bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies in grazing behaviour of dairy cattle: II. Bloat in relation to grazing behaviour
Authors: Hancock John
Published: March 2009

1. Four trials on methods of bloat-prevention vare described: (a) A comparison of ‘break’ grazing and normal ‘rotational’ grazing without restriction of feed in either case. Break grazing observations covered two and five breaks per day.

(b) A comparison of these two systems where ‘break’ grazing involved restriction of area available to the cows, and ‘breaks’ varied from seven to eleven per day.

(c) Comparison of ‘off and on’ grazing with normal rotational methods in an attempt to force changes in grazing pattern.

(d) Comparison of the same pasture grazed at different lengths under rotational grazing methods.

2. Grazing behaviour and degree of bloat were noted.

3. In general, the results showed that, irrespective of number of breaks, break grazing with or without restriction gave no effective control of bloat.

4. There were definite indications that a strictly enforced system of ‘off and on’ grazing could afford considerable practical control.

5. Long feed proved definitely safer than feed of the same botanical composition grazed at shorter stages of growth.

6. It was found that cows on potentially dangerous grass had short grazing times with few periods of intense activity. Thus, the oft-stated opinion that bloat is caused by cows eating greedily of dangerous pastures was not substantiated. On the contrary, cows on such pasture showed marked reluctance in their grazing activity.

7. Bloat-producing swards were also associated with reduced rumination time, even in respect to cows showing no symptoms. Bloated cows showed generally very low rumination times.

8. Many of these observations were made on identical twins. From the similarity in their behaviour, it can be concluded that inheritance is an important factor affecting the occurrence of bloat amongst cows grazing the same herbage.

9. In the early stages of bloat, ruminal movement and belching increased in frequency and intensity. This is contrary to the theory that bloat is due to rumen atony. Atony was observed only in the advanced stages of the trouble.
The pollination requirements of swede rape (Brassica napus L.) and of turnip rape (Brassica campestris L.)
Authors: Williams Ingrid H.
Published: March 2009

The pollination requirements of eight cultivars of swede rape (Brassica napus) and two of turnip rape (Brassica campestris) grown in a glasshouse, were compared. Cultivars differed in the number of pods, and of seeds per pod set by auto-pollination. Cultivars of turnip rape yielded more when cross-pollinated than when self-pollinated by hand but those of swede rape did not, although additional pollination of swede rape increased the set of early flowers. Inadequate pollination probably limits yield in self-fertile cultivars of swede rape that auto-pollinate poorly and in turnip rape cultivars that are nearly self-sterile.
Oestrogenic activity of fresh, wilted, dried and fermented berseem (Trifolium alexandrinum)
Authors: Shehata M. N. , Hassan Adel , El-Shazly K. , Yassen A. M.
Published: March 2009

An investigation was carried out to detect and evaluate the oestrogenic activity of three successive cuts of Egyptian clover berseem (Tifolium alexandrinum). Changes in oestrogenic activity due to wilting, drying and fermentation were also studied.

Oestrogenic activity was higher (P < 0·01) in first-cut berseem (49–6 ug diethylstilbestrol equivalency (DES)/kg D.M.) than in the second (38·2 ug) and the third cuts (36·1 ug), and was decreased in the three successive cuts by wilting and dehydrating to 88% D.M. It was greater (P < 0·01) in the wilted berseem than the dried material of the second cut. Oestrogenic activity was increased (P < 0·05) in all cuts by fermentation, but it was higher (P < 0·01) in the fermented second cut than the other cuts.

An intake of 10 kg D.M. of silage would be equivalent to 0·98 mg DES, which have no adverse effects on production and reproduction.
The reproductive performance of Border Leicester ewes in contrasting photoperiodic environments
Authors: Williams H. Ll. , Thwaites C. J.
Published: March 2009

Border Leicester ewes were kept in three contrasting photoperiodic environments, the rhythm at latitude 30° 32′ S (group 1) - 12 h light: 12 h dark interrupted by 6 weeks of continuous light (group 2a) and 12 h light: 12 h dark (group 2b) - from August 1972 to September 1973. In group 1 all ewes exhibited oestrus compared with 87·5% and 57·1% in groups 2(a) and 2(b) respectively. The mean number of oestrous periods per ewe ranged from 4·4 in group 1 to 3·0 in group 2(a) and 1·0 in group 2(b). It is concluded that the non-fluctuating light rhythm had an adverse effect on the reproductive potential of the treated groups and that Border Leicester ewes are dependent on a fluctuating light rhythm for normal reproductive function.
Nutrient indexing of lowland rice crop in Ludhiana
Authors: Arora C. L. , Hundal H. S. , Takkar P. N.
Published: March 2009

A nutrient indexing survey of the soils and rice crop was conducted on 300 fields of four villages in some floodplain areas of Ludhiana. The soils are, in general, alkaline in reaction, highly calcareous, medium in organic matter and mostly heavy in texture. Soil analysis (DTPA extraction) indicated that about 27% are deficient in available zinc. Leaf analysis indicated the concentration of N, Zn, Cu, Fe and B to be below their critical levels in 27, 25, 93, 39 and 6% of the samples respectively: the low levels of Cu(l–3 μg/g) are considered as a ‘hidden hunger’ as the crop lacked any visual Cudeficiency symptoms.

Correlation studies indicated the absence of any relationship between the micronutrient status of the soils, assessed by DTPA extraction, and leaf content. Consequently leaf analysis is recommended for evaluating the nutritional disorders of lowland rice.
Control of flowering in two commercial sugar-cane varieties
Authors: El Manhaly M. A. , Fadayomi O. , Abayomi Y. A. , Olofinboba M. O.
Published: March 2009

Experiments were conducted over two cropping seasons at the Sugar Cane Estate of the Nigerian Sugar Company, Bacita, Nigeria to determine the effectiveness of additional nitrogen fertilizer, chemical sprays and delayed planting in controlling flowering in two commercial sugar-cane varieties (Co. 1001 andCp. 29/116). Application of 150 and 250 kg N/ha, 8 weeks before initiation, reduced flowering in Co. 1001 by up to 13·5 and 11 % respectively. Flowering was as low as 2% in some of the above treatments while the average flowering in plots with no additional nitrogen application was more than 80%. imilarly, application of diuron (4·0 kg/ha) and paraquat (0'5 kg/ha) to the top leaves (3 weeks before initiation) of Co. 1001 reduced flowering in this variety up to 45 and 35% respectively. Neither the application of diuron and paraquat nor additional nitrogen fertilizer sufficiently reduced flowering in Cp. 29/116. The time of planting affected flowering. Over 85% flowering was observed in November 1982 from Co. 1001 fields planted in January 1982 (10 months before initiation time). However, fields of the same variety planted in June 1982 (4 months before initiation time) did not show any initiation until harvest in May 1983. The implications of the above results are discussed.
The effect of pH on the relative proportions of ruminal volatile fatty acids in sheep sustained by intragastric infusions
Authors: Macleod N. A. , Ørskov E. R. , Atkinson T.
Published: March 2009

Rumen pH was varied and controlled over the range 5·2–7·1 by manipulating the infusions of buffer solution to the rumen and by using an automated system of recording pH. The total concentrations of volatile fatty acids (VFA) in the rumen were not altered by changes in pH but there were changes in the relative proportions of VFA. As the pH of rumen liquor fell, the proportion of acetic acid increased, and the proportions of propionic and butyric acids decreased relative to their respective proportions in the infusate. At rumen pH of about 7·2 the molar proportions found were similar to the molar proportions infused while at pH 5·3 the molar proportion for acetic acid in the rumen was 100 mmol/mol higher than in the infusate. There was no apparent relationship between osmotic pressure and differences between VFA proportions in the infusates and in the rumen liquor.
Growth and muscle development of steers implanted with hexoestrol
Authors: Everitt G. C. , Carter A. H.
Published: March 2009

A muscle biopsy technique was employed in an experiment designed to assess the effects of hexoestrol implantation on 2-year-old and 6-year-old Aberdeen Angus steers under New Zealand grazing conditions. This paper reports the results concerning live-weight gains, carcass weights and detailed analyses of samples of m. semitendinosus and associated subcutaneous fat.

There was some evidence of an adverse effect of the biopsy operation on the older, less tractable, animals, despite the observation of no apparent effect of repeated muscle biopsies in a preliminary trial with sheep.

Hexoestrol implantation, of four 15 mg. pellets for the 2-year-old steers and six 15 mg. pellets for the 6-year-olds, led to significant increases in live weight gains during the later part of the trial only, and reduced the dressing-out percentage of the younger animals. Although there were indications of a positive response in carcass weight to hexoestrol implantation, it was concluded that, under the conditions of this experiment, implantation of relatively large dosages was not economically justified in terms of increased meat production.

Absorption of the implanted pellets varied from 42 to 85% of the total dosage, but evidenced little association with live weight changes.

Deposition of subcutaneous fat appeared to be reduced under the hormone treatment, but the responses in this respect of the 6-year-old steers were highly variable.
The Vitamin D3 requirement of pullet chicks: the relative values of genuine and a sample of controlled cod-liver oil in feeding poultry up to the age of 16 weeks
Authors: Wright M. D.
Published: March 2009

Calcification on 1% of controlled cod-liver oil was less satisfactory than on 1% of genuine cod-liver oil as judged by radiography at 5 weeks old. Growth rates were not significantly different.

⅔ of 1% of the genuine cod-liver oil promoted calcification as satisfactorily as (and significantly better on one diet than) 1% of controlled oil. The mean tarso-metatarsal distances on ⅔ of 1% of controlled oil were too wide for the calcification to be regarded as normal. It has thus been shown that satisfactory growth is no criteria of adequate calcification and bone structure.

From the age of 6—16 weeks, ⅔ of 1% of controlled cod-liver oil mixture was not adequate, as demonstrated by radiographic examination, for optimal calcification; but using the criteria of naked eye examination and weight, no significant difference would have been found between genuine cod-liver oil and the controlled mixture. These birds showing subnormal calcification could not be expected to stand up well to the strain of laying, which puts heavy demands upon the calcium metabolism.
The relationship between grass N yield and the total N supply to cut grass-white clover swards
Authors: Hobson R. D. , Richards I. R.
Published: March 2009

A relationship between grass N yield and total N supply was derived using data from experiments on grass-white clover swards. This relationship was very similar to that found previously using a larger pool of data from clover-free grass swards. The quantity of N released underground by the clover was estimated to be around 50% of the annual N yield in clover herbage. This is a much lower estimate than that reported by earlier workers.
Relationships between certain carcass measurements, weights of wholesale joints and sample joint composition of Hereford cross-bred steers
Authors: Tayler J. C. , Rudman J. E. , Kemp C. D.
Published: March 2009

1. In a population of Hereford crossbred steers carcass conformation was measured by weighing wholesale joints cut in London and Home Counties fashion and dissecting a single rib sample joint. Correlations were calculated between weight of joints and certain linear carcass measurements.

2. Weights of individual joints in a group of good cuts were studied in relation to carcass composition estimated from sample joint dissection. Carcass fatness at constant carcass weight was correlated positively with some joints and negatively with others. A thigh width measurement was related to the weight of these joints in a similar fashion. This accounted for the low value of thigh width as an index of the proportion of good cuts.

3. The weights of joints, and many of the measurements, were highly correlated with carcass weight. When carcass weight was allowed for, partial correlations were too low to support the use of linear measurements to predict weight of joints in individual carcasses.
Effect of the ingestion of wood shavings on magnesium and calcium utilization by milk-fed calves
Authors: Smith R. H.
Published: March 2009

1. The amounts of wood shavings eaten by a group of unmuzzled calves allowed unlimited access to the shavings but fed otherwise only on milk were estimated by a lignin ratio technique. The amounts increased to a mean value of about 250 g. dry weight/day at 13–14 weeks of age.

2. Although a marked decrease in net magnesium absorption from the diet occurred with age in a group of efficiently muzzled milk-fed calves the mean decrease was not as great as that in the group of unmuzzled calves when the latter were eating considerable amounts of wood shavings. Data are presented which show that the difference is accountable by the excretion in the faeces of some of the magnesium in the increased flow of endogenous fluid from the rumen (probably mainly saliva) in the unmuzzled calves. The results suggest that many milk-fed calves (assuming about 11–12 mg./100 ml. magnesium in the milk) will resist hypomagnesaemia for at least 5 months but only if they are effectively prevented from chewing foreign matter. This may partly account for previously observed variations in. the ages at which calves develop hypomagnesaemia.

3. Net calcium absorption from the diet decreased with age in both the muzzled and unmuzzled groups of calves but again to a greater extent in the unmuzzled group. The difference was much greater than could be accounted for by increased loss of endogenous calcium due to greater saliva production in the unmuzzled calves. It appeared that the shavings contained a factor (not phytate) which interfered with calcium utilization. It is suggested that the factor might act by inhibiting the action of vitamin D.
A comparative study of fleece growth in Tasmanian Fine Merino and Wiltshire Horn ewes
Authors: Slee J. , Carter H. B.
Published: March 2009

1. From repeated fibre samplings and several skin biopsies on six Tasmanian Fine Merinos and eight Wiltshire Horn adult ewes variations in fibre diameter, fibre growth rate, and fibre regeneration or shedding frequency were measured over a period of 15 months. Slight differences were present in the treatment of the two breeds, but from the combined evidence of the live weights and fibre diameters maintained, it was concluded that these were negligible, that both breeds were under closely comparable conditions, and that their performance was at a moderately high and typical level for each breed.

2. In the Merinos fibre diameter (ca. 20 µ) fluctuated little during the period of observation, whereas in the Wiltshires it varied over a wide range from less than 40µ in winter to more than 80µ in summer. There were negligible differences between the three body regions, back, side, and belly, in the Merinos, but in the Wiltshires the belly grew markedly coarser fibres than the other two regions.

3. The fibre growth rate in the Merinos did not vary greatly from 7 to 8 mm. per 28 days throughout the period of observation or between the body regions. In the Wiltshires, fibre growth rate showed extreme variations from a minimum of about 3 mm. during the winter to a maximum of about 12 mm. per 28 days at the end of summer, with significant differences between the three body regions. However, in spite of these differences in the mode of growth, the total length of fibre grown per annum at the midside was approximately the same (10 cm.). Thus, were it not for fibre shedding, the Wiltshire Horn breed would grow a short-wool fleece.
Magnesium in forage plants. II. Magnesium distribution in grasses and clovers
Authors: Todd J. R.
Published: March 2009

1. A procedure for fractionating the magnesium in fresh herbage into acetone-soluble, watersoluble and insoluble magnesium fractions is described.

2. Magnesium soluble in Analar acetone is shown to be virtually identical to chlorophyll magnesium, and generally represents less than 10% of the total magnesium.

3. Water-soluble material represents about 25% of the total dry matter, but contains more than 50% of the total magnesium when the herbage contains 0·2% or more Mg in the dry matter.

4. The fibrous material, which is soluble neither in acetone nor water, constitutes about two-thirds of the total dry matter, but has only about onethird of the total magnesium associated with it.

5. Highly significant correlations were found between total magnesium content and each of the three fractions, but regression coefficients showed that variations in total magnesium were largely reflected in the water-soluble fraction, the chlorophyll and fibre magnesium being affected to a much smaller degree.

6. Attention is drawn to the fact that at levels of pasture magnesium at which hypomagnesaemic tetany occurs in ruminants, water-soluble magnesium ceases to be the largest fraction and may be only about one-third of the total.
Studies on the efficiency of mating in the sheep II. The effect of freedom of rams, paddock size, and age of ewes
Authors: Lindsay D. R. , Robinson T. J.
Published: March 2009

A factorial experiment is described in which thirty-six aged and thirty-six maiden spayed crossbred ewes were used in four successive tests at intervals of 15 days in a study of factors affecting the detection of oestrus. Variates introduced into each test were: (a) freedom of rams (free or tethered); (b) size of mating paddock (17 acres or ⅕ acre); (c) age of ewe (maiden or aged); and (d) dose of oestrogen (oestradiol benzoate, ODB: 10·0, 15·6, 24·4 μg.).

All ewes were primed with progesterone for 12 days prior to ODB injection and joining. The number of ewes detected in oestrus and the number and identity of rams which served each ewe were recorded.

In the four successive tests 29, 33, 36 and 30 ewes were served.

Significant main effects were: (a) freedom of rams—free 77, tethered, 51 (P < 0·001); (b) size of mating paddock—17 acres 49, ⅕ acre 79 (P < 0·001); (c) age of ewes—aged 57, maiden 71 (P < 0·05); and (d) dose of ODB—10·0 μg., 20; 15·6 μg., 41; 24·4 μg., 67 (P < 0·001).

Significant interactions were: (a) test number × age (P = 0·01), and (b) test number × dose of ODB (P < 0·05). The number of maiden ewes served increased and that of aged ewes decreased withsuccessive tests. There was a barely significant ohange in the slope of the ODB D/R line.

Ewes showed no obvious preference for tethered rams of any particular breed. There was a positive correlation between the performance of rams when free and tethered.
Some carcass characteristics of commercial quality cattle in Mexico
Authors: Butterworth M. H. , García E. , Aguirre E. L.
Published: March 2009

Little is known about the carcass characteristics of unimproved commercial (or ‘Criollo’) cattle although these still account for a large proportion of slaughter animals in Latin America.

Data were collected from 52 commercial cattle in a commercial slaughterhouse in Monterrey, N.L. Mexico. They included carcass weight, length, total edible meat (carcass fat was negligible), total bone and eleven typical Mexican cuts whose anatomical relations are described. The age of the animals was judged according to dentition and data were stratified using this criterion for analysis. Variations in total edible meat, which averaged 77·4%, were almost entirely accounted for by differences in body weight. Data are presented to indicate amounts of various cuts in the carcasses and some significant differences were demonstrated in values for these cuts among age groups; possible explanations for this were discussed. Prediction equations were calculated to relate total edible meat with the selected cuts and carcass weight and it was found that carcass weight gave the best prediction of total edible meat and could also be used to predict expected weights of individual joints with reasonable accuracy.
Some effects of seed size and spacing on the yield and grading of two maincrop potato varieties: I. Final yield and its relationship to plant population
Authors: Wurr D. C. E.
Published: March 2009

Two experiments, which investigated the effect of three seed sizes and three withinrow spacings on the graded yield of the two early maincrop varieties Pentland Crown and Maris Piper, are described and the results discussed.

Relationships were established between yields in various grades and stem population, and are used to explain the response of yield to changes in seed size and spacing. Comparisons between any two levels of the same treatment were affected by the size grade in which they were made. In addition, the tendency towards interactions between variety and seed size and between variety and spacing suggests that comparisons between varieties are affected by the populations at which these comparisons are made.
The metabolism of glucose, acetate, lipids and amino acids in lactating dairy cows
Authors: Bickerstaffe R. , Annison E. F. , Linzell J. L.
Published: March 2009

Specialized techniques, previously used in surgically prepared goats, which simultaneously measure udder metabolism (arteriovenous difference of milk precursors x udder blood flow) and the whole body turnover of the milk precursors, have been successfully transferred to dairy cows. Methods of obtaining representative samples of arterial and mammary venous blood and of measuring udder blood flow are described.

The rates of entry into the circulation, as determined by isotope dilution, of glucose, acetate and plasma free fatty acids were 3·3–4·0, 1·7–2·1 and 0·5 kg/day respectively. Acetate and glucose contributed 32–50 and 4–11% respectively of the total CO2output by the animal.

Measurement of the uptake of precursors of milk constituents and their transfer into milk showed that there were substantial arteriovenous differences of glucose, acetate, triglyceride and β-hydroxybutyrate which were not significantly different between breeds or related to milk yield. Isotopic and balance data confirm that glucose is the main precursor of lactose and that the oxidation and transfer of glucose into lactose accounted for 69–98% of the glucose entry rate. As in the goat, plasma triglycerides and blood acetate accounted for 35–80% and 25–50% of the milk triglycerides respectively. Propionate was extracted from plasma but the uptake was only about 8% of the value for acetate.

There was no net arteriovenous difference of phospholipids, cholesterol esters or free fatty acids, but the fall in specific radioactivity of free fatty acids across the mammary gland indicated there was an exchange of free fatty acids between plasma and mammary tissue. In agreement with previous findings, acetate contributed to all the milk fatty acids up to a chain length of C14and part of the C16fatty acid. Plasma triglycerides contributed to the remainder of the C16 fatty acid and all the milk fatty acids with a chain length of C18or higher.

In contrast to the lactating goat, cow plasma contained very few chylomicrons. The majority of the triglycerides taken up by the udder were derived from the lowdensity lipoprotein fraction.

The essential amino acids were extracted from blood in amounts sufficient to account for the essential amino acids secreted into milk protein. Although the plasma level of methionine was low, 52–72% of the material reaching the mammary gland was taken up. The uptake of arginine was far in excess of the requirement for milk protein synthesis.
The effect of certain seed treatments on dormancy and emergence in groundnuts
Authors: Nur I. M. , Gasim A. A. E.
Published: March 2009

Two experiments were made in each of the seasons 1971/72 and 1972/73 to determine the effect of seed treatment on groundnut emergence.

In one of the experiments, groundnut seed germinated at a faster rate when the seed was dressed with Aldrex T at 2·2 g/kg of seed.

In the other experiment, no difference in emergence was found between varieties whether planting was on the same day as shelling or 12 weeks after shelling.
The effect of winter and spring sowing on the grain composition of oat varieties
Authors: Welch R. W.
Published: March 2009

Six spring varieties of oats were sown in a glasshouse in winter and in spring. The grain was analysed for oil, protein and kernel content and 1000-grain weight, and the maturation period was measured.

Oil content varied from 2·4 to 7·9% and protein content from 7·9 to 16·3%. Varietal differences in oil content between varieties were recognized and these were maintained at both sowing dates.

Winter sowing, in comparison with spring sowing, resulted in an increase in oil and kernel content and 1000-grain weight, and a decrease in protein content. The increased oil content was partly due to increased kernel content, while the decrease in protein content was partly due to changes in 1000-grain weight.

The maturation period was not affected by sowing date, but was positively correlated with oil content. Oil and protein content were not negatively correlated, and there were indications that it may be possible to select varieties which will produce grain high in both oil and protein.
The ‘teat order’ of suckling pigs: II. Fighting during suckling and the effects of clipping the eye teeth
Authors: Fraser D.
Published: March 2009

The development of stable suckling order, the incidence of fighting when suckling, weight gain during the suckling period, and the severity of facial wounding were studied with litters of piglets in which the canine and lateral incisor teeth were either clipped at birth or left intact. Facial wounding was largely confined to litters with unclipped teeth. Severity of wounding correlated with the observed incidence of fighting on the udder (P<0·01); and both wounding and fighting were more common among litters comprising a large number of piglets (P<0·05). When the effect of litter size was taken into account, there were no substantial differences in weight gain to 3 weeks between piglets with high and low scores for facial wounding, nor between clipped and unclipped litters. Piglets which habitually occupied the most anterior or most posterior teats had less facial wounding than middle-suckling piglets, and showed greater consistency in teat choice. No gross differences between clipped and unclipped litters were observed in the development of stable suckling order during the first week of life. It is concluded that the ‘eye’ teeth, although used in disputes over teat choice, have little influence on the frequency of such disputes or on the original development of stable suckling order.
Response of cotton to water and nitrogen in a tropical environment: II. Date of last watering and rate of application of nitrogen fertilizer
Authors: Hearn A. B.
Published: March 2009

Four rates of nitrogen fertilizer, three dates for the last application of water, and two varieties were combined factorially in two experiments in successive years. Leaf water potential was measured. There were large yield responses to water and nitrogen; in both cases the response in number of bolls was relatively twice as great as that in boll weight. Because one effect of nitrogen was to prolong the setting of bolls, which required continued watering for its full expression, there was an interaction between the nitrogen and water treatments which affected number of bolls, and thus yield. Deltapine 16 yielded more than Acala 1517BRI and responded more to nitrogen than did Acala 1517BRI. Heavy nitrogen rates decreased the initial rates of boll setting of Acala. Weekly picks of open bolls showed that, with early cessation of water and with the lightest rate of nitrogen, the boll weight decreased in the fourth and subsequent picks. This effect of nitrogen was more marked in Acala. These responses were analysed into the components of boll weight and are discussed in relation to the timing of the development of the bolls in order to explore the physiological implications. Nitrogen and water delayed harvest by prolonging effective flowering, by increasing boll maturation period, and by increasing the number of defoliant sprays required.
A note on the effect of genotype, density and row width on the yield and quality of forage maize
Authors: Phipps R. H.
Published: March 2009

The results are presented from a factorial experiment on the effects of genotype (Julia, Inra 200 and Caldera 535), density (4·9, 11·0 and 16·7 plants/m2) and row width (70 and 35 cm) on the quantity and quality of maize produced 136 days after emergence.

The later maturing the variety, the higher was the dry matter yield, but the lower was the dry matter percentage. There was little advantage in favour of the high density when compared with the medium density, while row width did not markedly affect the production character measured. Both density and variety significantly influenced the ripe ear. The dried grain/ear for the low, medium and high densities was 111, 89 and 74 g respectively. However, at the highest density nitrogen content, dry matter digestibility and digestible organic matter in the dry matter were all slightly reduced. With the exception of magnesium, the mineral contents showed similar trends.
Studies on the Carbon and nitrogen cycles in the Soil. IV. Natural and artificial humic acids
Authors: Toit M. M. S. Du , Page H. J.
Published: March 2009

The preparation of natural humic acids from soil, peat (Dopplerite) and “Adco,” and of artificial “humic” acids from sucrose, cellulose, dextrose and glycine (Maillard), furfural, hydroquinone and lignin, and their purification is described.

Their elementary composition and their behaviour under conductometric titration with ammonia have been studied. The artificial products from sucrose and furfural did not behave as acids, but all the natural products, and the artificial products from cellulose, hydroquinone and lignin possessed the properties of colloidal acids.

Preliminary investigations into the “humification” of furfural and ω-hydroxymethyl furfural, and into the interaction of dextrose with amino bodies, are described.
The effect of dietary energy concentration on protein utilization during late pregnancy in ewes
Authors: Guada J. A. , Robinson J. J. , Fraser C.
Published: March 2009

From 62 days of gestation to parturition, 20 Finnish Landrace x Dorset Horn ewes were each offered one of four diets with roughage to concentrate ratios of 20:80; 40:60; 60:40 and 80:20, at daily metabolizable energy and digestible crude protein intakes of 490 kJ and 3·55 g/kg W0·75respectively. Plasma concentration of free fatty acids, glucose and urea were determined weekly, and nitrogen balance and digestibility trials were carried out at 70–80 and 130–140 days of gestation.

On all treatments the concentration of plasma free fatty acids increased during pregnancy from approximately 200–600 μ-equiv./l and the concentration of glucose and urea decreased by approximately 25%.

Digestibility coefficients for dry matter and organic matter increased from 58 to 68% and from 60 to 70% respectively as the proportion of concentrates in the diet increased and were not affected by stage of gestation. The apparent digestibility of nitrogen was not affected by the energy concentration of the diet.

Between mid and late gestation there was a mean increase in daily nitrogen retention of 2·5 g and an improvement in the efficiency of nitrogen utilization of 19 percentage units.

Nitrogen retention and the efficiency with which the apparently digested nitrogen intake was retained increased as the dietary energy concentration was increased. The mean daily increases in nitrogen retention were 0·0135 and 0·0039 g for each percentage unit increase in the concentrate portion of the diet at mid and late gestation respectively. The corresponding values for the improvement in the efficiency of nitrogen utilization were 0·13 and 0·10%.
Nitrogen, phosphorus and potassium fertilizers for potatoes in Cyprus
Authors: Krentos V. D. , Orphanos P. I.
Published: March 2009

A number of experiments to test the effects of N and P fertilizers and a few testing K fertilizer were carried out mainly with Arran Banner and Up-to-Date potatoes in the major potato-growing area of Cyprus (Kokkinoohoria). The optimum nitrogen rate, all applied at planting in January-February, was 60–120 kg N/ha with yields reaching 50 t/ha. Phosphorus increased yields in only 4 out of 21 trials. In two of these cases the soil contained 8 mg bicarbonate-extractable P/kg soil or less. In the other two cases the soil contained 34 and 56 mg P/kg but irrigation was erratic. In only one experiment where soil potassium was depleted to 222 mg exchangeable K/kg through continuous cropping with irrigated crops, without potassium fertilizer, was a clear response to K fertilizer obtained; this, however, is the first response to K fertilizer by any crop reported in a plain area of Cyprus.

Concentration of NO2·N in the petiole of the first mature leaf from the top sampled at 80 days from planting under the 120 kg N/ha rate, beyond which seldom were yields increased, was about 0·5%. In the only experiment where a response to K was obtained, concentration of K in entire leaves sampled as above was about 2·5%.

It is argued that since growers in this area have used heavy dressings of P and K over recent years, they will seldom get any benefit from applying more than a maintenance dose of 70 kg P and 150 kg K/ha to the potato crop. It is suggested that since in semiarid regions leaching is limited, soil tests of NO3content can aid farmers in choosing the optimum amount of N fertilizer for each crop.
The engulfment and digestion of mixed rumen bacteria and individual bacterial species by single and mixed species of rumen ciliate protozoa grownin vivo
Authors: Coleman G. S. , Sandford Deborah C.
Published: March 2009

Five species of rumen ciliate protozoa, isolated from sheep in which they were the only ciliate protozoon, and mixed rumen ciliates were incubated with labelled bacteria and the rate of uptake and digestion of the bacteria was followed. Evidence is presented that mixed rumen bacteria labelled by incubation with14C-isoleucine,14C-guanine or35S-sulphate were engulfed more rapidly by the protozoa than those labelled with14C-glucose but that, withEntodiniumspp. at least, this apparent lower rate of uptake was associated with an increased rate of digestion. The rate of uptake of mixed rumen bacteria (at 109/ml) varied from 230 to 2670 bacteria/protozoon per hour, depending on the protozoal species, and increased with increasing bacterial population density. Starvation of the protozoa decreased the initial rate of uptake of bacteria by up to 60% and the length of time over which the protozoa would engulf bacteria.Entodiniumspp. andEpidinium ecaudatum caudatumengulfed fewer bacteria when these bacteria were prepared from the same sheep as the protozoa than when they were prepared from sheep with no or other protozoal populations. Of the protozoa tested, onlyEntodiniumspp. and the mixed large rumen protozoa digested mixed rumen bacteria,Eremoplastron bovisandEpidinium ecaudatum caudatumbeing inactive. It is suggested that previous estimates of the rate of uptake and digestion of bacteria based on studiesin vitrowere too high.

The non-rumen bacteriaEschericfoia coliandKlebsiella aerogenesand the rumen bacteriumMegasphaera elsdeniiwere not or only poorly taken up by the protozoa.Entodiniumspp. selectively engulfed bacteria of rumen origin and digested two cellulolytic bacteria rapidly. In contrast,Eremplastron bovisengulfed these cellulolytio bacteria more slowly than other bacteria.Entodiniumspp. and the large rumen protozoa digested more bacterial species than the other protozoa butButyrivibrio fibrisolvenswas digested more rapidly than other bacteria by all the protozoa.
Inverse relationship between concentration of progesterone and nutrition in ewes
Authors: Williams A. H. , Cumming I. A.
Published: March 2009

Mean progesterone concentrations were measured in the peripheral plasmas of Merino and Border Leicester × Merino ewes which were fed from day 2 to day 16 after mating on rations designed to provide twice maintenance (2 M), maintenance (M) and one quarter maintenance (¼ M) of food requirements. Mean plasma progesterone concentrations were consistently higher in the ¼ ewes than in the M or 2 M ewes whether they had two corpora lutea (CL) and two embryos surviving or one CL with either one embryo surviving or no embryo surviving, and tended to be lower in the 2 M than M ewes. It is concluded that there is an inverse relationship between levels of nutrition and progesterone within an oestrous cycle in ewes.
Embryonic mortality, calf production, calving interval and life span of imported Friesian cattle in western Nigeria
Authors: Adeneye J. A.
Published: March 2009

Abortion and stillbirth ranges of 1·8–16·1% and 1·26–6·5% respectively have been reported among Friesian cattle by Asker & El-Itriby (1957), Ragab & Asker (1959), Juma (1968) and Kassir & Juma (1968). Abortions and stillbirths occurred more frequently among heifers than among cows (Philipsson, 1971). Calving interval varied between 367 and 474 days, the first interval being the longest (Ragab & Asker, 1959; Zaki, Abdel Razek & Dessouky, 1965; Marples& Trail, 1967; Trail &Marples, 1968; Anon. 1969; Knudsen & Sohael, 1970; McLntyre, 1971; Kiwuwa, 1972).
The effect of maleic hydrazide and chlorocholine chloride on the growth, seed yield components and seed yield of S.23 ryegrass
Authors: Hebblethwaite P. D. , Burbidge A.
Published: March 2009

The effects of maleic hydrazide (MH) and chlorocholine chloride (CCC) on S. 23 perennial ryegrass grown for seed were investigated in a series of field experiments from 1972 to 1974. MH significantly decreased straw length and lodging, but also decreased all yield components, seed yield and germination percentage. All growth stages and harvest date were delayed and the seed production mechanism impaired. CCC had little effect on length of fertile tillers or lodging but seed yield was increased in 1972 and 1973 when the chemical was applied at spikelet initiation. In 1972 an increase in 1000-grain weight and in 1973 small but insignificant increases in numbers of fertile tillers and seeds per spikelet were responsible. This chemical had no visible effects on the growth and development of the crop or on germination percentage of the seed.
Breeding for protein percentage and seed weight in Phaseolus vulgaris L.
Authors: Polignano G. B.
Published: March 2009

Three successive generations (parents, F1, F2) and backcrosses of the common bean (Phaseolus vulgaris L.) hybrid between the cultivars Swedish Brown and Seafarer were used in this study.

The investigation has concentrated on assessing the relationship between the seed weight per plant and the protein percentage of the seed. Protein percentage showed a higher estimated heritability and a greater stability over environments than seed weight.

Partial dominance for low percentage protein and low seed weight was noted. Negative and low regression coefficients between these two characters was also observed.

SDS-gel electrophoresis was used to examine the variation in banding patterns of total seed polypeptides and their stability over environments.
The effect of sowing date, seed rate and nitrogen fertilizer on the growth and yield of Isbagol (Plantago ovata F)
Authors: Randhawa G. S. , Sahota T. S. , Bains D. S. , Mahajan V. P.
Published: March 2009

An experiment to study the effect of sowing time (21 October, 5 November, 20 November, 5 December and 20 December), seed rate (5, 7·5 and 10 kg/ha) and application of nitrogen fertilizer (0, 20, 40 and 60 kg N/ha) was conducted at the Punjab Agricultural University, Ludhiana, on a loamy sand soil during the winter seasons of 1974–5 and 1975–6. The delay in sowing from 21 October to 20 December produced shorter plants with fewer spikes. The crop sown on 21 October using 7·5 or 10 kg seed/ha and supplied with 20 or 40 kg N/ha gave better yield than those of later sowings.
The effects of underfeeding for 6 months during pregnancy and lactation on blood constituents, milk yield and body weight of dairy cows
Authors: Roberts C. J. , Reid I. M. , Dew Sally M. , Stark A. J. , Baird G. D. , Collins R. , Mather Denise
Published: March 2009

Long-term undernutritional stress is often a feature of sheep and beef cattle production, but has only become a major feature of dairy cattle husbandry in the United Kingdom in recent winters when food was short and expensive. An experiment was carried out to study the effects of long-term underfeeding during pregnancy and early lactation on some blood constituents, milk yield and composition and body weight of dairy cattle. Two groups of cattle were fed at 60 and 40% of the estimated requirements for maintenance and pregnancy or lactation for 13 weeks before and 13 weeks after calving, and one group was fed at the maintenance level only for the same period. A control group was fed at 100% of estimated requirements for this period. All groups were subsequently fed at the control level for a further 24 weeks.

The experiment showed that cows undergoing long-term nutritional deprivation were able to maintain concentrations of blood constituents within narrow limits; the concentrations of such constituents as glucose or non-esterifled fatty acid did not reflect energy deficit or surplus. The animals remained clinically healthy during the underfeeding and recovery periods. The results suggest that debility occurring under field conditions in association with reduced food supply may be due to a multiplicity of factors or to severe imbalance of specific nutrients, rather than to energy or protein deficit alone.

There was a difference in efficiency of utilization of energy of 19% between cows in the most severely underfed groups which maintained lactation and those which were not able to maintain lactation. There was evidence that this difference in efficiency was detectable within a few weeks of the start of the period of reduced nutrition. Animals which were less affected in the early stages of food deprivation were also those which maintained the advantage through the deprivation and recovery periods.
Some varietal differences in factors affecting nutritive value and in recovery after cutting in Lolium multiflorum
Authors: Wilman D. , Omaliko C. P. E.
Published: March 2009

Four varieties of Italian ryegrass (Lolium multiflorum), which have been found to differ in voluntary intake by livestock at the same level of digestibility, were examined in the year of sowing and in the two subsequent years in a field experiment. Eight dates of first harvest during May–June in the years after the year of sowing were compared. During May–June in these years the proportion of leaf in the crop was closely related to the stage of development of the crop relative to heading date, whereas yield and digestibility were more closely related to calendar date. As a result the later-heading varieties, S. 22 and Sabalan, had a higher proportion of leaf than the earlier-heading varieties, RvP and Tetila Tetrone, at a given yield and digestibility and this may at least partly account for higher intake in the former varieties. In addition, in Sabalan, the proportion of green leaf relative to dead was particularly high and the proportion of cell wall particularly low. The surface area per unit dry weight of leaf blade was much higher than that of ‘stem’, which may contribute to shorter retention time in the reticulo-rumen. Surface area per unit weight of both leaf blade and ‘stem’ declined with delay in date of first harvest.

The yield of RvP relative to the other varieties was modest at the first harvest in the years after the year of sowing and high at subsequent harvests, in accord with National Institute of Agricultural Botany results. The high yield of RvP relative to the other varieties after the first harvest appeared to be associated with a relatively large number of tillers with their shoot apex below cutting height at the time of first harvest. It seemed that most of these tillers had emerged during the few weeks before that harvest. The proportion of tillers with their shoot apex below rather than above cutting height at the time of first harvest was higher in all four varieties than casual observation would suggest and the proportion remained rather high throughout May and June. The rapid rate of turnover of tillers in Italian ryegrass was confirmed.
Studies on reproduction in prolific ewes:8. The concentrations and rates of accretion of amino acids in the foetuses
Authors: Robinson J. J. , McDonald I. , Brown D. S. , Fraser C.
Published: March 2009

Data are presented for the amino acid contents of 64 litters of Suffolk × (Finnish Landrace × Dorset Horn) foetuses varying in gestational age from 90 to 145 days and in litter size from one to five. The concentrations of glycine, cystine, arginine, proline and hydroxyproline in foetal dry matter increased with age, those for threonine, serine, glutamic acid, valine and methionine remained fairly constant while those for aspartic acid, phenylalanine, histidine and lysine tended to decrease. The most pronounced of these age effects were for cystine and hydroxyproline which increased in concentrations by 60 and 100% respectively over the final 2 months of foetal life. The rates of accretion of the individual amino acids are discussed in relation to estimates of the amounts that may be supplied by microbial protein.
A comparison of leaf and ear development in barley cultivars as affected by nitrogen supply
Authors: Dale J. E. , Wilson R. G.
Published: March 2009

Twenty-one two-row and 19 six-row barley cultivars, originating from the major barley growing areas, were compared in a duplicated experiment conducted under controlled environment conditions. Plants were grown in sand and supplied nitrate at two concentrations.

Number of leaves on the mainstem and leaf emergence rate both varied widely but there were no consistent differences between two- and six-row cultivars. The low nitrogen treatment led to significant reductions in number of leaves and emergence rates. As a result of these opposing effects the time of appearance of the flag leaf was not affected by treatment. The number of leaves unfolded was a linear function of time where nitrogen was supplied at high concentration but for plants supplied with low nitrogen, appearance of the third and fourth leaves was considerably delayed. Cultivars producing fewer leaves on the mainstem also showed faster leaf emergence and both these factors contributed to the earliness of a cultivar.

Low nitrogen treatments reduced number of spikelets per ear in both two-row and six-row barleys; this treatment also reduced the number of grain filled, although mean grain weight was not affected. Faster leaf emergence rates were associated with fewer spikelets per ear in both nitrogen treatments.

Since they are based on a relatively large number of cultivars it is likely that these results are general for barley. The importance of further detailed examination of apical development is indicated.