving monogerm triploid varieties from tetraploid seed-parents are indicated, and it is suggested that these may become increasingly important in the future.
Manipulation of rumen fermentation in sheep by increasing the rate of flow of water from the rumen
Authors: Harrison D. G. , Beever D. E. , Thomson D. J. , Osbourn D. F.
Published: March 2009

The effects of an altered rumen dilution rate (D) upon the molar proportions of volatile fatty acids (VFA) in rumen liquor, VFA production rate, microbial protein synthesis and carbohydrate digestion within the rumen were studied using adult wether sheep.

Dilution rate and VFA proportions were unaltered by the infusion of up to 121 water/day into the rumen of sheep fed dried grass and concentrate (9:1). There was a small but significant (P< 0·05) increase in the rumen volume when the infusion rate was increased from 8 to 12 1/day.

The intraruminal infusion of artificial saliva (41/day), or artificial saliva containing 4% or 8% w/v polyethylene glycol (PEG) caused a significant increase in D with an associated decline in the molar proportion of propionate (Pr) in the rumen liquor. A similar effect was obtained with the intraruminal infusion of 2·5% w/v sodium bicarbonate. The overall regression of Pr on D was highly significant: Pr = 32·5–82·1D;r= –0·99, P < 0·001.

A diet of flaked maize: dried grass (6:4) was offered to three sheep each fitted with a rumen cannula and with a re-entrant cannula at the proximal duodenum. The intraruminal infusion (4 1/day) of artificial saliva containing 4% w/v PEG caused a significant (P< 0·01) increase in D and a significant (P< 0·01) depression in Pr in two animals. The dilution rate and Pr in the third animal were virtually unaltered by infusion. The regression of Pr on D for the three animals was highly significant: Pr = 34·8–136·8D; r = –0·98, P < 0·001. Each increase in D was associated with an increased flow of α-linked glucose polymer, total amino acids and total microbial amino acids into the small intestine and with an increased efficiency of microbial protein synthesis within the rumen.
Variability in number of pods and yield in commercial crops of vining peas (Pisum sativumL.)
Authors: Hardwick R. C. , Andrews D. J. , Hole C. C. , Salter P. J.
Published: March 2009

Data were collected from 218 commercial crops of vining peas (Pisum sativumcv. Dark Skinned Perfection) to test the hypothesis that variability between commercial crops in the yield of vining peas is associated with variation in the number of pods per plant. Yield varied widely between crops; the coefficient of variation of crop yield adjusted to tenderometer reading 105 was 25%. Only a small part of this variation could be accounted for by the correlation between yield and the estimated number of pods per plant (r= 0·067, 216 D.F.), and significance levels were not substantially improved by allowing for the effects of sowing date and plant density, or by using data on number of pods at each separate node in place of the overall totals per plant. Consequently the hypothesis stated above is not supported and it is suggested that variation in the weight of peas per pod was the main cause of variation in yield between crops.

A number of significant relationships were noted in the correlation analyses; (1) the mean number of pods per node at adjacent nodes tended to be positively correlated; (2) the number of pods per node at the first podding node tended to be positively correlated with plant density; (3) the numbers at the upper nodes tended to be negatively correlated with sowing date and with harvest date.
A study on the salt and sodium tolerance of rice
Authors: Bajwa M. S.
Published: March 2009

Although salt injury in plants is due to both osmotic and specific ion effects, little is known about the reaction of rice plants to salinity under increasing sodium adsorption ratios (SAR) in the growth medium. Therefore, a glasshouse experiment was conducted to study the effect of four levels of salt concentration (20, 40, 60 and 80 m-equiv/1 with respect to the sum of Na+, Ca2+ and Mg2+) and four levels of SAR (2, 25, 50 and 75) on growth and mineral composition of rice cvs IR 2153-26-3 and IR 26. The results show that as salt concentration increased, dry-matter yield and percentage water content of shoots decreased regardless of the variety. The rate of decline with salinity was most pronounced under low SAR and in the salt-sensitive variety IR 26. With increase in SAR, the yield, percentage water content and concentrations of Ca, Mg, and K in shoots and roots decreased, but the effects were more marked at the lowest salt concentration and in IR 26. Variety IR 2153-26-3 showed greater tolerance, maintaining a higher concentration of Ca and higher Ca/Na and K/Na ratios and a lower concentration of Na and Cl in the tops compared with IR 26.

The degree of salt injury in rice seems to depend not only on salt concentration but also on SAR in the growth medium whilst salt tolerance is associated with tolerance for both high salt concentration and high SAR. Therefore, in studies on screening rice varieties for salt and sodium tolerance, the interactive effects of SAR and salinity must be considered so as to ensure greater adaptability by the varieties recommended for salt-affected soils.
Symbiotic nitrogen fixation efficiency of mutant strains of lentil (Lens esculenta)Rhizobiumgrowing from pH 4·5 to 7·5
Authors: Rai R. , Prasad V. , Prasad T. N. , Kumar S. B. , Srivastava B. S.
Published: March 2009

A strain ofRhizobiumisolated from the root nodule of lentil was caused to produce mutants and screened on a medium of pH 4·5. Five mutant colonies ofRhizobiumwere isolated from lentil which differed in growth over a pH range 4·5–7·5. Strains differed in their growth in acidic and calcareous soils and also in their effectiveness of N fixation.
Protein synthesis in muscle of mature sheep
Authors: Bryant D. T. W. , Smith R. W.
Published: March 2009

Protein synthesis was measured in wether sheep by constant intravenous infusion of [3H]tyrosine. The specific radioactivity of plasma tyrosine at plateau was used to calculate tyrosine flux and the rate of protein synthesis in the whole body was estimated. For wethers fed hay and concentrates tyrosine flux was 2·46 mmol/h and protein synthesized was 5·29 g/kg body weight per day. Corresponding values for wethers fed barley straw were 30–35% lower.

Fractional rates of protein synthesis in individual muscles were between 2 and 3% per day for diaphragm, longissimus dorsi, gastrocnemius, semitendinosus and vastus lateralis muscles from wethers fed hay and concentrates, but the value for vastus intermedius was higher. Corresponding rates for wethers fed barley straw were 18–36% lower.
Changes in yield, protein, oil and maturity of groundnut cultivars with the application of sulphur fertilizers and fungicides
Authors: Laurence R. C. N. , Gibbons R. W. , Young C. T.
Published: March 2009

Fungicide applications in Malawi have shown improvements in groundnut kernel yield. Improved fertility of sulphur-deficient soils contributes to such gains when sulphur dust is used as the fungicidal agent. Application of sulphur alone to deficient soils lowered the oil/protein ratio of kernels, whereas a singular fungicidal effect raised the oil content, probably through delayed plant maturity.
Nutritional evaluation of kale (Brassica oleracea) diets:4. Responses to supplementation with synthetic S-methyl-L-cysteine sulphoxide (SMCO)
Authors: Barry T. N. , Manley T. R. , Millar K. R.
Published: March 2009

Synthetic SMCO was added to basal diets of either fresh kale or lucerne at the concentrations 0, 0·2, 0·4, 0·8 and 1·6% D.M. and each diet offered ad libitum to groups of four lambs that were individually fed indoors. Within each group, two lambs were of haemoglobin genotype AA and two were AB. Initial live weight (W) was 21 kg and the experiment lasted for 6 weeks.

SMCO supplementation depressed voluntary intake, body growth and wool growth, caused the development of haemolytic anaemia and produced kidney hypertrophy. Effects were much more severe when SMCO was added to a kale than to a lucerne diet, with the lowest SMCO intake of kale-fed lambs (0·3 g/kg W) producing marked detrimental effects whereas the highest SMCO intake of lucerne-fed lambs (0·7 g/kg W) produced only small and transient effects. The intake depressions were evident during the first week of SMCO supplementation and persisted throughout the full 6-week feeding period. Approximately 80 and 65% of the changes in body growth and wool growth could be accounted for by changes in intake, and it was concluded that the most important effect of SMCO in ruminant diets is as an intake depressant.

It is suggested that the greater ratio of soluble to structural carbohydrate in kale (2·3) compared with lucerne (0·9) probably resulted in a microbial population developing in the rumen of kale-fed sheep that could metabolize SMCO to dimethyl disulphide at a faster rate than occurred in the rumen of lucerne-fed sheep. Dimethyl disulphide production is postulated as the cause of both the haemolytic anaemia and appetite depression. Plasma SMCO concentrations did not increase with increasing SMCO intake in sheep fed either diet, indicating that there must have been negligible absorption of this amino acid from tho digestive system.

No haemoglobin C was produced by any of the lambs fed lucerne, and kale-fed lambs produced significant amounts only during weeks 5 and 6, with type AA lambs producing more than type AB lambs. However, there was no difference between AA and AB lambs in rate of decline in total haemoglobin concentration or upon voluntary intake, body growth and wool growth.
Seasonal variation in some characteristics of ejaculated spermatozoa of Sudan Desert sheep in the tropics
Authors: Galil K. A. A. , Galil A. K. A.
Published: March 2009

The Sudan Desert sheep are well adapted to the hot tropical climate, are thirst tolerant and can travel for long distances under nomadic conditions in search of water and pasturage. The ejaculate volume, sperm cell concentration, total number of sperms per ejaculate, motility, percentage live and percentage abnormal spermatozoa and the fructolytic index of semen were estimated throughout the hot dry summer (March-June), hot rainy season (July-October) and the winter (November-February). The semen characteristics were normal for about 7 months (May-November) covering the last 2 months in summer, the whole rainy season and the 1st month in winter and deteriorated slightly during the rest of the winter and early summer. Thus the Sudan Desert rams appear to be able to breed throughout the year and their spermatogenesis is not seriously affected by high environmental temperatures.
The effect of seed treatment and seed covering medium on the establishment of crisp lettuce
Authors: Wurr D. C. E. , Fellows Jane R. , Gray D.
Published: March 2009

Three experiments examined the effects on seedling emergence and seedling weight of covering pelleted, natural and pre-germinated seeds of the variety Pennlake with soil and other media.

Covering seeds with a peat-vermiculite mix gave significantly greater, earlier and more uniform emergence and seedlings with a lower coefficient of variation (c.v.) of weight than covering with soil.

Seedlings from pre-germinated seeds emerged more rapidly than those from natural and pelleted seeds and tended to be heavier when harvested 24 or 41 days after emergence. However, natural seeds consistently gave more uniform emergence than the other seed treatments and the lowest c.v. of seedling weight.
Validation of intake estimates in grazing beef cattle
Authors: Moir K. W. , Ebersohn J. P. , Evans J.
Published: March 2009

Growing beef cattle grazed six pasture types (all-grass or grass-legume mixtures) for 4 months on each. Live weight (mean of ten animals) and dietary energy concentration were measured at 2- or 3-weekly intervals. Values for feed intake estimated by back-calculating from feeding standards were on average 2·5% higher (range, 10% less to 12 % higher) than intake values estimated directly from dietary energy concentration and live weight. In contrast to this level of agreement of means, differences between methods within pastures were so large as to suggest the presence of overriding effects on predictors of voluntary intake. It was concluded that until these overriding effects are explained, there are no means of validating measured intakes in grazing cattle, or of accurately predicting the amount of beef produced from pasture.
Age at puberty and possibility of early breeding in Awassi ewes
Authors: Younis A. A. , El-Gaboory I. A. , El-Tawil E. A. , El-Shobokshy A. S.
Published: March 2009

Sixty-four weaned Awassi ewe lambs were used in the present study to estimate age at puberty and to investigate whether early breeding from such ewe lambs is possible. After weaning at 4 months old ewe lambs were divided at random into two experimental groups. One group, designated as moderate, was fed to attain 40 kg live weight at 12 months of age, while the other (high) was planned to reach 50 kg at the same age. Fertile rams were run with the ewe lambs at 6 months of age. Twenty ewe lambs, 10 from each treatment, were slaughtered and their ovaries were examined for the presence of corpora lutea and largest follicles.

The overall age at first oestrus was found to be 293 days. Ewe lambs of the high nutritional treatment reached puberty earlier than those of the moderate one (274 v. 312 days). Likewise, single-born lambs reached puberty earlier than twin-born ones (273 v. 312 days). Treatment differences explained 16·5% while type of birth explained 16·3% of the total variance in age at first oestrus. Ewe lambs of the high nutritional treatment experienced more heats than those of the moderate one. Simple correlation coefficients between age at first oestrus and date of birth, daily gain and live weight at puberty were 0·21, 0·09 and 0·75, respectively. Results indicated that ovulation may not occur during the first and second oestrus. From 44 ewe lambs only 12, 10 from the moderate and 2 from the high treatment, lambed 13 viable lambs. Reasons for such a low conception rate (27·3%) are discussed.
Endogenous faecal loss of phosphorus in growing lambs and the calculation of phosphorus requirements
Authors: Braithwaite G. D.
Published: March 2009

The endogenous faecal loss of P has been investigated in growing lambs given diets either grossly deficient, moderately deficient or just adequate in P. This loss was found to increase in direct relation to the increased P intake, in spite of the high P requirements of the deficient animals, which suggests that some increased loss with increased P intake is inevitable. Results throw doubt on the validity of the assumption made by the Agricultural Research Council (1980) in their calculations of P requirements, that the endogenous faecal loss of P is maintained at a constant level equal to that which occurs at zero P intake, until requirements are met.

Even on the diet which was, according to Agricultural Research Council (1980) recommendations, just adequate in P, lambs were unable to retain the expected amount of P commensurate with their growth. This inability to retain P was not due to a failure of P absorption, since the efficiency of absorption from this diet was higher than the value used by the Agricultural Research Council (1980) in their calculations. Rather, it must have been due to an inevitable endogenous faecal loss of P that was considerably higher than the value assumed by the Agricultural Research Council (1980).

It is suggested that in future the value of endogenous faecal loss used in calculations of P requirements is the minimum one that allows a particular requirement to be achieved.
Responses of Yield, Components of Yield and Nutrient Content of Maize to Soil-Applied Zinc in Tropical Rainforest and Savannah Regions
Authors: Kayode G. O.
Published: March 2009

Results of a 2-year studyin the rainforest and savannah zones of Nigeria todetermine the responses of yield, components of yield and nutrient content of maize to soilapplied zinc showed that Zn significantly increased yield in the new and old savannah soils, whereas significant yield response was recorded only in an old field of the forest zone. Ear weight was the only yield component significantly influenced by Zn treatments in the two zones. Application of 2·5 kg Zn/ha appears adequate for successful maize production in the savannah and old forest zones in the tropics.

Soil-applied Zn significantly increased ear-leaf N and Zn, but P concentration was significantly decreased. Grain yield was positively correlated with ear-leaf Zn.