bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship between dry matter and fibre degradation characteristics of silage and silage intake in steers
Authors: Dawson L.E.R , Steen R.W.J.
Published: November 2021

The lower intake of silage relative to fresh grass or hay from the same sward has been attributed to the end-products of fermentation, both in the silo and in the rumen (Thiago, Gill and Dhanoa, 1992). However, research at this Institute has indicated that the relationships between silage fermentation products and intake are poor (R2<0.10) (Steen et al, 1995). Thorton and Minson (1972) noted that the voluntary intake of forage (mainly dried forage) was inversely related to retention time in the rumen. The relationship between breakdown of dried forages (e.g. hay and straw) in the rumen and intake has been extensively studied, whilst the relationship between rumen degradation of silages and intake has not been studied to the same extent. The aim of the current study was to determine if there is a relationship between silage intake and degradation characteristics in the rumen, with a view to providing a better understanding of the control of silage intake.
Rumen hydrogenation of long-chain fatty acids from fish meal
Authors: Carro M.D. , Miller E.L. , Fabb O.C.
Published: November 2021

In one in vitro study Ashes et al. (1992) reported that C20 and C22 fatty acids (FA) from fish oil were not hydrogenated to any significant extent by rumen microorganisms. However, to our knowledge, no measurement on hydrogenation has been performed on fishmeal (FM) FA. The aim of this experiment was to study the in vivo and in situ rumen hydrogenation of long-chain FA of two different FM: FMl (60 g FA/g DM) and FM2 (85 g FA/g DM).

Six sheep fitted with rumen cannulae and single duodenal cannulae were fed every 2 hours, receiving 1 kg/d of a 60:40 hay:concentrate diet, either alone (Control; C) or supplemented with 40 g FM/d (FMl and FM2). The experiment was carried out over four periods (two sheep received one of the diets in each period) and Cr-NDF was used as a marker to estimate duodenal flow. Data were subjected to analysis of variance using the ANOVA procedure of the Statistical Analysis Systems (SAS, 1994).
The use of n-alkanes for prediction of intake in dairy cows
Authors: Unal Y. , Garnsworthy P. C. , Gorton P.
Published: November 2021

Alkanes are the components of plant cuticular waxes. Recent studies have been shown that the faecal ratio of natural to dosed alkane concentration can provide accurate and precise prediction of herbage intake in grazing sheep ( Mayes et al. 1986; Vulich et al. 1991). Limited information is available on the use of n-alkanes with dairy cows, but they have the potential to predict intake of group-fed cows. The objective of this study was to evaluate n-alkanes as markers to predict the intake of hay based diets for dairy cows.

Three rumen-fistulated Holstein Friesian dairy cows were housed in individual standings. A three by three latin square design was used with a different level of hay (Diet A, 6; B, 8; C,10 kg/d) and 1 kg/d rolled barley for each cow. Each period was lasted 20 days. The first 10 days was a preliminary period and over the following 10 days total faecal collection took place.
Adrenergic and cholinergic modulation of insulin secretion in non-lactating cows exposed to heat
Authors: Itoh F. , Obara Y. , Rose M.T. , Hashimoto H. , Akema M.
Published: November 2021

The inhibition of insulin secretion in sheep exposed to cold has been reported to be mediated through adrenergic Î± receptors stimulated by sympathoadrenomedullary activity (Sasaki and Takahashi, 1980). Insulin secretion in Holstein non-lactating cows in response to various secretogogues was also suppressed during heat exposure (Itoh et al., unpublished data), however it is not obvious whether these responses were related to neural controls or not. However acetylcholine (parasympathetic nervous system neurotransmitter) has been shown to promote the release of glucagon and insulin (Jones et al., 1991). Therefore, the objective of this study was to examine the participation of adrenergic and cholinergic neural control on insulin secretion in thermoneutral and hot environments in non-lactating cows by administering, adrenergic and cholinergic blockers with an intravenous injection of glucose.
The detection and avoidance of heavy metals in feeds by chickens
Authors: Strojan S. T. , Phillips C. J. C.
Published: November 2021

Anthropogenic activities have lead to a redistribution of heavy metals within the environment, often with the effect of increasing the concentration in which they are found within farming ecosystems. This series of trials was conducted to determine whether farm animals could detect heavy metals in feeds, if so at what levels, and whether they preferred uncontaminated feeds. Both toxic and non-toxic metals were tested, but toxic metals were only tested at levels that would not induce clinical problems.
The effects of calf management and milking strategy on camel milk production in Kenya.
Authors: Simpkin S.P. , Rowlinson P. , Tullu D.
Published: November 2021

Milking strategy and calf management vary depending on the requirements of the owner and the production focus. In Kenya, survey results have shown the camel (Camelus dromedarius) to be primarily managed for milk production but considerable variations in calf and milking management exist between pastoralist groups. The aim of this study was to compare two traditional calf management and milking systems and determine their effects on actual milk production.
Effect of manipulation of prolactin and thyroid hormone profiles on hair follicle activity in cashmere goats
Authors: Villar D. , Rhind S.M. , Dicks P. , McMillen S.
Published: November 2021

Seasonal changes in secondary hair follicle activity and associated patterns of cashmere growth and moult are dependent on seasonal changes in profiles of hormones and growth factors. The aim of this study was to investigate the individual and interactive roles of prolactin and thyroid hormones in the activation of hair follicles and the onset of the spring moult.
Animal output in different management strategies of cashmere goats with sheep grazing summer dry perennial ryegrass/white clover swards
Authors: del Pozo M. , Osoro K.
Published: November 2021

Differences in grazing behaviour between sheep and goats could potentially be exploited in temperate sown swards to improve the efficiency of grazing systems (McGregor, 1985). However, integration of cashmere fibre goats with sheep in pastures from Northern Spain needs to be evaluated and compared with autoctonous breeds under different farming managements to allow assesments of the relative grazing profitability achieved on summer dry grass/clover pastures. The aim of the current study was to examine in lowland grass/clover swards the feasibility for animal performance of the integration of cashmere plus autoctonous goats with local sheep breeds under contrasting grazing managements (rotational, sequential or mix) with two different sward heights over a spring-summer period.
Estimating genetic progress in a Suffolk sheep group breeding scheme
Authors: Araghi M. , Pollott G. E. , Curran M. K.
Published: November 2021

In November 1989, ten Suffolk breeders co-operated to establish a nucleus flock at Wye College, University of London, known as the Wye Suffolk Improvement Group (WSIG). The members contributed 10 ewes each to the base flock. The objective of the group was to produce breeding stock with lean carcasses for the current lamb market. The objective of this study was to estimate breeding values (EBV) of live animal traits, measured annually on the lamb crop, and to plot any genetic trends over a six-year period.
Effect of partial replacement of barley with molassed sugar beet feed in concentrate given and winter shearing on the performance of pregnant ewes and survival of new-born lambs
Authors: Egan E.O. , Notman A.B. , Hill J.
Published: November 2021

Winter shearing of ewes has been shown to reduce the incidence of hypoglycaemia in twin bearing ewes (Symonds et al, 1986), increase litter birthweight and reduce lamb mortality especially in housed conditions (Austin. 1982. Vipond et al, 1987). It is however not clear if winter shearing effects lamb birth weight independently of nutrient intake or reflects solely an increase in the intake of nutrients in late pregnancy. The aim of the experiment was to study the interaction between changing the source of energy in the concentrate given in late pregnancy and winter shearing in multiparous ewes.
Variations in the maternal behaviour of primiparous, single-bearing ewes of a hill and a lowland breed of sheep
Authors: Dwyer C. M. , Lawrence A. B.
Published: November 2021

Perinatal lamb mortality can account for up to 20% of annual lamb losses, and at least a third of these deaths can be attributed to maternal factors (Mellor, 1988). Improvement in the quality of maternal behaviour may, therefore, lead to a reduction in lamb deaths. In order to identify if there is a genetic component to the expression of maternal behaviour, the behaviour of a lowland (Suffolk) and a hill (Scottish Blackface) breed of parturient ewe were quantified after the birth of a single lamb.
Determination of rumen fermentation characteristics of concentrate ingredients with the gas production technique
Authors: Cone J.W. , Van Gelder A.H. , De Lange P.G.B.
Published: November 2021

Concentrate ingredients for ruminants are valued with the help feeding tables, based on chemical composition, the Tilley and Terry technique and nylon bag incubations. However, tables only give averages, which cannot be used for individual lots, and the nylon bag technique is expensive, time consuming and accuracy may be low. The aim of this research was to investigate the possibilities to obtain feed characteristics of a broad range of concentrate ingredients with the gas production technique (Cone et al., 1996).
Quantification of Nitrogen fractions in milk using Near Infrared (NIR) Spectroscopy
Authors: Lister S.J. , Dewhurst R.J. , Dhanoa M.S.
Published: November 2021

Traditional methods for the determination of the different nitrogen fractions present in milk are very time consuming, involving two separate Kjeldahl analyses. The NIR technique requires little sample preparation and allows simultaneous determination of parameters once a suitable population has been compiled to make a reliable and robust calibration. This study investigated the use of NIR to determine crude protein, whey protein and casein protein fractions in fresh milk.
The effect of free amino acid supply on the contribution of peptide-bound phenylalanine and tyrosine to casein synthesis in late lactation goats
Authors: Bequette B.J. , Backwell F.R.C. , Kyle C.E. , Calder A.G. , Crompton L.A. , France J. , MacRae J.C.
Published: November 2021

The mammary gland of lactating ruminants (Guinard & Rulquin 1994) does not appear to extract sufficient quantities of free amino acids (AA) to account for their output as milk protein. Based upon application of a precursor (blood or plasma free AA):product (casein) labelling technique (Backwell et al. 1996) in goats, results suggest that blood peptides or proteins taken up by the gland probably account for this deficit. However, the deficiency appears to be alleviated when supplemental protein or AA are infused (Guinard & Rulquin 1994), suggesting that uptake of peptide bound AA is reduced while that of the free AA is increased. The objective of the current study was to corroborate these findings, thus the precursonproduct labelling technique was applied in lactating goats to determine whether arterial free phenylalanine supply affects the contribution of peptide bound phenylalanine and tyrosine to casein synthesis and compare the results to the net uptake (NU) method.
The degree of agreement shown by untrained observers in the qualitative assessment of pig behaviour
Authors: Wemelsfelder F. , Hunter E. A. , Mendl M. T. , Lawrence A.B.
Published: November 2021

Qualitative assessment of behaviour is based upon the integration by the observer of many pieces of information which in conventional quantitative approaches are recorded separately. Behaviour is for example summed up as ‘fearful’, ‘anxious’ or ‘distressed’. Such interpretations form the core of the lay public's concern for animal suffering, and therefore are frequently dismissed as ‘anthropomorphic’ and unscientific. However, in theory it is possible that such assessments reflect observable aspects of behavioural organization, and may be liable to scientific analysis. A first step in considering this hypothesis is to investigate the interobserver reliability of qualitative assessments. The aim of this study was to determine the extent to which untrained observers show agreement in their spontaneous qualitative descriptions of interactive behaviour in growing pigs.
Energy metabolism in high yielding cows
Authors: Beever D.E , Cammell S.B. , Sutton J.D. , Rowe N. , Perrott G.E.
Published: November 2021

Whilst current rationing systems are used to calculate the metabolisable energy (ME) requirements of dairy cows producing more than 50kg milk/day, the extent to which the digestive efficiency of the cow may be compromised at high intake levels has not been established. Equally the effect of a sustained energy deficit on milk composition is not known whilst the extent of energy contribution from mobilised tissue has not been quantified. This study was designed to examine energy metabolism in high yielding cows offered ad libitum total mixed ration during early/mid lactation.
The effect of Texel or Rouge de l'Ouest genes on lamb carcass quality
Authors: Carson A.F. , Moss B.W. , McClinton L.O.W. , Kilpatrick D.J.
Published: November 2021

Continued improvements in lamb carcass quality are important to the successful development of the UK sheep industry. A previous study at this Institute has shown that 50% Texel or Rouge de l'Ouest genes can be included in a traditional lowland crossbred ewe type without reducing lamb output. This present study was designed to provide information on the effects of using these continental genes in ewes on lamb carcass quality.
Conditioned feeding responses in sheep to flavoured foods associated with sulphur doses
Authors: Hills J. , Kyriazakis I. , Nolan J.V. , Hinch G.N. , Thomson E.
Published: November 2021

The development by ruminants of strong conditioned flavour aversions (CFAs) to foods associated with the administration of LiCl (an artificial toxin) has demonstrated their potential to avoid feeds that cause negative postingestive consequences (Provenza, 1995). Weaker CFAs are formed when they ingest foods with the detrimental secondary plant compound, oxalic acid (Kyriazakis et al. 1997). Moreover, animals may exhibit conditioned preferences (CFPs) for foods supplying appropriate amounts of nutrients such as nitrogen (Provenza, 1995). In this study we tested whether a continuum exists in the formation of CFAs and CFPs to foods that are associated with increasing availability of sulphur (S) in crossbred ewes.
The effect of food related cues on the specificity of appetite in the rat
Authors: Day J. E. L. , Rogers P. J. , Finch G. M. , Gaffan E. A.
Published: November 2021

It is known that if rats learn that a cue reliably precedes eating, its presentation can cause them to initiate a feeding bout when they are apparently sated (Weingarten, 1983, 1985). However, it is currently unclear precisely how such conditioned cues affect appetite. For example, does this type of conditioning elicit food specific appetites or do individuals merely experience a general increase in feeding motivation (Mela & Rogers, 1998)? To address this issue, the present experiment investigated the hypothesis that exposure to a cue (conditioned stimulus: CS) previously paired with a specific food biases diet selection in favour of that food when an individual is given a choice. The objective of the experiment was to enhance our understanding of the behavioural control of feeding, and hence our ability to predict diet selection and food intake.

The experimental subjects were 12 male Lister-hooded rats (initial body-weight 233; SD=20g). Throughout the experiment the subjects were maintained on a 1lh:13h light:dark cycle with lights on at 0700h, and had ad libitum access to a standard laboratory diet during the light phase.
The fatty acid composition of grass silages
Authors: Dewhurst R.J. , King P.J.
Published: November 2021

Ruminant products have been criticised for the possible adverse effects of their saturated fatty acids on human health. Conversely, the omega-3 polyunsaturated fatty acids, notably those in fish oils, have been identified as beneficial components of the human diet. Earlier studies have shown that a small, but useful, amount of forage α-linolenic acid (C18:3), an omega-3 fatty acid, appears in ruminant products (Wood and Enser, 1996). The objective of the current work was to evaluate the range of α-linolenic acid concentrations in laboratory grass silages in order to assess the opportunities to modify ensiling techniques to increase the natural delivery of omega-3 fatty acid from grass silage to milk or meat.
Rumen biohydrogenation of polyunsaturated fatty acids and their effect on microbial efficiency in sheep
Authors: Wachira A.M. , Sinclair L.A , Wilkinson R.G. , Hallett K. , Enser M. , Wood J.D.
Published: November 2021

Increasing the n-3 polyunsaturated fatty acid (PUFA) content of ruminant products may be important in reducing the incidence of cardiovascular diseases in man. However, there is some evidence to suggest that dietary PUFA are extensively biohydrogenated in the rumen (Choi et al., 1997) whilst other results indicate that long chain PUFA present in fish oil are resistant to biohydrogenation (Ashes et al, 1992). The objective of the present study was to quantify the extent to which n-3 PUFA from different sources are biohydrogenated in the rumen and determine their effects on rumen microbial efficiency.
Physiological effects of a short period of adaptation to the farrowing environment in gilts
Authors: Lawrence A.B. , McLean K.A. , Gilbert C.L. , Calvert S. , Chirnside J. , Deans L.A.
Published: November 2021

Moving gilts from a strawed pen to a crate during farrowing profoundly inhibits oxytocin, probably as a result of a stress-induced opioid-inhibition of hypothalamic oxytocin release (Lawrence et al., 1992). Other work suggests that confinement of gilts in crates for 5 days prior to farrowing protects the gilt against stressinduced inhibition of oxytocin. As producers introduce gilts and sows into farrowing crates at variable times prior to farrowing it is important to identify the minimal period of exposure to crates required to confer adaptation. This work tested whether only a short period of adaptation (1 day) to farrowing crates prior to expected farrowing date (EFD) would be sufficient to prevent stress-induced inhibition of oxytocin.
Genotype by environment interaction for milk, fat and protein yield in Holstein Friesian dairy cattle in Ireland
Authors: Cromie A. R , Kelleher D.L , Gordon F.J , Rath M.
Published: November 2021

The existence of genotype by environment interaction (G*E) can cause a change in the ranking of bulls tested in one environment when their daughters are subsequently milked in another environment. If the degree of re-ranking is large, the genetic correlation between milk production in the two environments will be substantially less than 1.0, with the implication that proofs made in one environment may not be reliable predictors of proofs in the second environment. The aim of this study was to investigate the effect of increasing the difference between environments, defined on the basis of herd average milk yield, on the genetic correlation (rg) for milk, fat and protein yield in Holstein Friesian dairy cattle in Ireland.
Estimation of rumen degradable organic matter of forages using different techniques
Authors: Deaville E. R. , Givens D. I.
Published: November 2021

The UK metabolisable protein system proposed an approach for calculating the energy (termed fermentable metabolisable energy) available for rumen microbial protein synthesis. This approach does not take into account rumen undegradable organic matter (OM; mainly protein and starch) and ignores the dynamic aspects of the value, such as rate of fermentation. The aim was to evaluate three techniques to estimate OM apparently degraded in the rumen (OMADR) of different forages.
Determination of total gas production and gas profile release from a bicarbonate buffer during addition of acetic acid to a carbonated-buffered medium
Authors: Mauricio R. M. , Vitti D.M.S.S , Mould F.L. , Owen E. , Dhanoa M.S , Theodorou M.K
Published: November 2021

The quantity of gas accumulated in the in vitro fermentation technique (e.g. Theodorou et al., 1994) results from gaseous end-products of substrate fermentation, lysis of rumen microorganisms and CO2 released when VFA are neutralised by the carbonate-buffered medium (Beuvink and Spoelstra, 1992). However the quantity of gas produced from this acid-buffer interaction is not directly related to substrate fermentation and therefore needs to be quantified if gas evolution from substrate fermentation is to be estimated. This study examined gas release following the addition of acetic acid to a bicarbonate buffered medium and used a Gompertz equation to describe both the rate and total volume produced.
Influence of protein fermentation on gas production profiles
Authors: Cone J.W.
Published: November 2021

Since automated gas production equipment became available (Cone et al., 1996), there is an increasing interest in this technique. The gas production technique is not only widely used in reasearch programms, but is also used as a routine feed evaluation technique and will soon be used in feed evaluation systems, as the gas production technique potentially can replace the nylon bag technique. Although many investigators use the technique, the interpretation of the gas production profiles is still difficult (Cone et al., 1997). The gas production caused by the fermentation of carbon hydrates is well understood and described (Beuvink and Spoelstra, 1992). Since, the gas production caused by fermentation of protein is not the same as that of carbon hydrates, comparing the gas production data of feedstuffs, differing largely in protein content, may lead to misinterpretation of the results. The aim of this study was to investigate the influence of protein fermentation of gas production profiles.
Investigation of direct gas production from silage fermentation acids
Authors: Deaville E. R. , Givens D. I.
Published: November 2021

During ensilage readily fermentable organic matter (OM) is fermented to lactic acid and short chain volatile fatty acids (VFA). These acids provide little energy as ATP for rumen microbial growth and are essentially absorbed intact. The UK metabolisable protein system defined the energy available for microbial growth, termed fermentable metabolisable energy (FME), as the proportion of metabolisable energy (ME) in a diet/feed less the ME in oil and fermentation acids. The aim was to establish if fermentation acids yield direct gas production resulting from microbial fermentation. Grass silage was simulated using grass hay (GH; containing no fermentation acids) with additions of individual fermentation acids in solution.

GH (~2 kg) was oven-dried overnight at 100°C, nulled (1 mm screen) and then sieved (25 μm screen). 0.5 g GH was weighed into 250 ml Duran bottles according to the treatments; 1) GH + anaerobic incubation mixture (AIM, 85/15 v/v anaerobic medium and strained rumen fluid) + ~5 ml distilled water; 2) GH + AIM + ~5 ml fermentation acid solution (100 mg DL-lactic acid (LA)/10 ml, 30 mg acetic acid (AA)/10 ml or 20 mg n-butyric acid (BA)/10 ml) (equivalent to 100, 30 and 20 mg/g GH dry matter (DM) for LA, AA and BA respectively); 3) anaerobic medium (85 ml) + 15 ml clarified rumen fluid + ~5 ml fermentation acid (as treatment (2)).
Evaluation of fermentation kinetics of different forms of starch and sugars using gas production technique
Authors: Hussain A. , Miller E. L.
Published: November 2021

Sugars and starch are used as fermentable metabolisable energy (FME) sources in ruminants. Compared with starch, sugars are associated with increased microbial protein supply to the animal when both types of carbohydrates are supplemented to the basal forage diet (Chamberlain et al., 1993). However different sugars respond differently which is associated to differences in their rates of fermentation. Knowledge of the fermentation kinetics of these FME sources is very helpful to synchronize energy and protein supply to the rumen. Limited data are available on the comparative rates of fermentation of starches and sugars. This experiment was conducted to determine fermentation kinetics of selected starch and sugars by measuring gas production, volatile fatty acids (VFA) production and protozoa changes in the fermentation medium
Comparison of bovine rumen liquor and faeces as sources of micro-organisms for the in vitro gas production technique assessed using twelve graminaceous forages
Authors: Mauricio R. , Abdalla A.L. , Mould F.L. , Altaf U.R. , Smith T. , Owen E. , Givens D.I , Dhanoa M.S. , Theodorou M.K.
Published: November 2021

The experiment was conducted using a range of forages with accurately predetermined OMD values (ADAS) to compare rumen liquor (RL) and faeces (FA) as sources of inocula in the pressure transducer technique (PTT) (Theodorou et al., 1994). Gas production results were examined in relation to OMD determined in vitro (PTT, Tilley and Terry) and in vivo.
Semi-automation of the in vitro gas production technique using a pressure transducer
Authors: Mauricio R.M. , Dhanoa M.S. , Owen E. , Channa K.S. , Mould F.L. , Theodorou M.K.
Published: November 2021

The use of a syringe (manual method) to measure gas production is time consuming and inaccurate. In addition the time taken prevents frequent measurements and therefore does not allow gas production kinetics to be fully described. According to Boyle's Law, gas volume corrected for temperature, is directly related to pressure. A simple, semi-automatic system recording of gas pressure and equations to estimate volume, was therefore developed.

Data for this work came from a study which compared rumen liquor and faeces as sources of inoculum using the method of Theodorou et al. (1994). Six substrates (wheat straw, hay, soyabean meal, wheat starch, maize starch, and potato residue) were utilized. Gas pressure readings (observations = 1187) were measured using a hand-held pressure transducer with an LED readout. Interfaced to a computer using a Mini-Pod 300 (AD converter). MS-Visual Basic (Microsoft) was used to convert the mini-pod readings and automatically enter them into an Excel spreadsheet. Gas volume was measured using a syringe to remove the gas produced until the readout indicated zero.
The effect of animal species and level of consumption by cattle on in vivo digestibility of concentrate ingredients
Authors: Woods V. B. , Moloney A. P. , O'Mara F. P. , Mulligan F. , Kenny M. J.
Published: November 2021

It has been suggested that cattle have a greater ability to digest fibrous feeds and a lower ability to digest non-fibrous feeds than sheep (Mc Donald et al., 1995). This statement applies mainly to forages and few direct comparisons have been conducted using concentrate ingredients. The digestibility of concentrate ingredients may be influenced by the level of consumption since an increase in intake of a complete diet resulted in a decrease in digestibility (El Khidir and Vestergaard Thomsen, 1983). The aims of this study were (a) to determine the effect of level of consumption by cattle and (b) to examine the effect of animal species (sheep and cattle) on the digestibility of concentrate ingredients.
Urinary recovery of allantoin in normally fed steers
Authors: Herrera Gomez F. , Deb Hovell F. D. , Sandoval Castro C. A.
Published: November 2021

Studies in the use of the purine derivatives technique in ruminants have been stimulated by the possible use of this technique as an estimator of the rumen microbial-N supplied to the host animal. The recovery factor influences the estimation of the total purines absorbed and therefore the microbial-N supply. The relationship between exogenous purine input and urinary excretion and recovery has been studied using cattle maintained with the intragastric infusion technique (Orskov et al., 1979). The urinary recovery of exogenous purines has been estimated to be 0.77-0.85 (Chen et al., 1990a, Verbic et al., 1990), and this relationship has been assumed to be applicable to normal feeding situations. To our knowledge there is no data to support or reject this approach. This study examined the urinary recovery of exogenous allantoin input in steers under normal feeding conditions.
The influence of supplementing rapidly degraded fibre with different forms of nitrogen on microbial protein synthesis in sheep
Authors: Chikunya S. , Miller E. L.
Published: November 2021

There is controversy in the literature concerning the effect of amino acid (AA) and peptide nitrogen on microbial activity in ruminants fed diets high in structural carbohydrates. Microbial protein is the most variable and uncertain element of current systems of evaluating protein requirements for ruminants (ARC, 1984). Some of the variability is attributed to the multiplicity of techniques for estimating microbial yield, some of which are both imprecise and cumbersome. This study investigates the effects of different forms of nitrogen on microbial activity in sheep fed a rapidly degraded fibrous basal diet and attempts to validate the recently developed purine derivative (PD) technique by comparing it to other procedures used to estimate microbial protein synthesis under the same conditions.
Influence of the pattern of nutrient release from grass silage and the effect of supplementation on the voluntary food intake of growing lambs
Authors: Blackburn W.E. , Sinclair L.A. , Wilkinson R.G. , Greenhalgh J.F.D.
Published: November 2021

Grass silage is an important feed for ruminants but it is well established that the voluntary food intake (VFI) is less than that of the same crop fed fresh or dry (Harris and Raymond, 1963). This effect has been associated with factors such as the products of ensiling as well as the asynchrony of nutrient release in the rumen. The objectives of the current experiment were to investigate whether the pattern of nutrient release in grass silage is a major factor contributing to its low intake and whether altering the pattern of nutrient release through supplementation would alter hourly and daily intake.
Evaluation of sugar beet feeds and maize distiller's dark grains as supplements for pregnant ewes fed straw-based diets
Authors: Chapple D G , Wheeler K P A , Perrott G
Published: November 2021

The feeding of lowland sheep on straw-based systems during pregnancy was developed at ADAS Rosemaund during the last decade (Davies and Chappie 1995). Results showed that ewe and lamb performance were satisfactory, providing adequate compound supplementation was fed. Whole barley and soya bean meal has been the standard ration, but feeds based on high protein molassed sugar beet feed (Probeet Trident Feed) and maize distiller's dark grains could improve palatability and be easier to feed. The objective of this work was to evaluate the effects on ewe and lamb performance of feeding sugar beet feeds and maize distiller's dark grains to pregnant ewes on a straw-based feeding system.
Behaviour and production of sows in an open pen farrowing system: effects of pen width
Authors: Marchant J.N. , Broom D.M. , Coming S.
Published: November 2021

A number of studies have been carried out on open pen farrowing systems and where these systems have appeared to function well, the minimum pen dimension has been 2.2m. The original pen system at ADAS Terrington had a maximum width of about 1.5m - the space occupied by a pen with a farrowing crate. The aim of this experiment was to determine whether increasing the pen width affected sow behaviour and production in a three-sow group farrowing system.

A total of 36 LW x Landrace sows of similar genetic stock (PIC, Abingdon, UK) and ranging from 1st to 7th parity were studied from 7 days before farrowing until 7 days after farrowing. The farrowing systems comprised three individual strawed pens, a communal passageway and an outdoor dunging area. Each pen had a heated creep at the rear and sloping walls along the sides of the pen with a piglet escape area at the bottom. Four replicates of 3 sows were studied in the Narrow Pen (width = 1.6m) treatment and eight replicates of 3 sows were studied in the Wide Pen (width = 2.4m) treatment.
Straw provision and the feeding behaviour of pigs
Authors: Morgan C.A. , Deans L.A. , Nielsen B.L. , Lawrence A.B.
Published: November 2021

One of the costs of living in a group is the imposition by certain group members of constraints on the behaviour of others (Mendl and Deag, 1995). This appears to be the case with feeding behaviour where individual pigs show a large number of small meals but group members have fewer larger meals (de Haer and de Vries, 1993). Morgan et al. (1997) found that grouped pigs given straw bedding had more smaller meals than those without, suggesting some alleviation of the group constraint. The aim of this experiment was to investigate if changing straw provision resulted in similar and reversible effects in this behaviour.

120 male pigs (40±0.4kg) were used in three blocks each with 4 pens of 10 pigs. In each block of 42d duration one pen had no straw throughout (treatment A); one pen had no straw for 21d (period 1) followed by straw for 21d (period 2)(B); one pen had straw followed by no straw(C) and one pen had straw throughout (D). The pens were situated in a naturally ventilated building with light from 0600 to 2000h.
Suckling frequency of group housed sows in two different space allocations
Authors: Burke J. , Brooks P.H. , Kirk J.A. , Eddison J.C.
Published: November 2021

The more frequent the opportunities for piglets to suckle, the higher their milk intake and subsequent liveweight gain during lactation (Newberry and Wood-Gush 1984). Studies of sows in communal farrowing systems revealed that suckling frequency decreased from week 2 of lactation onwards (Houwers, Buré and Koomans 1992; Boe 1993). The objective of this study was to investigate the effect of two different space allocations on the suckling frequency of group housed sows and on litter performance to day 17 of lactation.

Four groups of four multiparous sows were allocated to one of two pen areas, in a loose house farrowing system from 5 days before the expected farrowing date until the oldest litter was 21 days of age. The two pen areas provided 13.4m2 (L) and 8.6m2 (S) per sow respectively. A row of four farrowing enclosures, fitted with heated piglet creep areas and deeply bedded with straw, were provided, within an otherwise unbedded pen.
Effect of supplementation of a hay and concentrate diet with live yeast culture on the digestibility of nutrients in 2 and 3 year old riding school horses
Authors: Hill J. , Gutsell S.
Published: November 2021

Any method to increase the utilisation of nutrients from feeds given to horses exercised on a regular basis is important. Commercially-available dried yeast cultures, used as supplements to equine diets have been shown to increase the digestibility of gross energy and enhance the retention of N in yearling horses (Glade and Biesik, 1986). There is however, limited information on whether the increase in digestibility of GE or enhancement in retention of N occurs in mature horses (Glade and Campbell-Taylor, 1990). The aim of the research reported here was to determine the effect of a dried live yeast culture on the digestibility of nutrients from a mixed diet given to riding school horses.

Six 2 and 3 year old riding school horses (mean live-weight 433 (s.e. 11.1) kg) were allocated to three balanced 2 x 2 Latin squares with two treatments and two periods of 3 weeks. The first 14 days of each period was a preliminary and the last 7 days was for measurement. The horses were housed individually (bedded on saw dust) and given 13.5 kg DM hay and 3.0 kg DM concentrate mix as a base diet. The base diet was either supplemented with 10 g dried yeast culture (S) or not supplemented (N).
Effect of biotin on growth, viability and apparent DNA synthesis in cultured secondary hair follicles of the Angora goat
Authors: Tahmasbi A.M. , Galbraith H. , Scaife J.R.
Published: November 2021

Biotin is a water soluble vitamin which has a well proven function in corboxylation reactions in animal tissues. It is well documented that biotin deficiency in mammals causes pathological changes in the skin and its appendages such as desquamative dermatitis and alopecia. Previous work (Tahmasbi et al 1996) has suggested that deficiency of biotin in the culture medium reduced the viability of wool hair follicles in vitro by mechanisms unknown, but which may involve interference with cell division and or differentiation. The objective of this work was to investigate the effect of biotin deficiency and adequacy on cell proliferation and DNA synthesis as determined by incorporation of [methyl-3H]thymidine in isolated mohair follicles.
Effect of forage maize harvested at different stages of maturity on feed intake and performance by growing beef cattle
Authors: Browne E.M. , Bryant M.J. , Beever D.E. , Thorp C.L.
Published: November 2021

Dry matter (DM) concentration of maize silage is directly related to maturity of the crop at harvest and widely reported to be positively correlated with total forage DM intake. The objective of this experiment was to investigate these effects using a late maturing beef genotype and a contemporary forage maize variety.

Forage maize (variety Hudson) was harvested at four different stages of maturity during September and October 1996. Each stage of maturity was ensiled in a separate clamp with no additive. Resultant silage corrected dry matter contents were 247 (L), 305 (M/L), 331(M/H) and 388 (H)g/kgFW, respectively. Each diet was formulated to be isonitrogenous with fishmeal fed twice daily on top of the silage. Silage was offered ad libitum to 32 growing Simmental X Friesian heifers (mean initial weight 217kg), housed in individual pens in an open-sided Dutch barn and bedded on wheat straw. Eight animals were allocated to each treatment, in a completely randomised design with pre-treatment intake (non-experimental maize silage) used as a covariate in the statistical analysis.
Effect of maize silage quality in a mixed forage diet and the crude protein level in the concentrate supplement on milk production of dairy cows
Authors: Fitzgerald J.J. , Murphy J.J.
Published: November 2021

Good quality maize silage with a high starch content and DM digestibility when fed to dairy cows increased forage intake, milk production and milk protein concentration compared with grass silage or low starch maize silage (Fitzgerald, 1997). Due to the low crude protein (CP) content of maize silage compared with grass silage, additional protein supplementation is required in the concentrate. The optimum level of protein in the concentrate for maize silage based forages differing in starch content was investigated in this study.

Three forages consisting of either all grass silage (GS) or mixed forages of grass silage and maize silage (40:60 DM mix) which contained either a low (LSM) or a high (HSM) starch content were offered ad libitum to individually fed dairy cows in early lactation (12 cows/forage). Each forage was supplemented with concentrates (6 kg/day) containing 180, 230 or 280 g CP/kg according to a change over design (3 periods of 3 weeks/period).
Comparison of methods for the detemination of peptides nitrogen in grass silage
Authors: Nsereko V. L. , Rooke J. A.
Published: November 2021

There are few reports on the occurrence and amounts of peptide-N in silage. Previous studies (Nsereko and Rooke, 1993, 1996) have quantified the amounts of peptide-N in grass silage and how peptide-N can be modified by additive treatment. However, peptide N concentrations determined using fluorescamine were observed to be considerably higher than those measured by amino acid analysis (Nsereko, 1996). It was the objective of this study to compare methods for the analysis of peptide-N.

Triplicate silages treated with no additive, formic acid (5.4 g/kg) or formic acid (2.7 g/kg) and formaldehyde (3.75 g/kg) (Nsereko and Rooke, 1993) were used in an initial study to compare three methods of peptide analysis. Aqueous extracts were prepared from the silages which were deproteinised with trichloracetic acid.
The influence of supplementing a rapidly degraded fibre basal diet with different forms of nitrogen on microbial activity in continuous culture fermenters
Authors: Chikunya S. , Miller E. L.
Published: November 2021

A lot of controversy in literature still surrounds the way in which free amino acids (AA), peptides and true protein nitrogen influence fibre digestion and the activity of bacteria which ferment structural carbohydrates in the rumen. One of the major impediments in the understanding of ruminal microbial protein synthesis is the lack of a simple and accurate procedure for measuring its yield. The aim of this study was two fold: firstly, to make further investigations into the effects of feeding different forms of supplementary nitrogen to a rapidly fermented high fibre diet on microbial activity, and secondly, to compare three different procedures of estimating microbial protein synthesis under the same conditions in continuous culture (CC).
Influence of the concentration of peptides on [15N]ammonia incorporation and de novo synthesis of different amino acids by mixed microorganisms from the sheep rumen in vitro
Authors: Atasoglu C. , Walker N.D. , Newbold C.J. , Wallace R.J.
Published: November 2021

Ammonia plays an important role in providing N for protein synthesis by rumen microorganisms. Studies using [15N]ammonia or [15N]urea indicate that the proportion of microbial nitrogen derived from ammonia is highly variable, ranging from 18 to 100% (Nolan, 1975; Salter et al., 1979). Peptides and amino acids are also incorporated by rumen microorganisms. They generally stimulate growth (Argyle & Baldwin, 1989), but little is known about the factors which govern the relative proportions of microbial amino acids which are derived from pre-formed amino acids and from ammonia. The present study was undertaken to determine how the concentration of peptides affects ammonia incorporation and the de novo synthesis of individual amino acids by mixed rumen microorganisms.
Effects of dietary urea on embryo development in superovulated donor ewes and on embryo survival following transfer in recipient ewes
Authors: Fahey J. , Boland M.P. , O'Callaghan D.
Published: November 2021

Urea can be fed as a source of nitrogen for rumen micro-organisms to synthesize microbial protein. It is also applied to pasture as a source of nitrogen for grass growth. Reduced fertility and embryonic loss can occur when dietary urea is in excess (McEvoy et al., 1997). Elevated plasma urea resulting from excess rumen degradable protein or dietary urea can decrease uterine pH (Elrod et al., 1993) and pregnancy rate in cows (Butler et al., 1996). The aim of this experiment was to determine the effect of dietary urea on yield and quality of embryos in superovulated donor ewes and on embryo survival (to day 34-36) in recipient ewes following embryo transfer.
An examination of the metabolizable energy requirements of lactating dairy cows
Authors: Cammell S.B. , Dhanoa M.S. , Beever D.E. , Sutton J.D. , France J.
Published: November 2021

The last 4 decades has seen considerable research effort directed towards quantifying the energy requirements of dairy cows. The partitioning of food energy and the efficiencies with which it is used for maintenance (km) and milk production (kl) have been subjected to scrutiny through either individual animal studies or mathematical treatment of data pools, and in consequence several rationing systems have been proposed. Since 1992, CEDAR has undertaken research involving a series of rations fed to lactating Holstein-Friesian cows where energy and nitrogen balances have been conducted simultaneous with gaseous exchange. The purpose of this study was to consider this data in order to establish if either the cows or diets currently being used in the UK have any effect on maintenance metabolizable energy [ME] requirements or the efficiency with which ME is utilised to support milk synthesis.
Choice feeding of mid lactation dairy cows offered different levels of undegraded protein concentrate
Authors: Lawson R.E. , Forbes J.M.
Published: November 2021

Tolkamp et al. (1996) reported that dairy cows were able to choose between complete foods with different MP:ME ratios, and it was concluded that the selection the cows made was not random. Diet selection may remove nutritional constraints on milk production if the cow can choose the appropriate protein level to attain the milk yield determined by her genotype. At a specific DUP content the diet of an individual cow will be correctly balanced. When the cow is offered two foods, one in excess of predicted requirements for DUP, the other deficient in DUP for the predicted level of production, then the cow has the opportunity to select a diet which exactly meets her requirements for DUP. Most diet selection experiments have been completed under conditions of little or no competition; the aim of the experiment was to study the effects of offering lactating cows a choice between two protein concentrates under semi-commercial conditions.
Large scale field trials of a soluble glass zinc, cobalt and selenium bolus given to sheep
Authors: Kendall N.R. , Mackenzie A.M. , Illingworth D.V. , Jackson D.W. , Driver P.M. , Gill I.M. , Miller J.K. , Telfer S.B.
Published: November 2021

Many sheep in the United Kingdom are grazed on pastures deficient in cobalt and selenium. Proprietary products for selenium and cobalt supplementation often contain copper, which in certain breeds can induce copper toxicity. A soluble glass bolus has been manufactured to supply long term sustained release of cobalt and selenium similar to the commercially available Cosecure, but with the copper content being replaced by zinc. Sub clinical zinc deficiency has been suggested to be involved in disease conditions such as broken mouth periodontitis, footrot and mastitis. Therefore a long term continuous supply of zinc may be beneficial in these situations. This trial was designed to examine the effect of administering a zinc, cobalt and selenium soluble glass bolus on trace element status of over-wintered ewe lambs.
Influence of dietary potassium on the absorption of magnesium from herbage and dry diets by ruminants
Authors: Adediji O. , Suttle N.F.
Published: November 2021

A recent extensive review of the ‘bioavailability’ of magnesium (Mg) (Henry and Benz 1995) noted that the fractional efficiency of apparent absorption of Mg (AAMg) in ruminants could vary from -0.04 to +0.66. Little attempt was made to identify sources of variation, other than those between inorganic Mg supplements. Earlier, ARC (1980) had failed to find consistent differences between fresh herbage (FH) and dry diets but a reexamination of the literature suggested that AAMg was twice as high for mixtures of roughage and concentrate (R/C) as for FH and confirmed the marked inhibitory effect of dietary potassium (K) (Suttle, 1987). Since grass is usually richer in K than a dry diet, differences between diet types in AAMg may be largely attributable to differences in K concentration. The objective of the study was to identify systematic sources of variation in the absorbability of dietary magnesium (Mg) to sheep from published balance studies.