bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of protozoa, using phosphatidyl choline, and of bacteria, using nucleic acids, in the duodenal digesta of sheep fed chaffed lucerne hay (Medicago sativaL.) diets
Authors: John A. , Ulyatt M. J.
Published: March 2009

The use of phosphatidyl choline (PC) as a marker of protozoa in duodenal digesta was examined in sheep fed chaffed lucerne hay (Medicago sativaL.; 330–950 g organic matter/day) either once daily or hourly.

PC was present in rumen protozoa (N:PC-P = 185±6·4) but was not detected in rumen bacteria. Dietary intake of PC was less than 5% of the daily passage of PC from the stomach (7·49 mg PC-P/day). A comparison of the SA of PC-P in protozoa and in duodenal digesta of sheep given a continuous intraruminal infusion of32P-orthophosphate showed that the proportion of dietary PC-P in duodenal digesta was negligible.

The limitations and validity of PC as a marker of protozoa in duodenal digesta are discussed. The daily passage of protozoal N from the stomach (1·38 ± 0·125 g/day) estimated with PC was not affected by frequency of feeding but protozoal N yield (4·96 ± 0·509 g/kg organic matter apparently digested) declined with increasing feed intake.

The SA of DNA-32P, RNA-32P and readily extractable phospholipid-32P (REPL-32P) in rumen protozoa, bacteria and duodenal digesta were similar, showing that the DNA, RNA and REPL-P in duodenal digesta were of microbial origin. A method is described for the estimation of bacterial REPL-P and bacterial N in duodenal digesta using DNA, RNA or DAPA as markers.

The calculated total microbial REPL-P (bacterial plus protozoal) in digesta using DNA or RNA as markers was in close agreement with values obtained by direct measurement. It was estimated that protozoa contributed 22 and 14% of microbial REPL-P and microbial N, respectively. Bacterial REPL-P and bacterial N values estimated with DAPA as the marker were higher than values obtained with DNA or RNA. These results are discussed with regard to the use of these markers.
A study of sequential variety selection systems
Authors: Robinson Dorothy L.
Published: March 2009

Computer programs have been developed to evaluate sequential variety selection systems using Monte Carlo and numerical integration methods.

These methods are described in the paper and applied to official U.K. cereal variety testing. The consequences of alternative selection systems are examined.
Phosphate distribution in animal waste slurries
Authors: Gerritse R. G. , Vriesema R.
Published: March 2009

Results obtained previously on distribution and behaviour of phosphate between organic and inorganic forms in pig slurries are extended to slurries from wastes of hens, cows and calves. Organic P in the slurries varied from about 1 to 15% of total P, with slurries from veal calves having the lowest content of organic P. In all slurries roughly half of organic P in solution had a high molecular weight (50000 and higher) and is therefore potentially mobile in soils.
Effect of boronated saline irrigation water on linseed
Authors: Chauhan R. P. S. , Chauhan C. P. S. , Chauhan S. K.
Published: March 2009

Underground irrigation water, particularly saline, when in arid and semi-arid regions of India may contain toxic amounts of B, from a trace up to 10 mg B/l (Anon. 1981–82). Continuous use of such water for irrigation may lead to the accumulation of salts and B in soil and this creates toxicity problems. Kanwar & Mehta (1970) have reported that water containing 2 mg B/l is hazardous if used on heavy soils. For sandy loam soils of semi-arid tracts in India, Chauhan & Powar (1978) have reported reductions in the grain yield of wheat and pea at 4 and 6 mg B/l respectively, while under similar conditions grain yield of lentil and barley was reduced at 3 and 6 mg B/l respectively (Chauhan & Asthana, 1981). So far, few attempts have been made to evaluate the effect of boronated saline water on soil and crops, under different agroclimatic conditions. A study of the effect of boronated saline water on an important oil-seed crop, linseed, on alkaline sandy loam soil in the semi-arid region of Agra, India was therefore undertaken.
Prediction of beef carcass composition from organs and tissues of the non-carcass parts
Authors: Johnson E. R. , Vidyadaran M. K.
Published: March 2009

Individual muscles, individual bones and fat depots from the non-carcass parts (head, foreshanks and tail) of 40 steers (chilled carcass weight 142–174 kg) were studied in an attempt to predict carcass composition more accurately than in an earlier study where the crude non-carcass parts, head, tongue, foreshanks and hindshanks were used.

The technique did not improve the accuracy of prediction of muscle or bone. Carcass fat, which was calculated by difference in the earlier study, was predicted more accurately using intermandibular fat weight (requiring 3–4 min to obtain) plus fat thickness at the 12th rib. However, the accuracy of this prediction (carcass fatness range 14·0–33·6%, residual standard deviation 1·98%) was no greater than that using chilled side weight plus fat thickness at the 12th rib.

Careful dissection and trimming of anatomical entities from the non-carcass parts therefore offered a slight advantage only in the prediction of carcass components over existing techniques.

Substitution of hot side weight for chilled side weight, and sacral crest fat thickness for fat thickness at the 12th rib did not lead to a loss in the accuracy of prediction of muscle, bone or fat.
Interaction between finger millet (Eleusine coracana) genotypes and drug-resistant mutants ofAzospirillum brasilensein calcareous soil
Authors: Rai R. , Prasad V. , Shukla I. C.
Published: March 2009

Azospirillum brasilensewas treated with nitrosoguanidine and five drug-resistant mutant strains isolated. The effects of acriflavin on pre- and post-irradiation with u.v. light and the level of antibiotic resistance were studied. Variations in factors were found between the strains. Inoculation of finger millet withA. brasilenseand mutant strains led to significant increases in grain yield and nitrogenase activity compared with the uninoculated control, with significant strain x genotype interactions. Differential response of genotype and strain was noted on the protein and amino acid concentration of seeds.
Carbon dioxide enrichment and water stress interaction on growth of two tomato cultivars
Authors: Paez Alejandra , Hellmers H. , Strain B. R.
Published: March 2009

If atmospheric carbon dioxide concentration continues to increase, plant growth and crop yield could be affected. New Yorker and Better Boy cultivars of tomato (Lycopersicon esculentum) were used to investigate possible intraspecific variation in the response of crop species to increased CO2. Because precipitation and temperature are predicted to change with the increasing atmospheric CO2concentration, the response of the two cultivars to the interaction between CO2and water stress was also examined. Seeds of the two cultivars were germinated and grown under controlled environmental conditions, in either 350 or 675 μ1 CO2/1.

The plant water status of the two cultivars was inherently different but was little affected by the CO2concentration when the plants were well watered. When water was withheld for 5 days the total leaf water potential and osmotic potential decreased in both CO2treatments but less rapidly in high CO2than in low. Under low CO2total leaf water potential decreased to a lower value than osmotic potential. The differences were due, at least in part, to the reduced stomatal conductance and transpiration rate under high CO2.

Increased CO2ameliorated the detrimental effects of drought stress on plant growth. The results indicate that increased CO2could differentially affect the relative drought resistance of species cultivars.
A study of serum mineral changes in lactating Welsh mountain ewes under different grazing conditions with special reference to hypomagnesaemia
Authors: L'Estrange J. L. , Axford R. F. E.
Published: March 2009

Short-term grazing trials with daily blood sampling were carried out on Welsh mountain ewes in early lactation.

1. A small decrease in serum magnesium levels and a very marked decrease in serum inorganic phosphorus levels, were observed in two groups of four ewes, when one group was transferred from an old pasture to a fertilized (high nitrogen and potash) fresh spring ley, and the others to a similar fresh ley but untreated. There was little effect from the fertilizer treatment on the magnesium, calcium, potassium, sodium or phosphorus content of the herbage.
Field experiments comparing ammonium nitrate and ammonium sulphate as top-dressings for winter wheat and grassland
Authors: Devine J. R. , Holmes M. R. J.
Published: March 2009

Ammonium nitrate and ammonium sulphate wore compared as top-dressing applications in thirty-six field experiments on winter wheat and eighty-nine on grassland in various parts of Great Britain in 1956-62. The rates of application were 35-60 lb./acre of nitrogen for winter wheat and 30-100 lb./acre for grassland in one application only.
Comparison of the effects of autumn and spring sowing date on growth and yield of combining peas (Pisum sativutnL.)
Authors: Silim S. N. , Hebblethwaite P. D. , Heath M. C.
Published: March 2009

Experiments were conducted between 1978 and 1981 to investigate the effect of autumn and spring sowing on emergence, winter survival, growth and yield of combining peas (varieties ‘Frimas’, ‘Filby’ and ‘Vedette’). Effects of growth regulator PP 333 (Paclobutrazol, ICI pic) application and defoliation on winter survival of Filby were also investigated. Field emergence of autumn-sown Frimas (winter hardy) was less than Vedette or Filby but percentage winter survival was greater. PP 333 application, but not defoliation, increased percentage winter survival of Filby sown in September. Total dry-matter production and photosynthetic area of autumn- compared with spring-sown crops varied considerably between seasons. Yield data indicated that autumn-sown crops produce similar seed yields to spring sowings when winter survival is adequate. November sowings matured 2–4 weeks before March-sown crops, depending on variety and season. Optimum sowing dates were mid-November and early March. Large seed-yield reductions occurred when sowing was delayed until mid-April.
Interactions between Rhizobium strains and lentil (Lens culinaris Linn.) genotypes under salt stress
Authors: Rai R. , Nasar S. K. T. , Singh S. J. , Prasad V.
Published: March 2009

Three strains of Rhizobium able to fix nitrogen in symbiosis with lentils in saline soil were screened. Nodulation pattern, N2-fixation and grain yield were all influenced by Rhizobium strain and lentil genotype. Genotypes DL-443 and Pant L-406 were found to be more salt tolerant than others, and gave the highest grain yield.
Anin vivostudy of ruminal micro-organisms influencing lactate turnover and its contribution to volatile fatty acid production
Authors: Mackie R. I. , Gilchrist Frances M. C. , Heath Suzette
Published: March 2009

The ruminal metabolism of lactic acid was investigatedin vivounder normal feeding conditions in four sheep each adapted to one of the following diets: high-concentrate, intermediate, high-roughage containing 65, 43 or 10% maize meal and molasses respectively, or lucerne hay. A continuous basal turnover of ruminal lactate (0·01–0·02 mmol/1/min) was found which increased 10- to 40-fold immediately after feeding when production exceeded utilization and lactate accumulated in the rumen. This was followed by an increase in utilization rate which removed the accumulated lactate. Both lactate and glucose turnover were related to the amount of readily fermentable carbohydrate in the diet. Approximately 8, 6·5, 5 and 2·5% of the total VFA was formed through lactate on the high-concentrate, intermediate, high-roughage and lucerne hay diets respectively.

Rumen microbial counts of total culturable, glucolytic, amylolytic and lactateutilizing bacteria, and of ciliate protozoa were also performed on the four sheep. Numbers of micro-organisms in all groups were highest on the high-concentrate diet and lowest on the two roughage diets. The proportions of the predominant genera from the different metabolic groups of bacteria differed, although in most cases the same organisms were present in the rumen on all diets. The succinate pathway was found to be quantitatively more important in the conversion of lactate to propionate in the rumen. Although the numbers of lactate-utilizing bacteria increased as the amount of RFC in the diet increased, their metabolic activity was actually lower. Reasons for this finding are discussed, together with factors influencing the regulation of lactate production and utilization in the rumen.
The effect of feeding in early lactation on feed intake, yields of milk, fat and protein and on live-weight change over one lactation cycle in dairy cows
Authors: Johnson C. L.
Published: March 2009

An experiment has been made to study the effect of level of feeding in early lactation on the feed intake, yields of milk, fat and protein and on live-weight change over one lactation cycle. Adult British Friesian cows of high potential yield were randomly allocated to high (HP) or moderate (MP) levels of feeding for 20 weeks. They were then randomly allocated within treatments to controlled or ad libitum levels of feeding for the rest of the lactation.

There were significant effects of feeding in the early part of lactation on the yields of milk, protein and lactose but not on milk fat or live-weight change. Cows on the MP treatment produced about 450 kg milk from body energy reserves but were unable to supplement fully the dietary energy deficiency. There was no significant response to feeding ad libitum in the second part of lactation and the differences in yields established in the first part were maintained in the second. There was no relationship between feed intake and milk yield for cows fed ad libitum nor did the level of feeding in early lactation influence the level of intake in the later part.

There was little agreement between calculated energy balance and the live-weight changes but there was more between live-weight change and condition score.
Seasonal variations in the composition of young cotton leaves in the Sudan Gezira
Authors: Jewitt T. N.
Published: March 2009

The composition and weight of young cotton leaves at a fixed age are given for 3 years which had different rainfall before the sowing of the cotton, and for which the final yields of the cotton are also known. These yields are inversely related to the early growth and percentage composition of the crop. It is not possible to explain this, but the differences in early growth and nutrient absorption are in accord with expectation. In a year of heavy rainfall before sowing, surface soil nitrates are low, which accords with the smaller amounts of nitrogen taken up by the plants. Furthermore, there is evidence to suggest that in such a year the physical condition of the soil would be poor, which is consistent with poor growth and the low uptake of nutrients other than nitrogen.

In the Sudan Gezira the yields of irrigated cotton are positively correlated with the amount of rainfall in the 6 weeks before sowing. This is not due to increased nitrate in the top foot of soil nor is it due to increased efficiency of absorption of nutrients in years of high rainfall.
Observations on the vitamin metabolism of the common fowl III. The effects of oestradiol dipropionate, testosterone propionate and progesterone injections in immature pullets on the riboflavin content of the magnum
Authors: Bolton W.
Published: March 2009

1. The effects of injections of oestradiol dipropionate, testosterone propionate and progesterone in immature pullets have been studied.

2. Oestradiol dipropionate evokes hypertrophy of the oviduct, and increases in serum calcium and serum riboflavin.

3. Testosterone propionate evokes hypertrophy and reddening of the comb and wattles, it acts synergistically with oestradiol dipropionate in evoking hypertrophy of the oviduct.

4. Progesterone antagonizes the effects of oestradiol dipropionate and testosterone propionate on the growth of the oviduct.

5. Progesterone and/or testosterone propionate increase the percentage of free riboflavin in the hypertrophied magnum from 18% of the total vitamin present to 35%.
Ruminal ammonia formation in relation to the protein requirement of sheep: I. Duodenal administration and heat processing as factors influencing fate of casein supplements
Authors: Chalmers Margaret I. , Cuthbertson D. P. , Synge R. L. M.
Published: March 2009

1. Nitrogen-balance experiments showed that casein supplements fed to hill ewes on a low plane of nutrition in the later stages of pregnancy were used very ineffectively, despite the animals' need for protein.

2. In confirmation of McDonald (1948a, b, 1952) extensive conversion of casein to ammonia was found to occur in the rumen, with absorption of ammonia into the blood stream.

3. Casein administered to sheep by duodenal fistual was better utilized than when administered by ruminal fistula.

4. The course of dissolution in the rumen of casein in the form of tough lumps was observed by a staining procedure.

5. It was found possible to process casein in a way that led to better utilization as shown by nitrogenbalance experiments. This processed casein gave less ammonia in the rumen.

6. It is concluded that the formation in the rumen of ammonia from proteins may be an important factor determining their usefulness to the animal. Processing may have effects on the value of a protein for ruminants quite different from those on the value for non-ruminants. The tendency to value proteins for ruminants solely in terms of their digestibility is criticized, and it is suggested that casein has disadvantages as a ‘standard protein’ in nutrition experiments with ruminants.
The nutrition of maize in sand culture II. The uptake of nitrogen and phosphorus and its relevance to plant analysis
Authors: Glover J.
Published: March 2009

The materials and methods have been described in the first paper of this series (Glover, 1953). All experiments were of 33 factorial design (Yates, 1937) involving three different levels of supply of nitrogen, phosphorus and potassium.

The results of the measurements are shown graphically in Figs. 1–4 inclusive. Because of the limits set by reproduction of Figs. 1 and 2 it is impossible to show minor variations due to different treatments. Where the curves of uptake run together one broad line is used to denote this. Deviations from this line are shown where they occur. Superimposed on the figures are lines denoting the length of the tasselling and silking periods. Thus a line covering a period of, say, 10 days and bearing the symbol T shows that tasselling in the particular series was completed in that period, and the first tassel was set at the date corresponding to the start of the line.
Studies on piglet mortality I. Effect of low temperature and low plane of nutrition on the rectal temperature of the young pig
Authors: Pomeroy R. W.
Published: March 2009

1. The rectal temperature of piglets was determined (a) at intervals from birth up to 18 days, (b) at the same time daily until the piglets appeared to be fully thermoregulated.

2. The rectal temperature of a vigorous piglet during parturition may be as high as 104–105° F.

3. During the first few minutes after birth the temperature falls to about 100° F., partly as a result of the lower temperature of the external environment and partly as a result of rapid evaporation of amniotic fluid with which the young pig is covered. The fall in temperature is greater with lighter pigs than with heavier pigs.

4. The temperature falls until the young pig finds its way round to the teats and starts to suckle. This struggle and activity of suckling together with the warmth in the sow's nest causes a temporary rise in temperature. During the first rest the temperature falls again to about 100° F., but vigorous pigs have a normal temperature within 12 hr.

5. Piglets deprived of milk after 5 hr. and 16 hr. suckling experienced a more or less steady fall in temperature to about 98° F. in 2–3 days, when the pigs were comatose and were killed. In the case of a pig which had suckled for 7–8 days the temperature remained more or less normal for 2 days and then declined to 95° F. during 5–6 days. The length of survival depends largely on the initial weight, i.e. on the reserves accummulated during the suckling period, and possibly on the thickness of the insulating layer of subcutaneous fat.
The effect of flooring upon pigs reared in an otherwise cold environment
Authors: Lucas I. A. M. , Thomson W.
Published: March 2009

1. Piglets reared in a cold building but in pens provided with electrically warmed or wooden beds weighed considerably more at 8 weeks old than piglets reared in pens with solid concrete floors covered with thin permeable cork-tar bricks. At 3 days and 3 weeks old there were no differences in live weight between the three groups.

2. Before weaning at 8 weeks old the piglets reared on concrete floors had very much poorer appetites for solid food than had those from the other two groups.

3. Although the blood haemoglobin concentrations of piglets on warmed and wooden floors rose between 3 and 8 weeks of age, the haemoglobin concentrations in the group on concrete floors fell. The differences in concentrations between groups at weaning just failed to be statistically significant at P = 0·05.

4. Under the conditions of this experiment the provision of electrically warmed or wooden floors diminished but did not eliminate the incidence of a pathological liver condition in pigs which has been attributed to poor housing conditions.

5. The low weaning weights, poor appetites, low haemoglobin concentrations at weaning and the presence of the liver disease in piglets born on concrete floors were probably interdependent, but the mechanism and direction of this interdependence could not be explained from the data collected.
The effect on the health of lactating cows of treatment with galactopoietic doses of thyroxine or iodinated casein
Authors: Leech F. B. , Bailey G. L.
Published: March 2009

1. The effect on cow health of galactopoietic stimulation with thyroactive materials was determined from a statistical study of the results of a large field experiment involving 2000 cows over a 3-year period.

2. The same experimental procedure was followed on thirty-seven farms scattered over England, Scotland and Wales. This procedure was planned to ensure that half the cows in each herd would receive a course of treatment with iodinated casein or thyroxine, and that the other half would constitute a suitable set of controls. Cows that remained in the herds received second and third treatments in successive lactations.

3. The galactopoietic stimulation was started at a fixed interval after calving, irrespective of the season of the year.

4. The use of the thyroactive materials in successive lactations did not have any serious adverse effects on the health of cows. The effect on productivity was less than had been expected, since the increase in milk yield resulting during the period of hormonal treatment was often largely or completely negatived by a shortening of the lactation period.

5. The incidence of disease was somewhat greater in the treated than the control group, the principal contribution to this difference being from the diseases described as digestive disorders. There were some other differences of lesser significance.

6. The rate of disposal of treated and control groups was almost identical.

7. There were no adverse effects on the reproductive life of treated cows; factors studied were the efficiency of coitus, interval between parturitions, length of gestation and incidence of abnormalities at parturition.
Seasonal variations in semen characteristics of sheep in the subtropics
Authors: Hafez E. S. E. , Badreldin A. L. , Darwish Y. H.
Published: March 2009

Semen samples were collected from twelve fattailed rams of two breeds (nine Ossimi and three Rahmani), by the use of an artificial vagina. They were kept under natural conditions at Cairo, Egypt (30° N.). Three collections were made each month throughout one year (1951–2).
The lignin and cellulose contents of certain grassland species at different stages of growth
Authors: Armstrong D. G. , Cook H. , Thomas Brynmor
Published: March 2009

1. The lignin and cellulose contents of the dry matter of seven herbage species, including three grasses, two legumes and two herbs, have been determined at different stages of growth. Similar analyses of large samples of crude fibre isolated from early and late cuts of all species were made.

2. No considerable differences between the lignin contents of the dry matter of the species were found when comparisons were made at the same stage of growth.

3. In a majority of the species examined a marked rise in lignin content was found to occur at the flowering stage.

4. The cellulose content of grasses, whether expressed as a percentage of the dry matter or of the carbohydrate fraction, is much higher than that of either legumes or herbs. In consequence, crude fibre contents are greater in the former than in the latter.

5. The findings of earlier workers that the composition of the crude fibre varied as between species have been confirmed. It has been shown that, in any one species, the crude fibre make-up is dependent on the stage of growth.

6. The recovery of lignin and cellulose in the crude fibre of the different species has been studied. Several possible explanations of the variable recoveries found have been suggested and discussed.

7. The case for modification of the conventional method of feeding-stuff analysis, as it applies to the non-fatty and non-nitrogenous organic matter, has been discussed in the light of conclusions reached in the course of this work.
Apparatus for the determination of the energy exchange of calves and of sheep
Authors: Blaxter K. L. , Graham N. McC. , Rook J. A. F.
Published: March 2009

1. Details are given of the construction of one open-circuit and two closed-circuit respiration chambers suitable for the determination of the 24 hr. exchange of energy of calves or of other animals weighing up to 75 kg.

2. Gas analysis apparatus and the general technique employed in experiments with the closedcircuit apparatus are described.

3. From experience gained with both types of apparatus the closed-circuit apparatus is preferred for its simplicity and ease of working.
Relations of yolk, albumen and egg weight in inbred lines of brown leghorns
Authors: Erasmus J. E.
Published: March 2009

1. The relations of yolk, albumen and egg weight were studied in seven inbred lines of Brown Leghorns and reciprocal crosses of two of these lines.

2. In all the lines the eggs produced by hens had a bigger proportion of yolk than those produced by pullets.

3. Besides changes in both components accompanying differences in egg size the line means for albumen weight still differ significantly after adjustment is made for its covariance with yolk weight. This independent variation leads to differences in the yolk-albumen ratio of the hens.

4. Within the lines there is a significant negative association between egg size and the yolk/albumen ratio.

5. The wide differences in egg size, dividing the pure lines into two groups characterized by large and small eggs respectively, resulted from a marked decrease in the amount of albumen in the eggs of the latter group. Yolk weights, on the other hand, could be ranked in a fairly regular series with adjacent lines differing by 2 g. or less.

6. There is some source of variation in the yolk/ albumen ratio for line means which is not accounted for by differences in egg size.
Species and breed differences in the thermal reaction mechanism
Authors: Badreldin A. L. , Ghany M. A.
Published: March 2009

A total of fifty buffaloes, thirty-five Shorthorn and Shorthorn grades and twenty-nine Egyptian (Baladi) cows of different ages were used to study the thermal reaction mechanism by exposing the animals to direct solar radiation followed by shade. The thickness of the skin was also measured in all animals as it is one of the main factors in heat regulation. The results were as follows:

1. There were species and breed differences in the thermal reactions. Buffaloes were more hyperthermic when exposed to direct solar radiation than either Shorthorn or Egyptian cattle. The Shorthorns were more affected by ambient heat than Egyptian cattle.

2. The skin thickness of the buffalo was double that of the cattle. In all animals the thickness of the skin increased with age.

3. It is suggested that the adaptability of farm animals to tropical and subtropical zones is better assessed under shade and under normal husbandry conditions than by exposing them to direct sunlight.
Effect of acute water restriction on plasma proteins and on blood and urinary electrolytes in Barmer goats of the Rajasthan desert
Authors: Khan M. S. , Ghosh P. K. , Sasidharan T. O.
Published: March 2009

The effect of 96 h water deprivation on plasma proteins, blood and urinary electrolyte concentrations were studied in Barmer goats of the Rajasthan desert. The total plasma proteins, particularly albumin, increased significantly by water deprivation. Plasma potassium concentrations remained unchanged. The urinary K/Nu ratio increased considerably. There was a decrease in urinary sodium concentration after the 4th day of water deprivation.
The effect of undernutrition after calving on the quantity and composition of the milk produced by dairy cattle
Authors: Flux D. S. , Patchell M. R.
Published: March 2009

Fourteen pairs of monozygous twin cows of mixed ages were used to determine the effect of underfeeding from the 3rd to the 8th week inclusive after calving on milk and butterfat production and on the composition of the milk.

Those cows which were well fed over the 6-week period produced more milk and a larger weight of butterfat than their sisters which had been poorly fed. The milk from the well-fed cows had a lower percentage of butterfat, but higher percentages of solids-not-fat and total protein, than the milk from the poorly fed cows.

The complete lactation averages failed to show statistical significant differences in all characteristics except in the case of solids-not-fat percentage. The mean difference between the two groups for solidsnot-fat was found to be highly significant.

In general, the results support the conclusions of other workers, that underfeeding dairy cows may depress the solids-not-fat content of the milk.

It appeared that differences between the two groups in butterfat percentage over the 6-week experimental feeding period were strongly correlated with differences in weight changes and that the small amount of variance associated with milk yield differences was not significant.
The nutritive value for young pigs of cooked potato flake in comparison with maize meal
Authors: Whittemore C. T. , Taylor A. G. , Crooks P.
Published: March 2009

Digestibility, performance and carcass analysis trials were used to compare the nutritive value of two diets, containing 78% of either cooked potato flake (diet CPF) or maize meal (diet M). Diet CPF had slightly lower values for gross energy (GE) and nitrogen (N), markedly lower values for ether extractives and crude fibre, a slightly higher lysine concentration and a markedly higher potassium concentration.

Apparent digestibility coefficients were determined with ten piglets weighing 22 kg; digestibility values for GE and N were respectively 0·95 and 0·91 for diet CPF, and 0·84 and 0·88 for diet M. Digestible energy (DE) and digestible N (DN) values were 10·2 MJ and 26·9 g/kg dry matter for diet CPF, and 15·3 MJ and 27·9 g/kg dry matter for diet M. The performance of 30 piglets grown from 21 to 53 days of age and from 6·0 to 13·1 kg was similar for each diet, as were the empty body, water, N, lipid, ash and GE gains of 18 of these piglets. The efficiencies of conversion of nutrients ingested from diet CPF into the components of body gain were for GE, DE, N and DN; 0·21, 0·22, 0·48 and 0·52 respectively. Corresponding values for diet M were 0·17, 0·21, 0·38 and 0·44.

The greater efficiency with which the nutrients in the potato flake were used thus resulted in a growth response which was at least equal to that of the maize meal.
Measurements of the rate of production of bacteria in the rumen of buffalo calves
Authors: Singh U. B. , Verma D. N. , Varma A. , Ranjhan S. K.
Published: March 2009

A technique is described for thein vivoestimation of the rate of production of bacteria in the rumen of buffalo calves. The animals were given their daily ration in 12 equal amounts at 2-h intervals. The bacterial cells from the rumen were labelled either with14C or36S byin vitroincubation in the presence of [U-14C]DL-leucine or35S-sodium sulphate. Labelled bacterial cells were injected in a single dose into the rumen. Samples of the ruminal fluid were drawn at various time intervals for 9 h and the specific radio-activity of the bacteria determined. The dilution in the specific radioactivity was used to calculate the turn-over time and rates of production of bacteria in the rumen. The average turnover time was 308 min. The production rate of bacteria averaged 211 mg/min (20·3 g/mole VFA produced).
Carotenoid changes inBrassica oleraceavar.capitataL. with age, in relation to the Large White Butterfly,Pieris brassicaeL.
Authors: Feltwell J. S. E. , Valadon L. R. G.
Published: March 2009

Comparison of summer, winter and spring-grown cabbage showed that carotene synthesis differed considerably. Spring-grown cabbage was found to produce a peak of carotenoids during the first week of growth, and this decreased after one month. In comparison, winter-grown cabbage was still producing more carotenoids after 1 month and came to a peak of carotenoid production between 1 and 2 months. The winter-grown cabbage plants were maintained for 12 months and it was found that oxidative processes occurred at a later date than in spring- and summer-grown plants. It is shown that total carotenoids and interconversions of carotenoids are a useful indication of the metabolic processes, including oxidation and degradation of carotenoids, occurring in maturing and senescing plants.

The effect of variation of the vitamin A potent carotenoids in the cabbage, and the increased spring production of carotenoids in cabbage, are discussed in relation to the life style of P.brassicae.
Methods of analysing competition with special reference to herbage plants:III. Monocultures v. binary mixtures
Authors: Hill J.
Published: March 2009

A model is presented which considers the effects of competition between pairs of individuals in binary mixtures. Competitive effects are defined in terms of two parameters; a monoculture effect (Mo) which measures competition between like individuals and a mixture effect (Mi) which relates to competition between unlike individuals. If the data from a particular density replacement series conform to the proposed model the ratio of Mi to Mo can be used to determine whether it would be more advantageous to grow a mixture of the two components concerned or a pure stand of the better component. Where appropriate the optimal composition of the mixture may also be estimated. Theoretical considerations suggest that a 50:50 ratio only represents the optimal composition of a mixture when the two components possess a similar expression for the character concerned.

The model has been applied to dry weight data collected over two growing seasons from a glasshouse experiment which contained 5 genotypes ofLolium perennegrown as monocultures and in all 10 binary combinations. Each combination was represented by three mixture proportions. For the majority of these density replacement series the model was satisfactory, with mixture effects tending to be of greater significance during the first of the two growing seasons. Failure of the model was in general due either to a specific form of competition, which maintained the performance of the mixtures at the level of the better monoculture, or to the presence of more complex forms of competition.

The implications of this model for the development of productive herbage mixtures are briefly discussed, whilst the possible effects of invasion by unsown grass species upon the productivity of a pure sward are also outlined.
On increasing wool weight through breeding LK-type sheep
Authors: Taneja G. C.
Published: March 2009

The wool weight/m2 of LK progeny arising out of LK × LK matings (approximately a quarter were HK and were excluded) and HK progeny arising out of HK × HK matings (all were HK) of two coarse-wool producing breeds of sheep, Marwari and Magra, were compared with the mid-parent values. LK progenies produced significantly more than the mid-parent value in both the breeds, but there was no increase in HK progeny. The difference in wool weight between the HK progeny and their mid-parent value tended to be less for Marwari whereas it was much less for Magra breed.

The results suggest that improvement in wool weight of sheep can be made by maintaining LK stock and mating LK × LK, culling the HK arising out of these matings in each generation.
Effects of age and state of incisor dentition on the chemical composition of the skeleton of sheep grazing hill pastures
Authors: Sykes A. R. , Field A. C. , Gunn R. G.
Published: March 2009

The chemical composition of the skeleton, mandible and 4th lumbar vertebra of 59 Scottish Blackface female sheep from a ‘broken mouth’ farm was determined. There were 27 6½-year-old sheep (11 with sound mouths, 16 with broken mouths), 16 5½-year old sheep (with loose incisor teeth which at the outset of the experiment were clipped to gum level) and 16 2½-year-old sheep. Sheep from each group were slaughtered at the beginning of pregnancy and in mid-lactation and from those with broken mouths and from the 5½-year-old and 2½-year-old groups at the end of the subsequent dry period. The sheep grazed hill pastures and received an energy supplement during late pregnancy and early lactation.

There were no differences between the 6½-year-old sheep with broken mouths and those with sound mouths in total skeletal mineral content or in the density of ash (ash: volume ratio) or organic matrix (organic matter: volume ratio) in the mandible and lumbar vertebra at the beginning of pregnancy or in mid-lactation. Nor were there differences in the density of ash or organic matrix between any groups, although the skeletons of the 6½-year-old sheep were larger. The lumbar vertebra, which is rich in cancellous bone, had a lower ash and organic matrix density in the 5½- and 2½-year-old sheep. It is suggested that bone mineralization may proceed slowly on such hill pastures.

The rates of repletion of the skeleton during the dry period, 0·35, 0·47 and 0·66 g Ca/day, respectively, in the 6½-year-old sheep with broken mouths, 5½-year-old and 2½-year-old sheep were much slower than rates given in the literature for sheep under controlled conditions. It is suggested that factors other than the major nutrients, protein, Ca and P, may be limiting repletion of the skeleton.

Recovery of the ash density of the vertebra was not complete at the end of the dry period. This was especially so in the sheep with broken mouths and resulted mainly from a failure to replace bone organic matrix.

The implications for the development of broken mouth of cyclical changes in the density of cancellous bone and of evidence that the ability to maintain and to remineralize the skeleton deteriorates with increasing age, are discussed.
Effects of age and state of incisor dentition on faecal output of dry matter and on faecal and urinary output of nitrogen and minerals, of sheep grazing hill pastures
Authors: Field A. C. , Sykes A. R. , Gunn R. G.
Published: March 2009

Excretion of D.M., N, Ca, P and Mg in faeces, and N, P and Mg in urine were measured at intervals over 12 months in breeding Scottish Blackface sheep grazing hill pastures. These values were used with data on reproductive performance and body compositional changes, to calculate the energy, nitrogen and mineral balances. The sheep were: 11 6½-year-old with sound mouths (SM), 16 6½-year-old with broken mouths (BM), 16 5½-year-old with all permanent incisors clipped to gum level (CM) and 16 2½-year-old (Y). An energy supplement was given at the end of gestation and during early lactation. All faeces were collected and creatinine was used as an internal marker to estimate urine volume.

Faecal D.M. output ranged from 443 to 662 g/day, with highest values in November and lowest in May. Average values for the BM sheep were lower than those for the other groups but when output was expressed as a power function of body weight, the values for the Y sheep were 15% higher than those for the other groups. Faecal excretions of Ca and P in January and February were very low and the values for P were half the expected endogenous faecal loss.

Urinary output ofN ranged from 6·0 g/day in February to 22·2 g/day in August and the corresponding urinary urea N: total N ratios were 0·24 and 0·69. Urinary Mg output was highest in late summer and early winter but urinary P showed no consistent trends.

The estimated daily intakes of DOM (g) were 936 in November 1969, 599 in January, 414 in February, 1075 in May, 1150 in August and 946 in November 1970.

The loss of energy from the body between mating (November) and mid-lactation (June) ranged from 9·5 to 16·8% of the total calculated ME requirements in the Y and BM sheep, respectively. Maintenance requirements averaged 204 kJ/kg body weight/day and the value for the Y sheep was 12% higher than the mean for the older sheep.

Nitrogen and mineral balances were calculated for February, May, August and November. The sheep were protein-deficient in winter, not from a shortage of crude protein in the diet but because of its low digestibility (34%). Intakes of Ca and P in winter were low and a real possibility of a P deficiency exists. Estimates of the concentrations of N and of minerals in the herbage consumed by the sheep were made and compared with those obtained for cut herbage from the same pastures. It would appear that the sheep selected herbage of a higher protein content than that of the cut herbage. Herbage selection was greatest in November.
Some wool characteristics of Karadi sheep in northern Iraq
Authors: Ghoneim K. E. , Kazzal N. T. , Abdallah R. Kh.
Published: March 2009

One hundred and sixty-eight wool samples were collected from commercial flocks of Karadi sheep raised in the five provinces of northern Iraq. The wool characteristics dealt with were staple and fibre length, crimps, fibre diameter, medullation, fibre strength and elongation.

The results showed that the Karadi wool is a long type of carpet fleece with average staple and fibre lengths of 19·3 and 23·5 cm, respectively. It had an average fibre diameter of 48·1 μ and contained 19·45 % medullated fibres. The number of crimps per 2 cm was 2·4. Average fibre strength and elongation were 24·8 g/5 cm and 31·8 % respectively. Phenotypic correlations between wool traits were studied.
The effect of feeding sugar syrup to honey-bee colonies
Authors: Free J. B. , Spencer-Booth Yvette
Published: March 2009

1. Honey-bee colonies were fed either concentrated or dilute sugar syrup, or remained unfed, in spring, summer, and autumn of 1958 and 1959.

2. More concentrated than dilute syrup was accepted in every experiment, but the proportion of concentrated to dilute syrup accepted decreased during the course of both years.

3. The concentration of syrup fed made no apparent difference to the gain in weight relative to the sugar taken, probably because the greater efficiency in storing concentrated syrup was offset by the diminution in foraging produced.

4. Feeding dilute or concentrated syrup increased brood rearing during and after feeding in one year (bad weather) but had no effect on brood rearing in the other year (good weather).

5. While being fed colonies usually collected more pollen than they otherwise would.

6. Feeding either concentration of syrup probably decreased nectar gathering when foraging conditions were good, and concentrated syrup may have decreased it more than dilute syrup.
Sexual behaviour and reproductive performance of ewe lambs at and after puberty
Authors: Edey T. N. , Kilgour R. , Bremner Kaye
Published: March 2009

Observations were made on mating behaviour and reproductive performance during the puberal period in 61 well-grown Perendale (Cheviot × Romney) ewe lambs. In four animals, the first oestrus (as indicated by raddle marks) was not accompanied by ovulation, and three other lambs, though marked by the rams, were not inseminated.

The behavioural responses to a ram, of ewe lambs experiencing oestrus for the first and second times, showed many signs of inadequacy by comparison with those of mature ewes. Individual ewe lambs and mature ewes in oestrus were exposed to a ram in a pen for 3 h, and their responses were ranked on a scale of 1 (full adult response) to 5 (weak response). Of mature ewes 95% scored 1, compared with only 27% of ewe lambs. Across the lambs 59% scored 3 or more, indicating failure of some aspects of the courtship sequences which are required to sustain and reinforce the ram's interest. In a paddock-mating system many lambs showed a strong tendency to disassociate themselves from the rams after each courtship and mating sequence. Consequently there was little evidence of harem formation. Fifty-six per cent of services came in the first 2 h of oestrus, only 14% after the 6th hour and none after the 11th hour.

Duration of the first oestrus in lambs was 18·4 h compared with 29·3 h in mature ewes. Mating the 61 ewe lambs over the first three cycles after puberty resulted in 38 of them being pregnant with 46 foetuses at autopsy in mid to late pregnancy. The success rate did not differ between cycles.
A note on drought-resistance in the lucerne plant
Authors: Wilman David
Published: March 2009

1. Lucerne was grown in a glasshouse under different moisture regimes in order to determine the effect of soil moisture content at the time of defoliating on subsequent yield.

2. Drought conditions were found to reduce yield in the short-term, particularly in conditions in which demand for water was high, but the crop subsequently recovered when supplied with ample moisture. Defoliation during a drought period showed no long-term effect on yield.

This work was carried out as part of the programme of crop-husbandry experimentation at the University of Cambridge School of Agriculture, and the author welcomes this opportunity of thanking Mr F. Hanley, Reader in Crop Husbandry, for advice and suggestions.
The post-natal development of the follicle population in English Romney Lambs
Authors: Wildman A. B.
Published: March 2009

The follicle ratio S/P and the fibre ratio Sf/Pf have been determined for various post-natal ages of English Romney lambs in six lamb crops.

A maximum site-sampling error has been determined for use in assessing the degree of significance of differences in values of the ratio S/P determined from successive skin samples from individual lambs. Variations encountered in these Romney lambs in the level of their follicle and fibre ratios, in their rates of change and in the degree of their association with live-weight changes show that rigid conclusions based on data from one lamb crop only are not justified. An intensive study of birth and 8-day old samples has shown that follicles may regress in the early post-natal life of the lamb.

Not all follicle anlagen are initiated before birth and the ‘ceiling value’ of the adult ratio Sf/Pf is not necessarily determined or set pre-natally except in the sense of there being a genetic maximum which may or may not be attained. Low restricted follicle and fibre ratios at birth may increase rapidly postnatally and high ratios at birth may increase little, if at all, post-natally. The follicle and fibre ratio may increase even between the ages of 6 and 12 months.