bluuebunny/crossref_metadata_2025 huggingface dataset:
Options for genetic improvement of milk composition
Authors: Gibson J.P.
Published: June 2019

Genetic improvement is constrained by the long-term and cumulate nature of genetic improvement, by the economic rewards for making genetic change and by the variances and covariances among traits of interest. Genetic change is cumulate, so that small annual changes make substantial differences over time. This cumulate nature of genetic improvement dictates the importance of identifying long-term goals driven by robust economic signals and then adhering to them. The economic rewards for genetic improvement will ultimately determine the uptake and therefore the success of any breeding program. In developed countries the value of milk can be divided between the weight of water, fat and protein produced. Water generally has a negative value due the cost of handling, removal and disposal. Fat and protein have varying values depending on the market, but both will always have underlying positive values. Genetic variances and covariances among the aggregate composition traits, water, fat and protein, are such that simultaneous increase in the yield of all three is considerably easier than improvement of just one, or improvement of one while decreasing others. Selection for simultaneous increase of fat and protein percentage will also be successful, but at the price of not increasing fat and protein yield nearly as rapidly as when selecting directly on yield traits. In virtually all developed countries, the optimum selection goal will be for some combination of increased fat and protein yield that may lead to a gradual increase in the protein to fat ratio. Genetic polymorphisms in several protein genes have been associated with yield and with milk processing properties, but are unlikely to play more than a minor role in overall selection. There is some evidence of genetic variation in milk fat composition, but the level of variation and economic incentives for change mean that selection for milk fat composition is not worthwhile. Thus, with the exception of very slow changes in the water to fat to protein yield ratio, genetic improvement does not seem a particularly suitable route for altering milk composition.
Influence of dietary copper sulphate supplementation on the milk fatty acid composition of dairy cows
Authors: McNamee B.F. , Fearon A.M. , Pearce J.
Published: June 2019

The experiment was designed to investigate the effect of increasing the concentration of Cu2+ in the diet of the lactating dairy cow with a view to stimulating the activity of the mammary gland △9–desaturase enzyme system to increase the C18:1/18:0 ratio in the milk fat.

In a preliminary study, two lactating dairy cows were provided with ground rapeseed/maizebased concentrates containing either a normal or a high concentration of supplementary Cu2+, the animal offered the normal concentration supplement was also provided with an oral CuSO4 solution drench so that both animals received an equal daily supply of Cu2+. Daily blood samples were collected from the cows and total plasma Cu2+ concentration was determined. A blood plasma lipid analysis was also carried out. In a second study, eight lactating dairy cows were provided with a silage and concentrate diet. The lipid portion of the concentrates was provided by either ground or unground rapeseed while the Cu2+ in the mineral supplement of the unground rapeseed-based concentrate was manipulated to provide one of the following three concentrations of Cu2+ in the concentrate (mg/kg DM); <10, 50 or 100. The subsequent milk fat was analysed for fatty acid composition.

Presentation of an increased concentration of Cu2+ to the cow was more efficiently absorbed when provided in the concentrate mix than when provided as a CuSO4 solution in an oral drench. Increased dietary Cu2+ in the concentrates was successful at increasing the concentration of plasma Cu2+ from a normal concentration of 80–100 mg/cm3 to over 200 mg/cm3. An increased concentration of Cu2+ in the blood of the cows in the first experiment resulted in a significant increase (P<0·05) in the C18:1 content of the plasma lipid, possibly through the increased activity of the intestinal △9–desaturase enzyme system.

The composition of the milk, including the fatty acid composition of the milk fat, from the second experiment was unaffected by the concentration of Cu2+ in the diet of the dairy cows within the concentration range of <10 to 35 mg/kg DM per day.
Life-time organisation and management of reproduction in the dairy cow
Authors: Wathes D. C. , Beever D.E. , Cheng Z. , Pushpakumara P.G.A. , Taylor V.J.
Published: June 2019

Achieving adequate fertility is essential in any dairy unit, but is compromised by genetic selection for increased yield. Selection has altered the somatotrophic axis and resulted in cows which mobilise more body tissue for milk production in early lactation, thus prolonging both the depth and duration of the post partum negative energy balance. Poor energy status is reflected in altered metabolic parameters including raised urea and decreased insulin-like growth factor-I (IGF-I) and insulin concentrations, which adversely affect ovarian cyclicity and early embryo survival. Attempts to optimise the diet in terms of energy and protein content have generally been aimed at increasing milk production further rather than improving fertility. Advances in biosensor technology now provide us with the opportunity to monitor production, fertility and health parameters of each cow. Integration of this information should improve the timing for inseminations and could assist in selecting diets more suited to the needs of the individual cow. Genetic selection may in future be used to produce cows optimised for a particular type of management system. In both cases we need a greater understanding of the rules governing nutrient partitioning at different stages of the cows' life cycle to ensure that diets selected are cost effective and achieve an appropriate balance in promoting production, reproduction and health.
Nutritional and grazing management of the dairy cow
Authors: Dewhurst R. J. , Rutter S. M. , Rook A. J.
Published: June 2019

The pre-requisites for nutritional management of dairy cows are information about how much feed is being consumed as well as the nutrients that are being derived from that feed. Studies of feed intake and nutrient supply have been limited by difficult experimental techniques, particularly with grazing animals. The models derived from much earlier work are of only general applicability and there is a need for more site-specific information in order to benefit further from conceptual advances.

We have adopted a different approach to studying herbage intake and nutrient supply, using less-invasive approaches as well as techniques that monitor more accessible aspects of these processes, such as jaw movements. These techniques have a major advantage, in addition to their value as research tools, because they could translate directly into commercial applications in on-farm monitoring. The use of diagnostics and behavioural recording is well explored in relation to health monitoring; here we argue for its potential to advance the application of knowledge about grazing and nutrition. We will illustrate this approach using our experiences in measuring grazing behaviour, using IGER behaviour recorders and assessing rumen function, using a series of non-invasive techniques.

The IGER grazing behaviour recorder allows us to record jaw movements and hence grazing and ruminating time and bite dynamics. It also allows the recording of steps and is now being developed to incorporate non-invasive rumen state sensors. It has made a major contribution to our understanding of the foraging strategies of grazing animals and their effect on herbage intake. This technology has the potential to be developed for on-farm monitoring of foraging behaviour providing valuable inputs to the prediction of herbage intake, in decision support systems for grazing.

The introduction of concept of protein degradation and microbial synthesis in the rumen are significant advances in protein rationing schemes. However, real progress has been limited because the lack of consistent experimental results means that models have little relevance to specific farm situations. We foresee considerable opportunities to monitor products of rumen degradation and synthesis that appear in milk (e.g. odd-chain fatty acids) or breath (e.g. sulphides).

Taken together these technologies open the possibilities of an entirely new approach to nutritional management of dairy cows, with site-specific recommendations based on information gathered using new sensors that are incorporated into computerised feeding equipment and milking parlours.
A vision of poultry production in the UK
Authors: Perry G. C.
Published: June 2019

Current commercial poultry production in the UK faces many challenges which make it difficult to confidently predict the future. Changing legislation, responding largely to welfare pressures, is one such challenge. Additionally, consumer demands are widening. Eggs and meat from stock which is organically produced, or fed on rations containing no genetically modified ingredients, or free range produced, or corn fed are some of the assurances sought by the purchaser and consumer. Although the market place already offers such produce it is difficult to predict the extent to which they will penetrate a market which developed largely through the use of intensive production systems. The alternatives to intensively produced eggs and meat are more expensive to produce and therefore purchase and consequently are susceptible to changes in standards of living and the affluence of the consumer.

This paper briefly describes current commercial practices and some of the specific challenges arising from new legislation.

A description of some specific requirements of birds highlights areas where improvements, in terms of performance, production efficiency, and welfare might be gained. Since the overwhelming majority of eggs and meat is produced in intensive, highly automated systems, there is an obvious need for an integrated approach featuring engineers and the poultry industry to refine and further develop technology which better serves the birds, and ultimately, the consumer.

It is concluded that the UK cannot compete in production costs with some other areas of the world and as retailers increasingly source their goods worldwide, the UK poultry producer may have to resort to the production of products which satisfy niche demands.
Effects of legume silages on the quantity and particle size distribution of rumen contents in Holstein-Friesian cows
Authors: Dewhurst R. J. , Merry R. J. , Davies D. R. , Moorby J. M. , Scollan N. D. , Neville M. A. , Baker D. H.
Published: June 2019

Poor animal performance associated with low digestibility silages results partly from the reduced nutrient yield per unit intake, but also from the associated lower intakes which were presumed to be a consequence of rumen fill effects. Legume silages have a lower average digestibility than grass silages, and yet often have higher intake characteristics. The objective of this work was to compare rumen fill and rumen particle size distribution for animals fed grass silage or legume silage-based diets.
Feeder space requirement of growing pigs housed at different group sizes
Authors: Turner S. P. , Arey D. S. , Edwards S. A.
Published: June 2019

The resource requirements, such as feeding space, of pigs housed in large groups are poorly understood. The feed intake requirement may be unaffected by group size, but the ability to gain access to the feeders may be influenced by the changed social environment. The observation of pigs feeding may stimulate others to feed also. In large groups, the number of pigs attempting to feed simultaneously could lead to increased competition for access to the feeders (Spoolder et al., 1999). Consequently, the suitability of two feeder space requirements, derived from UK recommendations, for pigs housed at different groups sizes was investigated.
An assessment of potential metabolic determinants of reproductive cycle problems identified through milk progesterone monitoring during the service period in lactating dairy cows
Authors: Mann G.E. , Mann S.J. , Freeston-Smith C. , Daniel Z. , Miles M. , Garnsworthy P. , Webb R.
Published: June 2019

Recent studies have reported a substantial increase in the incidence of reproductive cycle problems in modern dairy cows (Opsomer et al., 1998; Royal et al., 1999). This increase is often attributed to the ever-increasing metabolic demands placed upon these cows by continually increasing milk yields. In this study we have monitored a variety of metabolic parameters in lactating dairy cows and related these to reproductive function in an attempt to establish metabolic predictors of impending reproductive failure.
Genetic control of the periparturient rise in faecal egg counts in Scottish Blackface ewes facing mixed, natural nematode infections
Authors: Bishop S.C , Stear M.J.
Published: June 2019

Infection by nematode parasites is an almost-inevitable consequence of sheep grazing improved pasture. Susceptible classes of sheep include growing lambs and ewes during the period of physiological stress caused by gestation and lactation. Nematode infections in lambs are well documented, less well documented is the decrease in resistance in ewes during the periparuturient period. The consequent elevation in faecal egg counts, the periparturient rise (PPR), leads to pasture infestation by worm eggs (Morris et al., 1998) - thus serving as a trigger for the subsequent epidemic in the lambs. Alternative control strategies to complement anthelmintics are continually being sought, with genetic selection of resistant animals a promising option (Woolaston, 1992). Unlike resistance in lambs, relatively little information exists on the genetic control of the PPR in ewes. The aim of this study is to quantify, and estimate the heritability of, the PPR in Blackface ewes grazing improved pasture and facing a natural mixed, nematode challenge.
Effect of xylanase addition in feed containing either pre-characterised wheat or wheat byproducts on the performance of growing pigs
Authors: Cadogan D.J. , Partridge G.G. , Simmins P.H.
Published: June 2019

Wheat and wheat by-products vary in their available energy and protein content (Batterham et al., 1980) leading to unpredictable growth rate and feed use efficiency. Carbohydrase enzymes, targeting the non-starch polysaccharides in these raw materials, may improve their nutrient availability. However, questions remain over the relationship between the quality of the dietary raw materials and the level of exogenous enzyme activity required in the feed to elicit a response from pigs. Hence, the response of pigs to the use of a fungal xylanase, produced by Trichoderma longibrachiatum, was studied in diets containing wheat and wheat by-products.
The performance and behaviour of finishing beef cattle accommodated during the winter on different floor types
Authors: Lowe D.E. , Steen R.W.J. , Beattie V.E.
Published: June 2019

The effect of rearing or finishing beef cattle on fully slatted floors on their welfare has recently been questioned. The objective of this experiment was to examine the effects of using different types of floors in accommodation for beef cattle on their performance and behaviour.
Behavioural and heart rate responses of cows and calves to each other's vocalisations after early separation
Authors: Marchant J. N. , Forde R.M. , Weary D. M.
Published: June 2019

Current commercial dairy practice involves the removal of the calf from the dam within the first two days of life. This early separation may result in stress for both cow and calf. However, it may also be that separation occurs before the cow-calf bond is established. The aim of this study was to determine if cows and calves respond to each other's calls after separation and whether they could distinguish their own calf's or dam's calls from another calf's or cow's calls.
The effects of straw availability for nest-building on maternal reactivity of crated sows after farrowing
Authors: Marchant J. N. , Jensen K.H. , Forde R.M.
Published: June 2019

Most indoor sows in Denmark and the UK continue to farrow in crates. Before farrowing, sows are highly motivated to nest-build and gilts farrowing in crates without straw have an especially large stress response over the nest-building period (Jarvis et al., 1997). In non-crated sows, the inability to nest-build affects the subsequent maternal behaviour of the sow after farrowing (Herskin et al., 1999). This study aimed to determine whether supplying straw before farrowing increased the anti-crushing and anti-predator behaviour of the crated sow after farrowing and improved piglet survival.
Protein nutrition, reproductive effort and resistance to nematodes in lactating ewes
Authors: Houdijk J.G.M. , Kyriazakis I. , Coop R.L. , Jackson F.
Published: June 2019

A nutrient partitioning framework has been developed to account for host nutrition-parasite interactions in mammals (Coop and Kyriazakis, 1999). The framework puts forward a nutritional basis for the occurrence of the periparturient relaxation of immunity (PPRI) to gastrointestinal parasites in sheep. The PPRI would be expected to occur because it is proposed that the reproductive effort has a higher partial priority than the immune functions when hosts are given access to scarce nutrient resources, such as metabolizable protein (MP). This would imply that i) immune functions towards parasites will benefit from an increased MP supply, and that ii) the degree of the PPRI depends on the level of reproductive effort. We studied these predictions by comparing performance and resistance in parasitized twin- and single-rearing ewes, which were offered increasing amounts of MP.
Returns from genetic improvement in dairy cattle over a twenty year horizon
Authors: Pryce J.E. , Simm G. , Amer P.R. , Coffey M.P. , Stott A.W
Published: June 2019

Genetic improvement is permanent and cumulative. Improvements made in one generation are passed onto the next. In the UK two selection indexes are currently available to the dairy industry, they are PIN (Profit Index; production only) and £PLI (Profitable Lifetime Index; production plus lifespan). Much of the current and anticipated index research and development will be on broader breeding goals that include health and fertility traits. Economic responses expected for PIN and £PLI over a 20 year period were calculated in addition to a hypothetical index where it was assumed that PTAs (predicted transmitting abilities) for mastitis (M) and calving interval (CI) were available (£PLI+M+CI).
The effect of stage of growth on the genetic and phenotypic parameter estimates of food intake in pigs using a covariance function model
Authors: Hall A.D. , Bampton P.R. , Webb A.J.
Published: June 2019

Many traits that are of interest to breeders, such as food intake, are expressed continuously during the life of an animal and the individual's phenotype will change with age. Traditional genetic analysis of these traits has treated as them as discrete traits, ignoring the correlations among records at different ages. Recently methods have been developed to overcome this deficiency and allow an infinite dimensional approach, which can provide more accurate estimates of genetic and phenotypic parameters (Kirkpatrick et al. 1994, Meyer and Hill 1997). The aim of this study was to investigate the effect of stage of growth on the genetic and phenotypic parameter estimates of daily food intake.
Genomic contributions in a cattle introgression program
Authors: Wall E.E. , Woolliams J.A. , Visscher P.M.
Published: June 2019

Not all commercial lines and breeds contain the best alleles for genes of economic importance. Introgression strategies transfer a gene from a non-commercial source to a commercial line by incorporating the favourable allele of a gene from the donor animals whilst retaining beneficial alleles affecting commercial traits in the recipient animals. This is achieved through generations of backcrossing and the resulting heterozygotes are selected and intercrossed to produce animals homozygous for the gene of interest. Animals produced from an introgression program can be inferior to commercial animals because of the contribution from the donor genome at loci not under selection. This genetic lag experienced in an introgression program can be partly attributed to the intercross as a higher number of animals are selected primarily upon genotype thereby reducing the selection intensity for other traits (Visscher and Haley, 1999). The chromosome segment containing the desired introgressed gene (linkage drag) can be quite large, e.g., 32 cM for a 100 cM chromosome in backcross 6 (Stam and Zeven, 1981). The aim of this study is to examine the genomic contribution of each generation to animals produced after the intercross and the level of homozygosity.
The consequences of carrying the Booroola fecundity (FecB) gene on sheep liveweight
Authors: Walling G.A. , Dodds K.G. , Galloway S.M. , Beattie A.E. , Lord E.A. , Lumsden J.M. , Montgomery G.W. , McEwan J.C.
Published: June 2019

The increase in ovulation rate caused by the Booroola gene was first observed in the Booroola Merino strain of sheep (Davis et al., 1982) and the gene was subsequently mapped to sheep chromosome 6 (OOV6) (Montgomery et al. 1994). The low heritability of fertility traits and the desire to produce more lambs per ewe from meat breeds has lead to many crossbreeding programs seeking to obtain the benefits of the Booroola gene. However, many producers report animals carrying a Booroola allele to be lighter than non-carriers (G. Davis, personal communication). The Booroola Merino strain of sheep is typically lighter than recipient breeds used in the introgression programmes e.g. Romney. This study aims to determine whether the Booroola gene has a pleiotropic effect on liveweight or whether there is any evidence to suggest a closely linked quantitative trait locus (QTL) affecting liveweight that may ‘hitchhike’ with the Booroola gene.
Reproductive performance of the Thoka Cheviot sheep
Authors: Rhind S.M. , Gittus G. , Potts J.M. , Bishop S.C.
Published: June 2019

The Thoka gene for fecundity, a gene which originally occurred in Icelandic sheep, was introduced to the UK in 1985 and through a programme of crossbreeding was established in Cheviot sheep (Russel et al, 1997). Ewes are now retained as "Thoka carriers" only if they have lambed in each of the first three years and had at least two sets of twins. The gene has been introduced into separate North and South Country Cheviot (NCC and SCC) lines which are now phenotypically indistinguishable from purebred animals and contain proportionately less that 0.2 of the Icelandic genotype. The purpose of this analysis was to determine the increase in fecundity in the two breeds and whether or not the reproductive response to the incorporation of the Thoka gene differs between NCC and SCC breed types.
The effect of laboratory on the rate and extent of gas production in vitro
Authors: Rymer C. , Williams B.A. , Brooks A.E. , Givens D.I.
Published: June 2019

In vitro cumulative gas production is a means to determine the rate and extent of feed fermentation. However, different apparatus and methods used at different laboratories cause variations in the gas production profiles (GPP) obtained. The objective of this experiment was to determine whether any significant difference between laboratories was observed when the same apparatus and method was used.
Value of ADIN as a measure of unavailable nitrogen in treated rapeseed meal
Authors: Moss A. R. , Metcalf J. A. , Givens D.I.
Published: June 2019

Acid detergent insoluble nitrogen (ADIN) is used in the UK Metabolisable Protein system (AFRC, 1992) to estimate the amount of indigestible nitrogen (N) in a feedstuff. A novel process has been developed which is intended to increase the proportion of undegradable protein in rapeseed meal. In situ work on this treated rapeseed product (TRSM) has shown a reduced rate of rumen degradation compared with the untreated product (UTRSM). However when these data were used in combination with ADIN content to calculate digestible undegraded protein (DUP), there was a minimal increase in DUP due to the high content of ADIN in the TRSM. There have been other cases where products have high ADIN content (e.g. distillery by-products; Webster, 1992) but when whole tract determinations of indigestible N were made, this was considerably lower than estimated from ADIN content. This raises some concerns about the use of ADIN to estimate indigestible protein for by- and treated- products. The objective of this study was to investigate whether the ADIN content of the untreated and treated rapeseed products was representative of the indigestible N.
The use of extracted lignin from steam-treated wheat straw to protect protein from rumen microbial degradation
Authors: Zahedifar M. , Castro F.B. , Ørskov E.R.
Published: June 2019

During steam treatment of lignocellulosic materials lignin is depolymerised (Zahedifar, 1996) to lower molecular weight phenolic compounds. Those phenolics may have protein precipitating capacity (PPC) due to bearing some hydroxyl groups on their molecule (Kawamoto et al, 1992) as do some other phenolics like tannins. Protein precipitating capacity of tannins may have a positive effect in ruminants by protecting proteins from microbial degradation in the rumen. The aim of this study was to assess the PPC of the phenolic compounds extracted from steam-treated wheat straw (STWS) and possible use of them to protect protein from rumen microbial degradation.
Mixture design to study in vitro associative effects of feed mixtures
Authors: Sandoval-Castro CA , Barrera J , Capetillo L , Cetina R
Published: June 2019

Associative effects of feed mixtures have been studied looking at the differences (i.e. gas production) between single and mixed substrates, and significant differences have been found when fodder trees were mixed (Rosales et al., 1998). This may not be the more appropriate form to analyze mixtures, because small departures from simple additivity may result in significant differences as the sum of all its components equals one. Taking this fact into account mixture designs have been suggested as an adequate tool when dealing with mixtures (Mead, 1988). Mixtures design are a special class of response surface designs in which the sample under study is made up of several components or ingredients, thus the response depends on the relative proportion of the components. The objective of the present study was to asses the power of mixture designs to identify associative effects in feed mixtures.
The influence of urea and white rot fungi on the nutritional value of wheat straw
Authors: Rouzbehan Y , Fazaeli H. , Kiani A.
Published: June 2019

In Iran, wheat straw which is produced in huge amounts has been used in animal feed. However, the use of straw as animal feed is limited by its low nutritional value and its low nitrogen content. Various chemical delignification methods to improve the digestibility of straw have extensively investigated (Sundstol and Owen, 1984). Biological methods of treating straw using fungi such as white-rot-fungi have also been reported (Zadrazil, 1984). The solid state fermentation (SSF) of wheat straw with white-rot fungi is a complex process which is influenced by factors such as the species of fungus, substrate, temperature and moisture (Zadrazil, 1984). The objective of this study was to investigate the effect of pre-treating the straw with urea and incubation with two species of Pleurotus fungi on the chemical composition and digestibility of wheat straw.
The impact of particle size on the rate and extent of in vitro fermentation investigated using the Reading Pressure Technique
Authors: Mould F.L. , Colombatto D. , Owen E.
Published: June 2019

The extent of rumen degradability of a feedstuff depends on the interaction between rate of degradation and residence time. In situ techniques require that substrates are ground to obtain a homogenous sample and to reduce result variability. However undegraded feed particle losses increase with bag pore size and fineness of grinding. If these particles are degraded at a similar or lower rate than the retained material, degradability, especially for short-term incubations, will be overestimated. In contrast if the feed particles lost are more readily degraded the degradability measurements obtained will be unaffected. Where improvements due to grinding have been recorded in situ these are assumed to result from variations in the proportion of fine particles that are immediately soluble or rapidly degradable. Gas-based in vitro feed evaluation systems offer the possibility of quantifying this effect directly and a study was therefore conducted to investigate the impact of particle size on the rate and extent of fermentation using the Reading Pressure Technique (Mauricio et al., 1999).
Additive direct and maternal breeding values of imported sires in the nucleus flock of a cooperative sheep breeding group
Authors: Woodington K. , Ap Dewi I.
Published: June 2019

Members of the CAMDA cooperative group breeding scheme have expressed concern about the breeding values of imported sires, with a suggestion that their breeding value was underestimated. Analyses were conducted to examine changes in estimated breeding values for sires imported into the CAMDA nucleus flock
Genetic resistance to internal parasites in lambs
Authors: Howells K. L. , Wolf B. T. , Haresign W. , Lewis R. M. , Davies M. H.
Published: June 2019

Progressive inefficacy of chemoprophylactic therapy to control gastro-intestinal (GI) nematode infection in sheep has been a major contributory factor in stimulating research into the development of alternative means of internal parasite control. This research aims to investigate the possibilities for selecting UK sheep for increased genetic resistance to naturally acquired GI nematode parasite infections.
The effects of genotype of crossbred ewes, evaluated under lowland conditions, on lamb output
Authors: Dawson L. E. R. , Carson A. F.
Published: June 2019

Lowland sheep farmers in Northern Ireland depend heavily on the hill sector for replacement breeding ewes. Thus changes in the genetics of the ewes and rams used in the hills are likely to have major implications on the performance of lowland breeding ewes. Crossbred females were produced in the study by Carson et al. (2000) as a result of crossing Scottish Blackface and Wicklow Cheviot ewes with a range of sire breeds. The objective of this study was to provide information on the productivity of these crossbred females for lowland producers.
The effect of a formulation of natural essential oils used as an additive with a milk replacer and a compound feed on the feed efficiency of calves
Authors: Greathead H.M.R. , Forbes J.M. , Beaumont D. , Kamel C.
Published: June 2019

Some in-feed antibiotic growth promoters have been suspended from use within the EU. Alternatives to these antibiotics are actively being sought, especially ‘natural’ alternatives, such as essential oils, to try and maintain the performance advantage attributed to the use of these antibiotics. Some essential oils, e.g. thyme and origanum, have been shown to have anti-microbial activities (Hammer et al., 1999). The active compounds responsible for this property have been identified, and include cinnamaldehyde, cineol and eugenol. A specific formulation of essential oils reinforced with their active compounds has been combined into a form suitable for use as a feed additive (Multi-Functional Feed Additive, MFA). An experiment was conducted to determine the effect of this MFA on the food conversion ratio (FCR) of calves.
Effect of inclusion of varying levels of green gram(Vigna radiata) Chuni in concentrate mixtures on nutrient utilization in native male buffaloes
Authors: Rao D.S. , G.Radhakrishna  , Prabhakara Rao Z. , Rama Prasad J.
Published: June 2019

Pulse chunies are byproducts obtained from processing of pulses while preparing dals and are available to an extent of 3 million tonnes annually in India. They contain broken seed coat, germ and small pieces of broken cotyledons constituting around 15-20% of total weight of pulses. Very little information is available in the literature on effective levels of inclusion of chunies in complete rations for ruminants. The objective of this experiment was to study the effect of inclusion of varying levels of green gram (Vigna radiata) Chuni in the concentrate mixtures for native buffaloes on the nutrient utilization.
Combining grazing with different periods of access to an indoor diet to alleviate high rates of decline in milk yield of dairy cows
Authors: Hernandez-Mendo O. , Leaver J.D.
Published: June 2019

High rates of decline in milk yield of >3.0% /week are common when dairy cows are grazing due to low herbage intakes. Under indoor feeding conditions rates of decline are often <2.0% /week. Behavioural factors control intake at grass, in particular the time spent grazing and the rate of intake. Low intakes produce high rates of decline in milk yield and potentially could lead to problems of poor fertility and welfare in high merit cows. The objective of this research is to examine the replacement of time available for grazing with time made available for eating forage-based diets indoors. This experiment was carried out in the spring.
Effect of legume silages fed to Holstein dairy cows on plasma alpha-tocopherol concentration, milk alpha-tocopherol and malonic dialdehyde in milk samples stored at 4°C and 20°C
Authors: Al-Mabruk R. M. , G. Beck N. F. , Dewhurst R .J. , Faithfull N. T.
Published: June 2019

Alpha-tocopherol is the natural antioxidant in milk preventing the oxidation of milk fat and development of off-flavour and off-odour. The feeding of dairy cows can significantly affect plasma and milk concentrations of α-tocopherol. There is growing interest in the use of legumes in milk production and so it is important to investigate their effects on milk a-tocopherol as well as the oxidation of milk fat during storage and, hence, shelf-life of milk.
Rumen and post-rumen digestion in lactating dairy cows fed fat from three sources
Authors: Reynolds C.K. , Humphries D. J. , Sutton J. D. , Lupoli B. , Phipps R. H. , Beever D.E.
Published: June 2019

Whole oil seeds represent an alternative to many commercial rumen-protected fat sources as energy supplements in rations for lactating dairy cows. Rumen protection reduces the potential for negative effects of unsaturated fatty acids on fibre digestion, but the structure of many whole oil seeds are thought to reduce the reactivity of their fat in the rumen. Cotton seed is often imported for inclusion in UK dairy rations, but rape seed represents a home grown oil seed which has potential as an economical fat and protein source in UK dairy rations. However, the seed must be crushed or chemically treated to be digested effectively and crushing may liberate oil to the extent that rumen digestion is altered. In a 20 week lactation study, supplemental fat from rumen-protected fat, cotton seed and rape seed fed at 25 g/kg dry matter (DM) in a grass-silage based total mixed ration (TMR) increased milk yield to a similar extent. However, DM intake was reduced by cotton seed and milk protein was reduced by rumen-protected fat (Reynolds et al., 1998). These responses may reflect alterations in digestive function, thus the objective of the present study, conducted simultaneously to the lactation study, was to evaluate the effects of the same diets on rumen, postrumen and total digestion in lactating dairy cows.
The effects of sequence of feed allocation within the day on microbial protein production and diet digestibility in lambs fed barley or sugar beet based diets
Authors: Richardson J. M. , Sinclair L. A. , Wilkinson R. G.
Published: June 2019

Feeding lambs diets formulated to be synchronous in terms of hourly energy and protein supply to the rumen has been reported to improve the efficiency of energy utilisation (Richardsonet al.1999). In a previous study Sinclairet al.(1995) reported that the efficiency of microbial protein production was improved when animals were fed a synchronous diet. The objectives of the present study were to investigate whether the changes in metabolism reported by Richardsonet al.(1999) may be related to rumen microbial protein production and diet digestibility.
The effect of choice feeding during the rearing period on reproductive function in the gilt
Authors: Lucas S. R. L. , Rooke J. A. , Bland V. C. , Sinclair A.G. , Edwards S. A.
Published: June 2019

Previous studies (e.g. Cia et al. 1998) have shown that modification of body composition of the prepubertal gilt has effects on responsiveness of gilts to exogenous gonadotrophin. Growing pigs are able to select a diet from different foods differing in protein:energy ratio (Dalby 1998); however there is little evidence of what effect the conflicting nutritional demands of growth and reproduction have on diet selection. The objectives of the experiment were to quantify the effects of choice feeding on responsiveness of gilts to exogenous gonadotrophin (Cia et al. 1998) and to investigate the effect of protein source on diet selection as Jones et al.(2000) have observed selection by breeding gilts against a high protein diet containing fishmeal.
Litter performance and glucose tolerance in lactating gilts of two different genotypes in response to choice-feeding in the pre-pubertal stage and pregnancy
Authors: Jones G.M. , Edwards S.A. , Sinclair A.G. , Gebbie F.E. , Rooke J.A. , Jagger S. , Hoste S.
Published: June 2019

The extent to which young sows, which still have a strong drive to continue maternal growth, partition nutrients from body reserves towards milk production, may be influenced by their genetic growth target. Modern genotype sows, with a high mature body protein mass, are thus particularly challenged. It has been suggested that to optimise their metabolic state for expressing lactational potential they will have to achieve a satisfactory proportion of their mature body protein mass before farrowing. This could be constrained by current feeding and breeding regimes. To test this hypothesis, gilts of genotypes differing in their body protein:lipid content were given the choice between a low and a high protein diet during rearing and pregnancy, and their intake, subsequent performance and metabolic state in lactation were measured.
The effect of feeding sows an increased feed level from day 28-56 of gestation on progeny performance
Authors: Penny P.C. , Varley M.A.
Published: June 2019

The consumption and utilisation of feed during the growth period from 40-100 kg live weight, is a major determinant of efficient pig meat production. It has been previously observed that feed inputs to the sow at different phases of gestation, can profoundly influence the efficiency of lean tissue deposition in progeny through changes to foetal development (Dwyer et al 1994). The aim of the present study was to examine the effect of increased energy intake during a specific period of gestation (days 28-56), on progeny growth from weaning to slaughter.
The effect of feeding salmon oil during pregnancy on causes of piglet deaths prior to weaning
Authors: Cordoba R. , Pkiyach S , Rooke J. A , Edwards S. A. , Penny P. C. , Pike I.
Published: June 2019

Pre-weaning mortality is a major source of economic loss to the pig industry which despite improvements in husbandry and farrowing crate design remains about 10% of piglets borne alive. The causes of death are multi-factorial (Varley, 1995) but a large proportion may be due to low neonatal vigor. Commercial pig diets do not normally contain long chain n-3 fatty acids, a deficiency of which has been implicated in reduced visual and neural development in premature human babies and in experimental animals. The objectives of the present experiment were to quantify the causes of piglet mortality in sows of modern genotype and to determine the effects of salmon oil supplementation of the diet of the sow, providing long-chain n-3 fatty acids, on this mortality.
Effect of dietary energy intake during pregnancy on liveweight gain and backfat gain of primiparous sows kept in an outdoor system under tropical conditions
Authors: Santos Ricalde R. H. , Lean I. J.
Published: June 2019

Energy requirements for maintenance in pregnant sows increase when they are kept outdoors under temperate climates in comparison to indoors. However, there is little information on the energy requirements of breeding sows kept outdoors in tropical environments. Knowledge about the correct feeding management for pregnant sows kept outdoors will optimise the utilisation of feeding resources available in the tropics. The aim of this study was to evaluate the effect of energy level supply during pregnancy on backfat change and liveweight change of primiparous sows kept outdoors under tropical conditions.
The economic value of somatic cell counts
Authors: Stott A.W. , Gunn G. , Humphry R. , Berry R. , Richardson H. , Logue D.
Published: June 2019

Veerkamp et al. (1998) make the case for including somatic cell count (SCC) in the index of total economic merit (ITEM, Veerkamp et al., 1995) used to rank dairy bulls and cows in the UK for breeding purposes. They go on to describe an empirical method to obtain a suitable economic value for SCC, reflecting the milk quality payment scheme. Since this work was carried out, the milk price has fallen while price penalties against SCC have risen. Bulk-tank SCC (BTSCC) has fallen in response. Some of this improvement may be due to culling cows with high cell counts. The objective of this work was therefore to establish an economic value for somatic cell counts which reflected the milk quality payment scheme and took into account culling strategy.
Relationships between bull proofs for lifespan (LS) in the United Kingdom (UK) and various countries
Authors: Lindberg C. M. , Swanson G. J. T. , Mrode R. A.
Published: June 2019

Longevity or lifespan has proved to be an important trait when it comes to profitability for the dairy farmer. Selecting for longer herdlife not only reduces the replacement rate and thereby the replacement cost, but also gives the opportunity to cull for low production (as opposed to health problems) and increases the milk yield through a higher proportion of mature cows in the herd. Predicted Transmitting Abilities (PTA's) for LS are calculated from a bivariate analysis including indirect information in the form of a phenotypic index of four linear type traits (fore udder attachment, foot angle, udder depth and teat length) closely related to longevity, and from direct lactation information, i.e. survival measured in number of lactations corrected for milk yield (Brotherstone et al., 1998). Genetic evaluations for LS were introduced in the United Kingdom (UK) in August 1998 (Mrode et al., 1999).
Effect of relationship between mastitis and somatic cell count on genetic selection for mastitis resistance in dairy cattle
Authors: Kadarmideen H. N. , Pryce J.E.
Published: June 2019

Differences in banding scales for milk quality penalties, as determined by bulk tank somatic cell count (SCC), prevent the use of a single economic value for SCC in an overall economic-genetic selection index (Veerkamp et al., 1998) such as, Profitable Lifetime Index or £PLI. But SCC could be used as a predictor of mastitis as genetic correlation estimates between mastitis and SCC are medium to high (review of Mrode and Swanson, 1996). This suggests that, although deriving a direct single economic value (EV) for SCC based on bulk tank SCC is difficult, a single financial value could still be assigned to SCC based on its relationship with mastitis. Here we use a genetic regression method to calculate the EV of SCC (EVSCC) as a predictor of mastitis. However, the dependency of regression coefficients on mastitis incidence (p) could make such EVSCC variable. The main objective of this study was to evaluate the impact of such relationship on EVSCC and genetic selection in dairy cattle using predicted transmitting abilities of SCC (PTASCC).
An examination of the effects of level of concentrate supplementation of dairy cattle in late
gestation on subsequent reproductive performance
Authors: Keady T.W.J. , Mayne C.S. , Fitzpatrick D A , McCoy M.A.
Published: June 2019

The transition period of the dairy cow is physiologically and nutritionally stressful as feed intake is reduced whilst nutrient demand for the support of foetal growth and initiation of milk synthesis are increased. Also during this period the diet of dairy cows changes from being predominantly forage, often of mediocre quality, to a diet often containing high levels of concentrate and high quality forage or mixture of forages. In the recent past nutritional management of the dairy cows during the transition period has centred on protein nutrition. While some studies have shown responses to milk yield or composition from protein nutrition in late gestation, many have shown no response. The objective of the present study was to examine the effects of level of concentrate in late gestation on subsequent reproductive performance. The effects of treatment on animal performance have been presented by Keady et al. (1999).
Factors affecting the eating quality of pork
Authors: Van Oeckel M.J. , Warnants N. , Boucqué Ch.V.
Published: June 2019

A Belgian study shows that the five most important meat attributes for the consumers are as follows: quality, taste, freshness, absence of hormones and healthiness (Verbeke and Viaene, 1999). This corroborates with the results of a French survey by Touraille (1992), who found that sensory properties and security aspects (hormones) of meat are of paramount importance for the consumer. It is important to direct pork production towards an acceptable product adapted to the consumer's demand. The objective of this study is to evaluate in which way and how strong the sensory quality parameters are influenced by different factors.
Relationship between tail-biting and aggression in pigs reared in two different environments
Authors: O'Connell N.E. , Beattie V.E.
Published: June 2019

A recent survey showed that 4.3% of pigs slaughtered in Great Britain were tail-bitten (Guise and Penny, 1998). This figure could be reduced through a better understanding of the individual traits associated with tail-biting. The objective of this study was to investigate the relationship between tail-biting and aggression in pigs reared in barren and enriched environments.
Effect of maturity of Napier grass (Pennisetum purpureum) hay on intake, digestibility, and rumen dynamics when given to zebu bulls
Authors: Ayala-Burgos A.J. , Hovell F.D.DeB. , Godoy R.M. , Saidén Hamana S. , López R. , Reyes R.R.
Published: June 2019

Cattle in the tropics mostly depend on pastures. During dry periods the forage available is usually mature, constraining both intake and digestion. These constraints need to be understood, for intake and digestibility define productivity. Intake depends on the rumen space made available by fermentation and outflow. Markers such as PEG (liquid phase), and chromium mordanted fibre (solid phase) can be used to measure rumen volume and outflow, but have limitations. The objective of this experiment was to measure intake, digestibility, and rumen kinetics of cattle fed ad libitum forages with very different degradation characteristics, and also to compare rumen volumes measured with markers with those obtained by manual emptying.