bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparison of the Holstein Friesian and Norwegian cattle breeds for milk production at two levels of nutrient intake
Authors: Keady T.W.J. , Crawford A.D. , Mayne C.S.
Published: June 2019

Breeding programmes for Holstein Friesian (HF) animals have been based on improved milk production with little emphasis on functional traits such as fertility. This has resulted in a rapid increase in milk production potential of the national dairy herd but unfortunately this has been at the expense of issues such as longevity, especially due to poor reproductive performance. In contrast Norwegian (NC) dairy cattle have been bred via a multi-trait selection procedure for 25 years and there is evidence that fertility has improved during that period. These differences in selection procedures for the two breeds may have major effects on overall herd output and profitability within the grass-based systems of milk production employed in Northern Ireland. The present study is part of an overall study comparing the effects of HF and NC genotypes on food intake, animal performance, nutrient utilisation, behaviour, health, fertility and longevity. The objective of the present paper is to present the effects of breed on food intake and utilisation, and animal performance when offered two levels of nutrient inputs based on grass silage-based diets.
Influence of group size on the performance and behaviour of 4 to 10 week old pigs
Authors: O’Connell N.E. , Beattie V.E. , Weatherup R.N.
Published: June 2019

Increasing the group size of weaned pigs can lead to more efficient use of resources by producers. However research with finishing pigs suggests that increasing group size can also lead to increased aggression and reduced performance (Spoolder et al., 1999). The objective of this study was to assess the effect of group size on the performance and behaviour of weaned pigs.
Effects of grass or concentrates on muscle fatty acids and flavour in 2 sheep breeds
Authors: Hewerdine J.S. , Jones D.A. , Whittington F.M. , Enser M. , Nute G.R. , Wood J.D.
Published: June 2019

In previous research the benefits of grass feeding in lambs for healthiness (fatty acid composition) and flavour have been demonstrated (Fisher et al., 2000). This work examined a very short period of feeding grass or concentrates in a hill breed (Beulah) and a breed noted for meat production (Texel).
Postmortem proteolysis in pork does not depend on fibre type distribution
Authors: Christensen M. , Henckel P. , Purslow P.P.
Published: June 2019

Proteolytic degradation is known to be faster in white muscles than in red muscles (Whipple & Koohmaraie, 1992). Variation in eating quality between muscles has often been correlated to their metabolic properties, as determined by the fibre type distribution. Correlations between fibre type distribution and postmortem proteolysis could result from two possible effects: (1) Due to their inherent differences in metabolic potential, composition and content of proteolytic enzymes, fibres of some types may degrade more than others. (2) The balance of fibre types controls postmortem (p.m.) metabolic characteristics of the muscle as a whole, with all fibre types within it being equally affected. An experiment was conducted to compare the rate of postmortem proteolysis in five porcine muscles differing in fibre type distribution and to compare the rate of proteolysis in type II fibres isolated from these muscles.
A decision support system for controlling bovine viral diarrhoea (BVD) in beef suckler herds
Authors: Stott A.W. , Jones G.M. , Humphry R. , Gunn G.J.
Published: June 2019

The success of any farm business relies on allocating resources optimally across all farming activities. This is particularly important for disease prevention activities because of their potential impact on farm business viability, the temptation to reduce such activity when funds are scarce and the possible implications for animal welfare and food safety. The objective of the current study was therefore to explore the relative impact of alternative disease prevention strategies under a range of different circumstances. This was done by example, using the case of BVD in a typical Scottish beef herd.
Effect of protein level in cereal based rations for Continental cross Holstein bulls and heifers
Authors: Marsh S.P , Walters E
Published: June 2019

The use of barley and a protein supplement such as soya bean meal as an ad libitum ration for intensively finished male beef calves has been well established and widely used since the conception of the cereal beef system in the 1960’s (Preston et al 1963). Rations on commercial beef units rearing Continental cross Holstein beef cattle are usually formulated to contain 175g CP/kg DM. With the recent fall in the price of barley there is increased interest in the cereal beef system for bull calves and late maturing Continental cross Holstein heifers. Increasing the proportion of barley in cereal beef rations can reduce ration costs and provided productivity is maintained, increase profit. There is also a paucity of information on the performance of heifers on the cereal beef system. The objective of this study was to evaluate feeding cereal based rations containing either 140 or 175g CP/kg DM to Continental cross Holstein bulls and heifers.
Simple mixes of molassed sugar beet feed, field beans and distillers grains for pregnant March-lambing ewes
Authors: Chapple D G , Wheeler K P A , Perrott G , Witt M
Published: June 2019

Feeding of lowland sheep on straw-based systems during pregnancy and in early lactation has shown that ewe and lamb performance can be satisfactory, providing adequate compound supplementation is fed (Davies and Chapple, 1995). Whole barley and soya bean meal has been the standard ration. However, soya bean meal is imported and may not be fully traceable. Maize or barley distillers fed with beans could provide traceable protein to replace soya bean meal in sheep diets. Experiments with housed early-lambing ewes and ewes suckling twin lambs at grass have shown that traceable feeds, based on molassed sugar beet and either maize or barley distillers grains, can replace a barley/soya supplement when fed with straw based diets in late pregnancy or at grass (Chappleet al., 1999 and 2000). The objective of this work was to evaluate the effects on ewe and lamb performance of feeding sugar beet feeds with distillers grains and beans to March-lambing ewes on a straw-based system.
The biohydrogenation of n-3 polyunsaturated fatty acids determined in-vitro
Authors: Cooper S.L. , Sinclair L.A. , Huntington J. A. , Wilkinson R.G. , Chikunya S. , Enser M. , Wood J.D.
Published: June 2019

Unprotected n-3 PUFA supplements fed to ruminants are subject to lipolysis and biohydrogenation in the rumen (Wachira et al. 1998). Improving the n-3 PUFA content of ruminant products therefore requires some form of protection of dietary lipid from microbial activity in the rumen. The in-vitro incubation of PUFA sources offers the opportunity of rapidly determining the level of protection offered against ruminal biohydrogenation. The objectives of the current experiment were therefore to determine the biohydrogenation of a number of sources containing a-linolenic acid using the in-vitro gas production technique.
Effect of fibre source on the efficiency of microbial synthesis by mixed microorganisms from the sheep rumen in vitro
Authors: Ranilla M. J. , López S. , Carro M. D. , Wallace R. J. , Newbold C. J.
Published: June 2019

The efficiency and rate of microbial protein synthesis in the rumen depend on several factors, of which the chemical and physical properties of the plant fibre are among the most important. Estimation of microbial yield and fermentation rate can be obtained from in vitro experiments, which combine gas production and substrate degradability measurements and/or use microbial markers. The aim of this study was to investigate the effect of different fibre sources on microbial protein synthesis in a batch culture system in vitro.
The effects of adding oil to liquid feed supplements on feed intakes and milk production of high yielding Holstein cows
Authors: Lawson R.E. , Derrick R. , Blake J.S.
Published: June 2019

The feed intake of high yielding, early lactation Holstein cows is often inadequate to meet the animal’s requirements for energy and a more concentrated energy source is essential. Oil has a high energy content, so feeds containing oil can help increase the overall concentration of energy in the diet. However, high oil inclusions can lower milk fat and protein level.

The objective of this study was to examine the effects of the addition of increasing levels of oil to a molasses blend (4 kg/cow/day) on feed intake, milk yield and milk composition of dairy cows.
The effect of variety and location of production on the chemical composition of barley
Authors: McCann M.E.E. , Urquhart R. , McCracken K.J.
Published: June 2019

Variety and location of production affect the chemical composition of cereal grain (Valajaet al1997). There are several varieties of Spring barley produced in Northern Ireland (NI) and in the Republic of Ireland (ROI). However, there is no information in the literature concerning the chemical composition of these varieties nor is there any information regarding location of production. The main aim of this study was to examine the effect of variety and location of production on the chemical composition of barley grown in these countries. Specific weight is traditionally used to predict nutritive value. However, a number of research reports including that of Stewartet al(1997) have not found a strong relationship between specific weight and chemical composition or nutritive value. For this reason the use of specific weight as a predictor of chemical composition was studied.
Improving lamb performance from Welsh Mountain Sheep breeding groups
Authors: McLean B M L , Davies O D , Evans D E
Published: June 2019

Sheep group breeding schemes have gained in popularity in recent years. The objectives of group breeding schemes are to improve desirable traits such as carcass conformation, weight and maternal ability whilst maintaining local type. However, if group breeding schemes were to work together then a larger genetic pool of performance recorded animals would be available to facilitate improvements. The objectives of this project were therefore twofold, 1.) was to improve traits such as weight and carcass conformation and 2.) to demonstrate the benefits of cooperative groups working together. In this project, group breeding schemes from North and Mid Wales have been working together with ram performance testing groups from North, South and Mid Wales to improve results from Welsh Mountain breeding schemes.
Genetic analysis of birth weight and related traits in Dorset Down and Hampshire Down sheep
Authors: Roden J. A. , Finch J. M. , Haresign W.
Published: June 2019

In recent years genetic improvement programmes for sheep in the UK have been primarily directed towards the improvement of growth and carcase traits. The possible correlated responses in other production traits, that may not be of such obvious economic importance, have not been fully assessed. Birth weight is such a trait.

Although of no direct economic importance, birth weight is an important trait in sheep production. There is a known relationship between birth weight and lamb survival, with lambs of both low and very high birth weight being at greater risk. There have, however, been very few genetic studies of the trait. The aim of this study, which is part of a larger project covering a number of breeds, was to estimate the direct and maternal heritability of birth weight and its genetic correlations with 8 week weight in the Dorset Down and Hampshire Down breeds. In addition the genetic trend in birth weight over a fourteen year period is assessed.
Land use and the environment – the scientist
Authors: Milne J.A.
Published: June 2019

Beef cattle can have a wide range of positive and negative impacts on the environment. Some of these impacts are general to ruminants, whilst other are specific to cattle, and, because of the type of management systems and habitats that they graze, there are some impacts which are specific to beef cattle. Impacts are often classified in terms of their potential to provide benefits and damage to the atmosphere, water, soil and vegetation. This classification will be issued below to explore the most important ways that cattle, and their land use, influence the environment and the extent to which scientists can increase understanding to influence these impacts.
Seasonal tissue changes in Scottish Blackface ewes over multiple production cycles
Authors: Lambe N. R. , Young M. J. , Simm G. , Conington J. , Brotherstone S.
Published: June 2019

A previous study using X-ray computed tomography (CT) of Scottish Blackface hill ewes found that carcass fat, internal fat and muscle are depleted during pregnancy and early lactation and deposited during late lactation and the dry period. Relationships were also found between fat and muscle levels and lamb production traits (Lambe et al., 2002a). Changes in tissue levels over multiple production cycles of the hill ewe, and how these changes relate to lamb production are also of interest. The aims of this study were to model changes in carcass fat, internal fat and muscle through three production cycles and to compare patterns of tissue change in ewes producing different numbers of lambs.
Pressed sugar beet pulp as an alternative fibre source for lactating dairy cows
Authors: Humphries D. J. , Sutton J. D. , Cockman D. M. , Witt M.W. , Beever D. E.
Published: June 2019

A significant proportion of the grass silage fed to lactating dairy cows may be of only modest quality due either to delayed harvesting and/or poor ensiling conditions. In such situations, both total feed intake and milk production are likely to be compromised with the consequent need to feed more concentrates. Part of this effect is considered to be due to the development of a solid mass of digesta in the rumen, with loss of the normal layered or biphasic stratification of rumen contents. Under such conditions, rumen motility, rate of forage digestion and hence voluntary feed intake will be compromised. Mertens (1997) stressed that chemical definition of dietary fibre such as neutral- (NDF) or acid-detergent (ADF) fibre content was an inadequate description of the fibre content of a diet as it affects rumen function and animal performance. Consequently he proposed both effective NDF (eNDF; ability of a feed to replace a roughage with no negative effect on milk fat content) and physically effective NDF (peNDF; a measure of the physical properties of fibre as it stimulates chewing activity and development of the biphasic stratification of rumen contents) as additional descriptors of the physical characteristics of dietary fibre but to date these concepts have attracted limited attention in the UK. This study examined the effect of replacing increasing amounts of grass silage (GS) on a dry matter (DM) basis in a silage:concentrate ration with pressed sugar beet pulp (PP) on various processes of digestion in the rumen of lactating dairy cows, specifically in relation to chewing activity and rumen mat density.
An evaluation of the effect of concentrate proportion of the diet during previous and present lactations on animal performance of two breeds of lactating dairy cows
Authors: Keady T.W.J. , Mayne C.S.
Published: June 2019

Studies undertaken to evaluate long responses to concentrate feeding, normally assess the direct effects (i.e. the effects during the period of increased feeding). However in addition to the direct responses to concentrate feeding during the experimental period, it has been recognised that additional nutrients fed during one stage of lactation may result in improvements in animal performance in later lactation or in the subsequent lactation. Keadyet al. (2002) reported that the milk yield response to concentrate proportion in the diet differed between Holstein (HF) and Norwegian (NC) dairy cattle with responses of 1.4 and 0.8 kg corrected milk/kg concentrate dry matter (DM) respectively. The objective of the present study was to evaluate the effects of concentrate proportion in the diet in the previous lactation on animal performance in the subsequent lactation. The effect of concentrate proportion in the diet on animal performance of HF and NC dairy cattle was also evaluated.
Changes in the mechanical properties and the lesion score of the sole horn in first lactation heifers
Authors: Winkler B. , Margerison J. K.
Published: June 2019

The start of the lactation period is related to an increase in the number and severity of claw horn lesions on dairy cows and heifers (Offer et al., 2000). Heifers have important physiological differences, presenting a different pattern of lesion formation when compared to cows (Offer et al., 2000). The rearing of heifers, their growth rate, feeding and the occurrence of foot problems have an influence over the health of their feet when the animals get older (Thomas et a., 1999). The objective of this experiment was to study the pattern of lesion formation of the sole horn in the pre- and postpartum period of first calving heifers and to compare it to mechanical tests.
Influence of social status on the welfare of growing pigs reared in barren and enriched environments
Authors: O’Connell N.E. , Beattie V.E. , Moss B.W.
Published: June 2019

Evidence suggests that low social status contributes to reduced welfare in pigs (O’Connell et al., in press). It may be possible to reduce this effect by rearing pigs in enriched environments, which has previously been shown to have welfare benefits (Beattie et al., 2000). The aim of this study was to assess the effect of social status on the welfare of pigs reared in barren or enriched environments.
Effect on average daily feed intake during lactation and piglet growth during the first 2 weeks of life of feeding sows fermented liquid feed, non-fermented liquid feed or dry feed
Authors: Demečková V. , Tsourgiannis C.A. , Brooks P.H.
Published: June 2019

Achieving adequate feed intakes by sows, and particularly gilts, in lactation can often be a problem under intensive farrowing-house conditions. It has been shown that sow feed intake during lactation can significantly affect subsequent reproductive efficiency such as remating interval, pregnancy rate and embryo survival (Einarsson and Rojkittikhun, 1993). There are many nutritional, environmental and physiological factors that influence the sow’s appetite during lactation. The physical form of the diet (wet or dry) has also been shown to affect feed intake as sows ate 12 % more feed given as a wet mash compare with dry form (O’Grady and Lynch, 1978; Genest and Dallaire 1995). The growth of the piglets during the first 2 weeks of lactation depends entirely on the milk supply of the mother. As this has been shown to be influenced by the level of feed intake (Koketsu et al., 1996), factors controlling feed intake during lactation should determine the rate and efficiency of piglet growth. The aim of this study was to investigate the effect of three different forms of diet on lactation feed intake of gilts and growth performance of their piglets.
The study of reproductive failures in dairy cattle by metabolic profile test in Tabriz
Authors: Moghaddam Gh. , Kia H. Daghigh , Yasan P. , Alijani S.
Published: June 2019

The deficiency of some blood elements and metabolites such as phosphorus, calcium, haematocrit, hemoglobin, glucose and protein, and also increased the urea and total protein in blood appears to have an important role to control reproductive failures in dairy cows. Recent studies showed that some metabolites and nutritional factors are responsible for dairy cows infertility (Mc Clure, 1994, Ramakrishna, 1996). The energy shortage in postpartum period led to decrease in luteinizing hormone secretion frequency and dynamic follicle diameter, however it increases interval calving time (Almeida, 1995). The objective of this study was to investigate the relation between blood metabolites and elements on reproductive failures in dairy cows.
The influence of birth order and duration of farrowing on concentrations of metabolites in the umbilical cord blood of newborn piglets
Authors: Ilsley S.E. , Miller H.M.
Published: June 2019

It was the purpose of this study to ascertain whether concentrations of glucose (GLU), urea and non-esterified fatty acids (NEFA) in blood collected from the umbilical cords of newborn piglets vary according to the position of the piglet in the birth order of a litter. Umbilical cord blood is representative of the piglets status at the time of birth. It would therefore be advantageous to know whether blood withdrawn from the umbilical cord of one piglet is representative of the litter in terms of these metabolites. This study was therefore designed to test the hypotheses that position in the birth order, and time of birth relative to delivery of the first piglet in a litter, will influence GLU, urea and NEFA concentrations in umbilical cord blood.
Estimation of the effects of some environmental factors and genetic parameters of linear type traits in Holstein cows of Iran
Authors: Toosi Ali , Eftekhari F.
Published: June 2019

The primary emphasis in dairy cattle selection is for yield traits because highest producing cows usually are more profitable. Selection on yield traits alone could decrease merit for other traits. Selection on type traits associated with increased herd life may be benefical to decrease involuntry culling and increase profitability. One of the primary reasons for collecting and utilizing information on type is to aid breeders in selecting profitable, functional cows. So that early culling for causes unrelated to yield (involuntry culling) can be avoided [Misztal et al, 1992]. The objectives of the present study were to evaluate the effects of some environmental factors on and to estimate genetic parameters of some type traits.
Lipolysis and biohydrogenation of linoleic and linolenic acid in vitro: comparison of linseed products and grass
Authors: Chow T. T. , Fievez V. , Raes K. , Demeyer D. , de Smet S.
Published: June 2019

With respect to human health, nutritional guidelines emphasise on increasing the ratio poly-unsaturated/saturated fatty acids (P/S) (> 0.7) and reducing the n-6/n-3 ratio (< 5). Beef is generally characterised by a low P/S ratio (0.1), while the n-6/n-3 ratio may vary between 2 and 10 depending on the feeding strategy. Hence, the provision of n-3 fatty acids by the diet is crucial for optimising the fatty acid composition of meat. However, PUFA are hydrolysed and subsequently hydrogenated in the rumen to more saturated fatty acids and intermediates that are absorbed from the intestinal tract and transported to the tissues. Lipolysis and hydrogenation may thus affect the meat fatty acid composition. For ruminants, important sources of linolenic acid (C18:3n-3) are linseed and fresh grass. Prior to use in animal nutrition, linseed needs physical treatment like extrusion or crushing. The aim of the present in vitro experiment was to study lipolysis and biohydrogenation of linoleic acid (C18:2n-6) and C18:3n-3 in fresh grass and extruded or crushed linseed products.
Changes in water soluble carbohydrate content during the day in Lucerne and Fescue cut in autumn
Authors: Repetto J. L. , Errandonea N. , Britos A. , Cozzolino* D. , Cajarville C.
Published: June 2019

The content of water-soluble carbohydrates (WSC) in plants is variable, and depends on plant species and environment conditions. This content may be the limitation for the fermentation during silage making and also for microbial synthesis in rumen. The objective of this study was to measure the variations of the WSC in temperate forages, during autumn, in different moments of the day and in different parts of the plant.
Effects of time spent on pasture and the characteristics of the concentrate on milk yield, milk composition and body reserves in the Latxa dairy ewe
Authors: Garcia-Rodriguez A. , Oregui L. M.
Published: June 2019

In the basque country, in the spring, dairy ewes can spend a limited number of hours between 4 and 8 hours on pasture (Oregui et al., 1997). Besides grazing, ewes receive a supplementation of concentrates and forages in parlour. Therefore the characteristics of this supplementation are very important. In this sense, there is evidence that an increase in rumen undegradable protein could lead to an increase in milk production (Santos et al., 1998). In recent years, it has been shown the potential of tannins to decrease protein degradation in the rumen (Hervas. 2001). However, there is a lack of knowledge concerning the effect of increasing the content of rumen undegradable protein of the concentrate in a production system like the one in the basque country.
The influence of different levels of fish meal on the performance and carcass characteristics of Raini goat
Authors: Rouzbehan Y. , Taghizade M. , Rezayazdi K.
Published: June 2019

Earlier investigations have been carried out with Raini goat for maximizing the ruminal microbial protein production by determining the requirement of the dietary ERDN:S ratio. Adding a supplement which contains high level of undegradable protein (UDP) may improve the animal performance, due to the increase the of the amino acids concentration in the small intestine (Orskov, 1992). Therefore, this trial was conducted to maximize the potentiality of the growth performance and carcass characteristics of this breed by adding a protein supplement, fish meal (FM), which contains a high percent of undegradable protein.
Gut morphology and nutritional management
Authors: Slade R. , Miller H. M.
Published: June 2019

In the natural situation, the piglet’s transition from a wholly milk to a wholly non-milk diet (weaning) is gradual and paralleled by progressive, appropriate modification of gut structure. The sow’s milk provides nutritional, trophic and immune support throughout this transition thereby mediating intestinal exposure to novel nutrients and pathogenic agents whilst the gut structures necessary to process them appropriately are maintained and developed. Commercial weaning deprives the piglet of lactogenic support and simultaneously necessitates the marked acceleration of gut development if piglet health and growth are to be maintained. Intestinal mass, growth (Slade and Miller 2000) and fractional protein synthesis rate (Ks) increase significantly following weaning (Le Dividich and Seve 2000). Correspondingly, the nutrient cost of post-weaning intestinal development is high. However, weaning is invariably associated with a dramatic reduction in feed intake and, in turn, with a decline in gut efficiency characterised by a reduction in villus height and an increase in crypt depth. Perversely, the gut morphology of the weaner thus appears a limiting factor in its own development. Here we introduce a simple histological method for estimation of individual crypt-villus structure surface area and then, in conjunction with conventional histomorphological measurements, use this to relate piglet performance, nutrition and gut morphology.
Dietary carbohydrates and management of the gut environment of pigs
Authors: Knudsen K. E. Bach , Lærke H. N. , Hedemann M. S. , Jensen B. B. , Hansen C. F.
Published: June 2019

Dietary carbohydrates constitute a major fraction of the diets for pigs. The carbohydrate fraction consists of mono-, di- and oligosaccharides and two broad classes of polysaccharides – starch and non-starch polysaccharides (NSP). The carbohydrate fraction has a diverse composition in terms of constituent sugars (pentoses, hexoses, deoxysugars, etc.), glycosidic linkages (alfa or beta), size (degree of polymerisation from one to several thousand), and physical form (soluble in water, insoluble, cation and adsorbing properties). It is now evidential clear that the composition of the carbohydrate fraction influences the digestion and absorption processes of carbohydrates and other nutrients in the various parts of the gastrointestinal tract, it has a profound influence on the secretory response of the gut to feed intake, the volume flow, the mucosal architecture, the composition of the gut flora and the development of the gastrointestinal tract.
Immunohistochemical localisation of aquaporin water channels in the bovine mammary gland
Authors: Kendall B. , Maxwell J.E.J. , German A.J. , Marples D. , Royal M.D. , Mobasheri A.
Published: June 2019

The aquaporins (AQPs) are a family of small integral membrane proteins 28-35kDa in size, sub classified into 2 groups; those selectively permeated by water (the aquaporins; AQP0, AQP1, AQP2, AQP4, AQP5, AQP6 and AQP8) or by water and small organic osmolytes such as glycerol and urea (the aquaglyceroporins; AQP3, AQP7, AQP9 and AQP10). AQPs are expressed in a variety of epithelial tissues where they are responsible for rapid water movement driven by osmotic gradients. The mammary gland produces and secretes milk which consists of water, lipids, electrolytes, vitamins, sugars and specific milk proteins. However, little is known about AQP expression, distribution and function in mammary tissue or about the process of water transport across the mammary epithelium. The only information available relates to the identification of AQP1 and AQP3 in capillary endothelia and epithelial cells of mouse mammary glands respectively (Matsuzaki et al., 2005). Since water delivery to the mammary gland is critical for milk production, which is of major economic importance to the dairy industry, it is necessary to understand the underlying physiology involved. The aim of this study was to determine the expression and distribution of AQPs within the bovine mammary gland.
Detecting dominance QTL in poultry pedigrees using variance component methodology
Authors: Rowe S. J. , Pong-Wong R. , Haley C.S. , Knott S.A. , de Koning D.J.
Published: June 2019

Methods that detect QTL within commercial populations circumvent the need for expensive experimental populations and facilitate direct application of results through marker assisted selection. Variance component analysis (VCA) uses phenotypic, pedigree and marker information within a mixed linear model to simultaneously detect QTL and estimate breeding values. The inclusion of non-additive effects has potential for greater accuracy of selection and understanding of underlying mechanisms. The linear model can be extended to include higher order effects such as dominance, however, there is little information on empirical power. Here VCA was applied to real and simulated commercial broiler data to detect additive and dominant QTL effects.
Effect of incremental dietary fish oil inclusion on bacterial diversity in the rumen
Authors: Huws S.A. , Kim E.J. , Sanderson R. , Muetzel S. , Wallace R.J. , Scollan N.D.
Published: June 2019

In vitroexperiments have revealed that members of theButyrivibriogroup can convert linoleic (C18:2n-6) and linolenic (C18:3n-3) acid to VA (C18:1trans-11), with some being able to further convert VA to stearate (C18:0). Advances in molecular microbial technology mean that we are now able to quantify these bacteria using quantitative PCR (qPCR) as well as look at total eubacterial andButyrivibrio–specific population changes using Denaturing Gradient Gel Electrophoresis (DGGE). The aims of this study were to assess the involvement ofButyrivibriospp. in the biohydrogenation pathwaysin vivoas well as investigate whether other bacterial species may be involved.
Variability in semen quality from British sport horses
Authors: Tucker L.A. , Matson T. , Morris L.H.A.
Published: June 2019

Recent advances in artificial insemination (AI) and semen preparation have led to an increase in the availability of equine genetics globally. Generally, less than half the stallion population produce semen of suitable robustness to maintain acceptable fertility post-freezing, and research is needed to improve not only the numbers of stallions whose semen can be successfully frozen, but also to increase the number of collections that meet fertility standards. The number of progressively motile sperm present during ovulation determines successful conception in horses. AI practitioners recommend that 500 million progressively motile sperm should be introduced into the mare’s uterus to ensure best chance of pregnancy (Matson and Pycock, 2006), and progressive motility is currently accepted as suitable for determining fertility in stallions. Established laboratory quality assessments are used to identify stallions with suitably robust semen for freezing and worldwide distribution, however fertility traits can be influenced by many factors, e.g. age, level of competitive performance or workload, nutrition, disease and stress (Tucker and Morris, 2006). In order to investigate the impact of such factors on semen quality, it is first important to determine the level of variation in semen quality between stallions that are currently used for frozen semen collections, which formed the main objective of the following study. This baseline can then be used to compare improvements in semen quality from various nutritional and management interventions, which form the basis of our ongoing research program.
The genetic parameters of lactation using a biological model on cows from UK dairy herds
Authors: Pollott G. E. , Albarran-Portillo B.
Published: June 2019

Recently, Pollott (2000, 2004) has proposed a biological model of lactation which mimics the three processes of cell proliferation, apoptosis and milk secretion rate per cell during lactation. This model has been used on dairy sheep and cattle to investigate several aspects of its utility to account for the factors which influence the milk production during lactation. Pollott and Gootwine (2001) and Pollott (2002) reported genetic parameters of the biological model for a single flock/herd sheep respectively. Here we report an extensive genetic study of over 400 UK dairy herds using the biological model of lactation.
Effect of different creep feeding treatments and group composition on the initiation of piglet feeding behaviour immediately post-weaning
Authors: Reynolds F. H. , Miller H. M. , Forbes J. M.
Published: June 2019

The post-weaning growth check of the piglet can be attributed to the inability of the animal to eat sufficient food in the initial post weaning period and hence grow at a maximum rate (Pluske et al., 1996). It is essential therefore to identify determinants of individual feed intake characteristics post weaning to improve piglet performance. A palatable creep-diet is often fed to piglets pre-weaning to increase performance and to allow piglets to become familiarised with solid feed sourced from a feeder. Bruininx (2002) et al., demonstrated using single spaced Feed Intake Recording Equipment (FIRE), that creep feed stimulates post-weaning feed intake and gain. In addition, Morgan et al. (2001) investigated feeding behaviour of piglets paired from creep or no creep backgrounds and concluded a learning effect which increased the feeding behaviour of the naïve piglet. The purpose of this experiment, therefore, was to investigate the effect of offering selected litters either creep feed or zero creep (naïve) pre-weaning on their latency to initiate feeding post weaning. It was hypothesised that learning behaviour between piglets may influence feeding initiation and so this experiment would also look at the effect of mixing piglets from the two lactation backgrounds.
Effects of housing system and litter grouping on performance and physiological maturity in entire boars and gilts
Authors: Salmon E.L.R. , Edwards S.A.
Published: June 2019

Slaughter weight in UK pig production is increasing annually, with an associated increase in age at slaughter. This increases risk of reaching sexual maturity and a reduction in carcass quality and production efficiency. In entire boars, puberty is associated with increased aggression levels and the production of hormones causing carcass taint. Management systems and production practices may affect these risks. Thomas et al (1979) found that extensive housing and management systems increased the risk of pigs reaching puberty. In previous Scandinavian research, Fredriksen et al (2005) found that maintaining stable litter groups reduced aggression and mounting behaviour, and gave a lower propensity for carcass taint at slaughter. To date, there is a lack of research examining the effects of these factors on physiological development and aggression under UK conditions. This study explored the effect of stable litter grouping and housing system on performance, aggression and physiological maturity in entire males and gilts over the 60kg-130kg weight range.
The effect of crude protein and lysine level in diets for finishing pigs on nutrient digestibility and nitrogen balance
Authors: McCann M.E.E. , Magowan E. , Beattie V.E. , McCracken K.J. , Bradford R. , Gordon F.J. , Robinson M-J. , Mayne C.S.
Published: June 2019

Due to the introduction of more stringent environmental controls through the implementation of current and impending environmental legislation, dietary crude protein (CP) levels for finishing pigs are an important area of research. Canh et al (1998) reported that nitrogen (N) excretion could be reduced through lowering CP levels and the aim of this study was to investigate the effect of decreasing CP levels of diets containing two levels of lysine (while maintaining the ideal protein balance through amino acid supplementation) on nutrient digestibility and N balance.
Effects of secondary nematode infection on anorexia and leptin levels in growing lambs of two different breeds
Authors: Zaralis K. , Tolkamp B.J. , Wylie A.R.G. , Houdijk J.G.M , Kyriazakis I.
Published: June 2019

A primary infection of a parasite naïve animal has detrimental effects on intake (anorexia), which in turn results in impaired animal productivity. Recent studies have indicated that anorexia in nematode infected lambs is a direct consequence of the acquisition of immunity (Greer et al., 2005). In many models of disease, immune system activation results in elevated leptin levels and these have been associated with anorexia. However, whether the expression of acquired immunity following a secondary nematode infection results in elevated leptin levels and/or anorexia in growing lambs it is not known. In addition, it is not known whether the expression of acquired immunity differs between breeds that differ in production potential. The aim of the present study was to test the hypotheses a) that a secondary nematode infection results in increased leptin levels and anorexia in growing lambs and b) that lambs of a high production potential breed exhibit a higher degree of anorexia than lambs of a low production potential.
Effects of protein supplementation on anorexia and expression of immunity in parasitized periparturient ewes of two different breeds
Authors: Zaralis K. , Tolkamp B.J. , Houdijk J.G.M. , Kyriazakis I.
Published: June 2019

The breakdown of acquired immunity during the periparturient period in the ewe can be reduced by metabolizable protein (MP) supplementation (Houdijk et al 2001). Recent evidence suggests that the development of immune response results in reduced food intake (anorexia) in many disease models (Materase et al, 2005). However, it is not known whether an immune response following the periparturient relaxation of immunity is associated with a reduction in food intake and whether this is affected by protein supplementation in parasitized ewes. In addition, differences in nutrient partitioning between sheep breeds that differ in production potential may affect the ability of the hosts to express immunity and this may be reflected by differences in their magnitude and/or duration of anorexia. The aim of the present study was to test the hypotheses that: a) nematode infection during the periparturient period results in anorexia and protein supplementation can effect the degree of anorexia in ewes, and b) ewes of a high production potential breed show higher breakdown of acquired immunity than ewes of a low production potential breed, and exhibit higher degree of anorexia.
Effects of an algal biomass supplement on the periparturient rise in nematode egg output from ewes and the subsequent effects on their offspring
Authors: Scott-Baird E. , Leifert C. , Edwards S.A. , Butler G.
Published: June 2019

The periparturient rise in nematode eggs at lambing is a crucial part of the epidemiology of nematode infections as it allows a large number of infective larvae to be present in the pastures when the lamb is young and most immunologically naïve. With a rapidly rising level of anthelmintic resistance and increasing public concern over drug residues remaining in animal products, it is necessary to achieve more long-term, sustainable nematode control programmes. Some plant products could provide alternatives or adjuncts to conventional control with anthelmintics and ease the selection pressure for anthelmintic resistance. The polyunsaturated fatty acid, docosahexaenoic acid (DHA), which can be produced in high concentrations by some marine algae, has been shown to modify immune response in many species and decrease the production of proinflammatory cytokines (Calder, 2001). This action could reduce inflammation in the gut in response to parasite infestation and reduce the extent of associated hypophagia. The objective of this study was to investigate the long term effects of providing an algal DHA dietary supplement in late pregnancy, on the periparturient rise and the resulting effects on the infection levels and production consequences for their lambs.
Isolation of lactic acid bacteria from chickens that demonstrate probiotic properties of autoaggregation and coaggregation with Salmonella enteritidis
Authors: Savvidou S , Beal J. , Brooks P.
Published: June 2019

The association of salmonella infections with the consumption of poultry products and the fact that in the live bird the Salmonella carriage is mainly asyptomatic have led to a demand for finding ways of preventing infection of commercially reared poultry and product contamination (Revolledo et al., 2006). One approach is the use of probiotics. The probiotic properties of lactic acid bacteria have been widely studied. Their capacity for adhesion to mucus, ability to autoaggregate and potential for coaggregation with pathogenic bacteria are potential mechanisms for providing a competitive advantage in the intestinal microbiota (Ghadban et al, 2002) and forming a barrier that prevents colonization of pathogenic microorganisms (Kos et al, 2003). In this study, a total of 53 lactic acid bacteria (LAB) were isolated from the contents of the crop, caecum and small intestine, and from the mucosa of the crop, jejunum and ileum of three organically farmed chickens, were examined for autoaggregation and coaggregation with Salmonella enteritidis.
Holo-analysis of the efficacy of exogenous dietary enzymes in beef and dairy cattle
Authors: Rosen G.D.
Published: June 2019

Holo-analytical models are used for the prediction of nutritional responses, product comparisons and the setting of future research priorities. Following holo-analyses of the efficacy of exogenous enzymes in monogastrics (Rosen, 2006), this study in ruminants comprises holo-analyses of all available data from beef and dairy cattle, negatively-controlled, start-to-finish tests in meat and milk production. The beef enzymes mainly contain amylases, cellulases and xylanases, with a total of eight other side activities and the dairy, betaglucanases, cellulases and xylanases, with 12 declared side activities.
Analysis of variance on economic traits of Karakul sheep for determination selection index
Authors: Delavar Malek Hossein , Kouhkannejad Mohammad Reza , Elahi Torshizi Mahdi
Published: June 2019

The selection index is a method for estimation the breeding value of an animal combining all information available on the animal and its relatives. Research shows that genetic and phenotypic correlation between traits is completely different among breeds. In baluchi sheep, genetic and phenotypic correlation between weaning weight and yearling weight are 0.93 and 0.59 respectively. Another study on hamshire sheep shows that correlation between birth weight and yearling weight is 0.48 and 0.23. The objective of this study is to predict different type of correlation in karakul sheep traits for determination selection index.
Relationship between type characteristics and length of productive life in Iranian Holstein dairy cattle
Authors: Asgari Jafarabadi Ghobad
Published: June 2019

Type traits have been used as indirect measures of selection for herd life in last few decades, because type traits can be measured earlier in first lactation, they have relative higher heritability than longevity traits and are correlated moderately with herd life. Increased herd life leads to lower replacement costs, longer use of high performance animals in their herds and also obtaining more progenies from high yielding animals.
Study of genetic and environment trends for milk fat yield trait in an Iranian dairy herd
Authors: Jahandar Mohammad Hassan , Moradi Shahre Babak Mohhamad , Elahi Torshizi Mahdi
Published: June 2019

In order to evaluate genetic improvement in a selected population, variation resulted from environment and genetics should be dissociated. Because of the positive genetic correlation between milk fat yield and milk and protein yield, selection for milk production has often resulted in an increase in fat and protein yields however response for fat percentage is negative. However positive genetic trends between 0.73 to 0.95 kg per annum for milk fat yield in Holstein cattle have been reported in some studies that milk fat yield had less importance in selection index, also negative values are reported. Based on previous research, genetic improvement of milk fat yield up to 1 percent due to selection is possible and from a theoretical view, an improvement of about 2 percent is reported. With attention to selection in the herd and using progeny tested semen from foreign countries that have suitable genetic potential, this study was accomplished in order to estimate genetic parameters for milk fat and investigate genetic and environmental trends during 1990 to 2001.
Association of prolactin polymorphism with milk fat content in Iranian Sarabi cows
Authors: Heravi Moussavi A. , Nassiry M.R. , Tahmoores Pour M. , Javadmanesh A. , Sekhavati M.H.
Published: June 2019

Prolactin (PRL) is a polypeptide hormones produced by cells of the anterior pituitary. The bovine PRL gene consists of 4 introns and 5 exons, located on chromosome 23. Different biological functions of PRL were subdivided into five broad categories: reproduction, osmoregulation, growth, integument, and synergism with steroids. Also, It has been shown to be important for control of mammary growth, lactogenesis and lactation (Skinkyteet al., 2005). Chung et al, (1996) showed that PRL-RsaI locus had a significant effect on milk fat percent in dairy cattle. Therefore the PRL gene was chosen as a candidate gene for milk traits in dairy cattle. The objective of this study was to evaluate the association of genetic differences in bovine PRL gene and milk fat content in Iranian Sarabi cows.