bluuebunny/crossref_metadata_2025_split huggingface dataset:
Postnatal care in pigs
Authors: Hughes P. E. 
Published: June 2019

AbstractIn the pig industry the mortality of piglets both during the birth process and in the subsequent 3 to 5 weeks is unacceptably high. This review attempts to summarize the major causes of these losses and to suggest means whereby such losses may be minimized in the commercial situation. Stillbirth rate is discussed in relation to various management regimes and it is concluded that anoxia (the primary cause of intra-partum piglet deaths) may be minimized by the provision of careful assistance during the birth process. Pre-weaning mortality is presented as a complex interaction of factors predominant amongst which are overlying by the sow, chilling, starvation and infection. Each of these areas is discussed in detail and recommendations are made to reduce their negative influence on the survival rate of piglets. Finally, the rōle of piglet activity level/vigour is considered in relation to pre-weaning survival rate. Various factors are discussed in relation to piglet vigour and it is concluded that the two major contributors to low activity level/vigour are intra-partum hypoxia and the endocrine status of the sow and piglet at birth. To reduce hypoxia, careful intervention is again suggested. The rôle of endocrine status is yet to be fully established but promising results are presented on the use of oestradiol treatment of piglets at birth to raise activity level and reduce pre-weaning mortality rate.
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.
Implications of genotype X nutrition interactions for efficiency of milk production systems
Authors: Mayne C. S. , Gordon F. J. 
Published: June 2019

AbstractMajor 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

AbstractMilk 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

AbstractThis 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

AbstractIn 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.
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.