bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of sex and gonadectomy on the growth and development of Southdown × Romney cross lambs. Part I. Effects on live–weight growth and components of live weight
Authors: Everitt G. C. , Jury K. E. 
Published: March 2009

The influence of sex and gonadectomy on liveweight growth and its components was examined in a comparative slaughter experiment using Southdown – Romney cross lambs run under New Zealand pastoral feeding conditions.Twenty ram lambs were castrated and 20 ewe lambs spayed at docking, at approximately 4 weeks of age. Ten ram and 10 ewe lambs were killed at this age and 5 lambs from each of the four ‘sexes’ (entire and gonadectomized, male and female) were killed 4, 8,12 and 24 weeks after docking.Live-weight gain was higher for males than females and higher for entire than gonadectomized lambs, with some evidence of a greater depression in growth associated with castration than spaying. Effects on carcass weight followed those on live weight; weights for entire rams, wethers, entire and spayed ewes were 16.92, 14.72, 14.02 and 12.46 kg. respectively at approximately 7 months of age.
The distribution of herbage at different heights in ‘grazed’ and ‘dung patch’ areas of a sward under two methods of grazing management
Authors: Tayler J. C. , Rudman J. E. 
Published: March 2009

A study of the horizontal and vertical distribution of herbage in grass-dominant swards was made to assess the relative importance of different sources of wastage during grazing. A sward grazed by cattle under two contrasting managements was divided, for the purpose of herbage sampling, into two categories: ‘grazed’ herbage, on ground with no obvious dung contamination, and ‘dung patches’, which were of ungrazed or lightly grazed herbage resulting from the effects of faeces dropped at previous grazings. In each category, samples were cut at two successive heights to provide an estimate of the quantity of herbage in the upper region of the sward (over 2½ in. from ground level) and in the lower region (½-2½ in. from ground level).After grazing, some 35% of the original crop remained in ‘grazed’ areas, and some 20% in ‘dung patches’. In terms of vertical distribution, most of the residue (40% of the original crop) was in the lower region, from ½ to 2½ in. above ground level.Total production as live-weight gain was not significantly different, but the yield of conserved herbage was greater in treatment R (five rotations) than in treatment RR (nineteen rotations). Frequent grazing reduced herbage production, and this effect was not offset by any less intense defoliation of the frequently grazed sward. The average quantity of herbage residue was no higher in treatment RR than in treatment R, although the time of occupation per plot by the cattle in RR was only a quarter of that of the cattle in treatment R.
Heat tolerance in dehydrated steers
Authors: Bianca W. 
Published: March 2009

Six steers kept in an environment of 15°C. were deprived of water for four consecutive days. This treatment, by depressing appetite, caused a reduction in voluntary hay intake to one-quarter of its normal level and a decrease in body weight by 10%.In spite of this reduction in feed intake, which must have been accompanied by a fall in metabolic heat production, the animals were less able to tolerate heat than when they were normally watered: during 4 hr. exposures to temperatures of 40.0°C. dry bulb and 32.5°C. wet bulb the waterdepleted animals showed higher values of rectal and skin temperature. This was associated with a slower initial rise and lower final values of respiratory rate (130 versus 155 respirations/min.).
The effect of year, suckling, dry season and type of dam (ewe or gimmer) on milk production in East African Blackheaded sheep as measured by lamb growth
Authors: Sacker G. D. , Trail J. C. M. 
Published: March 2009

1. The mean daily live weight gains of lambs were used to estimate the milk production of ewes and gimmers during the first 8 weeks of lactation. Records of 1178 lambings of East African Blackheaded sheep between the years 1952 and 1962 were available.2. Gimmers had significantly lower production than second and subsequent lamb ewes. Ewes rearing twins had a significantly higher yield than ewes rearing singles. There appeared to be no difference in yield between ewes producing twins but rearing singles, and ewes rearing natural singles.3. A long dry season with resultant lowered plane of nutrition significantly reduced the live-weight gain of lambs.
Rothamsted irrigation 1964–76
Authors: French B. K. , Legg B. J. 
Published: March 2009

SummaryA series of irrigation experiments was done at Rothamsted where the soil is a flinty silty clay loam over flinty clay. The results are compared with those obtained by Penman (1962, 1970, 1971) at Woburn where the soil is a loamy sand over sand. The limiting deficits, Di, above which irrigation increased yields, were about 2·5 times greater at Rothamsted than at Woburn; this ratio approximates to the ratio of the water-holding capacities of the soils (– 0·1 to – 15 bar) to a depth of 1 m. The limiting deficits at Rothamsted were 80 mm for spring-sown field beans, 84 mm for main-crop potatoes, 100 mm for spring barley and 140 mm for spring and winter wheat. The responses to irrigation were not determined accurately as there were few years with a large response for any crop. However, the evidence is that the maximum response that could be expected for potatoes was 0·19 t/ha/mm water, and for grain dry matter of beans 0·006 t/ha/mm. The figure for potatoes agrees with that obtained by Penman at Woburn; the response of beans was much smaller at Rothamsted, partly because of severe attacks of broad bean stain virus.
Body composition in lactating sheep and its indirect measurement in the live animal using tritiated water
Authors: Foot J. Z. , Skedd E. , McFarlane D. N. 
Published: March 2009

SummaryIn two experiments with female Scottish Blackface or Border Leicester x Scottish Blackface sheep nine or ten animals were slaughtered in mid lactation and the remainder either in November at the time of the subsequent mating (Expt 1) or at weaning (Expt 2).The sheep were infused periodically, including just before slaughter, with 100 μCi tritiated water (TOH) in order to measure total body water by dilution and to estimate body fat using the inverse relationship between the proportions of fat and water in the body. The accuracy of the methods was assessed when the sheep were slaughtered. In the ton lactating Scottish Blackface sheep of Expt 1 fat made up 11.5% of the total body weight with an S.D. of 8·38% whereas the 11 sheep slaughtered at mating were twice as fat (23·2, S.D. 4·01 %). The 25 Border Leicester × Blackface sheep were all thin, whether they were slaughtered in mid lactation (4·4, S.D. 2·56%) or at weaning (3·4, S.D. 2·81%).The standard error of estimate of body water from TOH space in Expt 2 was 1·2 kg c.v. 2·8%) and lower in Expt 1.The precision with which an animal could be weighed was very important in determining the accuracy with which body fat could be predicted from live weight and TOH space. In both experiments the standard error of estimate for body fat in lactating sheep was between 600 and 700 g, compared with 1·3–2·7 kg when body fat was predicted from live weight alone. These estimates were sufficiently accurate to be of value in following changes in body composition in live animals as their nutritional and physiological state alters and for comparing animals in groups where the average fatness is greater and the range wider than in the sheep used in Expt 2.
The distribution of insect pests on crops of oil-seed rape (Brassica napus L.) and the damage they cause
Authors: Free J. B. , Williams Ingrid H. 
Published: March 2009

SummaryDuring 3 years the distribution of pests on ten crops of winter rape and two of spring rape, and the damage they caused, has been determined.During immigration the adults of all pests infested crop edges more than crop centres, particularly on large crops, irrespective of the presence of wind breaks. The proportion of M. aeneus and G. assimilis at the crop edge gradually diminished as they moved further into the crop, and their larvae and pods with C. assimilis emergence holes were more evenly distributed over the crops than the adults. Damage by M. aeneus was not the only cause of podless stalks. The larvae of D. brassicae were largely confined to the edges of crops; split pods were largely but not solely confined to the edges.In winter rape crops correlations were found between the percentage of podless stalks per plant and the number of M. aeneus present, and the percentage of pods infested with C. assimilis larvae and the adult C. assimilis population. In two fields infested with D. brassicae the diminution in the proportion of split pods from crop edge to crop centre was positively correlated with diminution in the number of adult D. brassicae.
Thermoneutral zone of chickens as determined by measuring heat production, respiration rate, and electromyographic and electroencephalographic activity in light and dark environments and changing ambient temperatures
Authors: Kampen M. Van , Mitchell B. W. , Siegel H. S. 
Published: March 2009

SummaryElectromyographic (EMG) activity, electroencephalographic (EEG) activity, heat production (H), respiration rate (RR), and body temperature (TB) of unacclimatized chickens were measured during periods of light and darkness at ambient temperatures (Ta) between 7·7 and 37·7 °C. The difference between pectoral muscle and abdomen temperature was less than 0·1 °C over the entire temperature range. Body temperature increased (P ≤ O·l) when Tawas above 27·5 °C and was higher in the light than in the dark (P ≤ 0·05). Respiration rate decreased significantly with increasing Ta. The decrease, however, was not as great during the dark (P ≤ 0·05) as during the light period (P s£ 001). Heat production decreased (P ≤ 0·01) with increasingTaup toTa= 22·3 °C. There was no significant difference between heat production during the light period and that during the dark period. EMG amplitude declined (P ≤ 0·01) with increasingTaup to 27·5 °C in the light and 22·3 °C in the dark and was higher (P ≤ 0·05) in the light than in the dark. Mean frequency of EMG activity was independent of light andTa. The percentage of low-frequency EEG activity in the dark did not change significantly over the entireTarange, but in the light it decreased asTaincreased above 25·7 °C (P ≤ 0·05). The percentage of high-frequency EEG activity appeared as a mirror image of low-frequency activity. Overall results indicated a thermoneutral zone between 32·2 and 37·7 °C in the light and between 27·5 and 37·7 °C in the dark.
Evaluation of the number of spermatozoa in bull semen. A comparison between electronic counting, light scattering and absorptiometry
Authors: Iversen Simon 
Published: March 2009

The number of spermatozoa in bull semen was determined by electronic counting, light scattering and absorptiometry. Electronic counting was found to be accurate, fast and reliable and seems to be the method of choice.Determination of the light scattering was found to be the more sensitive of the indirect methods, but absorptiometry also yields consistent and reliable results. The accuracy obtained by absorptiometry was found to be independent of the sensitivity of the instrument.
The relationships between tuber size and tuber concentrations of nitrogen, phosphorus and potassium
Authors: Allen E. J. , Wurr D. C. E. 
Published: March 2009

SummaryIn each of two experiments two potato varieties were grown at a range of plant densities in order to provide mature tubers of different sizes for the study of the relationshipsbetween tuber size and tuber concentration of nitrogen (N), phosphorus (P) and potassium (K). As tuber size increased, the concentrations of tuber nutrients (g/100 g dry matter) declined to a minimum value and then tended to increase with a further increase in tuber size. This suggests that when tuber samples are taken for the determination of tuber nutrient concentration on a dry-weight basis the sampling procedure should ensure that results do not vary because of differences in the tuber size distribution.
Intake and utilization of food by growing lambs with parasitic damage to the small intestine caused by daily dosing with Trichostrongylus colubriformis larvae
Authors: Sykes A. R. , Coop R. L. 
Published: March 2009

SummaryFour groups of eight lambs, 4 months of age and reared parasite-free from birth, were used to investigate the effect of the intestinal parasite Trichostrongylus colubriformis on the intake and efficiency of utilization of food, using balance trial and comparative slaughter techniques. One group (CI) was killed initially as control. Two further groups (ALC and ALI) were offered ad libitum a complete ruminant diet. The ALI group was dosed orally each day for 14 weeks with 2500 infective larvae. Sheep in a further group (PF) were individually paired to members of the ALI group, and given the same amount of food as their pair. Balances of nitrogen, Ca and P and the digestibility of dry matter and energy were determined for the ALI and PF groups during weeks 6–7 and 12–13 and after 98 days of infection the sheep were killed. The bodies of these and the CI and ALC sheep were analysed for water, fat, nitrogen, Ca and P contents.Parasitism reduced food intake over the whole experiment by 9%, but had no effect on the digestibility of energy or nitrogen. At the first trial the N balances of the ALI group were inferior to those of the PF group due to increased urinary N excretion, but there was no difference at the second trial. Ca and P balances of the ALI group tended to be inferior to those of the PF group at both trials. The weight gain of the ALI sheep was only 50 % of that of the PF sheep with the same digestible energy and protein intakes. The protein content of the gain in empty body weight of the ALI sheep was 80 g/kg compared with 112 and 124g/kg in the ALC and PF groups, respectively. Possible causes of the poor protein anabolism are discussed.The gross efficiency of utilization of metabolizable energy for growth was calculated to be 13·3 % in the ALI sheep, compared with 26·2 and 24·2 % respectively, in the ALC and PF groups. It was not possible to determine whether this was due to change in maintenance requirement or in efficiency of fattening.The Ca and P content of the skeletons of the ALC and PF sheep increased by 55 % during the 98-day period, while no net change occurred in the ALI sheep. It was concluded that this was caused by an induced mineral deficiency resulting from parasitic damage in the small intestine.
The effect of tri-n-butyl phosphate on the drying rate and respiration rate of grass leaves measured in the laboratory
Authors: Harris C. E. , May-Brown R. 
Published: March 2009

SummaryIn laboratory tests tri-n-butyl phosphate applied by spraying as an emulsion at a rate equivalent to 0·25% of leaf fresh weight doubled the drying rate of individual S.24 perennial ryegrass leaves measured at 28 °C, relative humidity 22% and air speed 40 cm/sec. Increasing the rate of application produced no further increase in drying rate. In other experiments the same rate of application stopped respiration of leaves and no resumption of respiration was found in the subsequent 4 days. Comparisons of the dry-matter contents of leaves when removed from the plant and after being allowed to dry for 1 week at 27 °C and relative humidity 80%, indicated that inhibition of respiration resulted in large reductions in dry-matter losses. The potential value of a chemical spray which will both increase drying rate and reduce respiration as an aidto the field drying of grass crops is discussed. While it would be incautious to extrapolate from laboratory tests on single leaves to the field situation, evaluation under more practical conditions is clearly warranted.
Improvements in calcined magnesite as a magnesium fertilizer
Authors: Durrant M. J. , Draycott A. P. 
Published: March 2009

SummaryA laboratory and glasshouse study investigated whether it was possible to improve the availability of magnesium from calcined magnesite (MgO). Samples varying from largely unchanged magnesite (MgCO3) to overburnt MgO were made by calcining small quantities of magnesite ore for up to 6 h at several temperatures between 500 and 1000 °C in the laboratory. The effect of calcining conditions on weight loss on ignition, particle size distribution, total, water-soluble and NH4+ -exchangeable Mg was determined and results compared with the current commercial oxide and kieserite (MgSO4. H2O).The results indicated that an oxide could be produced containing nearly double the amount of readily-exchangeable Mg of the oxide used at present. The analysis showed that the most reactive oxide was produced either by burning for 3 h at 700 °C or about half-an-hour at 800 °C, i.e. the minimum time at each temperature for complete conversion of the carbonate to the oxide. Either of these two oxides increased the Mg in plants of the three crops grown in the glasshouse by 0·3% on average, whereas plants given the commercial oxide increased it by only 0·2%. The three crops removed about 70% of the applied Mg from the most reactive oxides but only 50% of the Mg from the commercial oxide. The results of an incubation experiment suggested that burning at 700 °C for 3 h gave a marginally more reactive oxide than the short burn at 800 °C. However, the most reactive oxide produced supplied magnesium at a slower rate than kieserite. This may not necessarily be a disadvantage since most of the soils where Mg deficiency of sugar beet and similar crops is a potential problem need a Mg fertilizer which maintains or gradually increases soil Mg. Thus the improved oxide may bo suitable and a comparison in field experiments of the effects of kieserite and oxides produced under different calcining conditions is needed.
Depot fatty acids of Aberdeen Angus and Friesian cattle reared on hay and barley diets
Authors: Leat W. M. F. 
Published: March 2009

SummaryAberdeen Angus and Friesian cattle were reared from 4 months of age to slaughter weight at 18–24 months on either high-barley or high-hay diets. Samples of subcutaneous fat were taken by biopsy at 3 monthly intervals, and the degree of fatness of each animal was estimated ultrasonically prior to slaughter, and by visual inspection of the carcasses.The barley-fed animals gained weight more rapidly, and fattened more quickly than the hay-fed animals with the Angus being fatter than the Friesian at the same age. The percentage stearic acid (C18:0) in subcutaneous fat decreased with age and was replaced by octadecenoic acid (C18:l) and hexadecenoic acid (C16:l), these changes being more rapid in barley-fed than in hay-fed animals. At the same degree of fatness the depot fats of the Friesians were more unsaturated than those of the Angus, and in both breeds the fatter the animal the more unsaturated was its depot fat.In the hay-fed cattle the percentage C16:0 in subcutaneous fat increased during the last half of the experiment and at slaughter the percentage C16:0 was significantly higher, and C18:l significantly lower, in all depot fats compared with those of the barley-fed animals.It is concluded that the fatty acid composition of bovine depot fats is modulated by the degree of fattening, and can be affected by diet.
Relationships between energy intake, nutritional state and lamb birth weight in Greyface ewes
Authors: Russel A. J. F. , Maxwell T. J. , Sibbald A. R. , McDonald D. 
Published: March 2009

SummaryIndividual feed intakes of housed mature Greyface (Border Leicester × Scottish Blackface) ewes were adjusted weekly to maintain plasma 3-hydroxybutyrate concentrations during the final 6 weeks of pregnancy at the following values: treatment 1 (adequately nourished; 17 ewes) less than 0·7 mmol/1; treatment 2 (moderately undernourished; 15 ewes) at about 1·1 mmol/1; treatment 3 (severely undernourished; 15 ewes) at about 1·6 mmol/1.The mean energy intakes (MJ metabolizable energy (ME)/day) required to maintain the prescribed nutritional states in single- and twin-bearing ewes were: treatment 1, 14·3 and 16·3; treatment 2, 10·6 and 11·6; treatment 3, 8·1 and 10·0 respectively.The moderate degree of undernourishment had no significant effect on the birth weight of single lambs, but reduced the birth weight of twins by 8·2%, while the more severe undernourishment reduced the birth weights of singles and twins by 21·5 and 25·8% respectively.Foetal energy requirements, estimated by regression analysis, appeared to decrease from more than 2 MJ ME/kg/24 h at 35 days prepartum to 1·54 MJ ME/kg/24 h in the week before parturition.The amounts of energy required to sustain the nutritional states of treatments 1–3 in non-pregnant ewes were calculated to be 348, 271 and 231 kJ ME/kg0.75/24 h, compared with a maintenance requirement, determined in this experiment, of 344 kJ ME/kg0.75/24h.It is concluded that in individually fed ewes a nutritional state characterized by plasma 3-hydroxybutyrate concentrations of 1·1 mmol/1 would constitute an acceptable compromise between an uneconomically high energy input and an excessive reduction in lamb birth weight.
Bone weight distribution in steer carcasses of different breeds and crosses, and the prediction of carcass bone content from the bone content of joints
Authors: Kempster A. J. , Cuthbertson A. , Jones D. W. 
Published: March 2009

SummaryDissection data for 753 steer carcasses from 17 breed-type × feeding system groups were used to examine the distribution of bone weight between 11 standardized commercial joints, and the prediction of bone content in side (half carcass) from the bone content of individual joints. Breed types included Ayrshire, Friesian, Friesian × Ayrshire and crosses out of Friesians by Angus, Charolais, Hereford, Limousin, Simmental and South Devon sires. Group means for bone weight in the side ranged from 14·9 to 21·0 kg with a pooled within-group S.D. of 1·97 kg.The increase in bone weight in each joint relative to that in the side was examined using the allometric equation. Pooled within-group growth coefficients (b values) were lowest for the leg (hind shin) and shin (fore shin) joints (b = 0·86 ± 0·02 and 0·94 ± 0·02 respectively) and highest for the sirloin (b = 1·10 ± 0·05).At equal total bone weight, there were significant (P < 0·001) but relatively small differences between groups in the weight of bone in each of the joints tested.Bone weights in the top piece, shin and coast joints gave the most precise prediction of bone weight in the side: the pooled within group residual standard deviations were 0·62, 0·67 and 0·71 kg respectively. The limited variation between groups in bone weight distribution was reflected in the robustness of common prediction equations across groups.
Time of application of farmyard manure and fertilizer nitrogen on the growth, yield and nutrient uptake of dryland wheat
Authors: Singh R. K. , De R. , Turkhede B. B. 
Published: March 2009

SUMMARYExperiments made for 4 years in the seasonally dry period of the monsoon environment of north-west India showed that the application of farmyard manure (FYM) with the onset of monsoon rains (in early July) was more advantageous for the growth and yield of wheat than its application at the end of the monsoon season in mid-September. Fertilizer N drilled into the soil with the cessation of rains was better utilized by wheat than that applied at sowing in mid-November. A combination of the organic matter and urea was better than their application separately. N, P and K removal by the wheat crop was significantly increased by FYM and urea application. The time of their application influenced the nutrient removal by the crop in the same way as it affected its growth and yield.