bluuebunny/crossref_metadata_2025 huggingface dataset:
Mantle structure and dynamics under East Russia and adjacent regions
Authors: Zhao Dapeng , Pirajno Franko , Dobretsov Nikolai L. , Liu Lucy
Published: September 2010

We present seismic images of the mantle beneath East Russia and adjacent regions and discuss geodynamic implications. Our mantle tomography shows that the subducting Pacific slab becomes stagnant in the mantle transition zone under Western Alaska, Bering Sea, Sea of Okhotsk, Japan Sea, and Northeast Asia. Many intraplate volcanoes exist in these areas, which are located above the low-velocity zones in the upper mantle above the stagnant slab, suggesting that the intraplate volcanoes are related to the dynamic processes in the big mantle wedge above the stagnant slab and the deep slab dehydration. Teleseismic tomography revealed a low-velocity zone extending down to 660 km depth beneath the Baikal rift zone, which may represent a mantle plume. The bottom depths of the Wadati–Benioff deep seismic zone and the Pacific slab itself become shallower toward the north under Kamchatka Peninsula, and the slab disappears under the northernmost Kamchatka. The slab loss is considered to be caused by the friction between the slab and the surrounding asthenosphere as the Pacific plate rotated clockwise at about 30 Ma ago, and then the slab loss was enlarged by the slab-edge pinch-off by the hot asthenospheric flow and the presence of Meiji seamounts.
Recent volcanism in relation to plate interaction and deep-level geodynamics
Authors: Kovalenko V.I. , Yarmolyuk V.V. , Bogatikov O.A.
Published: September 2010

The spatial distribution of recent (under 2 Ma) volcanism has been studied in relation to mantle hotspots and the evolution of the present-day supercontinent which we named Northern Pangea. Recent volcanism is observed in Eurasia, North and South America, Africa, Greenland, the Arctic, and the Atlantic, Indian, and Pacific Oceans. Several types of volcanism are distinguished: mid-ocean ridge (MOR) volcanism; subduction volcanism of island arcs and active continental margins (IA + ACM); continental collision (CC) volcanism; intraplate (IP) volcanism related to mantle hotspots, continental rifts, and transcontinental belts. Continental volcanism is obviously related to the evolution of Northern Pangea, which comprises Eurasia, North and South America, India, Australia, and Africa. The supercontinent is large, with predominant continental crust. The geodynamic setting and recent volcanism of Northern Pangea are determined by two opposite processes. On one hand, subduction from the Pacific Ocean, India, the Arabian Peninsula, and Africa consolidates the supercontinent. On the other hand, the spreading of oceanic plates from the Atlantic splits Northern Pangea, changes its shape as compared with Wegener’s Pangea, and causes the Atlantic geodynamics to spread to the Arctic. The long-lasting steady subduction beneath Eurasia and North America favored intense IA + ACM volcanism. Also, it caused cold lithosphere to accumulate in the deep mantle in northern Northern Pangea and replace the hot deep mantle, which was pressed to the supercontinental margins. Later on, this mantle rose as plumes (IP mafic magma sources), which were the ascending currents of global mantle convection and minor convection systems at convergent plate boundaries. Wegener’s Pangea broke up because of the African superplume, which occupied consecutively the Central Atlantic, the South Atlantic, and the Indian Ocean and expanded toward the Arctic. Intraplate plume magmatism in Eurasia and North America was accompanied by surface collisional or subduction magmatism. In the Atlantic, Arctic, Indian, and Pacific Oceans, deep-level plume magmatism (high-alkali mafic rocks) was accompanied by surface spreading magmatism (tholeiitic basalts).
Ore-magmatic systems of the Noril’sk ore field
Authors: Spiridonov E.M.
Published: September 2010

Plutonogenic ore-magmatic systems of the Noril’sk ore field are unique constituents of the P2–T1 trap formation in the East Siberian Platform. We consider the formation of ore-bearing intrusions, evolution of Cr-spinels in intrusive magmatites, possible mechanisms of formation of massive, disseminated, and impregnated magmatic sulfide ores, possible reasons for the abundance of sulfide melts, quasi-anhydrite isotopic composition of sulfur of sulfide ores, and products of interaction of sulfide melts with ore-hosting basites. The unique contents of PGE, Ag, and Au in ores (eutectic Iss–PbSss intergrowths, crystallization products of low-temperature Ni-Fe-Cu-Pb-S melts) have been estimated for the first time. We have established that pneumatolytic Ag-Au-Pt-Pd mineralization is intimately related to the fluid aureoles near magmatic sulfide bodies. Pneumatolytic PGM are subdivided into early (tetraferroplatinum with lamellae atokite, paolovite with lamellae of insizwaite-geversite and niggliite, etc.), middle (rustenburgite-atokite-zvyagintsevite, mayakite, stannopalladinite, polarite, plumbopalladinite, maslovite, tatiyanite-taimyrite, Pd-Pt-containing tetraauricupride, etc.), late (sobolevskite, froodite, hessite, michenerite, cabriite, minerals of Au-Ag series, etc.), and the latest (sperrylite). The direct, reverse, oscillation, and complex zoning of gold particles is much due to variations in the Te activity in the fluids. Pneumatolytic noble-metal minerals were produced at <490 ºC in strongly reducing conditions with extremely low S2 fugacity. The Pb isotope composition evidences that all systems of the trap formation in the Noril’sk region had the same mantle source. The Pb isotope compositions of ore-bearing intrusions, magmatic sulfide ores, PbSss, and Pd-Pt intermetallides in the Noril’sk and Talnakh ore clusters differ significantly: Lead in the Talnakh cluster is more radiogenic. This evidences genetic relations between sulfide ores and particular intrusions as well as different intermediate magma chambers in the Noril’sk and Talnakh clusters, and a higher degree of contamination of mantle magmas in the Talnakh cluster, which might be the explanation of its giant area.
Explanation and Teleology in Aristotle's Science of Nature
Authors: Leunissen Mariska
Published: September 2010

In Aristotle's teleological view of the world, natural things come to be and are present for the sake of some function or end (for example, wings are present in birds for the sake of flying). Whereas much of recent scholarship has focused on uncovering the (meta-)physical underpinnings of Aristotle's teleology and its contrasts with his notions of chance and necessity, this book examines Aristotle's use of the theory of natural teleology in producing explanations of natural phenomena. Close analyses of Aristotle's natural treatises and his Posterior Analytics show what methods are used for the discovery of functions or ends that figure in teleological explanations, how these explanations are structured, and how well they work in making sense of phenomena. The book will be valuable for all who are interested in Aristotle's natural science, his philosophy of science, and his biology.
The performance of the suckled progeny of cows of beef or dairy type
Authors: McCubbin A. , Ball C. , Broadbent P. J. , Howie A.
Published: September 2010

A comparison was made of beef-type and dairy-type suckler cows in 17 herds by forming pairs when cows of both types calved within 7 days of each other in the same herd. Cows and calves were weighed within 14 days post partum and when turned out to grass. The calves were weighed again at weaning. Winter food intakes were recorded by weighing feeds on one day of each month. Sixtynine pairs of cows were formed and 23 different levels of winter food input to the cows were computed.

Calves out of dairy-type cows were significantly heavier at turn-out (8-4 kg) and at weaning (8-3 kg). These differences were greater at higher levels of winter food intake per cow.
Some aspects of energy metabolism of the sow during pregnancy
Authors: Verstegen M. W. A. , van Es A. J. H. , Nijkamp H. J.
Published: September 2010

Sixteen energy and N-balance trials with six sows were performed to study the energy requirement and protein gain of the animals during different stages in the second half of pregnancy. Energy and N-balances were measured during periods of 1 week and gaseous exchange was measured in a respiration chamber. The animals received 2·0,2·5,2·75 or 3 0 kg/day of a normal concentrate ration for sows. In one experiment, one animal had a negative energy balance on the 2 kg ration in the sixth week of pregnancy but in the other experiments the dietary energy intake was sufficient for positive energy balances until a few days before parturition. The N-balances were about 20 to 32 g/day in the second half of the gestation period. With 2·5 and 2·75 kg feed there was a negative deposition of fat at about 2 weeks before parturition. Heat production increased during pregnancy, but at a greater rate during the last 2 weeks. Until 2 to 3 weeks before parturition 2·5 to 2·75 kg of feed seemed to be adequate to meet the energy requirement of a pregnant sow of 180–200 kg live weight. During the last 2 weeks 3 kg was sufficient.
A note on the protein content of the empty body of young Polish Black-and-White Lowland bulls
Authors: Osińska Zofia , Ziołecka Aleksandra
Published: September 2010

Data on the protein content of the empty body were obtained for 44 young Polish Black-and-White Lowland bulls ranging from 10-day- old calves to bulls more than 400 kg live weight. The percentage of protein of the empty body was found to be practically constant (19–19·5%) over the weight range investigated. Less than a half (up to 48 %) of the total protein content was found in the edible parts of the carcass.
The effect of weaning date on the performance of autumn-calving, single-suckled cows
Authors: Chestnutt D. M. B.
Published: September 2010

In each of 4 years, 24 autumn-calving, single-suckling Aberdeen Angus × Friesian cows with Charolais cross calves were subjected to different winter feeding regimes and to a range of weaning dates, and the effect on cow and calf food intake and performance was measured. Giving 257 kg concentrate dry matter to cows on an ad libitum silage diet over winter increased calf and cow weights in the following September by 17·8 and 11·7 kg respectively. Weaning after 4 months of lactation resulted in a net saving in winter forage requirements when compared with weaning in March/April but a high input of concentrate was necessary to achieve satisfactory calf performance. Weaning in July increased calf weights in August/September by 22·1 kg and reduced cow weights by 22·3 kg compared with weaning in March/April. Later weaning at pasture might be preferable, producing heavier calves, provided that cow weights can be restored at pasture.
The effect of body condition and nutrition during late pregnancy on the performance of grazing ewes during lactation
Authors: Gibb M. J. , Treacher T. T.
Published: September 2010

Ewes with body condition scores of 2·6 (T) and 3·3 (F) on day 90 of pregnancy were allocated to one of two feeding regimes calculated either to maintain ewe body reserves (H) or to mobilize body reserves and produce a daily loss of 150 g in ewe body weight (L) during the last 8 weeks of pregnancy. Eight ewes with twin lambs from treatments TL, TH, FL and FH, and six ewes with single lambs from treatment TH, were grazed for the first 10 weeks of lactation at a mean daily herbage dry matter allowance of lOOg/kg live weight.

Feeding treatments applied during pregnancy produced differences in ewe live weights and body condition scores at lambing (68·6, 72·4, 76·7, 831 (s.e. 2·40) kg and 1·9, 2·9, 2·8, 31 (s.e. 011) for treatments TL, TH, FL and FH respectively) that persisted through lactation, but had no effect on herbage organic matter intake by ewes (mean 21 (s.e. 0·05) kg/day) milk yield (2·4 (s.e. 0·13) kg/day), lamb growth rate (mean 245 (s.e. 4·7) g/day) or herbage intake by lambs in weeks 7, 8 and 10 (mean 0·23, 0·28 and 0·36 (s.e. 0·007) kg/day).

Ewes with single lambs, when compared with ewes with twins, had similar intakes of herbage organic matter (mean 2·2 (s.e. 0·14) kg/day), produced 0·28 less milk (mean 1·7 (s.e. 010) kg/day) and increased in weight (mean 5·0 (s.e. 1·96) kg). Single lambs had significantly higher growth rates (322 (s.e. 13·1) g/day) overall but had similar intakes of herbage organic matter in weeks 7, 8 and 10 (means 0·25, 0·29 and 0·39 (s.e. 0·03) kg/day).

The range of ewe body condition and feeding in late pregnancy examined in this experiment had little subsequent effect on milk production by the ewes suckling twin lambs, given a plentiful supply of herbage.
A comparison of different breeds and crosses from the suckler herd 2. Carcass characteristics
Authors: Kempster A. J. , Cook G. L. , Southgate J. R.
Published: September 2010

A comparison was made of the carcass characteristics of purebred Galloway, Luing and Welsh Black steers, and crossbred steers out of Blue-Grey and Hereford × Friesian dams by Aberdeen-Angus, Charolais, Devon, Hereford, Limousin, Lincoln Red, Simmental, South Devon and Sussex sires, in winter and summer fattening systems. A total of 1430 cattle were involved and the trial extended over 6 years.

The cattle were slaughtered when their fatness was estimated, using the Scanogram ultrasonic machine, to be in fat class 3L of the Meat and Livestock Commission Beef Carcase Classification Scheme. Carcasses were evaluated using a standardized commercial cutting technique.

The data for crossbred and purebred cattle were analysed separately within the fattening system using leastsquares models, which included effects for year, sire breed and dam breed, and with regression on age at the beginning of the trial and carcass subcutaneous fat concentration estimated by visual appraisal.

Limousin and Charolais crosses killed out best. Their carcass weights were, on average, 20g/kg live weight heavier than those of Aberdeen-Angus, Devon, Hereford and Lincoln Red crosses. There was a range of 20 to 30 g/kg carcass weight between sire breeds in carcass saleable meat yield: the highest values were recorded for the Limousin crosses (evaluated on winter fattening only) followed by Charolais and Aberdeen-Angus crosses; Lincoln Red crosses had the lowest values among the crossbreds and Luing cattle among the purebreds. These differences were more a reflexion of differences in fat trim than of differences in meat to bone ratio.

Continental sire breeds had significantly more of their total saleable meat in the higher-priced cuts (P<0·05), although the range between sire breeds was only 15 g/kg.
The effect of body condition of dairy cows at calving on their food intake and performance when given complete diets
Authors: Garnsworthy P. C. , Topps J. H.
Published: September 2010

In two trials, three groups of eight dairy cows were fed for 2 months before calving to achieve condition scores at calving of 1·5 to 2 (low), 2·5 to 3 (medium) and 3·5 to 4 (high). For 16 weeks after calving, all cows were given a complete diet composed of silage, malt distillers' grains, barley, swedes and soya bean meal (metabolizable energy 12·25 and 12·35 MJ/kg dry matter in trials 1 and 2 respectively).

In both trials, significant differences were found between groups in dry-matter intake after calving. Cows that had higher condition scores at calving ate less and reached maximum intake of dry matter later than cows with lower condition scores (high, medium and low condition-score cattle attained maximum intakes in 14·5, 12·7 and 9·3 weeks in trial 1, and in 141, 9·6 and 7·9 weeks in trial 2). In trial 1, no difference was found in milk yield but, in trial 2, cows that had lower condition scores at calving produced slightly more milk. In both trials, cows that had higher condition scores at calving lost more body weight and condition, over a longer period, and started to regain the losses later than cows with lower condition scores. The biological efficiencies of milk production (energy output/energy input) from 8 weeks before calving until 16 weeks after calving were 0·302, 0·299 and 0·295 in trial 1, and 0·312, 0·290 and 0·306 in trial 2, for the low, medium and high groups respectively.

It was concluded that cows with lower condition scores at calving produced more milk directly from food rather than via body fat, were in positive energy balance earlier in lactation and over the total period were biologically more efficient than cows with higher condition scores. There appears to be no benefit from feeding cows to achieve a condition score greater than 1·5 to 2 at calving if high-energy complete diets are offered in early lactation.
A comparison of different models of the lactation curve in dairy cattle
Authors: Rowlands G. J. , Lucey S. , Russell A. M.
Published: September 2010

A study of 468 lactations in two herds of British Friesian cows sampled weekly between 1976 and 1979 was undertaken to investigate seasonal variations in milk yield and to compare four models of the lactation curve: (i) logey(n)=loge a + b logen—cn; (ii) y(n) = anbe-cn; (iii) y(n)= ae-pn—ae-qn; and (iv) y(n) = a—p'n—ae-q‘n.

Model (i) was fitted by unweighted linear regression and the remainder by maximum likelihood. Average peak yield was 29 kg/day and 305-day yield was 5720 kg.

Model (ii) fitted the data slightly better on average than models (iii) and (iv), and all were better than model (i). Compared with model (i), model (ii) reduced the average residual mean square proportionally by 0-10 in cows and 004 in heifers (first calvers). Model (iv) described the initial rise in milk yield up to week 5 better than models (i) or (ii) but reached a maximum value slightly early. Models (i), (ii) and (iv) slightly underestimated and (iii) slightly overestimated maximum milk yield, but model (ii) provided the best estimate of the position of maximum yield.

Peak yields for heifers occurred on average at approximately 10 weeks post calving compared with 7 weeks for cows. Mean persistency of lactation, calculated as s= -(b+1) logec, did not vary from the second lactation onwards, whereas the average rate of decline p' in model (iv) increased with parity.

When milk yields were adjusted for stage of lactation, significant variations were found that were related to the week of recording but this seasonal variation in milk production was smaller than that found nationally in the United Kingdom.
The effect of birth status on the level and efficiency of wool production by new zealand corriedale two-tooth rams and ewes
Authors: Butler L. G.
Published: September 2010

Forty-four single- and twin-born New Zealand Corriedale two-tooth ewes and rams aged 14 months were fed individually, in pens, a pelleted ration adjusted to maintain body weight after allowing for wool growth. The sheep were fed for a 3-month settling period, followed by a 3-month experimental period, during which wool growth, fibre diameter, fibre length and net efficiency of wool growth were measured.

Since the wool-growth cycles of the two sexes were found to be out of phase, a valid comparison of the sex data was not possible. Such phase differences may be important in some experimental designs. Significant sex by birth status interactions were identified for all wool production parameters except fibre length, confirming that care must be taken in assigning correction factors during selection of rams and ewes. The general trend was for single-born ewes to produce more and coarser wool more efficiently than twin-born ewes, while the differences between single- and twin-born rams were much smaller. Single-born animals were heavier than twin-born (P<0·01).

Individual values for wool growth and net efficiency varied by a factor of three within sex groups, indicating a considerable scope for selection
A comparison of boars, gilts and castrates for bacon manufacture 1. On farm performance, carcass and meat quality characteristics and weight loss in the preparation of sides for curing
Authors: Ellis M. , Smith W. C. , Clark J. B. K. , Innes N.
Published: September 2010

A total of 182 pigs from one farm and comprising 65 boars (B), 65 gilts (G) and 52 castrates (C) from 48 litters, were reared from birth to 89 kg live weight. Sex of pig did not influence age at slaughter but B compared with G and C had lower killing-out proportions (0·748 v. 0·756 v. 0·753) and reduced backfat measurements. Skin damage in transit to slaughter and/or in lairage was more prevalent in B compared with C, with G being intermediate. Muscle pH measurements were not influenced by sex except ultimate pH of the m. semispinalis capitis, where B compared with G and C had a higher incidence of values above 6·1 (0·246 v. 0·060 v. 0·120). Carcasses of B had proportionately more shoulder (0·04 unit) and more leg (0·011 unit), at the expense of middle, than those of C with G being intermediate. Weight losses in the preparation of de-boned sides for curing were higher in carcasses of B compared with G and C.
Effects of castration and subdermal silastic implants containing oestradiol-17 β-dipropionate on feedlot performance and carcass characteristics of male cattle
Authors: Schanbacher B. D. , Prior R. L. , Smith S. B.
Published: September 2010

Feedlot performance and carcass characteristics were examined in bulls and steers with and without a subdermal Silastic capsule containing oestradiol-17β-dipropionate. Castration and/or oestrogen treatment was imposed at approximately 8 months of age. The implants were removed 56 days before slaughter, i.e. 140 days after the trial commenced. Bulls gained more rapidly (12·9%), converted food to live-weight gain more efficiently (18·0%) and yielded leaner carcasses than did steers (P < 0·05). The oestrogenic implant elevated serum oestradiol concentrations substantially (> ninefold) over that of bulls and steers and induced a castration-response in the former. Serum luteinizing hormone, testosterone and testicular growth were suppressed (P < 0·05) during the first 140 days of the trial in bulls, but returned to normal following implant removal. This response was paralleled by a reduction in average daily gain (P < 0·05) and food: gain ratio (P < 0·10). Contrary to expectations, average daily gain and food: gain ratio were not significantly improved in implanted steers. Oestrogen treatment reduced hot carcass weight, loin eye area and quality grade in both bulls and steers; the last as a result of decreased marbling and internal fat deposition. Results of this study suggest that excessive oestrogen as provided in this study via the implant fails to improve feedlot performance and carcass merit in steers and may, in fact, diminish the inherent anabolic attributes of the intact male. Additional studies are required to understand the complex interactions of androgens and oestrogens in the regulation of body growth and composition of male cattle.
Hormonal changes in post-partum blood plasma and milk of buffaloes (Bubalus bubalis)
Authors: Pahwa G. S. , Pandey R. S.
Published: September 2010

Post-partum changes in the concentration of progesterone, oestradiol-17β and prolactin were measured by radioimmunoassay in the blood plasma and milk of 28 buffaloes. The mean concentration of progesterone in the plasma of normal animals was 0·24 ± 0·04 μ.g/1 on the day of calving and decreased linearly during the post-partum period, until the complete regression of the residual corpus luteum of pregnancy occurred, when the plasma concentration was recorded as 0μ05 to 0μ08 μg/l. The concentration at a silent oestrus was 0μ17 ± 0·02 μ.g/1. The milk progesterone profile was parallel to that of plasma but the level was 2 to 4 times higher.

The mean concentration of oestradiol-17β in plasma was 41·0 ± 2·34 ng/1 on the day of calving; it declined significantly by day 1 post partum (P < 0·001) and fluctuated between 8 and 16 ng/1 until oestrus, when the concentration was approximately 25 ng/1. The oestradiol-17β concentration in milk was significantly higher than that of plasma on the day of calving. During the first 20 days post partum, a similar concentration of oestradiol-17β was maintained in both fluids but thereafter the concentration in milk was 2 to 3 times that of plasma.

The mean concentration of prolactin in plasma was 212·6± 19·08 μg/1 on the day of calving and then declined and fluctuated between 70 and 270 μg/1 during the rest of the period. A minor elevation occurred around oestrus. The prolactin concentration for the first 2 days post partum in milk was significantly higher than that in plasma but during the rest of the period it was similar to that in plasma.

The progesterone concentrations were slightly lower in anoestrous animals than in those cycling. The concentration of prolactin was significantly higher in multiparous animals (P < 0·001), whilst the progesterone and oestradiol values were similar in primiparous and multiparous animals.
Amino acid requirements of growing pigs 4. Methionine plus cystine
Authors: Taylor S. J. , Cole D. J. A. , Lewis D.
Published: September 2010

The response of the growing female pig (25 to 55 kg live weight) to increasing dietary methionine plus cystine concentrations was assessed by measurement of growth rate, food utilization, ham dissection and changes in blood metabolite concentrations. A range of 13 methionine plus cystine concentrations from 3·5 to 5·79 g/kg resulting from combinations of three basal diets and synthetic methionine, was studied. The diets were formulated using barley, a yeast protein, tapioca and synthetic amino acids to contain similar energy concentrations, 9·5 g lysine per kg diet, and adequate concentrations of other essential amino acids and non-essential nitrogen. They were offered once daily according to a restricted feeding scale.

Responses were interpreted by broken line functions which indicated, from the growth performance experiment, a requirement between 4·5 and 4·8 g/kg of the diet, when the complete range of methionine plus cystine concentrations was studied. The influence of a range of dietary methionine plus cystine concentrations from 4·1 to 5·3 g/kg diet on changes in plasma urea, methionine, lysine and threonine concentrations indicated a requirement for methionine plus cystine of 4·5 g/kg of the diet.
Correlated responses in lamb mortality due to long term selection for cannon bone length and fleece medullation in sheep
Authors: Cue R. I.
Published: September 2010

Lamb mortality in a Scottish Blackface hill sheep flock subjected to long term selection for cannon bone length and fleece medullation score was investigated, using maximum likelihood analyses. The selection for cannon bone length and for medullation score had no significant effect on lamb mortality.
The use of blood metabolites in the determination of energy status in beef cows
Authors: Russel A. J. F. , Wright I. A.
Published: September 2010

The objective of the studies reported was to examine the potential usefulness of measurements of concentrations of plasma glucose, 3-hydroxybutyrate and non-esterified fatty acids as means of assessing in quantitative terms the adequacy of energy intake of beef cattle.

Relationships between the concentrations of these metabolites and of either energy intake or energy status were examined in three experiments conducted respectively on 56 housed, mature, non-pregnant, non-lactating cows, on 115 housed, mature, pregnant cows, and on groups of 10 to 12 mature, non-pregnant, non-lactating cows grazing five plant communities.

The results indicated that under the conditions pertaining in these studies plasma glucose concentration was not likely to constitute a useful index of energy status in housed or grazing animals.

Plasma 3-hydroxybutyrate concentration was closely related to estimates of energy status in the pregnant cows and was considered to be potentially valuable as an index of energy status in animals in which there is a relatively high glucose demand.

Plasma non-esterified fatty acids concentration was closely related to and a potentially useful index of either energy intake or energy status in all cases, but postulated effects of diurnal variations in circulating concentrations make it imperative that relationships used for predictive purposes are derived under the conditions in which they are to be applied.
Effects of plane of nutrition and environmental temperature on the growth and development of the early-weaned piglet 2. Energy metabolism
Authors: Close W. H. , Stanier M. W.
Published: September 2010

1. Measurements of heat loss, energy and nitrogen balance were made on 18 groups of piglets weaned at 2 weeks, at environmental temperatures of 18, 23 and 28°C, and at three levels of feeding at each temperature.

2. From the experimental results, values of heat loss, energy retention, protein and fat deposition were derived for each temperature, at each of the three levels of metabolizable energy (kJ/kg M0·75 per day) intake: 550 (1·0MEm), 825 (1·5MEm) and 1100 (2·0MEm). The lowest of these levels was the calculated thermoneutral maintenance energy requirement (MEm).

3. From the results the following deductions were made, (a) Heat loss varies with both environmental temperature and metabolizable energy intake, and at an intake of 2·0MEm is minimal between 23 and 28°C. Energy retention varies in an inverse manner to heat-loss, and at 1·0MEm is negative at all environmental temperatures below 28°C. (b) Protein and fat deposition increase significantly with increase in metabolizable energy intake (P < 0·05), with fat deposition being more dependent on temperature than protein deposition. The mean increase in protein deposition per 1°C increase in environmental temperature is 2·05 kJ/kg M0·75 per day. Fat deposition is negative at all temperatures at l·0MEm; at l·5MEm it is zero at 23°C and negative at temperatures below this.

4. Critical temperature was calculated to decrease from 26·9°C at l·0MEm to 23·9°C at 2·0MEm.

5. The efficiency of energy utilization (k) was 0·58 at 18°C, 0·81 at 23°C and 0·74 at 28°C. The corresponding values of the maintenance energy requirements were 739, 615 and 550 kJ/kg M0·75 per day. Estimates of the energetic efficiency of protein deposition (kp) of 0·60 to 0·65, and of fat deposition (k/) of 0·82 to 0·86, were determined at 23 and 28°C.
The effect of nutrition on the reproductive performance of first-litter sows 1. Feeding level during lactation, and between weaning and mating
Authors: King R. H. , Williams I. H.
Published: September 2010

A factorial experiment was conducted with 80 first-litter sows and involved two levels of feeding during lactation (ad libitum or 2·0 kg/day), and two levels of feeding between weaning and mating (4·0 or 1·5 kg/day).

Average lactation length was 32·2 days. Sows given 2·0 kg/day during lactation lost more backfat (6·3 v. 0·9 mm; P < 0·05) and more live weight (36·8 v. 9·1 kg; P < 0·05) during lactation than sows fed ad libitum and whose average daily food intake was 4·47 kg. Sows receiving 20 kg/day during lactation took longer to return to oestrus after weaning. Within 8 days of weaning more sows fed ad libitum during lactation ovulated (0·90 v. 0·40; x2 = 20·0; P < 0·001) and exhibited oestrus (0·78 v. 0·38; x2 = 12·8; P < 0·001) than sows whose food intake throughout lactation was restricted. Ovulation rate, subsequent litter size and embryonic mortality were not significantly affected by feeding level during lactation.

Post-weaning feeding level did not affect the interval between weaning and oestrus. However, sows receiving 4·0 kg/day between weaning and mating had higher ovulation rates (14·8 v. 13·0; P < 0·05) and a greater litter size (10·0 v. 8·8; P < 0·1) at the subsequent farrowing.
The effect of genotype and metabolizable energy intake on protein and fat gain in veal calves
Authors: Meulenbroeks J. , Verstegen M. W. A. , Van der Hel W. , Korver S. , Kleinhout G.
Published: September 2010

An experiment was carried out with 20 male veal calves to study differences in energy metabolism between pure Dutch Friesian and Holstein Friesian crossbred calves, containing a high proportion of Holstein Friesian genes (0·79). Two metabolizable energy (ME) intakes were given. The effects of genotype and ME intake on live-weight gain and its fat and protein composition were measured by indirect calorimetry and by the total collection of faeces and urine. Energy and nitrogen balances were measured for each calf during the last 5 weeks of the fattening period of 22 weeks.

The difference in live-weight gain between the Holstein Friesian crossbreds and the Dutch Friesian calves was not significant but small differences in protein and fat composition of live-weight gain were found. Fat gain was closely related to ME intake (r = 0·95), but the correlation coefficient between ME intake and protein gain was only 0-36. Live-weight gain had a high correlation with protein gain (r = 0·70) but a lower correlation with fat gain (r = 0·29).

Veal calves at the end of the fattening period had a declining protein gain as age increased. Calves given a high ME intake (> 2 × maintenance) may require diets containing less than 216 g crude protein per kg diet at the end of the fattening period.

The study indicates that Holstein Friesian crossbred veal calves and Dutch Friesian veal calves have similar ME requirements.
The effects of dietary fibre, source of fat and dietary energy concentration on the voluntary food intake and performance of growing pigs
Authors: Campbell R. G. , Taverner M. R.
Published: September 2010

Ninety entire male pigs were used in two experiments to investigate the effects of energy concentration on the performance of growing pigs given diets containing relatively high or low levels of fibre. A blended fat product was also compared with tallow as a source of dietary energy for pigs in the first experiment.

In experiment 1, 60 pigs growing between 20 and 45 kg live weight were given 10 diets containing approximately 120 g acid-detergent fibre per kg (80 g crude fibre per kg), and 10, 30, 50, 75 or 100 g/kg of either tallow or the blended fat product.

Although the source of fat had no significant effect on food intake or growth performance, voluntary energy intake and growth rate increased with increase in the level of fat added to the diet and with concomitant increase in dietary digestible energy (DE) concentration up to 50 g/kg and 13·2 MJ/kg respectively. Further increase in the level of fat added to the diet and in DE concentration resulted in a decline in voluntary food intake, whilst energy intake and growth rate remained relatively constant at 27 MJ/day and 720 g/day respectively.

In experiment 2, 30 pigs were used to investigate the animals' response to five levels of dietary DE concentration (11·8 to 15·1 MJ DE per kg) between 20 and 50 kg live weight. The highest level of acid-detergent fibre in the diets was 62 g/kg (50 g crude fibre per kg) and this declined with increase in energy concentration to 30 g/kg (25 g crude fibre per kg) in the diet of highest energy concentration.

Voluntary food intake was not significantly affected by dietary energy concentration, and voluntary energy intake and growth rate increased linearly with increase in dietary energy concentration up to 14·5 MJ DE per kg. Maximum energy intake (31 MJ DE per day) and growth rate (905 g/day) in experiment 2 was proportionately 0·15 and 0·26 higher than that achieved by pigs given the higher fibre diets in experiment 1.

The results for voluntary food intake and growth rate suggested that the pig's demand for energy and consequently its response to dietary energy concentration was affected by dietary fibre concentration.
Comparative determination of beta-adrenergic receptors in muscle, heart and backfat of Piétrain and Large White pigs
Authors: Böcklen E. , Flad S. , Müller E. , von Faber H.
Published: September 2010

The number of beta-adrenergic receptors which influence the effectiveness of catecholamines was determined by 3H-dihydro-alprenolol in muscle, heart and fat tissue of stress-susceptible pigs (Pietrains) and non-susceptible pigs (Large Whites). In all investigated tissues proportionately 0·31 to 0·38 more receptors were found in the Pietrains than in the Large Whites, the differences being significant (P< 0·05). That the higher numbers of beta-adrenergic receptors in Pietrain pigs may be involved in accelerated muscle glycogenolysis (poor meat quality) and increased lipolysis (low carcass fat) in these animals and in other breds showing poor meat quality and low carcass fat is discussed.
A study of sexual development in ram lambs
Authors: Al-Nakib F. M. S. , Lodge G. A. , Owen J. B.
Published: September 2010

Two experiments were designed to study the effect of rearing method, female company, and repeated libido and semen tests on the pattern of sexual development of ram lambs. Four artificial rearing treatments (AR) were compared with natural rearing (NR) in one experiment and four artificial compared with three natural rearing treatments in a second experiment. Lambs on AR treatments in both experiments, as well as naturally reared lambs in the second experiment, were reared with or without females either before and/or after weaning. Half the lambs in the second experiment were libido and semen tested, and their mean plasma testosterone level was also measured, while the rest were only tested at the end of the experiment. The effect of method of rearing and female company on body growth, testes diameter, libido and semen quality were also investigated.

A close relationship was found between body weight and sexual characteristics (for example, testis diameter, semen traits, libido, testosterone level and age at the onset of sexual maturity). NR resulted in faster growth than AR but was not appreciably different from early weaned-naturally reared treatments. It was also observed that mating performance improved steadily with advancement in age and increase in body weight. The onset of sexual maturity was attained at a minimum of 23 kg body weight and a minimum of 198 days of age. However, the heavier the lamb when sexually mature, the better its mating performance.

Previous libido tests of ram lambs improved their subsequent mating performance, but had no effect on semen quality. However, libido tests did not improve the performance of those ram lambs which did not exhibit initial libido.

It is suggested that early weaning at 2 months of age could be a suitable system for ram lambs weaned off their mothers for breeding purposes. These lambs should be reared as an all-male group but libido tested at monthly intervals commencing at 3 months of age. The criteria for selecting these lambs at an earlier age should be body weight and testis diameter.
Performance of British Landrace pigs selected for high and low incidence of halothane sensitivity 2. Growth and carcass traits
Authors: Webb A. J. , Simpson S. P.
Published: September 2010

The effects of halothane phenotype on growth were estimated from generations 1 to 3 of British Landrace positive and negative selection lines. A total of 241 full-sib pairs (castrated male and gilt) from 133 second litters were performance tested from 25 to 85 kg live weight on either ad libitum or scale (0·69 g/g ad libitum daily food intake) feeding.

Compared with negative reactors over feeding regimes, positive pigs showed significant advantages in food conversion ratio (−0·07, s.e. 0·02), eye-muscle area (0·8, s.e. 0·3 cm2), proportion of lean in sample joints (16, s.e. 7 g/kg), and visual conformation scores, accompanied by disadvantages in meat colour (5·9, s.e. 2·1 EEL units), incidence of pale, soft, exudative (PSE) meat (0·36 v. 0·05, P < 0·001), post-weaning mortality (0·09 v. 0·01, P < 0·001) and ad libitum daily food consumption (−0·08, s.e. 0·02 kg). In addition, there were non-significant indications of an advantage in carcass lean proportion (11, s.e. 10 g/kg), with disadvantages in carcass length (−14, s.e. 7 mm) and proportion of lean in high-priced cuts (−6, s.e. 2 g/kg). Only daily food consumption showed significant selection line × feeding level interaction.

Averaged over feeding regimes, an estimated extra return of £1·70 (s.e. 0·50) from lean growth would be offset by increased PSE and mortality to give a net loss of roughly £3·90 (s.e. 1·00) per positive reactor. Taking these results as the minimum difference between homozygotes, and if the gene is additive for lean proportion but recessive for stress susceptibility, the heterozygote would have an advantage of £0·90 over the normal homozygote. The effects of the gene on growth and carcass traits in British Landrace appear similar to those reported in other breeds, although the advantage of positive reactors in lean proportion may be slightly smaller.
Protein nutrition of growing cattle: food intake and growth responses to rumen degradable protein and undegradable protein
Authors: Newbold J. R. , Garnsworthy P. C. , Buttery P. J. , Cole D. J. A. , Haresign W.
Published: September 2010

Groups of eight Friesian steers were given one of eight diets from 114 to 300 kg live weight. The iso-energetic diets were formulated to supply four levels of protein degradability within two concentrations of crude protein (CP), giving a range of rumen-degradable protein (RDP) and undegradable dietary protein (UDP) concentrations both above and below Agricultural Research Council (1980) recommendations. There were significant (P < 0·05), positive, linear responses of mean daily dry-matter (DM) intake (DMI) (g/kg M°75) to RDP concentration (g/kg DM) for both the low CP diets (DMI = -98·0 + 1·76 (RDP); P = 0·013) and the high CP diets (DMI = -157·5 + 218 (RDP; P = 0017). For the high CP diets, there was a significant (P = 0·045) positive, linear response of live-weight gain (LWG) (kg/day) to UDP concentration (LWG = 0·47 + 0·017 (UDP); P = 0·045). No such response was observed for the low CP diets, where the range of UDP concentrations supplied was smaller than expected. For both the low and high CP diets, LWG decreased as metabolizable energy, UDP and RDP intake increased. These negative responses to nutrient intake were reflected in a wide discrepancy between observed rates of gain and those predicted by current energy and protein nutrition systems. Interactions between food intake and digestive processes, which obstruct effective interpretation of these results, should form an explicit part of any revised protein nutrition scheme.
Carcass composition of veal calves dependent on genotype and feeding level
Authors: Korver S. , Vos H. , Bergström P. L. , Verstegen M. W. A. , Kleinhout G.
Published: September 2010

Dutch Friesian purebred and Holstein Friesian-Dutch Friesian crossbred veal calves were used to study effects of genotype and feeding level on carcass composition. Carcass analyses were carried out on a total of 56 calves of two genotypes. Calves were reared for 22 weeks and given food dependent on age. From 1 to 16 weeks calves were given the same amount of milk replacer. At week 16, calves were assigned to either a high or low feeding level. Total energy intakes for the two groups were 5062 MJ metabolizable energy (ME) and 5408 MJ ME, respectively. Carcass weight and carcass composition traits showed no significant interaction between genotype and feeding level. Dutch Friesians had higher lean: bone ratios than Holstein Friesian crossbreds (3·85 v. 3·67). Differences between the two genotypes for fat and lean proportions in the carcass were not significant. Average proportions for lean and fat were 653 and 134 g/kg.

Differences between the two feeding levels for carcass composition were significant. Calves on the low feeding level had 655 g lean and 131 g fat per kg, while calves on the high level had 645 g lean and 143 g fat per kg.

The influence of the dissection technique on the differences in lean and muscle proportion between groups was studied on 18 carcasses using a standardized butcher's method (the Institute of Animal Husbandry (IVO) standard method) and the European Economic Community (EEC) reference method for beef. Average proportion of lean was 640 g/kg by the IVO method and of muscle was 557 g/kg by the EEC method. The difference between the two genotypes for lean proportion was smaller by the' EEC method due to the more complete separation between muscle and fatty tissue. Dutch Friesians had more intermuscular fat than Holstein Friesian crossbreds. Results of the EEC reference method indicate differences between the two feeding levels for fat as well as for protein deposition.
The influence of a formulated excess of rumen degradable protein or undegradable protein on milk production in dairy cows in early lactation
Authors: Sloan B. K. , Rowlinson P. , Armstrong D. G.
Published: September 2010

Following a 3-week covariance period, 30 group-housed dairy cows were individually given one of three diets from week 4 to week 13 of lactation to determine any possible advantage in milk yield and production of feeding levels of undegradable protein (+UDP) or rumen-degradable protein (+RDP) above the minimum levels (control) proposed by the Agricultural Research Council (ARC, 1984). The three concentrates given were formulated to be of equivalent metabolizable energy (ME, 13·5 MJ/kg dry matter (DM)) concentration and each consisted of rolled barley plus a protein supplement: control (crude protein (CP), 129 g/kg DM) 0·35 kg DM fish meal per day; +UDP (CP, 167 g7kg DM) 1·0 kg DM fish meal per day; and +RDP (CP, 167 g/kg DM) 1+5 kg DM soya per day. For each group the total ‘concentrate’ allowance per animal per day was 11·6 kg fresh weight and was given in three equal feeds. Grass silage (CP 122 g/kg DM, ME 106 MJ/kg DM) was given ad libitum. For the control, +UDP and +RDP treatments, respectively, mean grass silage intakes were 8·29, 8·62 and 8·65 kg/day and mean milk yields were 26·6, 26·3 and 26·1 kg/day. These were not significantly different (P > 0·05). Milk fat concentration was lower (P < 0·05) for the +UDP treatment (36·4 g/kg) in comparison with the control (38·6 g/kg) or the +RDP treatment (39·7 g/kg) but no other milk constituent was significantly influenced by treatment. There was a trend for a greater live-weight gain with treatment +UDP (0·81 kg/day) compared with the other two treatments (control 0·50, +RDP 0·51 kg/day) but there were no differences in condition-score change between treatments. In this trial there was no advantage to feeding formulated levels of UDP or RDP above those proposed by ARC (1984).
Modelling lactation curves of Friesian cows in a subtropical climate
Authors: Papajcsik I. A. , Bodero J.
Published: September 2010

Monthly herd recording data from Friesian cows in south-east Queensland are used to evaluate 20 models of the lactation curve, 10 being drawn from the literature and 10 being original. The curve of Wood (1967) with equation y =a nb exp(–cn),and its modificationy =a nfc/cosh(en), generally gave the lowest values for the error mean square across all seasons of calving. However, the model which predicts a constant initial yield, followed by a linear decline,y =a forn =Sc, y =a - b(n –c) forn > c, is as good as the previous two models for winter calving cows. Hence it is a useful representation of the lactation curve in south-eastern Queensland, where about 40% of cows are calved in winter. The inverse polynomial modely =nl(a +bn + en2) is a useful model for lactations commencing in the summer months.