bluuebunny/crossref_metadata_2025 huggingface dataset:
Results from experiments measuring the residues of nitrogen fertilizer given for sugar beet, and of ploughed-in sugar beet tops, on the yield of following barley
Authors: Widdowson F. V.
Published: March 2009

Five sugar beet experiments were made from 1964 to 1968 to measure yields of roots, of sugar and of tops from dressings of 0, 63, 126 or 188 kg N/ha. In 1964 and 1965 the sugar-beet tops were ploughed-in on all plots, but afterwards on only half of the total number of plots. Barley followed the sugar beet and was given 0, 41, 83 or 126 kg N/ha, in all combinations with the dressings of N to the sugar beet; grain was weighed and analysed for % N.

The maximum yield of sugar (8·24 t/ha) was with 126 kg N/ha. The yield of barley was increased greatly by giving it 83 kg N/ha, but not with more. When the barley was not given N, the residues of 126 kg N/ha for sugar beet increased grain yields by 0·17 t/ha, where the tops were carted away, and by 0·77 t/ha, where the tops were ploughed-in, but when the barley was given 83 kg N/ha, the residues increased yield negligibly (by 0·07 t/ha). Together the two sources of residue were equivalent to giving about 30 kg N/ha to the barley. Percentage N to the grain was consistently increased by both kinds of residue, but the grain never recovered more than 10 kg N/ha from them. So, sugar-beet tops had little residual value for barley, but offer a largely unused source of animal feed, rich in N.
Miscible displacement of reactive solutes in saline-sodic soils under varying flow conditions
Authors: Dahiya I. S. , Abrol I. P. , Hajrasuliha S.
Published: March 2009

The paper reports a laboratory study on miscible displacement of reactive solutes during leaching a highly saline-sodic soil rich in soluble sodium carbonate with solutions of calcium chloride. The effect of varying flow velocities, initial soil moisture content and concentration of calcium in the leaching water on the extent of carbonate precipitation and replacement of sodium by calcium from the exchange positions was studied in soil columns. The results showed that precipitation of soluble carbonates in the soil increased with increasing flow velocity, initial soil moisture content and concentration of calcium in the leaching solution. The results further showed that the calcium exchange capacity of the soil was reduced significantly and nearly proportionally with decrease in the degree of water saturation as a consequence of decreased water application rate and initial soil moisture content. In view of the results obtained, a simple model to describe calcium-sodium exchange under unsaturated flow conditions in saline-sodic soils under consideration has been proposed. Possible implications of the results in actual field situations is discussed.
Copper in diets for growing pigs
Authors: Braude R. , Hosking Zena D.
Published: March 2009

Twenty-eight centres participated in two co-ordinated trials to obtain further evidence on responses of growing pigs (20–86 kg) to different levels of copper sulphate (CuSO4. 5H2O) supplementation, and on effect of lowering the amount of copper in the ‘finishing’ diet. The levels of copper supplied were 141, 232 and 276 mg Cu/kg diet in the ‘starting’ diet in trial 1 and 125, 200 and 250 in the ‘starting’ diets continuing or reducing to 125 mg Cu/kg diet in the ‘finishing’ diets in trial 2. The results varied to such an extent that no definite conclusion could be drawn, but there was a tendency to support rather than dispute the accumulated evidence in world literature that the most effective levels of copper supplementation are from 200 to 250 mg/kg diet throughout the growing period.
The effects of nitrogen upon three stiff-strawed winter wheat varieties
Authors: Widdowson F. V.
Published: March 2009

Eleven winter wheat experiments were carried out from 1955–57, to compare the effects of nitrogen on three stiff-strawed varieties of winter wheat, Heine 7, Hybrid 46 and Minister. In 1955 the experiments tested ‘Nitro-Chalk’ top-dressings at rates supplying 0·45, 0·90 and 1·35 cwt. N/acre. In addition, drilled dressings supplying 0·15 cwt. N/acre were supplemented with either 0·30 or 0·75 cwt. N/acre as a top-dressing.

In the 1956 and 1957 experiments ‘Nitro-Chalk’ top-dressings were applied at 0·60 and 1·20 cwt. N/acre. In addition, divided dressings were compared by supplementing 0·15 cwt. N/acre by combine-drill with 0·45 cwt. N top-dressing.

Significant increases in yield were obtained from the first increment of nitrogen in twenty-three of the thirty-three available comparisons. There were significant additional gains from the second increment of nitrogen in only seven of the same comparisons. Responses to nitrogen varied considerably between seasons. Large and consistent responses were obtained at all centres in 1955 and dressings supplying 0·9 cwt. N/acre were well worthwhile. In 1956 responses were generally smaller and dressings in excess of 0·6 cwt. N/acre could only be justified at two centres. Mean responses in 1957 were lower than those obtained in either of the previous season and 0·6 cwt. N/acre was sufficient for maximum yields at three of the four centres.

There was little advantage in dividing dressings of nitrogen between autumn and spring in any of the experiments and none of the differences reached significance. On average, higher yields were obtained by retaining the whole of the nitrogen until the spring, than by applying part of the dressing in autumn by combine-drill.

Comparisons between the varieties show that Hybrid 46 was the only variety which was able to take consistent advantage of the heaviest rates of manuring. In each year Hybrid 46 produced the highest percentage increase in yield and Minister the lowest. In addition Hybrid 46 contained the highest percentage of nitrogen in the grain when averaged over each level of manuring. The percentage recovery of nitrogen was calculated for each year and each variety. Comparisons of this data show that Hybrid 46 converted more of the fertilizer nitrogen into grain or crude protein than either of the other two varieties. The experiments provide evidence that there are considerable variations in the efficiency with which present-day winter wheat varieties can utilize nitrogen, and that varieties with both high fertilizer efficiency and high unmanured yields are likely to increase the level of crop production.
The early weaning of pigs VI. The effects of early weaning and of various growth curves before 50 lb. live weight upon subsequent performance and carcass quality
Authors: Lucas I. A. M. , Calder A. F. C. , Smith H.
Published: March 2009

The experiment involved nine litters, each containing four male and female pairs of pigs. At about 10 days of age the four pairs within each litter were randomized one to each of the following treatments. (1) Pigs left with their dams, weaned at 56 days old and then fed ad lib. until they each weighed 50 lb. (2) Pigs weaned at 10 days old and fed ad lib. until they each weighed 50 lb. (3) Pigs weaned at 10 days old, given restricted feed allowances so that they weighed 30 lb. at 56 days old, then fed ad lib. until they each weighed 50 lb. (4) Pigs weaned at 10 days old and given restricted feed allowances so that they weighed 30 lb. at 56 days old and 50 lb. at 90 days old. Between 50 lb. and slaughter at 205 lb. all pigs were kept to the same very high plane of feeding, which was based on live weight. All pigs were individually fed from weaning onwards.
The use of progesterone and serum gonadotrophin (P.M.S.) in the control of fertility in sheep. I. The hormonal augmentation of fertility in the ewe during the breeding season
Authors: Gordon I.
Published: March 2009

1. Over four breeding seasons (1952–6) field trials, involving a total of 2504 treated and control ewes of nine breeds (Romney, Clun, Suffolk, Cheviot, Lincoln, Welsh Mountain, Ryeland, Southdown and Hampshire) were conducted in an attempt to increase flock fertility by injections of p.m.s. hormone. The hormone employed was in three forms of preparation: purified, freeze-dried and whole serum. Dosage levels from 250 to 1000 i.u. were injected subcutaneously.

2. There is no evidence that the treatment affected the ability of the ewe to conceive.

3. A significant increase in fertility was induced by treatment. The extent of the increase apparently depended on the dosage level and form of p.m.s. employed, and was found to be affected by the normal fertility status of the sheep undergoing treatment. At any given dosage level of p.m.s. the increases induced by treatment were greatest where flock fertility was very low.

4. When used at comparable dosage levels, whole serum tended to be more effective in inducing superfertility than freeze-dried or purified serum. Freezedried serum tended to be more effective than purified serum.

5. 1047 injected sheep that conceived to service at the treatment oestrus produced 1898 lambs (1·81 lambs per ewe); 997 control ewes that conceived at the same time produced 1506 (1·51 lambs per ewe).
Effect of dose of Gronolone in intravaginal sponges on lambing outcome to fixed-time artificial insemination
Authors: Smith P. A. , Boland M. P. , Gordon I.
Published: March 2009

Research has shown that it is now possible to control the oestrous cycle of ewes with a high degree of precision (Robinson et al. 1967; Gordon, 1975; Boland, Kelleher & Gordon, 1978). There is general agreement that a high concentration of progestagen, followed by rapid withdrawal and adequate ovarian stimulation is necessary for acceptable fertility (Robinson et al. 1967; Gordon, 1975; Colas, 1975). Application of artificial insemination in France has involved the use of a 40–45 mg Cronolone sponge (Cognie, Mariana & Thimonier, 1970; Colas et al. 1973) while controlled breeding in sheep in Ireland has been used in conjunction with a 30 mg Cronolone pessary (Gordon, 1975; Smith, Boland & Gordon, 1978, 1981). The present experiment was designed to compare the relative effectiveness of two doses of Cronolone (30 or 45 mg) when administered in conjunction with two quantities(375 or 750 i.u.) of pregnant mare serum gonadotrophin (PMSG), given by intramuscular injection.
Maternal influences on litter size in pigs
Authors: King J. W. B. , Young G. B.
Published: March 2009

The effects of inbreeding of the sow and plane of nutrition after mating on litter size at 28 days were investigated.

Outbred Large White sows were mated at first heat after weaning to inbred boars, and inbred sows to outbred boars, so that both groups of sows carried the same type of embryo. The sows were then placed at random on either high or low planes of nutrition until slaughter 28 days later, when their corpora lutea and number of embryos were counted.

Litter size was significantly higher in outbred than in inbred sows by 2·52 ± 0·93 pigs. This resulted from 2·89 ± 0·94 more ova shed and 0·37 ± 0·93 more embryos dying. The general conclusion is that inbreeding of the sow reduces early litter size mainly by depressing ovulation rate.

The different planes of nutrition produced negligible differences in within-litter mortality and, therefore, on litter size, but resulted in a marked difference in conception rate. All animals on the high plane were pregnant, whereas on the low plane 25% were empty, this difference being highly significant.

Age of the sow, but not her weight, was found to be significantly correlated with number of corpora lutea (r = 0·39). The latter had a correlation with litter size of 0·55 and with mortality of 0·45. The correlation between litter size and mortality was −0·50.

Parity increased and inbreeding reduced the length of the uterus which was not, however, significantly correlated with litter size.
Factors affecting birth weight of Holstein-Friesian calves in Western Nigeria
Authors: Adeneye J. A. , Bamiduro T. A. , Adenbanjo Adetowun K. , Akinyemi A. A.
Published: March 2009

The birth weight of Friesian and Holstein calves in Western Nigeria was generally lower than that recorded in other tropical countries. This was attributed to a low plane of nutrition during pregnancy and a consequent reduction in length of gestation of the dams. On average, pure-bred Friesian, pure-bred Holstein and Holstein x Friesian calves weighed 29·1, 30·8 and 30·7 kg respectively at birth. Male and female Friesian, Holstein and cross-bred calves averagely weighed 29·9 and 28·2 kg, 29·9 and 31·7 kg, and 32·6 and 28·8 kg respectively. Both the sex differences and breed x sex interaction were not significant.

Positive correlation coefficients of 0·45, 0·38 and 0·26 found between calf birth weight and gestation length for the Friesians (P < 0·05), Holsteins (P < 0·01) and their crosses (P > 0·05) respectively suggest that gestation length had a significant effect on Friesian and Holstein calf birth weight. In many cases, parturition occurred 8–16 days earlier than expected.

Calves born during the rainy season (April–September) were approximately 10% heavier at birth than those born during the dry season (October–March). The heaviest calves were born during the second half (July–September) of the rainy season. The breed x sex x season of calving interaction was significant for the Holstein breed (P < 0·05). Holstein male calves born during the rainy season were significantly (P <; 0·05) heavier than those born during the dry season. Friesian dams with three or more parities and Holstein dams that were 3 years old and above produced calves that were significantly (P < 0·01) heavier at birth than calves of younger dams.
The growth and carcass characteristics of crosses of Hereford and Friesian with Angoni, Barotse and Boran cattle in Zambia
Authors: Thorpe W. , Cruickshank D. K. R. , Thompson R.
Published: March 2009

Seven hundred and fifty purebred Angoni, Barotse and Boran cattle and their crosses sired by Friesian and Hereford bulls were compared for live-weight and carcass characters in Zambia. The cattle were born between September and December in three consecutive years and were reared on unimproved veld. In the first year all females and a random half of the males received supplementary feed in winter and the males were slaughtered at 2·5 years of age. The remaining males received the same total amount of winter supplementary feed prior to slaughter at 3·0 years of age. The males born in the second year were pen fed for a period prior to slaughter at 3·0 years of age. Males born in the third year were slaughtered at 3·5 years of age and received no supplementary feed.

Genotype differences were important at all live weights and there were year of birth x genotype interactions at the 0·5, 1·0 and 1·5 year weights and a genotype × feed treatment interaction at the 2×0 year weight. Boran purebreds were heavier than the Angoni and Barotse purebreds; at 3·0 years the differences were +42·3 kg ( + 12·9%) and + 25·2 kg (+ 7·7 %) respectively. Cross-breds had heavier live weights than their corresponding purebreds with Boran crosses consistently heavier than the Angoni and Barotse crosses. The Friesian and Hereford sired Boran cross-breds were + 51·0 kg (+13·5 %) and + 43·0 kg (+ 11·6 %) heavier respectively than the purebred Borans at 3·0 years of age.

There were large differences between the genotypes for all carcass characters with Borans having heavier carcasses than the Angonis and Barotses by + 20·3 kg (+ 10·6 %) and + 19·1 kg ( + 10·0%) respectively. The average carcass weight advantages of Friesian and Hereford crosses with the Angoni, Barotse and Boran breeds over the corresponding purebreds were + 40·3 kg ( + 19·0%), + 33·6 kg ( + 16·2%) and + 31·0 kg ( + 14·0%) respectively. There were few important carcass differences between the corresponding Friesian and Hereford crosses.

The mortality rate during the experiment was 8·2% with only small differences between genotypes.

The interactions found in the experiment indicated that breed comparisons should be conducted over a number of years and at various management levels. For growth and carcass production under the conditions of the experiment the use of exotic crossbreds is clearly advantageous.
Lysine and nitrogen measurement by infra-red reflectance analysis as an aid to barley breeding
Authors: Gill A. A. , Starr Carol , Smith D. B.
Published: March 2009

The feasibility of measuring lysine and protein nitrogen in barley using an infra-red reflectance analyser was examined. This is a very rapid technique, requiring no manipulative skills, and measuring several components simultaneously using milled grains. The results show that this instrument is sensitive to changes in lysine and protein nitrogen and can be calibrated to measure these components to a high degree of accuracy. It is shown that the gross morphological and biochemical abnormalities of high lysine mutants do not affect these measurements, indicating that this method is suitable for the rapid screening of material from breeding programmes designed to improve the lysine content of barley proteins.
Observations on the occasional depressing influence of fish meal on the hatchability of hens' eggs
Authors: Coles R.
Published: March 2009

The failure of a high proportion of fertile eggs to hatch still remains a major cause of financial loss to the poultry industry. Payne (1919) pointed out the consistent manner in which embryonic mortality manifested peak periods at the fourth day and the nineteenth day of incubation, and he drew attention to the fact that the latter period of susoeptibility showed an increased level of mortality with artificial incubation compared with natural methods. Romanoff (1949) summarized the explanations put forward to account for these two peaks of embryonic mortality. Riddle (1930) suggested that the first period was caused by respiratory maladjustments, and he, and others, considered that the failure of the developing embryo to make the fine adjustments at this time and to deal effectively with the excretion of various toxic substances may be a major cause of death. The second peak period of mortality occurs at the transition from allantoic to pulmonary respiration. Failure to achieve this change, with the consequent death of the chick in the last stages of development, may be greatly influenced by the cumulative effect of all the unfavourable conditions to which the hatching egg has been subjected. Not the least of these will be environmental conditions in the incubator and the incubator house adversely affecting the oxygen supply and the relative humidity.
Artificial cooling of buffaloes (Bubalus bubalis) in a hot environment, and plasma oxytocin concentration
Authors: Sharma A. K. , Gangwar P. C. , Srivastava R. K. , Dhingra D. P.
Published: March 2009

Nine normal lactating Murrah buffaloes from the Punjab Agricultural University Dairy herd were used to assess the effect of showers and evaporative cooling on plasma oxytocin concentration, let-down time, milking time and milk yield in buffaloes. The animals were showered four times daily between 10.30 and 16.30 h or provided with evaporative cooling from 07.00 to 21.00 h. In the hot and dry period the oxytocin concentration in buffaloes given a shower was significantly greater than that of the buffaloes of the control group. In the hot and humid period there was a similar trend.

It is concluded from these studies, that cooling may increase the effective milk ejection reflex because the milk-ejection response to a given blood oxytocin concentration is different when the animal is heat stressed from when it is cooled.
Competition and the superparasitism of Spodoptera littoralis (Boisd.) larvae by Microplitis rufiventris Kok.
Authors: Hegazi E. M. , Shabaan M. A.
Published: March 2009

An experiment to compare the effect of diverse ratios of 0–6 h old Microplitis rufiventris Kok. progeny within Spodoptera littoralis (Boisd.) larvae is described and the results discusssed. Five to 21% of parasite progeny was eliminated during the egg stage. Surplus parasite larvae were eliminated mainly by physical attack, physiological suppression and perhaps by encapsulation. Parasite larvae which escaped competition during their first instar were subjected to physiological suppression. Some of the super-numerary parasite larvae other than the winners survived competition mechanisms and developed in the host haemocoele. Nevertheless, most of these parasites suffered from moulting failure and emergence problems at the end of their endoparasitic development. The development of the winning parasite was retarded by 1–2 days during its egg-larval stage while the duration of its pupal stage was about the same as parasites from singly parasitized hosts.
Triple test cross analysis in first backcross populations of four wheat crosses
Authors: Singh S. , Singh R. B.
Published: March 2009

The triple test cross analysis (Kearsey & Jinks, 1968; Jinks & Perkins, 1970) was used to detect and estimate the additive, dominance and epistatic components of genetic variation for four metric traits, namely, final plant height, number of spikelets per spike, 100-kernel weight and yield per plant, in the first backcross populations of four wheat crosses (Norteno 67 α Moti, Sonalika α Moti, Kalyan Sona α Sonalika and Kalyan Sona × NP 876). Epistasis was a more important component of variation for final plant height and yield per plant than for number of spikelets per spike and 100-kernel weight. On the other hand, the additive component was highly significant for all four characters in all eight backcrosses.
Calcium and phosphorus balances with laying birds
Authors: Tyler Cyril , Willcox James Stuart
Published: March 2009

1. A series of balance experiments to compare calcium carbonate, calcium sulphate and calcium gluconate as sources of calcium for laying hens is described.

2. Not one of the three supplements showed all-round superiority, but calcium sulphate was the worst.

3. The main results indicate that:

(a) Calcium sulphate and gluconate cause scouring but carbonate does not.

(b) The best retention of calcium occurs with gluconate and the worst with sulphate.

(c) Calcium carbonate gives the best shells and calcium sulphate the worst.

4. The experiments also throw fresh light on some more general aspects of calcium and phosphorus metabolism.

5. On the basis of these general results and a review of the literature of blood calcium and phosphorus in laying hens a theory dealing with certain aspects of egg-shell formation is presented.
Observations on the value of whale-meat meal as a constituent of chick diets, with a note on the influence of added protein on the efficiency of utilization of the gross energy of a ration
Authors: Halnan E. T.
Published: March 2009

1. A method of assessing the biological values of proteins by the slaughter method, using day-old chicks as experimental material, is outlined.

2. Whale-meat meal, when added to a cereal basal ration, is shown to possess a high biological value for chicks.

3. The method of preparation of animal proteins is shown to affect their nutritive value, whale meat dried at a low temperature giving better results than that dried at a high temperature.

4. The nature and amount of a protein added to a cereal ration materially affects the efficiency of utilization of the gross energy of the ration. Arising therefrom, support is given to the system of expressing the nutritive value of feeding stuffs, and the nutritive requirements of animals, in terms of digestible protein and digestible nutrients or metabolizable energy.

5. Outbreaks of feather picking in the whale-meat meal groups occurred, whereas none occurred in the basal group. A possible explanation for these outbreaks is given in the text.

6. The presence of gizzard erosion was noted in all individuals in the whale-meat meal groups, whereas none occurred in the basal group.
Studies in soil cultivation: X. The results of a six-year cultivation experiment
Authors: Russell E. W. , Keen B. A.
Published: March 2009

1. The results of a six-year cultivation rotation experiment are given. The rotation used was wheat-mangolds-barley and the seed-beds for these were prepared either by ploughing, using a rotary cultivator or a tractor-drawn grubber.

2. The yields of these crops were barely influenced by the depth of ploughing, a 4 in. depth giving throughout the six years just about the same yield as an 8 in. depth. The mangold crop was possibly a little larger on the deeper ploughed plots.

3. The mean yields of the seed-beds prepared with the tractor drawn grubber or cultivator followed by harrows etc. were lower than the ploughed seed-beds for all the crops, and this was particularly so on those seed-beds prepared by only one grubbing down to 4 in. depth.

4. The mean yields on the seed-beds prepared by the rototiller were lower than on the ploughed seed-beds for wheat and mangolds. If the seed-bed was prepared by rototillage to a depth of 8 in. by going over the land twice, the yield of barley was the same as on the ploughed seed-beds, but was definitely less on the seed-bed rototilled only once to 4 in.

5. Seed-beds prepared by the rototiller or grubber have only a small residual effect on the crop yields in the following year.

6. It is concluded that the primary function of ploughing is weed control, and that it is only advisable to omit ploughing either if the land is already fairly clean or if the crop will be hoed very early on in its development.

7. For wheat and mangolds differences in weed infestation of the seed-bed were probably of greater importance than differences in tilth in so far as the crop yield was concerned. The reverse may have been true for barley.
Further investigations on artificial insemination of cattle
Authors: Anderson J.
Published: March 2009

An account is given of artificial insemination of 733 grade cows in Kenya from January 1936 to August 1939. 76·8% of the cows inseminated calved, with an average of 1·88 inseminations per conception. The different doses and dilution of sperm used gave very similar results, as did two inseminations, compared with one insemination, in a single heat period.
The composition of different kinds of silage
Authors: Smith A. M. , Comrie A.
Published: March 2009

The chemical composition of eight samples of fresh material and ninety-one samples of different kinds of silage has been determined. The crude protein varied from about 10 to 20 %. Judging by the appearance and edibility of the material, the silage samples made by the A.I.V. process were almost uniformly good. TheirpH values were mainly between 3·5 and 3·8, and they contained less volatile acids and volatile bases than the other silages, and showed the highest proportions of lactic to acetic acid and amino-acids to volatile bases. The results as a whole show a fairly close agreement betweenpH., volatile acids and volatile bases, but attention is directed to the possibility of anomalous figures when, through secondary changes, thepH value has risen to about 6 or 7.
Studies in soil cultivation: VII. The effect of cultivation on crop yield
Authors: Russell E. W. , Keen B. A.
Published: March 2009

1. Wheat, barley or mangolds gave nearly the same yield if grown on seed beds prepared by ploughing and harrowing, by using the grubber or cultivator and harrowing and by using the Rototiller, provided that the cultivators were used for one year only. If used for several years in succession deterioration of yield sometimes sets in, possibly due to the increased weediness of the non-ploughed plots.

2. There was no advantage in ploughing deeper than 4 in. but it is advantageous to use the grubber of Rototiller deeper.

3. The effect of cross-ploughing, subsoiling or heavy rolling the seed bed for spring-sown crops was without effect on the yield.

4. Spring rolling and harrowing improved the yield of winter wheat but had little effect on the yield of straw. Rolling alone may have produced a slightly increased yield of grain but it improved the straw yield while harrowing depressed the straw yield.

5. There was strong evidence that intensive hoeing of sugar-beet or kale is detrimental. Two to three hoeings appear to be ample.
The chemical composition of grass silage
Authors: Watson S. J. , Ferguson W. S.
Published: March 2009

A short account is given of the main changes which take place during the ensilage process. Details are given of the methods of analysis used in examining samples of silage for pH, crude-protein, volatile base, amino acid, lactic acid, total volatile acid, acetic acid and butyric acid contents. The results of the examination of 293 samples of silage are discussed. Of these 258 were made from grassland herbage, 24 from silage crops, 9 from sugar-beet tops, and 2 from potatoes. The silages were made in towers, wood-lined pits, and a small number in stacks or clamps. The samples are divided up into those made by the ordinary process, with added molasses, with added whey, with moderate amounts of mineral acid with or without molasses, and with mineral acids added in amounts sufficient to bring the mass rapidly to a pH of 3·0–4·0—the A.I.V. process.

For comparative purposes the silages made by these processes have been divided, within each process, into groups of varying pH. reaction.
The analysis of groups of experiments
Authors: Yates F. , Cochran W. G.
Published: March 2009

When a set of experiments involving the same or similar treatments is carried out at a number of places, or in a number of years, the results usually require comprehensive examination and summary. In general, each set of results must be considered on its merits, and it is not possible to lay down rules of procedure that will be applicable in all cases, but there are certain preliminary steps in the analysis which can be dealt with in general terms. These are discussed in the present paper and illustrated by actual examples. It is pointed out that the ordinary analysis of variance procedure suitable for dealing with the results of a single experiment may require modification, owing to lack of equality in the errors of the different experiments, and owing to non-homogeneity of the components of the interaction of treatments with places and times.
A critical survey of investigations on the “wilting coefficient” of soils
Authors: da Costa J. V. Botelho
Published: March 2009

The experiments of Briggs & Shantz led them to conclude that the “wilting coefficient” is a soil “constant” which is (a) independent of the kind of plant used as indicator, (b) independent of the conditions under which the plant was grown, and (c) directly related to several other soil constants.

Subsequent research as well as an examination of their own results has shown that (c) is untrue, while (a) and (b) are substantially correct for hygrophytes and mesophytes. Earlier writers have been led to wrong conclusions regarding (a) and (b) through assuming (c) to be correct and through disregarding the particular nature of “permanent wilting” as defined by Briggs & Shantz.

The fact that considerable variation is to be found between the osmotic pressure found in different plants, in different parts of the same plant and in the same part under different conditions is not at variance with conclusions (a) and (b) when properly understood.

An important factor making for the substantial constancy of the “wilting coefficient” for a given soil is the extreme steepness of the curve connecting suction pressure and soil moisture content, in consequence of which differences of suction pressure of unquestionable significance from the standpoint of plant physiology give rise to differences in soil moisture content that are too small to be detected.
The response of permanent grassland to nitrogen and the efficiency of its recovery
Authors: Gardner H. W.
Published: March 2009

Experiments over six years on the use of different kinds and amounts of nitrogenous fertilizers on small plots of permanent pasture are described and summarized.

Up to a level of 4·5 cwt. sulphate of ammonia per acre applied in February there was a proportionate response in dry matter production in April. Omitting the single year when scorching occurred, the average increase per cwt. of sulphate of ammonia applied was 2·3 cwt. dry matter with an additional 0·85 cwt. in the second (May) cut. The average recovery of the nitrogen applied in February was 35·9% in April, and 8·6% in May.

With nitrogen applied in June the response in dry matter production in July and September–October was similar, but the recovery varied widely with the varying effect of nitrogen on clover production. With heavy depression of clover, percentage recovery was low or negative.

On plots not receiving nitrogen the dry matter production for the whole year was at the rate of 1·92 cwt. per inch of rain reckoned on the harvest year (Oct.–Sept.). The largest variation from this was only 0·1 cwt.

For the whole year the response to nitrogen was greatest in the years of lowest rainfall.

The nitrogen applied in February considerably increased the protein in the “grasses” at the first cut, and to a small extent in the second cut. For the third and fourth cut it is suggested that the protein differences are correlated with differences in amounts of clover.

For the first cut of the year “clovers” also show a much higher protein content on the nitrogen plots.
The Determination of the Surface Area of Swine and Other Animals (With Plates I and II and Three Text-figures.)
Authors: Deighton Thomas
Published: March 2009

The unsatisfactory nature of empirical formulae for the determination of surface area in metabolism work, especially with reference to pigs, is discussed, and the conclusion reached that the actual estimation of the area is the only satisfactory method where an accuracy greater than ± 10 per cent. is desired.

It is pointed out that surface area is to some extent variable in animals and that direct determinations are from this point of view less satisfactory than might have been thought.

A new method is proposed for estimating the surface area of a pig in a definite standing position depending on mathematical and photographic conditions only, and therefore applicable to the living animal, and to the same animal at different times during its life. Full sets of computations are given and one case is noted where the method affords a correct estimate as between two pigs where the formulae are all clearly wrong.
Estimates of phenotypic and genetic parameters of some measures of efficiency of milk production in buffaloes
Authors: Bhalaru S. S. , Dhillon J. S.
Published: March 2009

The least-squares means for first lactation milk yield, yield per 100 kg of body weight at first calving, yield per day of first lactation length, yield per day of first calving interval and yield per day of age at second calving were 1692 ± 28·2, 339·8 ± 7·30, 5·51 ± 0·97, 3·37 ± 0·81 and 1·07 ± 0·03 kg and the heritabilities of those traits were 0·192 ± 0·086, 0·078 ± 0·078, 0·287 ± 0·096, 0·192 ± 0·086 and 0·305 ± 0·097 respectively. The genetic correlations of first lactation milk yield with various measures of efficiency of milk production (except with yield per 100 kg of body weight) were positive and high (> 0·80). These results indicate that milk yield per day of age at second calving may be used for the selection of buffaloes.
Effects of potassium and magnesium fertilizers on yield and size distribution of potatoes
Authors: Simpson K. , Crooks P. , McIntosh S.
Published: March 2009

Thirteen field experiments were made during 6 years on seed-potato growing farms in south-east Scotland, comparing three rates, 70, 140 and 280 kg K/ha as potassium chloride and four rates of 0–54 kg Mg/ha as kieserite in 3 × 4 factorial experiments.

More than 70 kg/ha of potassium increased total yield only at one site, which had a recent history of low K application and very low available K. Yields were decreased by more than 70 kg/ha of potassium at three sites in a season with abnormally dry conditions just after planting. Applied magnesium had little effect on total yield.

Extra potassium increased ware yield but decreased seed yield, both consistently, probably because the fertilizer damaged some stolons at or before tuber initiation and fewer tubers developed. The ware/seed ratio was generally increased by extra K, but after the dry spring this ratio was unaltered or reduced. Applied magnesium had little effect on the ratio.

Our results suggest that the present rates of K fertilizer, used for commercial seed-potato crops (114–138 kg K/ha) in south-east Scotland are excessive, and a much lower rate of approximately 70 kg K/ha would be adequate except on very low K sites.
Effects of reproduction in sheep on the rate of cell division and nucleic acid content of the ruminal mucosa
Authors: Moon Susan J. , Campbell Rosa M.
Published: March 2009

The weight of the ruminal mucosa of breeding Blackface ewes and its total DNA and RNA content rose after parturition to reach a peak at 45 days post partum. There were no constant significant changes with time in the concentration of the nucleic acids.

It was found that there was a positive correlation between the amount of food eaten during the final week of life and the weight of the ruminal mucosa and the length of ruminal papillae. The mitotic index of the ruminal epithelial cells was very variable but most of the higher values occurred between 7 and 80 days post partum. The mitotic index could not be correlated with the amount of food eaten in the week before slaughter, but high values were not recorded when the food intake of lactating ewes was restricted to that of non-breeding controls. It is suggested that the most likely explanation for these findings is that in the ruminal epithelium of lactating ewes fed to appetite, oell division occurred in waves or bursts.

Hyperkeratosis of the ruminal epithelium occurred in pregnant and control animals but regressed during lactation and reappeared in the post-weaning period. The inverse relationship between the hyperkeratosis and the rate of cell division is of great interest when considering the aetiology of ruminal disease.
Effects of restrictions of energy, protein or both on growth and body composition of pigs
Authors: Carden A. E. , Goenaga P. R.
Published: March 2009

An experiment was carried out, using Duroc Jersey barrows, to test the hypothesis that relationships within the pig fat-free carcass remain unaltered when varying the principal dietary factors: energy, protein or both. Twelve pigs were assigned to each of the following diets: high energy-high protein (HEHP), used as control group; low energy-high protein (LEHP); high energy-low protein (HELP) and low energy-low protein (LELP). From 30 kg live weight onwards the animals were individually penned and fed once a day the experimental rations, on a restricted scale of feeding related to live weight. Compared with the control group, daily intake of metabolizable energy was approximately 37% lower in LEHP and LELP groups while daily protein intake was approximately 25% lower in HELP and LELP groups.

In each group the 12 pigs were slaughtered between 60 and 110 kg. The right half carcasses were completely dissected using strictly anatomical criteria. The main growth characteristics of the four treatments were described by second degree polynomials fitted to the live weight-age data. Each treatment produced a characteristic growth curve. In every case significant differences were found in the polynomial coefficients. Data on body composition were subjected to analysis of covariance, using the linear model y = a + bx. When growth of different parts of a whole were studied the weight of that whole was used as the independent variable. When muscle:bone ratio was examined the weight of total side muscle was used as covariate in the covariance analysis for total side bone.

The major treatment effects were on the relationship between fat and non-fat tissues in the carcass. Thus, in relation to dissected side weight, HELP animals had more fat and less muscle and bone than controls, while LEHP and LELP pigs had more muscle and bone and less adipose tissue. Within the fat-free carcass several differences were found on muscle weight distribution. LEHP, HELP and LELP pigs had a higher proportion of ‘expensive muscles’. However, the magnitude of these changes was small and likely to be of little commercial importance. On the other hand, only minor differences were found in bone weight distribution. These were confined to the scapula and femur. Muscle:bone ratio was not affected by the treatments. Within the adipose tissue differences were observed in growth rates from the different depots relative to total side fat. Thus, it would appear that the growth rate of the subcutaneous depot was higher and that of the intermuscular one lower in LEHP and LELP animals. The body cavity depot was less in these animals.
Relation between hot-water-soluble boron and uptake of boron by cacao (Theobroma cacao L.) in Nigeria
Authors: Chude V. O.
Published: March 2009

Boron (B) nutrition problems of cacao (Theobroma cacao L.) in Nigeria deserve continuous attention in view of the fact that more cocoa-growing areas showing B deficiency are being brought to light. Omotoso (1975) examined plant tissue B and B extractable by hot water in relation to the appearance of B deficiency symptoms on cacao leaves and found that B deficiency symptoms had no direct relation to hot-water-soluble (HWS) B in the Nigerian soils studied. Omotoso (1975) then suggested further investigations to identify soil properties that can improve the capacity of HWS B to predict cacao uptake of B.
Inoculation of irrigated soya bean in the Sudan Gezira
Authors: Mukhtar N. O. , Naib Sayda A. Abu
Published: March 2009

Soya bean variety Semmes failed to nodulate with a number of R.japonicum strains. Some of these were applied to the seed in a carrier based on Nile silt.

A three-strain composite in peat gave good nodulation and reasonable N fixation. Inoculation significantly outyielded 100 kg N/ha added as urea in three equal portions at sowing, 1 and 2 months after sowing. Plant dry matter, nodule dry matter, yield, yield components and seed protein were also significantly enhanced by inoculation.

Phosphorus applied at 50 and 100 kg P2O5/ha in combination with a starter dose of nitrogen (10 kg/ha) with inoculation both gave erratic and inconclusive results.
Productivity and yield stability in cassava (Manihot esculenta) as affected by stake weight
Authors: Okeke J. E.
Published: March 2009

The influence of weight of stakes planted on subsequent cassava yields and the stability of yields was investigated in a 4-year study (1986–90) in Nigeria using two cultivars (TMS30572 and TMS91934). Harvest yields were dependent on the weight of stakes planted and an optimum weight of 875 kg/ha for both cultivars was established; which corresponds to an average stake weight of 88 g. Cultivar TMS30572 consistently outyielded TMS91934 (P <0·05). Tissue analysis of 25 cm long stakes from the mainstem and from the primary and secondary branches of both cassava cultivars showed differences in the amounts of food reserves stored in the stakes. More carbohydrate was found in each of the three stakes of the mainstem than in the stakes from the primary and secondary branches of both cultivars. The yields of each cultivar for the three growing seasons did not vary significantly, which suggests that sustainable high root yield appears to be achievable and is greatly aided by the appropriate management of the stakes.
Nitrogen management of potatoes in the presence of farmyard manure and PK fertilizer on acid hill soil of Shimla
Authors: Sharma R. C.
Published: March 2009

A field experiment was conducted on acid soil of Kufri (Shimla) from 1980 to 1982 to study the effect of 30 t farmyard manure/ha (FYM) and 88 kg P + 160 kg K/ha (PK) on the response of potatoes to N fertilizer and on soil properties. There was a highly significant response of potato to N and the response was greater in the presence of PK than in the presence of FYM. The dose of N for maximum tuber yield with PK (39·9 t/ha) was 194 kg/ha, whereas for maximum yield with FYM (33·2 t/ha) it was 128 kg/ha. FYM met the P and K needs of potato when 100 kg N/ha was applied but not when 180 kg N/ha was applied. N fertilizer increased N concentration but decreased P and K concentration in leaves and tubers. The concentration of P and K was higher but that of N was lower with PK than with FYM. N fertilizer enhanced the uptake of P and K but its effect was not significant with FYM.

After 3 years of treatment FYM improved organic carbon, total N and NO3 status of the soil. N as calcium ammonium nitrate increased organic carbon in the presence of PK but decreased it in the presence of FYM. N fertilizer had little effect on total N, NO3 and available P content. N application depleted available K and the depletion was proportionate to the rate of N applied. The application of FYM and PK increased available P and K content of the soil and the increase was more with PK than with FYM.
Leaf development in eight related grasses
Authors: Gao Y. , Wilman D.
Published: March 2009

Leaf development was studied in eight related grasses, grown in field swards cut at 5-week intervals, during the year of sowing and the subsequent year (1989 and 1990). The rate of leaf expansion was in the order Westerwolds ryegrass > Italian ryegrass (Lolium multiflorum), Italian ryegrass × meadow fescue > hybrid ryegrass > perennial ryegrass × meadow fescue, meadow fescue (Festuca pratensis), tall fescue (Festuca arundinacea) and perennial ryegrass (Lolium perenne). The order of grasses was similar, but not identical, for rate of leaf appearance, rate of leaf extension, weight of leaf blade emerging per shoot per week and rate of increase in length of exposed leaf sheath, and the order was approximately the reverse for weight per unit area of emerging leaf blade. The area per leaf blade increased greatly between May and October of the year of sowing, particularly in Westerwolds, Italian and hybrid ryegrasses and Italian ryegrass × meadow fescue. Area per leaf blade in tall fescue increased greatly between May and July of the year of sowing and May–July of the subsequent year. Rate of leaf expansion in meadow fescue was much higher in May of the year after sowing than in the previous May.
Effect of selection for glucose tolerance in sheep on carcass fat and plasma glucose, urea and insulin
Authors: Francis S. M. , Bickerstaffe R. , Clarke J. N. , O'Connell D. , Hurford A. P.
Published: March 2009

Over 5 years (1987–91), the progeny of rams selected for fast (Low T-half) or slow (High T-half) glucose clearance after an intravenous glucose tolerance test, differed significantly in glucose tolerance. In comparison with an unselected control, the line differences were mainly in the direction of Low T-half. They appear to have arisen during the establishment period, with little evidence of enhanced divergence over the four subsequent years of continued selection (heritability 0·10±0·03). The Low line had higher plasma insulin concentrations during the glucose tolerance test than the High line. Basal plasma concentrations of glucose were lower, and urea higher in the Low than the High line. In addition, carcasses of Low line ram progeny had more subcutaneous fat at the same carcass weight than High line carcasses (11% higher GR in the final year of the experiment). Selection of sheep for glucose clearance appeared to be associated with differential partitioning of nutrients into adipose tissue, the pooled genetic correlation between T-half and GR being −0·28±0·13.