bluuebunny/crossref_metadata_2025 huggingface dataset:
Diversification of Land Plants in the Early and Middle Devonian
Authors: Gensel Patricia G.
Published: June 2019

While fossil evidence supports a mid-Silurian or earlier establishment of land plants, it is clear that major diversification occurred in the Devonian. This has been summarized in several ways in recent years - the number of plant taxa (perhaps best expressed at the generic level) rapidly increases from the Early to Middle Devonian (Knoll et al., 1984; Niklas et al., 1980; Knoll, 1985); the first appearance of new structures increases through the Early and Middle Devonian and then tends to level off (Chaloner and Sheerin, 1979; Knoll et al., 1984); structural and reproductive complexity of plants increases (Chaloner and Sheerin, 1979; Edwards, 1980; Banks, 1980; Gensel and Andrews, 1984); and floral composition changes such that generalizations about plant diversity or communities can be made and seven biostratigraphic zones can be recognized (Chaloner and Sheerin, 1979; Banks, 1980). I will discuss specific aspects of these trends in the Early and Middle Devonian in this section, including consideration of biogeography and paleoecology. Vascular plants will be emphasized, but one should keep in mind that a number of non-vascular, ones also existed, some of which will be mentioned briefly. Banks' (1980) biostratigraphic zones, of which the first five are most applicable, provide a useful framework in which to discuss major events in the diversification of land plants.
Floras of the Devonian - Mississippian Transition
Authors: Scheckler Stephen E.
Published: June 2019

Taken as a whole, Devonian and Carboniferous floras represent vastly different evolutionary stages in the colonization of the Earth's surface by plants. When only Late Devonian and Mississippian floras are considered, however, all of the floral innovations that led to and characterize the increasingly sophisticated plant communities of the Carboniferous began in the Famennian. When examined carefully enough, the stratigraphical succession of floras at the Devonian/Mississippian boundary reveals a gradual decline of typical Late Devonian elements and an equally gradual increase of plant types that eventually characterize the Early Mississippian. Furthermore, significant floral changes occur throughout the Late Devonian as archaic genera, that originated in Middle Devonian or earlier, disappear and new types appear that will become important in the Mississippian. Within the Mississippian too, the earliest floras contain elements left over from the Devonian, but show the origins or expansions of groups that ultimately were of great importance in the Pennsylvanian.
Morphology and Paleoecology of Pennsylvanian-Age Coal-Swamp Plants
Authors: DiMichele William A. , Phillips Tom L. , Willard Debra A.
Published: June 2019

There were two major kinds of Pennsylvanian-age tropical swamps: coal swamps, represented by most coal seams, and clastic swamps, commonly associated with coal as roof shale or sandstone floras. Such environments were part of depositionally-complex lowlands that also included non-swamp habitats. In general, the Pennsylvanian-age coal and clastic swamps were dominated by non-seed (lower vascular, spore-producing) plants, and the mesic, non-swamp vegetation was characterized by seed-plant (pollen-producing) dominance. On occasion, some drier-site kinds of vegetation are preserved, providing a glimpse of other kinds of plants in the lowland regions of the tropical belt; among these are the earliest known conifers (Scott and Chaloner, 1983) in the Middle Pennsylvanian.
Summary and Implications of the Fossil Plant Record of the Potomac Group
Authors: Hickey Leo J.
Published: June 2019

Study of the angiosperm pollen and leaf record contained in the sediments of the Potomac Group has elucidated the history of early angiosperm diversification. Although records of angiosperm pollen now extend back to the Barremian in a number of areas (see reviews by Doyle, 1977 and 1978), the Potomac sequence is significant because it provides the longest and most complete sample of data on early angiosperm evolution in a context where the pollen and megafloral records can be examined together with the sedimentology. This has provided an unparalleled opportunity for the development of insights into the ecological and adaptive aspects of the initial radiation of the flowering plants.
Tertiary Floras and Paleoclimates of the Northern Hemisphere
Authors: Wolfe Jack A.
Published: June 2019

Studies of Tertiary plant megafossils typically have aimed at gathering paleoclimatologic and/or biogeographic data. The apparent similarities of Tertiary fossil plants to extant plants have made tempting the use of present plant/climatic relations to infer past climates. Additionally, plant-bearing, nonmarine deposits of Tertiary age are more widespread than older deposits, which allows stratigraphic and geographic distributions of Tertiary plants to be determined with greater accuracy than for older plants.
Dinoflagellates
Authors: Edwards Lucy E.
Published: June 2019

Dinoflagellates are single-celled organisms of the Division Pyrrhophyta. Most people, although not familiar with dinoflagellates, are familiar with their effects. Bioluminescent dinoflagellates cause a sparkling of the sea at night as the waves break, and certain dinoflagellates may produce blooms called “red tides,” which poison marine life or which cause toxins to accumulate in shellfish, poisoning those who eat them. The Old Testament (Exodus 7:20–21) and the writings of the ancient Greeks refer to red water and the killing of fish. The Red Sea may have gotten its name from dinoflagellate blooms.
Acritarchs
Authors: Mendelson Carl V.
Published: June 2019

In 1934 the Geological Society of America published its second Memoir: “Paleozoic Plankton of North America,” by Rudolf Ruedemann. This work was concerned primarily with invertebrates, especially the enigmatic and now-extinct graptolites. The primary producers of that era were virtually unknown; accordingly, the author devoted only a few pages to description and discussion of seaweeds. And although Ruedemann (1934, p. 25) recognized that “the microscopic algae must be considered as the very basis” of Paleozoic life, he submitted that “obviously it will be difficult to find their remains in the Paleozoic rocks.” O.M.B. Bulman (1964, p. 467), another graptolite expert, condensed his discussion on the primary producers to two paragraphs in “Lower Palaeozoic Plankton,” his Anniversary Address as President of the Geological Society of London; but at least he acknowledged the “universal occurrence” of fossil phytoplankters.
Silicoflagellates, Ebridians, and Archaeomonads
Authors: McCartney Kevin
Published: June 2019

The silicoflagellates, ebridians and archaeomonads are three groups of quite dissimilar organisms. However, they are sometimes discussed collectively because each group has a relatively small siliceous skeleton, and is relatively less common, and much less understood, than the diatoms or radiolarians. The silicoflagellates are the most abundant of the three groups. They usually make up one or two percent of the siliceous component of marine sediments (Riedel, 1959), and can be viewed as the least abundant of the major plankton groups. The ebridians and archaeomonads, when found at all, are generally only a minor constituent of the sediment.
Radiolaria
Authors: Casey Richard E.
Published: June 2019

Radiolaria are marine holoplanktonic animal-like protists belonging to the Superclass Actinopodea of the Subphylum Sarcodina. When biologists speak of radiolarians they usually mean the subgroup Acantharia that are common in nearshore waters and are sometimes involved in plankton blooms. When paleontologists speak of radiolarians they usually mean the subgroups preserved in the fossil record; the Polycystina (or polycystine) encompassing Spumellaria and Nassellaria, which possess solid opaline skeletal structures, and the Phaeodaria (or phaeodarians), which possess hollow skeletal structures of an admixture of silica and organic matter.
Effects of pre-calving nutrition on the performance of twin bearing cows and their calves
Authors: Topps J.H. , Nurul Islam Md , Broadbent P.J. , Paterson G.F.M.
Published: June 2019

With the advent of twinning in beef cows there is a need to obtain information on the nutritional requirements of these animals during the last three months of pregnancy and to assess the effects of pre-calving nutrition on cow and calf performance in the subsequent lactation. Three experiments have been carried out With 10, 9 and 14 multiple bearing Hereford x British Friesian cows. In each experiment a comparison was made With single bearing cows but the results from these animals are not considered in this paper. The cows were given different energy intakes in a factorial arrangement with low or high levels of UDP over the last three months of pregnancy. After calving all cows were given 125 MJ ME/d for the first 12 Weeks of lactation and performance monitored to assess any carryover effect of pregnancy nutrition.

Similar diets were fed during the last three months of pregnancy in all three experiments. The diet containing a low level of UDP (0.19 of total protein) consisted of barley straw, barley grain, molassed meal and urea. While that With a high UDP content (0.33 of total protein) contained barley straw, barley grain, malt distillers dark grains and special propietary cubes.
Interrelations between beef carcass type, chilling rate and weight loss, and heat quality
Authors: Fisher A.V. , Gigiel A.J. , Nute G.R. , Swain M.V.L.
Published: June 2019

There is a belief, held by many in the meat industry, in catering, and by consumers alike, that meat from leaner carcasses is inferior in eating quality to that from fatter ones. In addition, meat from leaner continental breeds has been suggested by some to be inferior to that from the more traditional British beef breeds which fatten more readily at lighter weights, and meat from bulls has been similarly implicated. This may be an extrapolation of the belief in the role of fat, or it may be a separate issue concerned with other underlying genetic or physiological differences. Other factors known to influence meat quality are pre-slaughter handling and post-mortem chilling rates and conditioning. Rapid chilling of beef carcasses has economic advantages through a faster turnover and lower evaporative losses, but may impair eating quality by inducing muscle cold-shortening. Chill rate may be influenced by carcass type, in particular by the amount of fat present and by the thickness of the tissues. It is possible that the role of fatness (and conformation) in eating quality of meat may be manifested indirectly through its effect on rate of cooling.
A comparison of wheat and barley as supplements to grass silage for beef cattle
Authors: Steen R. W. J.
Published: June 2019

Two randomised-block experiments have been carried out to examine the relative feeding value of wheat and barley as supplements to grass silage for finishing beef cattle. In each experiment unwilted, formic acid-treated silage was offered ad libitum and supplemented with 500 g soyabean meal and 50 g minerals and vitamins to 44 twelve month old bulls for 157 and 172 days in experiments 1 and 2 respectively. In addition 12 animals received 2.5 kg rolled spring barley (LB), 12 received 4.0 kg barley (HB) and 20 received 3.25 kg rolled wheat (W). Silage was offered once daily and concentrates twice daily in two equal meals.

Eleven British Friesian bulls and thirty-three bulls which were Friesian x Continental beef breed were used in each experiment. They were initially 402 and 385 kg live weight in experiments 1 and 2 respectively. In both experiments the animals were housed and fed in groups of four in slatted pens. All animals were slaughtered at the end of the experiments to obtain carcass data.
Modern techniques for enhancing reproduction in suckler cattle systems
Authors: Gordon I.
Published: June 2019

For those involved in suckler cattle systems, there are likely to be several new opportunities for increasing production efficiency in the years ahead. As a result of recent developments in embryo production technology the future is likely to see embryo transfer being used on an increasing scale and eventually taking over from artificial insemination as a major factor influencing the production of beef calves. Sex control techniques, applied to sperm or to embryos, are likely to be of particular value in making bull calves available for twinning or heifer calves for once-bred heifer production systems. The paper examines the various possibilities for applying reproductive technology in enhancing fertility, controlling oestrus and ovulation, inducing twin births, increasing the efficiency of once-calved heifer production systems,in the application of cloning techniques and the use of recombinant DNA technology.
Optimum selection indexes for production traits of holstein/friesian cattle in britain
Authors: Gibson J.P.
Published: June 2019

The goal of livestock genetic improvement is maximun increase in the economic efficiency of production (economic merit). When several traits contribute to economic merit, optimum genetic improvement can often be achieved by use of a discriminant function of available information (known as a selection index) which maximises expected genetic progress in the aggregate genotype, economic merit. This approach assumes that economic merit is a linear function of genetically controlled outputs. Although this may not always be true, since genetic responses are usually relatively small (0.005 to 0.020 of the mean per year) any non-linear effects are second-order and can generally be ignored. Economic optimization procedures which match production environments to genotypes would generate effectively non-linear functions, such non-linearity will generally be small. Thus the selection index approach can be applied, provided that functions describing economic merit are based on previously optimized production environments.
A selection Index for hill sheep
Authors: Al-Nakib F.M.S. , Simm G.
Published: June 2019

Apart from the MLC indices for hill sheep (MLC, 1986) and Atkins’ (1984) study for Scottish Blackface sheep, little attention has been directed towards the general implementation of selection indices in hill sheep production, despite the fact that hill sheep constitute the backbone of the British sheep industry (eg. the genetic contribution of hill sheep to lamb carcass meat was estimated at 33 per cent, to total lambs slaughtered 36 per cent, and to dams of the lambs slaughtered 56 per cent - see MLC, 1988)

The purpose of this paper is to try to define appropriate breeding objectives for hill sheep that could be incorporated in a selection index, in order to improve output and efficiency of sheep production in such a limiting environment.
The effect of long-term daily administration of bovine somatotrophin on the performance of dairy cows over a second consecutive lactation
Authors: Butterwick R.F. , Weekes T.E.C. , Rowlinson P. , Parker D.S. , Armstrong D.G.
Published: June 2019

The objectives of the trial were to investigate the effects of bovine somatotrophin (BST) from either week 2 or week 10 post-partum on the yields of milk, milk components, body weight, body condition, feed intake, health and reproductive status of dairy cows over a second consecutive lactation. The results from the heifer lactation have been reported previously (Butterwick et al. 1988).

17 Friesian dairy cows in their second lactation were continued on the same treatment as in their heifer lactation: daily subcutaneous injection of recombinantly derived bovine somatotrophin (BST;25mg/d) from either week 2 (BST2;n=6) or week 10 (BSTl0;n=5) post-partum, or injection of a buffer solution from week 2 of lactation (C;n=6). Treatments continued until week 42 of lactation or until 60 days prior to predicted calving date, if this occurred before week 42 of lactation. Initially cows were housed in cubicles and fed ad libitum through Calan doors, on a diet consisting of concentrate and grass silage (Table 1) on a 60:40 dry matter ratio. After day 110 of lactation cows were turned out to pasture but continued to receive concentrates according to milk yield and body condition score. Milk yield and feed intake were recorded daily, milk composition, body weight and body condition score were recorded twice weekly. Health and reproductive status were monitored over the lactation.
Evaluation of a slow release form of recombinantly derived bovine somatotropin (BST) in dairy cattle
Authors: Kim J. , Campling R.C. , Tarrant M.E.
Published: June 2019

Two experiments were conducted with British Friesian/Holstein cattle to evaluate the response in milk production to the long-term use of recombinantly derived bovine somatotropin in a slow release form (somidobove, Lilly Research Centre Ltd). The first compared three doses of BST and the second measured the effect of BST given to animals receiving two levels of concentrates.

Thirty-eight and forty autumn calving cattle were used in experiments 1 and 2 respectively. A randomised block design was used in the first experiment and a 2 x 2 factorial in the second. Animals were blocked on the basis of similarity in calving date and milk yield during the preliminary period. Treatments were allocated at random within blocks, animals remained on the same treatment throughout each experiment. In experiment 1 animals received seven successive subcutaneous injections of BST at intervals of four weeks, the initial injection was given about 11 weeks after calving. A control and three doses of BST were compared: 320, 640 and 960 mg. In experiment 2 animals were given given six injections of 640 mg BST at the same intervals.
The interaction between level of protein and the response to specific nutrients in high silage diets
Authors: Thomas C. , Crocker A. , Fisher W. , Walker C. , Reeve A.
Published: June 2019

Previous studies have indicated that supplements to high quality grass silage based on molasses and sodium bicarbonate can enhance microbial efficiency and milk output. However these experiments showed that there was still a need to include preformed protein in the supplement to maximise the response. Also, work at this Institute (M. Gill, unpublished data) had indicated marked responses to branched chain volatile fatty acids (vfa) in high forage diets, but only in the presence of protein supplements. The aims of the experiment were to firstly examine whether preformed proteins in high forage diets could be replaced by either protected or unprotected amino acids (methionine and lysine) in dairy cow diets and secondly, to investigate the interaction between branched chain acids and the supply of protein.

Eighty British Friesian cows in their second and subsequent lactation were offered grass silage ad libitum together with 4 kg of molasses and sodium bicarbonate (Alkacarb, ICI plc) at 30 g/kg silage dry matter (DM). They were given a protein supplement consisting of soyabean meal and fishmeal in a 3:1 ratio at either 2 (L) or 3.2 kg/day (H).
High forage diets for beef Cattle
Authors: Steen R W J
Published: June 2019

The use of high-forage systems for beef production is a particularly diverse subject area encompassing the role of both grazed and conserved forage and a wide range of production systems. These include systems such as 12-16 month silage-cereal beef, 16-18 month grass-cereal beef and 22-24 month grass beef for dairy-bred cattle, hill and lowland systems of suckled calf production and systems for finishing store cattle. Consequently, within the constraints of this paper it will be possible to examine only some of the most recent developments in the use of forage for beef production.

Digestibility is the most important factor influencing the value of conserved forage for beef production. From a review of eight comparisons in which silage has been offered as the sole feed, silage dry matter (DM) intake, live-weight gain and carcass gain were increased by 17 g/kg, 45 g/day and 33 g/day respectively per 10 g/kg increase in digestibility. In a further nine comparisons involving silages supplemented with concentrates, concentrates constituting 200 to 370 g/kg total DM intake, silage DM intake, live-weight gain and carcass gain were increased by 14 g/kg, 37 g/day and 28 g/day respectively per 10 g/kg increase in digestibility.
The influence of fodder beet on growth performance and carcass characteristics of growing/finishing pigs
Authors: Boyd P.A. , Cole D.J.A. , Wiseman J. , Thorne P.J.
Published: June 2019

In certain parts of the world the use of grain crops for animal feeding is limited and where there is competition for direct human use, alternative feeds must be considered. Root crops are a potential feedstuff for growing pigs in some situations and the objective of the present programme of work is to establish the nutritional value of these materials and to investigate factors which effect their utilisation in pig diets.

The high moisture content of root crops results in low nutrient density and the current experiment was designed to examine whether this resulted in any limitation on food intake and subsequent growth performance of growing pigs. This was achieved by formulating diets to contain different proportions of root crop and concentrate; these diets were isoenergetic/isonitrogenous when based on dry matter but varied in nutrient density when expressed on a fresh weight basis.
The use of growth hormone and beta agonists to improve animal production
Authors: Roche J.F. , Enright W.J.
Published: June 2019

The factors that affect output in animal production systems are growth rate, feed conversion efficiency (FCE), carcass conformation, muscle and fat content, and kill out percentage. These factors are affected by genetic potential, provision of optimal nutrition and environmental conditions to disease free animals. In addition, certain exogenous chemicals are known to affect animal performance, and these can be classified as follows:

i)use of chemical messengers which bind to specific receptors in target tissue

ii)use of anti-microbial compounds which alter the microflora in the gastro-intestinal tract and thereby improve performance.

This paper will deal specifically with the use of beta adrenergic agonists and growth hormone (GH) which are currently being researched.
Use of intrarumlnal soluble glass boluses containing two levels of melatonin for early lamb production
Authors: Brown D.C. , Thomas E.M. , Jones R A , Poulton A L
Published: June 2019

It has been shown that giving mule ewes a soluble glass bolus which contained 150 rag melatonin on 2 July, advanced the onset of the oestrus cycle. This experiment was designed to investigate whether the dose rate of melatonin could be reduced.

1.40 ewes not treated (control).

2.40 ewes given glass bolus containing 150 mg melatonin.

3.40 ewes given glass bolus containing 100 mg melatonin.

120 mule ewes (Blue-faced Leicester x Swaledale) aged between 4 and 6 years all of proven breeding ability were divided into 3 similar groups by age, weight and body condition on 2 July. One group was left untreated and 2 groups received a polymer-bonded soluble phosphate glass bolus (Pilkingtons P.L.C.) which contained the appropriate level of melatonin (Sigma Chemicals Corporation). Each bolus was cylyndrical in shape measuring 1.8 cm in diameter and 3.0 cm in length. Tho average mass and specific gravity of boluses were 23 g and and 3.0 respectively.
Stimulation of seasonally anovular mule ewes by rams
Authors: Ibraheem H. F. , King M. E. , Hutchinson J. S. M. , Gunn G. J. , Taylor L. , Atkinson T.
Published: June 2019

Early lamb production is a specialist enterprise in which profitability is highly dependent on getting all the lambs sold while prices are still high in Spring when lamb is in short supply. This involves lambing in late December/early January. Hence ewes must be mated in August. Conventionally in the UK, this has been achieved by the use of progesterone-impregnated sponges and pregnant mare's serum gonadotropin (PMSG). The ram effect is a powerful technique for the control of sheep reproduction. The objective of the present study was to reinvestigate the value of teasers for the stimulation of seasonal activity in the ewe.

125 (2-3 yr) Mule ewes (Blue-faced Leicester x Swaledale or Blackface), isolated from rams for two months, were used to investigate the effect of different durations of teasing on the stimulation of seasonal activity. Groups of 25 ewes were exposed to either teaser vasectomised rams and teaser ovariectomised ewes (induced into behavioural oestrus by an intramuscular injection of 0.2 mg of oestradiol benzoate) for 1 month (group l), 3 weeks (group 2) and 2 weeks (group 3); or vasectomised rams only for 2 weeks (group4); or left untreated (group 5). At the imposition of treatments, groups were isolated from each other and from contact with other 3heep by a distance of at least 1 km. Plasma progesterone was measured twice weekly on 8 animals, per group to determine ovarian activity.
The effect of the nature, level and frequency of feeding of supplement on the voluntary forage intake of wether sheep
Authors: Eayres H.F. , Anderson D.H. , Oldham J.D.
Published: June 2019

The physical limitation of rumen capacity frequently restricts forage intake of ruminants to be within that needed to achieve their nutrient requirements for maintenance and production. It has been observed that, in some circumstances, supplementation can enhance the intake of forages, particularly those of low digestibility, while forage intake will reduce at high levels of supplementation, but in ways which are difficult to predict (Weston, 1982).

In a previous trial it was observed that in sheep with an adequate supply of protein, barley supplements caused a decline in hay intake equivalent to 1:1 on a dry matter basis (Eayres el al, 1988). The present study was designed to investigate further the influence of barley and protein supplements on the intakes of hay and straw by sheep.

Thirty two wether sheep (12 months old; Greyface) were placed in individual pens with wire floors and offered chopped hay ad libitum for 21 days in order to allow adaptation to the pens and to a forage based diet.
An assessment of the potential of a lactobacilli inoculant as a silage additive
Authors: P.G. Hooper  , R. Sharp  , P. Rowlinson  , D.G. Armstrong
Published: June 2019

The trial reported here forms part of a long term research project at Newcastle investigating the suitability or a bacterial inoculant (Pioneer Hi-bred Int. Inc. brand 1177) for U.K. silage production. In designing the feeding experiment, note was taken of previously conducted trials with both beef animals (Hooper et al. 1988) and sheep (Hooper et al. 1984; Hooper and Armstrong, 1987). Results to date have indicated nutritional advantages to those silages prepared with the inoculant when compared to control silages produced from the same material but without any additive treatment. This response to inoculation in terms of higher apparent digestibility coefficients and higher intake levels when fed on an ad libitum level have generally been associated with quantified improvements in silage quality, though this has not always been the case. The inoculant used in this experiment though of the same bacterial composition as used previously, was applied as a liquid additive rather than in a granular formulation.
Effects of replacing barley/soya with malt distillers grains (draff) in silage based complete diets for dairy cows
Authors: Hyslop J J , Roberts D J
Published: June 2019

In a previous experiment outlined at last year's conference (Hyslop and Roberts, 1988), it was demonstrated that replacement of a proprietary pelleted concentrate with malt distillers grains (draff), should be limited to 15% of total dry matter intake (DMI) when draff is offered in two feeds per day. However there is little evidence to validate such a limitation when draff is used as a concentrate replacement in complete diets. This experiment examined the effect of replacing barley/soya with draff plus additional minerals in silage based complete diets.

In a cyclic changeover design experiment consisting of 4 three week periods, fifteen British Friesian cows in early lactation were offered five treatments. Cows were given ad libitum access to one of five complete diets based on grass silage (69 “D”). Draff plus additional minerals gradually replaced barley/soya at increasing rates in diets 0-4 respectively.
The possibility of predicting the sheep voluntary dry matter intake of hays from their rumen degradation characteristics
Authors: Lopez S. , Carro Dolores , Gonzalez J.S. , Ovejero F.J.
Published: June 2019

Ability to predict accurately the intake of digestible nutrients by ruminants is of great interest. The feed intake can be limited mainly by the amount of undigested residue remaining in the rumen. Ingested feed disappears from the rumen in two ways: through digestion and through passage. So, forages with easily degraded cell-walls, may promote faster rates of digestion and passage and allow the animal to consume more feed (Hovell et al., 1986).

The objective of the present study is to determine the rate and extent of rumen degradation of various hays “in situ” and to evaluate the ability to predict the voluntary intake from these rumen degradation characteristics.

Eleven sun-cured hays from three cultivars (alfalfa, red-clover and vetch-cereal), two sown grasslands (grass-clover mixture and mixed grass sward) and six permanent meadows were used to study the relationship between some rumen degradation characteristics and the voluntary dry matter intake (VDMI) by sheep.
The Effects of rate of protein degradation in silage supplements on performance of beef cattle
Authors: Belete-Adinew A. , Garnsworthy P.C.
Published: June 2019

Much interest has been shown recently in synchronising the supply of nitrogen and energy yielding substrates to microorganisms in the rumen. It is argued that when supplies are synchronised, rumen fermentation will be more efficient and improved performance will result. Previous trials with beef cattle at Nottingham and elsewhere have investigated the effect of single protein sources (e.g. fishmeal, soya bean meal) on rumen fermentation and performance. However, the majority of silage-fed beef cattle in this country receive supplementary protein in compound feeds. It is possible that the digestion of the carbohydrate portion of the compound feed could compete with silage digestion for nitrogen supply. Therefore, degradation of silage should be investigated in animals actually fed on the compound feeds, rather than just considering the degradation of the protein components in a compound. A trial was carried out to investigate the influence of protein source in compound feeds on rumen fermentation and performance in beef steers given silage.
Simple simulation: prediction of intake by dairy cows using a spreadsheet model
Authors: Forbes J M
Published: June 2019

Spreadsheet computer programs provide a two-dimensional matrix into whose cells numbers and text can be placed and manipulated. A cell can also contain a formula which causes a calculation to be performed on values In other cells and the answer shown on the screen. Graphs can be produced from specified ranges of values in cells. Thus a spreadsheet is well suited to financial accounting. Modelling biological systems has often been thought to be complicated and to involve writing a computer program. Simulation languages take away much of the detailed programming effort but still require the user to learn the syntax and capabilities of the language.

The aim Is to develop a simple model of voluntary feed Intake by the lactating cow using a spreadsheet program. The basis is the model described by Forbes (1988) simplified for a complete feed rather than forage and concentrates but with the level of intake determined by both metabolic and physical factors rather than by which ever of those two Is the lower.
Combined effects of intraruminal application of acetate, propionate and distension on silage intake by dairy cows
Authors: Mbanya J.N. , Anil M.H. , Forbes J.M.
Published: June 2019

There Is considerable evidence that end products of carbohydrate fermentation and distension of the rumen are involved in limiting intake in ruminants. Intraruminal Infusion of acetate or propionate (Montgomery et al., 1963) distension of the rumen (Campling and Balch, 1961) depressed hay Intake in cattle It is unlikely, however, that any single factor is entirely responsible for terminating feeding but that the effects of the changes that occur In the rumen during a meal, such as production of SCFA, changes In pH, osmolality, rumen distension, are Interpreted as a whole to induce satiety.

In a previous study with dairy cows distension of the rumen together with Intraruminal infusions of sodium acetate and sodium propionate had additive effects on hay Intake (Anil et al, 1987) and a similar experiment has now been carried out with silage.
Depression in silage intake by infusion of propionate into the rumen of the dairy cow
Authors: Anil M.H. , Mbanya J.N. , Forbes J.H.
Published: June 2019

It is important to understand the factors which limit forage intake in ruminants. Most work carried out on sheep has now been extended to the dairy cow. The effects and possible roles of the short chain fatty acids In the control of forage intake in the dairy cow, in particular, hay intake have already been reported (Mbanya, 1988). One of the factors in question is propionate which depresses intake when given intraportally in sheep, but hay intake in the dairy cow was not affected by intraruminal propionate. The aim of this study was to test the role of propionate in the control of silage intake which has economical importance in the dairy industry.

Five rumen fistulated Friesian cows in early lactation (mean yield 25 kg/day) were used in a Latin-square experiment and individually fed grass silage (DM: 229g/kg; CP: 158g/kg DM; MAD fibre = 349g/kg DM; ether extract: 42g/kg DM; ash: 96g/kg DM) ad libitum plus 6 kg of concentrate fed twice daily. 3h intraruminal infusions of the following were made on different days: Control (no infusion), 4,6 and 8 moles of sodium propionate in 41 water. Silage intake was measured during the 3h and for 2h post-infusion.
The Effect of moving onto silage aftermath in mid-season on the intake and performance of young growing cattle
Authors: Wilkinson S C , Mackie C K
Published: June 2019

Moving onto silage aftermath is an integral part of the 1.2.3 grazing system. In this system two thirds of the grass area are conserved for first cut silage while the other third is grazed. Between first and second silage cuts the silage aftermath is grazed while the original grazing area is closed for silage. After the second silage cut the whole area is grazed. In this trial the contribution of silage aftermath to the system was investigated by comparing the intake and performance of young cattle moved onto aftermath in raid-season with that of similar animals grazing the same sward continuously.

Thirty-two Hereford x Friesian and thirty-two Limousin x Friesian steers (mean liveweight 193 ± 16.8 kg) were allocated to either Treatment C, grazed continuously on the same sward throughout the experiment or Treatment S where the animals were turned onto silage aftermath in mid-season. Treatments were replicated twice and balanced for breed and liveweight of animals.
Studies on the firmness of backfat in bacon-weight pigs
Authors: Briggs C. , Wood J.D.
Published: June 2019

Backfat firmness is an important aspect of pig carcass quality. National values for backfat thickness have been falling annually whilst softer backfat has been increasingly reported by the meat trade. The problems of soft backfat have been well documented: it is unsightly, difficult to slice and prone to separation (MLC, 1983). All these factors can lead to downgrading of the product and consequent financial loss to the processor. Leanness of pigs is one cause of softer backfat and unsaturation of the backfat lipid, especially by the exogenous fatty acid linoleic acid (C18:2), is also an important factor (Prescott, 1988). The present study investigates the effect of backfat thickness and consequent chemical composition on fat tissue quality and considers some histological aspects of the soft fat problem.

Forty-six NPD gilts were reared to obtain carcasses having a wide range of backfat thickness values at a slaughter live weight of 90 kg. Two diets containing different levels of linoleic acid and energy but the same ratios of linoleic acid to energy were used to achieve this.
Preliminary observations on skatole production in pigs
Authors: Hawe M. , Walker N. , Porter M. , Moss B.W.
Published: June 2019

Skatole and indole, compounds formed in the large intestine by microbial breakdown of tryptophan, are associated with carcass taint (Hansson et al., 1980). The present work involved the development of a method for detecting the absolute values of the analytes in fat and faeces. The effect on faecal excretion of skatole was also examined following infusion of skatole directly into the caecum. Finally as substrate effects the type and extent of fermentation in the large intestine, different diets were fed and the corresponding faecal and fat skatole levels were determined.

Skatole analysis involved homogenising adipose tissue with methanol and removal of fat by cooling and filtering. Solid phase extraction columns concentrated the analytes to produce samples which gave good resolution by gas liquid chromatography (Porter, Hawe and Walker, 1989). Due to higher levels of skatole in faeces, no concentrating phase was required before detection.
Evaluation of fibrous by-product feeds for the pregnant sow using antibiotic suppression to measure degree of fermentation
Authors: Edwards S A , Njotu B A , Fowler V R
Published: June 2019

The use of fibrous by products in diets for pregnant sows offers possible economic and welfare advantages. To correctly determine their nutritional value it is essential to know the relative roles of enzymatic digestion and fermentation. Techniques developed previously for this purpose have involved the use of surgically modified animals, making them costly and limiting their widespread use. This experiment was designed to investigate the possibility of using short term administration of bacteriostatic levels of antibiotics for this purpose.

Twenty Landrace x Large White pregnant sows were individually housed in unbedded stalls and allocated to one of five dietary treatments with differing levels of the two fibrous by-products - distillers dark grains (DDG) or dried, unmolassed sugarbeet pulp (SBP)

1)Basal diet (BAS) 850g/kg barley, 120g/kg soyabean meal,30g/kg vitamins and minerals

2)70% diet BAS, 30% distillers dark grains (30DDG)

3)40%diet BAS, 60% distillers dark grains (60DDG)

4)70%diet BAS, 30% unmolassed sugar beet pulp (30SBP)

5)40% diet BAS, 60% unmolassed sugarbeet pulp (60SBP)
The Influence of free fatty acid on the apparent metabolisable energy value of tallow fed to broiler chicks
Authors: Salvador F. , Wiseman J.
Published: June 2019

Fats are important but variable energy-yielding ingredients in diets for broilers. One of the factors that may affect the dietary energy value of fats is the proportion of free fatty acids which, together with rate of inclusion of fat and the age of the bird, must be considered in fat evaluation. The current experiment was designed to investigate the effect of free fatty acid content of tallow on the apparent metabolisable energy values for broilers.

Tallow and tallow acid oil (Table 1) were obtained for evaluation. Tallow (A) of free fatty acid content 138.4 g/kg was hydrolysed to produce a fat (E) of free fatty acid (FFA) content 952.1 g/kg. Fat A and B were blended in the proportions A75:B25, A50:B50 and A25:B75 giving fats of 341.5, 545.3 and 748.7 g/kg FFA respectively which were included at rates of 40 g/kg, 80 g/kg and 120 g/kg at the expense of the energy-yielding ingredients. The 16 experimental diets - basal (Table 2) together with 15 containing fats - were evaluated with Ross 1 broiler chicks of 1.5 weeks (5 replicates of cage of 2 birds) and 7.5 weeks of age (5 replicates of cage of 1 bird).
Analysis of individual differences in behavioural responsiveness in pigs
Authors: Terlouw C. , Lawrence A.B. , Illius A.W.
Published: June 2019

Animals show considerable individual variation in many behaviour patterns such as feeding and mating behaviour. Often, this individual variability is ignored in favour of a more general description of the population. However, this may mask important information regarding the causes and functions of this individual variability. Behavioural work on other species has suggested that individuals tend to respond actively or passively to environmental challenge. It is of interest to know if a similar dimension of responsiveness exists in pigs as it may serve, amongst other things, to explain the considerable individual variability in pigs responses to putitive stresses such as tethered housing. This paper describes a series of tests made of behavioural responsiveness in pigs to assess the extent of consistent variability in individuals responses to a wide variety of environmental challenges.

The subjects were two groups [Group A and B: n = 26 and 36 respectively) of modern hybrid non-pregnant gilts [Cotswold Pig Development Company Ltd, UK). Initially, the gilts were subjected to a number of tests of behavioural responsiveness at the Cotswold unit.
The effect of dietary Intake and litter size on the productivity of first-litter sows
Authors: Mullan B.P. , Close W.H.
Published: June 2019

The partition of nutrients during lactation, In particular the extent to which body reserves are utilised to support milk production, is important in determining the reproductive performance of sows. For example, if the mobilisation of body reserves by young sows during lactation is excessive then the Interval between weaning and re-mating may be extended. The aim of this present experiment was to manipulate the use of body reserves by sows during their first lactation by altering both feed Intake and suckling intensity (litter size) in an attempt to investigate how the dynamics of nutrient metabolism during lactation may influence reproductive function.

In a 2 X 2 factorial experiment, 28 Landrace x Large White gilts were fed a diet containing 12.5 MJ DE and 156 g CP per kg either to appetite (H) or 3.0 kg/day (L) with litter size adjusted to either 6 (6) or 12 (12) piglets at each feeding level for a 21-day lactation..
Ensiling grass and strain mixtures: effect of an enzyme additive and urea on chemical composition and nutritive value for sheep
Authors: Jakhmola R.C. , Weddell J.R. , Greenhalgh J.F.D.
Published: June 2019

Straw mixed with grass before ensiling absorbs excess water and reduces effluent, but dilutes nutrients like crude protein and water soluble carbohydrates, and increases cell wall constituents of the mixture. Earlier studies by the authers showed that treating straw with urea before ensiling with grass increased the digestibility of grass+straw silages. A cellulase enzyme preparation had small but positive effects on fermentation and digestibility. The present paper describes the effect of treating straw with urea and a cellulase enzyme preparation on chemical composition and nutritive value of Silages.

Shredded barley straw was treated with urea (60 kg/t of straw dry matter) and a cellulase enzyme preparation (FS01, Forum Feeds Finland; 2 1/t of straw), just before mixing with the precision chopped perennial ryegrass in the ratio of 40:60 on a DM basis, in a 2 X 2 factorial experiment. All the four premixes were ensiled in polythene silos ( 1 t capacity). Eight male sheep were fed four silages in a 4 X 4 latin square design. Each feeding period consisted of a 4-day adjustment period, a 10-day preliminary feeding period and a 7-day period for measurement of digestibility.
The effect of dietary sodium on the energetic efficiency of microbial yield from the rumen of sheep
Authors: Dewhurst R.J. , Webster A.J.F.
Published: June 2019

It has long been recognised that there is a strong positive relationship between the level of absorbed (microbial) purines and purine derivative excretion in the urine. We have used estimates based on urinary allantoin N excretion (AN) to investigate some of the factors influencing the energetic efficiency of microbial yield from the rumen (E). Figures 1 and 2 illustrate the model that has been adopted.

It has been tentatively assumed that, at reasonable levels of intake, exogenous purine supply exceeds “a” moles (Figure 2) so that purine salvage is saturated (Condon & Hatfield, 1970), de novo synthesis inoperant (Condon, Hall & Hatfield, 1970) and the net endogenous contribution to AN negligible. In these circumstances AN will be linearly related to microbial (purine) yield from the rumen.
Effect of ammonia treatment and supplementation on barley straw intake by sheep
Authors: Fondevila M. , Castrillo C. , Gasa J. , Guada J.A.
Published: June 2019

Twenty-eight lamb ewes (44 + 0.45 kg live weight) were used to study the effect of type and level of supplementation on voluntary intake of barley straw, treated with 30 g/kg of anhydrous ammonia (TS) or untreated (US) but given with urea to ensure the same nitrogen content as TS (18 g/kg DM). Each type of straw was offered ad libitum, supplemented with grass hay, rolled barley and sugar beet pulp at rates of 150, 300, 4 50 and 600 g/d, in 6 Latin Squares (4 x 4). In addition, another 2 sheep received each straw alone during the same periods. Supplements were totally consumed, except hay, which was refused in 10 - 13 and 28 - 34 per cent for US and TS, respectively.

Daily dry matter intake (DMI) of US (OMD = 0.423) and TS (OMD = 0.515) offer as sole feed were 511 ± 29.1 and 858 ± 45.2 g. As show TABLE 1, US was consumed at rates of 527, 576 and 568 g DM when supplemented with 150 g of hay, barley and sugar beet pulp, and no significant differences were found with further levels of supplementation. DMI of TS decreased linearly from 850 to 618 g/d (r = 0.75) and from 717 to 518 g/d (r = 0.63) when the level of barley and sugar beet pulp increased from 150 to 600 g/d. Substitution rates were estimated to be 0.31 and 0.27 for barley and sugar beet pulp, respectively. Decrease in TS intake when supplemented since 150 to 600 g/d of hay (720 to 605 g, respectively) were found not significative.
Long-term patterns of food selection in sheep growing towards maturity
Authors: Hou X.Z. , Anderson D.H. , Illius A.W. , Emmans G.C. , Oldham J D
Published: June 2019

Previous work at the Edinburgh School of Agriculture has suggested that sheep, like pigs, can select amongst foods which differ in protein:energy content according to their protein needs. The proportion of high protein feed which was selected by young sheep gradually diminished as the animals grew towards maturity over a period of measurement of 10 weeks (Cropper, 1988). The experiment reported here was designed to test this idea further by allowing sheep, initially differing in age and weight, to select between a high and low protein food (both available ad libitum) throughout their growth to a stable mature weight and body composition.

Two pelletted feeds were formulated and prepared which differed in protein concentration but with similar calculated energy (metabolisable energy, ME) (Table 1) concentration and abundant in minerals and vitamins. Seven sheep (Suffolk x Greyface wethers) aged 3 months (n = 3), 18 months (n = 2), and 30 months (n = 2) at the start of the experiment were individually penned and given experience of each of the two feeds individually before having ad libitum access to both. Tap water was freely available from a bucket. Voluntary consumption of each feed was recorded daily by weighing and drying refusals. The sheep were weighed weekly and scanned using a Vetscan ultrasonic scanner to estimate fat and muscle depths at the 13th rib on days 126, 225, 336, 436 and 539.