bluuebunny/crossref_metadata_2025 huggingface dataset:
Colostrum and lamb production of prolific ewes
Authors: Pattinson S. , Davies D. A. R. , Winter A.
Published: June 2019

The prolific ewe can be regarded as a valuable asset only if she produces viable lambs and, at the same time, sufficient colostrum to meet their needs for energy (MJ) and immunoglobulin (Ig) in the first days of life.

The energy requirements of the lamb will depend on its weight and the climatic conditions of its surroundings. Mellor and Murray (1986) recommend 180 ml colostrum per kg body weight during the first 18 h of life for lambs born indoors and 210 ml/kg body weight for lambs born in field conditions. The Ig requirement of the lamb will depend on its size and the disease challenge of the environment into which it is born.

Although lower immunoglobulin G (IgG) levels have been recorded in dead lambs compared with live lambs (Halliday, 1968 and 1978; Khalaf, Doxey, Baxter, Black, FitzSimons and Ferguson, 1979), it has been shown that many lambs having low serum IgG levels do survive (Halliday, 1974) and some with high levels die (Halliday, 1978).

The minimum intake of colostrum required for passive immunity is not known, but it is probably considerably less than that needed to meet the energy requirements (Mellor and Murray, 1986). Spedding, Treacher and Penning (1970) showed that as little as 8 g colostrum per kg lamb birth weight can provide protection from disease. Under poor conditions of hygiene this would probably not be sufficient. It thus seems likely that provided that the energy requirement of the lamb is met by feeding it colostrum, the Ig requirement will also be met.
Effects of cobalt deficiency in the pregnant ewe on neonatal lamb survival
Authors: Fisher G. E. J. , MacPherson A.
Published: June 2019

It has been suggested (Mills, 1981) that there was a lack of research on the effects of cobalt (Co) deficiency on the reproductive performance of sheep. Duncan, Morrison and Garton (1981) reported that clinically Co-deficient ewes produced fewer lambs with a higher incidence of stillbirths and neonatal mortalities than Co-sufficient animals. Garton, Duncan and Fell (1981) related these findings to the vitamin B12 and methylmalonic acid status of dams. However, their investigations used few animals and were therefore inconclusive. The objectives of this work were to investigate the effects of subclinical Co deficiency in pregnant hill sheep on reproductive performance and neonatal lamb viability.

Experiment 1 (1985/86) comprised 60 Scottish Blackface × Swaledale ewes, while experiment 2 (1986/87) included 30 of these animals plus 30 pure Scottish Blackface sheep. In both experiments the ewes were housed and bedded on sawdust and a Co-deficient diet of timothy hay, micronized maize, maize gluten, dibasic calcium phosphate and sodium chloride was offered. Skimmed milk powder was introduced to the diet during lactation. The Co content of the diet was 0.06 mg Co per kg dry matter.
Brown adipose tissue development in the ovine foetus during the final month of gestation
Authors: Clarke L. , van de Waal S. , Lomax M. A. , Symonds M. E.
Published: June 2019

In the ovine foetus brown adipose tissue (BAT) is mainly found in the perirenal region and grows rapidly relative to body weight between 70 to 120 days of gestation (Alexander, 1978). After this stage only a small amount of BAT growth occurs in comparison with that of the whole foetus, and in the case of undernutrition may decline (Alexander, 1978). Maternal cold stress, induced by winter shearing twin-bearing pregnant ewes 8 weeks before parturition improves lamb birth weight and lamb growth rate independently of effects on maternal food intake (Symonds, Bryant and Lomax, 1986 and 1990). At the same time this can stimulate the in vivo capacity for non-shivering thermogenesis in newborn lambs (Stott and Slee, 1985). The following study extends these findings by investigating the extent to which changing the maternal metabolic environment influences BAT development over the final month of gestation.

Thirty-two Bluefaced Leicester × Swaledale ewes were housed individually at ambient temperature (−6 to 19°C) 6 weeks prior to lambing and 2 weeks later 15 ewes were shorn. Ewes were offered daily a diet comprising 200 g barley concentrate and 1 kg chopped hay. Between 116 and 145 days of gestation and within 2 h of birth ewes were humanely slaughtered with an overdose of barbiturate and foetal or neonatal perirenal BAT sampled, born from shorn or unshorn ewes. The thermogenic capacity of BAT was assessed by guanosine-5′-diphosphate (GDP) binding to uncoupling protein in mitochondrial preparations (Cooper, Dascombe, Rothwell and Vale, 1989) and the amount of mitochondrial protein measured from cytochrome Coxidase activity.
Relations between piglet weights and survival
Authors: Rydhmer L.
Published: June 2019

The birth weight of the piglet has an important influence on many aspects of later performance. There are, for example, relations between birth weight and growth rate as well as between birth weight and litter traits at farrowing (Rydhmer, Eliasson, Stern, Andersson and Einarsson, 1989). In a shorter perspective, birth weight affects piglet survival during the first weeks of life.

High Utter size (number born) is a common breeding goal. Piglet weight is related to the number of piglets in the Utter. Piglet weight is also related to survival; thus mortality increases with litter size.

The aim of this work was to study variation in piglet weight, some factors that may influence piglet weight and relations between litter size, piglet weight and piglet survival.

Individual piglet weights were registered in 747 litters from an experimental farm. Of the 8134 piglets born, 2326 were Swedish Yorkshire, 239 Swedish Landrace, and the rest were crosses between these two breeds. One-third of the piglets were born in gilt litters. The piglets were creep fed from the 2nd week and weaned at 6 weeks of age. They were individually weighed at birth and at 3, 6 and 9 weeks of age. Birth weight in this report refers to the weight of all piglets born, including those stillborn.
Glucocorticoids influence the development of gastric proteases in the neonatal pig
Authors: Sangild P. T. , Foltmann B.
Published: June 2019

Adrenal glucocorticoids are known to stimulate the development of digestive enzymes in the sucking rat. In the pig, Cortisol concentrations in plasma reach peak levels at birth. We studied the effect of neonatal Cortisol levels on the development of two proteases, chymosin (rennin, EC 3.4.23.4) and pepsin A (EC 3.4.23.1) in the stomach of the pig.

Material and methods Three vaginal-delivered (VD) pigs (114 to 115 days gestation) were killed at birth. The remaining 40 newborn pigs were removed by caesarean section (SC) at 111 to 112 days gestation (i.e. 2 to 4 days before term). After birth these pigs were injected intramuscularly with either saline, metyrapone (an inhibitor of adrenal 11-deoxyhydrolase activity and Cortisol synthesis, 10 mg/kg per day) or ACTH (adrenocorticotropic hormone, 100μ/kg per day).
Piglet mortality as affected by a two-food system and ad libitum feeding of the sow
Authors: Neil M.
Published: June 2019

In designing feeding regimens for sows much attention should be paid to the effects on piglet performance and piglet mortality, as these traits are of great economic significance. Clearly, piglets may be influenced by sow feeding regimen in several ways. For example, sows offered food ad libitum may be calmer and hence step upon or overlay fewer piglets than sows restrictedly given food. A gestation diet with a low protein content and protein of vegetable origin may reduce the frequency of agalactia (Ringarp, 1960; Göransson, 1989) and thereby enhance piglet survival.

In a sow feeding experiment performed at the Swedish University of Agricultural Sciences, the Swedish feeding standards (Simonsson, 1988) were compared with offering food ad libitum in lactation and a simplified gestation diet. The main objective was to study effects on sow weight and backfat changes and reproductive traits, but effects on piglet mortality were also studied.

The experiment was performed at the pig research station of the Swedish University of Agricultural Sciences from 1986 to 1990. The following treatments were applied.
Adaptation of fat metabolism to environmental temperature in the newborn pig
Authors: Herpin P. , van Os M. , Dividich J. Le
Published: June 2019

Susceptibility to cold is usually reported as a major factor involved in the neonatal mortality of piglets (English and Morrison, 1984). Low energy reserves and poor insulation largely contribute to the limited thermoregulatory capacities of the newborn pig (Mersmann, 1974; Curtis, 1974). Glycogen is the predominant source of energy accounting for about 0.6 of the total energy available at birth (Mellor and Cockburn, 1986) but glycogen stores are rapidly depleted after birth. In addition, the total body fat content is very low at birth, ranging from 10 to 20g/kg (Manners and McCrea, 1963). Whereas attempts made to increase the energy stored as fat in the newborn pig by manipulation of the sow diet during late gestation have given variable results (Seerley, 1984), colostrum has proved to be an efficient route for depositing fat and hence for the supply of energy to the piglet during the first postnatal day (Le Dividich, Esnault, Lynch, Hoo-Paris, Castex and Peiniau, 1991). The present study was designed to determine the effects of colostral fat level on the energy and fat metabolism of the newborn piglet when maintained during the 1st day of life at thermal neutrality (34°C) or in the cold (21°C).

A total of 35 newborn Large White pigs averaging 1140 (s.e. 54) g in weight were used. Within each litter five piglets were selected according to their live weight. One was killed in order to determine the initial body composition. The remaining pigs were fitted with umbilical artery catheters and stomach tubes. They were placed in individual cages in closed temperature-controlled chambers maintained at either 34 or 21°C and were fed normal colostrum (60 g fat per kg, NFC) or a colostrum deprived of fat (< 10 g fat per kg, LFC) at the rate of 15 to 18 g per meal per kg birth weight. A total of 24 meals were given at about 65-min intervals.
2.2 The Effect of Conservation Processes on the Nitrogenous Components of Forages
Authors: McDonald P.
Published: June 2019

During field drying, the cut crop continues to respire, resulting in the oxidation of sugars and organic acids. In addition, protease activity increases the soluble nitrogenous components. The importance of plant enzymes in this process was first recognised by Lamb (1917), who treated maize with chloroform, toluene and cresol to inhibit bacterial growth. More recently, studies using gamma irradiated herbage (Gouet, Fatianoff and Bousset, 1970; Clark, 1974) have confirmed Lamb's conclusion that, in harvested crops, plant enzymes are mainly responsible for proteolysis.
5.2 Alternative Systems for Assessing the Nitrogen Value of Feeds for Ruminants
Authors: Black J. L. , Faichney G. J. , Beever D. E. , Howarth B. R.
Published: June 2019

Systems suitable for evaluating the nitrogen status of feeds for ruminants must consider (i) the requirements of the animal's tissues for nitrogenous substances, (ii) the amount and nature of the nitrogenous substances absorbed by the animal and (iii) the efficiency with which absorbed nitrogen is used for various body functions. Such systems must also include aspects of energy utilization because, in ruminants, both the tissue needs for nitrogen and the flow of protein to the intestines are affected by energy availability. Several systems which attempt to include all three considerations in more or less detail have recently been proposed (Burroughs, Nelson and Mertens, 1975; Satter and Roffler, 1975, 1977; Kaufmann, 1977; Jarrige, Journet and Vérité, 1978; Fox, Sniffen, Van Soest and Robinson, 1979; Agricultural Research Council (ARC), 1980; Chalupa, 1980).
8.3 The Digestion of a Wilted Silage made with and without an Additive
Authors: Overend M. A. , Armstrong D. G.
Published: June 2019

It has been shown by Beever, Thomson, Cammell and Harrison (1977) that formaldehyde treatment of silage increased amino acid absorption from the small intestine of sheep by 13% and increased the amount of food protein passing through the rumen undegraded by 66% compared to sheep receiving untreated silage. This paper details the digestion of N and apparent uptake of N, non-ammonia N and amino acid N from the small intestine of Jersey cattle fed a silage made from a second growth, mixed S24 perennial ryegrass/red clover sward which was wilted for 24h and then ensiled either without an additive or with a 50/50 mixture of formic acid and formaldehyde (formalin), each at the rate of 2.2 litres/tonne of grass ensiled. The method of ensiling was by use of an Eberhardt Silopresse (Benedict Agricultural Ltd., London). Each of the three cows fed each diet was equipped with a rumen fistula and re-entrant cannulae into the proximal duodenum and terminal ileum.
9.7 Effect of Ensiling on the Release of Soluble Carbohydrates and Nitrogen During Eating and its Relationship to Intake and Nitrogen Retention
Authors: Austin A. R. , Gill M.
Published: June 2019

The object of the experiment to be reported was to determine the extent to which intake and eating behaviour are influenced by differences in the ratio of nitrogen (N) to water soluble carbohydrates (WSC) in the feed and the liquid phase of boli obtained from oesophageal fistulae. Four feeds were chosen as being likely to cover a range of N to WSC ratios in the liquid phase; these were frozen lucerne, lucerne silage, grass silage and grass silage treated with formaldehyde (46 g/100 g crude protein).
Implications of genotype X nutrition interactions for efficiency of milk production systems
Authors: Mayne C. S. , Gordon F. J.
Published: June 2019

Major increases in the rate of genetic improvement in the dairy herd have been obtained in the United Kingdom and the Republic of Ireland since the mid 1980s. The implications of increases in genetic merit and the possible consequences of genotype X nutrition interactions on the efficiency of milk production systems are reviewed. The majority of previous studies with dairy cattle of moderate genetic merit suggest little evidence of genotype X nutrition interactions across a range of nutritional and management regimes, with higher milk production of high merit cows largely accounted for by effects on nutrient partitioning. However, more recent results suggest a significant re-ranking of sires when evaluated under either intensive feeding systems or in systems with a high reliance on grazed pasture.

Under intensive feeding systems higher animal performance has been obtained with high merit cows across a range of concentrate inputs and feeding systems. However, recent results from the Langhill studies provide the first tentative evidence of a genotype X nutrition interaction, with significantly different regression coefficients between genetic merit (as assessed by pedigree index) and milk production, under either low or high forage diets. The implications of these results are that high merit cows may be unable to express their full genetic potential for milk production when offered a high forage (or low energy density) diet. Consequently, the influence of other factors which have a major effect on voluntary food intake, and hence nutrient intake, e.g. forage dry matter content and forage digestibility, may be relatively more important with high genetic merit dairy cows.

It is concluded that higher milk production in high merit cows is largely attributable to variation in partitioning of nutrients, rather than to changes in food intake or digestive efficiency. Consequently, it is important fully to assess the animal performance and welfare implications of maintaining high genetic merit dairy cows under systems which may limit nutrient intake, e.g. under high forage regimes involving a high reliance on grazed or conserved forage. The major challenge for research and dairy herd management is to increase food intake with grass- and/or grass silage-based diets, thereby reducing the need for high levels of concentrates input to prevent excessive body condition loss with high genetic merit dairy cows in early lactation.
Udder characteristics and relationship to efficiency of milk production
Authors: Knight C. H. , Brown J. R. , Dewhurst R. J.
Published: June 2019

Milk yield is ultimately constrained by the number of mammary secretory cells and the amount produced by each cell; increasing yield during early lactation is associated with increased output per cell, whilst decreasing yield during declining lactation correlates with reduced number of cells. Overall, yield is highly correlated with mass of secretory tissue but strategic control of lactation involves a galactopoietic complex of hormones including GH, prolactin and oxytocin acting to ensure efficient milk ejection and maintenance of secretion. Fine control, on the other hand, is achieved locally within the mammary gland by an autocrine mechanism which matches supply of milk to demand. The feedback inhibitor of lactation (FIL) is a milk protein which is inhibitory to secretion, so as milk accumulates between milkings, secretion rate gradually falls. The more frequently FIL is removed by milking, the greater the overall secretion rate. Storage of milk occurs within secretory tissue (alveolar milk) but also in the cistern (cisternal milk); FIL is effective in alveolar milk but not in cisternal milk, because it is then remote from its site of action. Therefore predictions would be that for a given mass of secretory tissue, large-cisterned cows should produce more milk, be more tolerant of infrequent milking but be less responsive to frequent milking. Methods developed by us for determining cisternal and alveolar milk storage spaces have obtained statistically proven support for the latter two predictions in dairy cows; the first prediction has been proven in goats. It has been shown that cisternal milk fraction increases during the course of lactation and with increasing parity. It is now intended to investigate the feasibility of incorporating storage characteristics into future selection strategies.
Setting donor research agendas
Authors: Freeland G.
Published: June 2019

This paper uses the United Kingdom (UK) government's Department for International Development (DFID) centrally funded renewable natural resources research strategy (RNRRS) programme as an example to answer the key questions of: (i) what research; (ii) why conduct research; and (iii) why set an agenda?

Donor research organizations may fund research through various channels. DFID funds research through its multilateral programmes (e.g. to the system of International Agricultural Research Centres which constitute the Consultative Group for International Agricultural Research); as components of its bilateral development programmes with individual countries (e.g. assistance to the development of the Kenya Agricultural Research Institute (KARI) and the Kenyan National Agricultural Research Programme) and sometimes through projects with non-governmental organizations (NGOs), as part of the Joint Funding Scheme. Research funded through these avenues is, however, part of a larger agenda to which the DFID has agreed but not necessarily set. In the interests of pursuing strategic and wider research objectives, the outputs of which may later be applied through development programmes, DFID also has a centrally controlled fund for research, which is not specific to any one country or organization. The part of that research programme relevant to natural resources is called the RNRRS (Research Task Group, 1994). Other donors have similar centrally funded research programmes and it is these to which the title refers and for which it is appropriate that the donor organization sets its own agenda.
The rôle of livestock in natural resources management
Authors: Thome P. J. , Herrero M.
Published: June 2019

This paper discusses some of the unique aspects of the interactions of livestock with the natural resources base. It argues the nature of these interactions make the use of a systems approach of particular importance when planning and executing livestock research if it is to be of any relevance to farmers in developing countries. The key issues are illustrated in two contrasting case studies.

In Nepal, shifts in land use patterns have led to marked changes in the availability and use of fodder resources. Farmers indicate that they are no longer able to use these optimally. Fodder from at least 90 different types of tree (some of which have yet to be properly classified botanically) are used to supplement the diets of buffalo, cattle and goats during dry seasons when food is in short supply. The nutritive value of each of these is affected by a wide range of management and environmental factors. Furthermore, diet selectivity means that fractions consumed differ markedly amongst both tree species and classes of livestock. It is clearly not feasible for researchers to evaluate this diversity using existing in vitro or in vivo indicators of nutritive value. Initial studies suggest that this variability is implicitly catered for in farmers' own assessments of relative nutritive values. A mechanistic understanding of this indigenous technical knowledge and the development of appropriate techniques for integrating it with models of the biological responses of animals to nutrients might, therefore, allow more effective assessment of strategies for tree fodder utilization.

Highland dairy systems in the humid tropics of Costa Rica (3000+ mm/year rainfall) could be very productive but suffer from a substantial dependence on imported inputs. Concentrate use is very high causing substantial underutilization of grazed pasture (the local resource), which is available year-round under these high-rainfall conditions. Over-supplementation with protein, which is the most expensive nutrient in the diet, at levels in excess of 200% of the requirement has been reported widely in these regions. Farmers want new strategies that enable them to manage their land and other resources in an alternative way, in order to be less dependent on grains and other imports. A decision-support system based on simulation and multiple criteria models representing a dairy farm has enabled the design and development of such strategies. Using this approach, farmers' objectives can be incorporated with a holistic understanding of the farming system in terms of management practices that will permit demand-driven animal production research at the farm level.
Assessing the impact of diseases and their control on livestock productivity: the rôle of quantitative epidemiology
Authors: Perry B. D. , McDermott J. J.
Published: June 2019

In determining research priorities, as well as in evaluating the relative merits of different disease control options, there is an increasing demand for impact assessment, in order to justify and support research and development investments. In this process, quantitative epidemiology has a significant role to play. This paper first outlines the categories of impacts that diseases have on society and discusses how these can be measured. Using the example of tick-borne infections of livestock, the paper describes five quantitative epidemiological tools that can be used in impact assessment. These are: geographical information systems (GIS) to estimate disease distribution; mathematical models to quantify infection dynamics; observational field studies to link infection status with production loss; statistical models to enhance study design; and spreadsheet models for economic impact assessment. In each category, examples are given of recent studies.
Relationships between gas release in vitro and in vivo quality measures of tropical forages
Authors: Fernández-Rivera S.
Published: June 2019

Robust techniques that predict accurately and precisely the quality of forages are needed for developing improved feeding strategies and screening of large numbers of forage samples in breeding programmes. The release of gas in vitro (Menke et al., 1979) is attractive for this purpose because it does not require filtration and one single sample can be used to examine the kinetics of fermentation. The objective of this study was to determine the relationships between gas release in vitro and digestibility in vivo and intake of tropical forages.
Factors affecting the amount of indirect gas produced by thein vitrogas production technique
Authors: Rymer C. , Moss A. R. , Deaville E. R. , Givens D. I.
Published: June 2019

When a food is ingested by a ruminant animal, the carbohydrate fraction of the food is fermented by the rumen micro-organisms to produce gas (predominantly carbon dioxide and methane) as well as volatile fatty acids (VFA). The gas production technique simulates this fermentation process and provides an estimate of both the rate and extent of fermentation. Comparing the gas production (GP) profiles of foods enables a comparison to be made of the fermentative characteristics of different foods. However, the technique uses a bicarbonate-based medium system with the rumen liquor. This complicates the GP profile because of the production of ‘indirect’ gas resulting from the reaction between the VFA and the bicarbonate ions.

Beuvink and Spoelstra (1992) measured the volume of gas produced from buffered rumen fluid when known amounts of VFA were added and observed that 20·8 ml gas were released per mmol VFA. However, there is variation between laboratories in terms of the composition of the medium that is used. Even when the same medium is used, significant differences have been observed in the GP profile when different types of apparatus were employed (Rymer and Givens, 1997). Media are gassed with carbon dioxide before they are added to the gas production system and it is possible that the concentration of carbon dioxide dissolved in the medium varies between experiments. The objective of this experiment, therefore, was to determine whether the volume of indirect gas produced was affected by the composition of the medium, the addition of carbon dioxide, and the technique employed to measure gas production.
Potential of enzymes or a centrifuged rumen fluid to estimate proteolysis of foods
Authors: Chaudhry A. S.
Published: June 2019

The need to develop an in vitro method to simulate ruminal digestion of protein foods has long been recognized. An in vitro method must be more rapid, consistent and convenient than in sacco methods. Purified enzymes have been examined in the past to estimate in vitro degradability of protein foods (Poos-Floyd et al., 1985; Aufrere et al., 1991; Luchini et al., 1996) or their fractions (Chaudhry and Webster, 1994). However, the selection of an appropriate enzyme for a range of foodstuffs remains to be realized. This study examined the potential of two enzymes and a centrifuged rumen fluid (CRF) to estimate proteolysis of food proteins.
Development, validation and application of a three-step in vitro procedure for estimating intestinal digestion of protein in ruminants
Authors: Calsamiglia S. , Stern M. D.
Published: June 2019

The total amount of dietary protein available for absorption is dependent on the flow of dietary nitrogen (N) to the duodenum and its intestinal digestibility. Variation in intestinal digestion among protein supplements has been reported in vivo (Stern et al., 1985) and in situ (Hvelplund, 1985). Obtaining estimates of protein digestion in the small intestine is expensive, labour intensive and requires the use of surgically prepared animals. The objective of this study was to develop a reliable in vitro technique to estimate intestinal digestion of proteins in ruminants.
The rumen simulation technique (Rusitec) as a method to determine thein vitrocarry-over period following monensin treatment by measuring volatile fatty acid molar proportions
Authors: Mackintosh E. D. , Phipps R. H. , Grubb H. J.
Published: June 2019

Ruminant and ruminal responses to feeding the gram-positive ionophore, monensin, have been researched extensively over the past 20 years. A proportion of many suchin vivoexperiments have used a change-over design. In doing so, the researcher either paid no attention to or was reasonably confident that any possible carry-over effects would have dissipated. Evidence does exist which leads to an estimation of duration to maximum treatment effects but such comparable evidence surrounding the duration of carry-over to monensin treatment is not available.

Anin vivotrial was proposed at the Centre for Dairy Research (CEDAR), to investigate the ruminal effects of feeding monensin to lactating dairy cows with 4-week periods of which 3 weeks was for change-over and adaptation. Therefore, before conducting such an expensive experiment, in terms of both time and money, anin vitrostudy using the rumen simulation technique (Rusitec) was carried out to determine if 3 weeks was considered adequate to eliminate carry-over effects when measuring volatile fatty acid (VFA) molar proportions.
Comparison of parameters from the Theodorou gas production technique using nitrogen-free and nitrogen-rich media as predictors of dry-matter intake and digestibility
Authors: Romney D. L. , Cadario F. C. , Owen E. , Murray A .H.
Published: June 2019

Parameters from in vitro gas production techniques could have potential as predictors of dry-matter intake (DMI) and digestibility. Fermentation is usually carried out under conditions where nitrogen (N) is not limiting. Therefore where N supply is a constraint to intake and digestibility, prediction equations may be inaccurate. This study compared the use of N-free and N-rich media in an in vitro fermentation method (Theodorou et al., 1994) and studied the relationships between in vitro and in vivo parameters obtained using both media.
Associative effects in vitro of mixtures of tropical fodder trees
Authors: Rosales M. , Gill M. , Wood C. D. , Speedy A. W.
Published: June 2019

Previous work in animal nutrition has focused on single foods and assumed additivity during in vitro fermentation. In the tropics, farmers are likely to offer mixtures of foods, including tree fodders, which may not be simply additive in nutritional terms. There is little information about the nutritional interactions between tropical foods. The objective of this research was to test the existence of associative effects of mixtures of tropical fodder tree leaves.
Effect of fat content on degradability and fermentability of concentrate foods in situ, in vitro and with gas production technique
Authors: Moss A. R. , Fakhri S. , Givens D. I. , Owen E.
Published: June 2019

Fat content is one of the main factors affecting the degradability and fermentability characteristics of oil-rich foods estimated by means of the in situ, in vitro and gas production techniques. Filtered fat, considered degraded/fermented, is of limited value to the rumen microbes and may inhibit fermentation. Pre-extraction of oil may be one way to solve this problem. The rumen organic matter degradability (OMD) and fermentability (FOM) of concentrate foods were evaluated in this study with and without oil extraction.
Development of the gas production technique to assay for anti-nutritive compounds in temperate tree fodders with polyphenol adsorbents using inoculum based on fresh cattle faeces
Authors: Lane I. R. , Boying W.
Published: June 2019

The polyphenol concentration in various tree fodders has been assayed by the gas production technique using rumen fluid inoculum either by fermentation of whole samples +/- a polyphenol adsorbent (Khazaal et al., 1994) or simply by the reduction of gas production caused by acetone extracts of the fodders (Wood and Plumb, 1995). Successful replacement of rumen fluid as a source of anaerobic bacteria by faeces from ruminant animals has been reported both for two-stage Tilley and Terry dry-matter digestibility (DMD) (El Shaer et al., 1987) and for the gas production technique (Davies, 1991). The use of faeces based inoculum +/- polyphenol adsorbents was therefore tested and optimized for fallen paulownia and poplar leaves using the gas production technique (the trees were commercial hybrids of Paulownia and Populus species respectively). A series of trials was carried out to: develop the use of preliminary incubation of the faeces inoculum; optimize the adsorbent type, molecular weight (MW) and quantity; optimize the faeces concentration in the inoculum and the use of glucose as a pre-incubation stimulant; and evaluate the use of differences in Tl /2 for gas production and end DMD +/- adsorbent to assess the effect of anti-nutritive compounds (ANCs) on the relative rate and extent of fermentation.

All trials were carried out using 100 ml plastic vaccine flexibottles as containers maintained at 39°C in water baths. Gas was manually extracted with disposable syringes, generally at 3, 6, 9,12,15,18, 21, 24, 30, 36, 42, 48, 60, 72 h and bottles were well shaken at these times.
Relationship between in vitro gas production and in situ degradability for forage components
Authors: Ichinohe T. , Shand W. J. , Kyle D. J. , Chen X. B. , Ørskov E. R.
Published: June 2019

Recently in vitro and in situ techniques have been used for assessing forage nutritive value for ruminants instead of laborious in vivo trials. Although, Blummel and Ørskov (1993) have shown that an in vitro gas production technique gives reliable estimates of forage nutritive value, whether the estimates could be correlated with in situ degradation are not well established. There is little known about the differences in degradation characteristics of neutral-detergent fibre (NDF) and cellular contents (CC: soluble carbohydrates, lipids and crude protein) in the rumen, and also about the relationships between component degradation rate in the rumen and gas production rate for different forages. This is because most in situ kinetic studies have followed the disappearance of insoluble cell wall constituents and comparative studies of in vitro and in situ estimates was not performed sufficiently.

The objective of this experiment was to investigate the relationship between in situ degradation of forage components and in vitro gas production rate for the three forages.
Fermentable energy of concentrate foods estimated using four techniques
Authors: Fakhri S. , Moss A. R. , Givens D.I. , Owen E.
Published: June 2019

Fermentable energy (FE) was defined in the latest United Kingdom metabolizable protein system as energy available for microbial protein growth and multiplication in the rumen (Agricultural and Food Research Council, 1992). In this system the FE value was calculated by subtracting the metabolizable energy (ME) of fat and ME of any fermentation products from the ME of the food. This estimation is indirect and largely based on whole tract digestion data, thus it can not take into account the influence of rumen outflow, fermentation and degradation rate and digesta retention time in the rumen. In addition, this approach does not take into account undegradable protein and /or starch. As a result, the precision of the FE values are questionable. Therefore a precise, accurate, rapid, cheap and direct technique to measure FE from food ingredients should be developed. Such a technique should consider the factors mentioned above. This work evaluated the ability of four techniques to estimate the FE value of concentrate foods for ruminants.
Evaluation of genetic variation in nutritive value of Gliricidia sepium in feeding trials and by an in vitro gas production technique
Authors: Stewart J. L. , Wood C. D. , Kass M. , López Ortíz S. , Larbi A. , Premaratne S. , Tangendjaja B. , Wina E. , Vargas J. E.
Published: June 2019

Gliricidia sepium (Jacq.) Steud. is widely used as a high-protein supplementary food for ruminants in many parts of the tropics. Native to Central America and Mexico, it has become widely naturalized elsewhere but the introduced populations are mostly of unknown origin and uncertain quality. Studies of the genetic resources from the native range, under a research programme at OFI, have shown great variation between populations in yield (Dunsdon and Simons, 1996). The objective of the research described here was to investigate whether there is also important genetic variation in fodder quality, to inform decisions on future distribution of ‘superior’ germplasm of G. sepium under the OFI programme.
Estimation of in vitro degradation of dietary proteins in ruminants by using enzymes
Authors: Chaudhry A. S.
Published: June 2019

Protein degradation in the rumen determines the supply of dietary nitrogen (N) to microbes and undegraded amino acids for direct absorption. The current systems of feeding ruminants identify rumen degradable protein (RDP) from undegraded protein (UDP) which is digestible post ruminally (Agricultural and Food Research Council (AFRC), 1992; Huntington and Givens 1995). The in sacco method has been useful to estimate RDP, UDP and rate of degradation of proteins in ruminants. However, its use is constrained by the fact that it requires surgically modified animals, is laborious, inconsistent and does not differentiate between proteins that disappear from the bag or which are digested by microbes. It is therefore important to develop rapid, robust and reproducible alternatives (in vitro) to simulate ruminal digestion of proteins. Chaudhry (1998) has shown a potential in Streptomyces griseus protease (enzyme) to estimate ruminal digestion in vitro given its consistently high proteolytic activity with purified proteins. This study examined the validity of this enzyme to estimate degradability of food proteins.

Buffer, enzyme and foods A potassium phosphate buffer (buffer) with a pH 6-8 was used to prepare protein suspensions and a solution of the protease (P5147, SIGMA). Samples of sunflower meal (SF), maize-gluten meal (MG), distillers’ dark grains (DG) and field beans (FB) were dried and ground through 1 or 4 mm sieves for in vitro enzyme and in sacco studies respectively.
Potential application of cellulase and hemicellulase assay techniques for assessing the forage quality and performance of rumen micro-organisms
Authors: Bhat M. K.
Published: June 2019

Cellulose and hemicellulose are the major structural polysaccharides of plant cell wall. The efficient utilization of these polysaccharides by ruminants is often restricted by the presence of lignin. Cellulose and hemicellulose are hydrolysed by a group of enzymes called cellulases and hemicellulases. The present paper describes the cellulase and hemicellulase assay methods and their potential applications.

Carboxymethyl (CM)-cellulose, Avicel, cellobiose, xylobiose, p-nitrophenyl-p β-D-glucoside (pNPG), p-nitrophenyl-β-D-cellobioside (pNPC), p-nitrophenyl-β-D-xyloside (pNPX) and p-nitrophenyl- α-L-arabinofuranoside (pNPAf) were from Sigma. Birchwood xylan and filter paper are from Carl Roth GmbH and Co., Germany and Whatman International Ltd, UK, respectively. H3P04-Swollen cellulose and 4-O-methyl-α-D-glucuronyl-xylotriose (mGpA-Xyl3) were prepared as described (Wood, 1988; Khandkeet al., 1989a).
The effect of animal species on the ruminal degradation of dry matter and nitrogen fractions in urea-treated whole-crop wheat
Authors: Adesogan A. T. , Abdalla A. L. , Dhanoa M. S. , Givens D. I. , Owen E. , Sutton J. D.
Published: June 2019

At maintenance at least, the whole tract digestibility of several foods in sheep and cattle is similar, consequently much of the information on the nutritive value of dairy cow foods in food composition tables is derived from studies conducted in sheep. However, Adesogan (1996) reported that in whole-crop wheat (WCW), starch digestibility is higher in sheep than in dairy cows. This study examined the validity of using sheep to model the ruminal degradation of WCW in cows by comparing the degradability of dry matter (DM) and nitrogen (N) of urea-treated WCW in both species.

Winter wheat (cv.Hussar) was harvested at 540 g DM per kg and conserved following urea application at target rates of 20 or 40g/kg DM (WCW2 and WCW4 respectively). The degradability of the forages was examined in dairy cows given 6 kg dairy concentrate and grass silagead libitumand in wethers given 2.4 kg/day of grass silage supplemented with 0.36kg/day of rolled, mineralized barley.
Nutritional evaluation of stovers of various strains of sorghum: chemical composition,in saccodry matter disappearance and silage quality
Authors: Misra A. K. , Singh A. P. , Katiyar D. S. , Dhanoa M. S. , Longland A. C.
Published: June 2019

Sorghum is a multipurpose crop where all parts of the plant are used for human food, animal food, fuel and fabrication. In comparison to other cereal crops it requires little water and it is tolerant to poor soils and adverse climatic conditions. It is one of the most widely grown crops in India particularly in semi-arid and rain-fed regions where the potential for crop and livestock production is limited by the availability of water. During thekharifseason (July to October), it occupies about 10 million ha of land and produces a large quantity of stover which is given to farm livestock. Therabiseason crop (November to February) occupies about 6 million ha of land and is mainly dependent upon residual moisture in the soil and provides both grain and forage. The economic value of sorghum stover as fodder sometimes exceeds that of the grain because seasonal shortage of food is an acute problem during the dry season. Much effort has been expended on improving sorghum varieties (Burton, 1973; Guptaet al., 1976; Dongi and Paroda, 1978), mostly directed towards increasing the yield. Pedersonet al. (1982) compared the quality and agronomic traits of 49 forage sorghum hybrids and suggested that the most rapid way to improve the quality of forage sorghum would be to improve itsin vitrodry-matter (DM) digestibility. There are several new strains of sorghum which have been improved in terms of agronomic characters but there is little information on the nutritional quality of their stovers. Therefore the objective of this study was to evaluate the stovers of several new sorghum strains in terms of chemical composition,in saccoDM disappearance (DMD) and their silage quality.
Relationship betweenin vitrosolubility and rumen degradability of forage nitrogen
Authors: Komwihangilo D. M. , Deaville E. R. , Givens D. I. , Owen E.
Published: June 2019

It is widely accepted that robust and accuratein vitrotechniques are required to predict the proportion of food nitrogen (N) degraded in the rumen. One such technique is to estimate the solubility of food N. In these experiments, relationships between solvent soluble N andin siturumen degradability of forage N were investigated.

Samples of 11 fresh grasses (FG) (mainly perennial ryegrass) and their corresponding silages (GS) were used. GS was prepared from material ensiled in laboratory scale silos for 90 days. Prior to the experiments, FG and GS samples were initially hand chopped to approximately 1 cm lengths. In thein situstudy a fresh sample equivalent to 0-5 g DM was weighed into polyester bags (pore size 43 μ 200 X 90 mm internal diameter). Duplicate bags for each of FG or GS were incubated in the rumen of three wethers for 0, 3, 8, 16, 24, 45 and 72 h. The incubated residues including the 0 h samples were washed in a washing machine and freeze-dried for 48 h. Rumen degradability characteristics and effective degradability (ED, at rumen outflow rate of 0.08 per h) of N were calculated using the exponential model of Ørskov and McDonald (1979).In vitrosolubility of N (S) was determined by incubating for 1 h (at room temperature) the fresh sample (0.5 g on dry matter basis) in each of the four solvents: Borate phosphate buffer (BFB), Durand's buffer (DB), clarified rumen fluid (CRF) and distilled water within a balanced three way factorial design (three operators; four solvents; 11 forages; Deavilleet al., 1997). Residues from S were filtered under vacuum and the filter paper plus residue were oven dried for 18 h at 100°C. All samples and residues were analysed for total N using Kjeldahl method (Ministry of Agriculture, Fisheries and Food, 1986). Factorial analysis on the general linear model (Minitab®, 1994) was used in the analysis of variance(ANOVA) forin vitrodata and regression analyses ofin situandin vitrodata were performed (Minitab®, 1994). Only the regression results are reported here.
The degradation of protein and non-starch polysaccharides from botanically diverse sources of dietary fibre by ponies as measured by the mobile bag technique
Authors: Moore-Colyer M. , Longland A. C. , Hyslop J. J. , Cuddeford D.
Published: June 2019

Fibrous foods are major sources of energy and protein for equids. The potentially energy yielding fraction of dietary fibre consists of non-starch polysaccharides (NSP). NSP cannot be digested by equine enzymes and in order for the animal to obtain energy from NSP it must be fermented by the gut microflora to yield volatile fatty acid. This fermentation process is less efficient in terms of yield of ATP than the digestion of starch to glucose, and is generally believed to occur solely in the large intestine. Plant protein may be associated with the NSP or the protoplast. However, horses can only utilize that protein which has been digested and absorbed in the small intestine. Thus, knowledge of the site and extent of nutrient degradation is important to enable the accurate formulation of diets for horses. Therefore in the current study the site and extent of NSP and crude protein (CP) degradation from four fibrous foods commonly given to horses in the United Kingdom were determined in caecally fistulated ponies using mobile bags.

The trial was a 4 X 3 incomplete Latin square design with three caecally fistulated Welsh X pony geldings (ca. 250 kg live weight) and four botanically diverse sources of dietary fibre. The ponies were maintained on a basal diet of hay and grass nuts and water was available ad libitum. Bags (6X1 cm) of monofilament polyester mesh pore size 4 μm were filled with 350 mg of either unmolassed sugar-beet pulp (SB), hay cubes (HC), soya hulls (SH) or oat hulls : naked oats (2:1) (OH: NO), which had been ground to pass a 1-mm steel mesh. On two consecutive mornings 20 bags were introduced into the ponies via a naso-gastric tube. Each bag contained two 100 mg steel washers which enabled their capture by a magnet placed inside the caecal fistula: the cannulae were positioned just posterior to the ileo-caecal junction. Between 10 and 16 bags were recovered on the magnet, the remaining bags were allowed to continue through the hind-gut and were subsequently collected in the faeces.
Walking the animal welfare tight-rope: an egg industry view
Authors: Jorêt A. D.
Published: June 2019

There is a wealth of animal welfare legislation affecting the egg industry. Legislation can be over-prescriptive and can be a barrier to progress even where welfare benefits would result. Codes of practice (e.g. Freedom Food; The Lion) present a more flexible way forward, but to be effective they have to be both understood and credible in the eyes of the consumer.

With the increasing globalization of trade, welfare legislation must be framed to protect domestic industry from unfair competition.