bluuebunny/crossref_metadata_2025_split huggingface dataset:
A further study of a rigid grazing management system for dairy cows
Authors: Marsh R. , Campling R. C. , Holmes W. 
Published: September 2010

SUMMARY1. An experiment was conducted with dairy cows over two grazing seasons to investigate the feasibility of fixed rotational grazing. Each year a comparison was made between treatment A, which consisted of four equal paddocks grazed for 1 week and rested for 3, and treatment B, which contained five paddocks grazed for 1 week and rested for 4. The influence of the length of the rest periods on output per hectare and per cow was measured. Within each paddock approximately one-seventh of the area was allocated daily to each treatment group, there were no back fences and the paddocks were not topped or harrowed. Stocking rates were identical on both treatments at all times at 6·2 cows per ha throughout 1964; 7·1 cows per ha for weeks 1·9 inclusive and 6·2 cows per ha for weeks 10·20 inclusive in 1968. The fertilizer nitrogen applied (282 kg/ha) was equivalent to a daily rate of 2·02 kg/ha. The feed intake of each cow was measured on three occasions during 1967 and four in 1968.2. Differences between treatments in outputs per ha were small and on average about 13 000 kg milk and 890 cow grazing days were produced per ha during the 20-week experimental period.3. Differences between treatments A and B in herbage intake, milk production, milk composition and live-weight change were not statistically significant.4. When 3·6 kg of a supplementary concentrate was given to some cows, positive responses in milk production, milk composition and live-weight change were found, but the value of the extra milk produced was less than the cost of the concentrate.
The growth of young cattle fed on dried grass alone and with barley 1. Feed intake, digestibility and body gains
Authors: Lonsdale C. R. , Poutiainen E. K. , Tayler J. C. 
Published: September 2010

SUMMARY1. The primary growth of a sward of S24 perennial ryegrass was harvested between 23 April and 9 May 1968, artificially dried and either chopped or coarsely milled. The two physical forms of grass were wafered either alone or together with 50% by dry weight of rolled, anaerobically stored barley, and given to 7-month-old, Hereford × British Friesian steers in an experiment of 2 × 2 factorial design.2. A representative group of animals was slaughtered at the beginning of the experiment, and the remainder were individually fed ad libitum for 70 days, after which they also were slaughtered. During the feeding period digestibility was determined by total faecal collection from all the animals individually on two occasions.3. Dry-matter intake and live-weight gain were similar on all feeds. The weight of gut contents as a percentage of final live weight was significantly lower and the carcass-weight gain was significantly higher for animals given wafers containing barley compared with those for animals given wafers of grass alone.4. Coarse milling compared with chopping reduced the apparent digestibility of dry matter, organic matter, cellulose and energy; the addition of barley increased the digestibility of organic matter but further reduced that of cellulose.5. The efficiency of conversion of digested energy to empty-weight or carcass gain was similar for wafers containing the two forms of forage, but the digested energy of wafers containing barley was converted to carcass weight with significantly greater efficiency than that of wafers consisting solely of grass.6. Physical separation of the tissues of sample joints failed to show any significant differences in the proportion of fat, muscle and bone as a result of either differences in physical form or the inclusion of barley.7. The results indicate that live-weight gain is an insufficiently sensitive measurement by which to assess the true productive potential of feeds given to ruminants in short-term experiments.
A note on the consumption of water by the growing pig at several environmental temperatures and levels of feeding
Authors: Mount L. E. , Holmes C. W. , Close W. H. , Morrison S. R. , Start I. B. 
Published: September 2010

SUMMARYThe voluntary intake of water by 24 groups of 3 to 6 Large White pigs (range of mean body weight: 21 to 73 kg) was measured during a total of 48 periods lasting 3 to 12 weeks each in a large calorimeter equipped as a pig pen. The calorimeter temperature was controlled between 7° and 33°C and the pigs were fed at levels ranging from 42 g feed/kg body weight per day to maximal intake. The mean water: feed ratios were between 2·1 and 2·7 at temperatures between 7° and 22°C, and between 2·8 and 5·0 at 30° and 33°C. The range of mean water consumption extended from 0·092 to 0·184 litre/kg body weight per day.
Effect of level of feed intake on the performance and carcass composition of growing pigs
Authors: Barber R. S. , Braude R. , Mitchell K. G. , Pittman R. J. 
Published: September 2010

SUMMARY1. Twelve blocks of six enzootic-pneumonia-free Large White litter-mate pigs were individually fed, wet, from 20 to 92 kg live weight on six different levels of feed intake. Four groups were fed according to scales based on live weight and two were fed on a ‘semi-ad libitum’ system. One of the scales used was based on the ARC (1967) recommendations.2. Pigs on ‘semi-ad libitum’ feeding grew significantly faster than those on scale feeding although the feed: gain ratios were similar. Differences in performance between the four scale-fed groups were relatively small.3. Although treatment differences in carcass measurements were in the main small, the commercial grading results favoured the carcasses from the scale-fed pigs. The firmness of backfat assessed by thumb pressure was reduced as the level of feeding was increased.4. The results were compared with those obtained in a similar trial carried out at Shinfield in 1957 using pigs of a completely different genetic background. The general conclusions reached were similar in the two trials, that to obtain the most satisfactory overall results some form of controlled scale-feeding was necessary.
Utilization of cellulose by pigs and its effects on caecal function
Authors: Farrell D. J. , Johnson K. A. 
Published: September 2010

SUMMARY1. Six pigs, four with caecal cannulae, were given diets containing 8% or 26% cellulose. Cannulation did not affect the digestibility of dry matter or cellulose.2. Digestibility of cellulose, though variable, was higher for the 8%-cellulose diet.3. Pigs on the 26%-cellulose diet had larger amounts of digesta in the caecum, and lower caecal retention times, than pigs on the 8%-cellulose diet.4. Measurements of production rates of volatile fatty acids in the caecum indicated that only 2·7% and 1·9% of the apparent digestible energy of the 26%- and 8%-cellulose diets respectively came from the acids, and it was concluded that the caecum played only a small role in the breakdown of feed substances.
Influence of energy and protein concentration in the diet on the performance of growing pigs 4. Effects of sex on response to dietary protein level
Authors: Lodge G. A. , Hardy B. , Lewis D. 
Published: September 2010

SUMMARYTwo barrows and two gilts from each of 16 litters, by Landrace sires out of Large White × Landrace females, were fed individually one of 4 dietary protein levels (approximately 14%, 17%, 20% and 23% CP) at a common energy level (approximately 3165 kcal/kg DE), from an initial weight of 23 kg to slaughter at 59 kg.The 17% CP diet gave 19% faster growth and 17% better feed conversion than the 14% CP diet (P < 0·01) with no evident change resulting from further increase in protein level, while the 23% CP diet gave 29% more lean than the 14% CP diet (P< 0·01), as assessed by dis-section of a sample joint.There were no significant differences between sexes in growth rate, efficiency of feed conversion or carcass composition. Only depth of backfat on the shoulder and at ‘K’ and carcass length showed significant (P < 0·05) sex differences, and the only sex × diet interaction was in eye-muscle area. The results are discussed in relation to those presented in the previous three papers of the series.
A note on mating ability in clun forest ram lambs
Authors: Dýrmundsson Ó. R. , Lees J. L. 
Published: September 2010

SUMMARYSome aspects of sexual development and mating behaviour in Clun Forest ram lambs having a wide range of birth dates were studied during two seasons. The 61 ram lambs studied were introduced individually to Clun ewes in oestrus, for short periods at fortnightly intervals during late summer and autumn. Complete matings, i.e. intromission and ejaculation, were first achieved at a mean age of 6 months (range 142–223 days) and a mean body weight of 35 kg (range 24–49 kg). The attainment of physiological puberty preceded the first copulation, often by several weeks. A few individuals had abnormal testes and were partly or completely sterile, but exhibited normal mating behaviour. Early-born lambs tended to complete their first matings at a higher age and heavier body weight than late-born lambs, which suggests a possible seasonal influence on the development of breeding activity in the ram lamb.
A comparison between a rigid rotational grazing system for dairy cows and a system in which grazing alternated with cutting
Authors: Holmes W. , Campling R. C. , Joshi N. D. 
Published: September 2010

SUMMARYTwo experiments were made with dairy cows in 1969 and 1970 to compare two grazing systems. Treatment A was a rigid rotational system and B was a system in which cows always grazed on an area which had been cut 4 weeks earlier for conservation. For both treatments the stocking rate was 6·2 cow/ha and fertilizer N was applied at a rate equivalent to 2·5 kg/ha per day.Individual records of milk yield, milk composition and live weight were kept, the quality of herbage available was estimated weekly, and individual intakes were estimated by faecal index methods at approxi- mately monthly intervals. In 1969 the cows remained on the same treatment throughout the season and in 1970 a reversal design was adopted.The quantities and quality of herbage available per cow were generally similar under both treatments. There were no significant differences in feed intake, or animal production between the treatments. High yields of 11900 kg milk and 28 000 Meal ME per hectare were recorded.
A note on the voluntary intake of Andropogon gayanus hay by cattle, as affected by level of feeding
Authors: Zemmelink G. , Haggar R. J. , Davies J. H. 
Published: September 2010

SUMMARYUnchaffed Andropogon gayanus hays, harvested in July, September, early-October, late-October and November, and the July to November regrowth, were offered to White Fulani heifers at three levels of feeding.Animals on all hays selected for protein and the mean intake of the different hays was closely related to the protein content of the consumed forage. At the low level of feeding all animals, except those on the July hay, left more than 15% residue. Nevertheless, higher levels of feeding had a marked linear effect on feed intake. This effect was largely independent of the effect of level of feeding on the protein content of the consumed ration and was associated with a strong selection for leaves.
Responses to variations in dietary energy intakes by growing pigs 2. The effects on feed conversion efficiency of changes in level of intake above maintenance
Authors: Davies J. L. , Lucas I. A. M. 
Published: September 2010

SUMMARYAllowances of about 1·4M, 1·8M, 2·2M, 2·6M, 3·OM, and 3·4M (M = feed required for maintenance) were compared for pigs growing over the live-weight ranges 20·40, 40·60, 60·80, and 80·100 kg, with feed conversion efficiency (FCE) as the main response criterion.Response to increased digestible energy (DE) allowance was curvilinear; FCE improved rapidly up to 2·2M-2·6M, and changed much less with intakes above 2·6M. It is concluded that optimum FCE occurs at about 2·7M for pigs of 30 kg and at about 3·OM for pigs of 50, 70 and 90 kg.Allowances of dietary DE suggested by the Agricultural Research Council correspond to 2·56M, 2·95M, 3·04M and 3·08M for pigs of 30, 50, 70 and 90 kg live weight, respectively. It appears that these are near to the optima in promoting the best FCE.Changes of −25%, −15%, −5%, +5% and +15% in daily intake around the optimum levels caused FCE to deteriorate by averages of about 13%, 4·5%, <1%, <1% and 4·5% respectively. Daily weight gains would then change by about −34%, −18%, −5%, +4% and +10%, respectively.
Stimulation of protein absorption in the newborn piglet's intestine through the use of polyvalent cations
Authors: Smith M. W. , Burton K. A. 
Published: September 2010

SUMMARYThe transport of protein across the small intestine of the newborn pig was measuredin vitro. The transport of both bovine immune globulin and bovine plasma albumin showed a large variation between piglets. The polycations poly-ornithine, poly-arginine and poly-lysine stimulated both the transport of globulin and albumin. Protamine, histone and arginine were without effect on protein transport. Poly-ornithine became bound to albumin and to the piglet intestinal mucosa. The amount of poly-ornithine needed to stimulate albumin transport was of the same order as that needed to change the electrophoretic mobility of brush border membranes and some 30 times less than that needed to change the charge on the protein. It is concluded that polycations stimulate protein transport by a direct action on the brush border membrane of the pig intestinal mucosa.
Some factors affecting reproducibility in ultrasonic scanning of animals 1. Cattle
Authors: Miles C. A. , Pomeroy R. W. , Harries J. M. 
Published: September 2010

SUMMARYSix Hereford and Shorthorn cross steers were ultrasonically scanned in parallel planes perpendicular to the spine. Scanning was performed at the level of each vertebra and extended from the head of the 9th rib to the articulation of the 3rd and 4th lumbar vertebrae. Scans of each live animal were compared with those of its hot carcass and related to dissected sections of the frozen carcass. In general, the difference between an ultrasonic estimate and the carcass measurement was found to depend on the anatomical parameter being investigated, the location on the animal at which measurement was made and the individual interpreting the scan. Results are presented for fat thickness, Mm. longissimi thoracis et lumborum depth, ‘A’, ‘B’ and area measurements. Possible explanations for some discrepancies between the ultrasonic and carcass measurements are discussed.Additional results showed that whilst judges are consistent within themselves, in general their interpretations of ultrasonic scans differ significantly from each other.
Urine protein levels in the pig
Authors: Wah Loh San , Bourne F. J. , Curtis Jill 
Published: September 2010

SUMMARYSows housed with free access to water were found to have urine protein levels comparable to those recorded for man, dog and sheep. However, in stalled sows with restricted access to water, urine protein levels were twice as high as those of penned sows.Physiological proteinuria has been found to occur in the piglet, in which respect it is similar to the ruminant and the dog. Proteinuria reaches a peak within 20 hr of birth and lasts for approximately 48 hr. The rapid decline in urine protein levels after this period coincides with gut closure. Proteinuria did not occur in piglets fed on glucose saline, only in those receiving colostrum; however, the continued feeding of colostrum did not prolong the period of proteinuria. In piglets fed varying levels of colostral protein there was a direct correlation between serum protein levels and mean urinary protein concentration during the period of proteinuria, but there was no direct correlation between the amounts of colostral protein ingested and the serum protein level.
The survival of embryos transferred in large groups to sheep of breeds with different ovulation rates
Authors: Land R. B. , Wilmut I. 
Published: September 2010

SUMMARYThe possibility that embryo survival in a breed of sheep may be related to the number of embryos normally present after natural mating was investigated by transferring large numbers of embryos to sheep of breeds with an approximately two-fold difference in ovulation rate. When the same number of embryos (14) was transferred to each of 12 Scottish Blackface and 11 Finnish Landrace ewes survival was greater in the Finn ewes (10%) than in the Black-faces (4%). The survival of 28% of embryos when transferred in groups of 7 to each of 14 Scottish Blackface ewes indicated that survival was not similar in the two breeds when the number of embryos present was a similar multiple of their natural ovulation rates. When the number of embryos transferred to Scottish Black-face ewes increased from 7 to 14 the decline in survival rate was so great that the number of lambs born also declined, indicating an intermediate optimum ovulation rate for maximum litter size.
Teat orifice stretchability associated with teat diameter gradient and milk yield in lactating cows
Authors: Rathore A. K. , Sheldrake R. F. 
Published: September 2010

SUMMARYTeat canal stretchability was measured on 119 lactating cows from two dairy farms, using a probe. Diameter of one hind teat was measured by calipers at the proximal end of the teat and 20 mm above its distal end. Teat canal stretchability, teat diameter at the proximal end and teat diameter gradient were highly correlated with milk yield. Cows with higher teat diameter gradient (i.e., funnel-shaped teats) had higher teat canal stretchability values compared with the cows with lower teat gradient values (i.e., cylindrical teats). Stretchability of the hind teat canal was significantly greater than the stretchability of the fore teat canal.
Open nucleus breeding systems
Authors: James J. W. 
Published: September 2010

SUMMARYA theoretical analysis of open nucleus breeding systems, in which there is some introduction of breeding females to the sire breeding nucleus, is presented. Numerical analysis of a discrete generation model shows that the rate of genetic gain may be increased by 10 to 15% by opening the nucleus when selection intensity in females is low. In sheep and beef cattle breeding the optimal structure would be to have about 10% of the population in the nucleus, to get half of the nucleus female replacements from the base population, and to use all nucleus-born females not needed as nucleus replacements for breeding in the base population. The genetic gain, however, is not very sensitive to variation in these parameters. The rate of inbreeding in such an open nucleus would be about half that in a closed nucleus of the same size.
Coordinated trials on the protein requirements of sows 1. A comparison of four levels of dietary protein in gestation and two in lactation
Authors: Greenhalgh J. F. D. , Elsley F. W. H. , Grubb D. A. , Lightfoot A. L. , Saul D. W. , Smith P. , Walker N. , Williams D. , Yeo M. L. 
Published: September 2010

SUMMARY1. Gestation diets formulated to contain A, 9; B, 11; C, 13 or D, 15% protein, and lactation diets with C, 13 or E, 17% protein provided eight treatment combinations. They were given at seven centres at 2 kg/day in gestation and approximately 5·7 kg/day in lactation to sows which remained on experiment for three to five parities and produced in total 468 litters. Mean results for parities one to four are given in this summary.2. For gestation diets A to D mean litter size at birth was 9·7, 10·1, 10·3 and 10·4 live pigs, and at weaning (at 6 weeks), 8·2, 8·7, 8·8 and 8·8. Sows which received lactation diets C and E subsequently produced 10·4 and 10·3 pigs at birth and 8·9 and 8·3 at weaning.3. Gestation diets had no consistent effects on piglet weights. During lactation, however, diet E gave heavier pigs than C, by 0·2 kg at 3 weeks and 0·5 kg at weaning.4. Extra protein for either gestation or lactation had a positive effect on sow weight at that stage, but a negative effect in the following stage. There were no direct treatment effects on the time required for re-conception.5. Twenty experimental sows at the Rowett Institute, together with an additional group given diet A for both gestation and lactation, showed strong positive relationships between lactation protein intake and milk yield or composition.6. The treatment combination AC (i.e. 9% protein in gestation and 13% in lactation) gave the lowest weight of weaned pigs per litter, and CC gave the highest. The remaining treatments gave similar weights; of these BC (nominally 11 with 13, but actually 11·5 with 13·5% protein) was concluded to provide the lowest protein intake consistent with satisfactory performance.
Litter performance characteristics of pigs in tropical south-western Nigeria 1. Breed differences and effects of some non-genetic sources of variation
Authors: Leigh A. O. 
Published: September 2010

SUMMARYData for 432 litters of pigs were collected from 1965 to 1975 inclusive, at the Fasola Stock Farm, near Oyo in the Western State of Nigeria. The breeds represented were Large White, Duroc and Hampshire, and their crosses. The main objective was to investigate the effects of certain identifiable environmental sources of variation on litter performance characteristics such as litter size, mortality and weight at birth, 3 weeks and 8 weeks of age. Breed and year effects were significant for the litter size traits, but parity of dam, season and breed × season effects were significant only for litter size at birth which increased up to the fifth parity and then declined steadily in subsequent parities. Postnatal pig mortality was affected significantly by breed, litter size at birth and breed × season interaction. It was found that the larger the size of litter at birth the higher the postnatal mortality. Average pig weight at birth was reduced by approximately 0·01 kg for each additional pig in the litter.
The response of early weaned pigs to sub-optimal protein diets supplemented with synthetic lysine
Authors: Campbell R. G. 
Published: September 2010

ABSTRACTThirty male piglets weaned at 20 days of age were fed on either a control diet with 20% crude protein containing 1·1 % lysine or one of two diets with 14·6 or 16·6% crude protein. Synthetic lysine was added to the latter two diets at the rate of 0·00, 0·18, 0·36 and 0·54% to provide four diets with 14·6% crude protein and 0·54, 0·72, 0·90 or 1·08% lysine and four diets with 16·6% crude protein and 0·72, 0·90, 1·08 or 1·26% lysine. All diets were offered ad libitum to piglets between 5·5 and 20·0 kg live weight.Over the live-weight periods 5·5 to 20·0 and 12·0 to 20 kg, live-weight gains and food conversion improved with increasing total lysine to 1·08 % and 0·90 % respectively when pig performance was equal to that achieved on the control diet. The improvement in performance with an increasing level of total lysine during these two periods did not depend on the total protein content of the diet. During the live-weight period 5·5 to 12·0 kg, optimal performance was obtained when pigs were fed on the highest lysine level in the diets with 14·6 and 16·6% crude protein. However, only the diet of 16·6% crude protein promoted pig performance equal to that achieved on the control diet.Carcass quality did not respond to lysine supplementation independently of protein level. With thedietof 14·6% crude protein, optimal carcass quality was obtained with 0·90 % lysine but was significantly poorer than that for the control. With the diet of 16·6% crude protein, carcass quality improved over the entire range of lysine supplementation and with 1·26% lysine was superior to that for the control.