bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of nutritionally-mediated placental growth restriction in adolescent sheep on the yield, nutrient composition and immunoglobulin content of colostrum
Authors: Davidson L. , Aitken R.P. , Bourke D.A. , Wallace J.M.
Published: June 2019

In adolescent sheep, high nutrient intakes to promote rapid maternal growth during pregnancy results in a major restriction in placental growth which leads to a significant reduction in lamb birthweight relative to moderate intake adolescents of equivalent gynaecological age (Wallace et al 1996). Placental hormones play a crucial role in the development, differentiation and function of the mammary gland and we have previously reported that maternal concentrations of progesterone, growth hormone and pregnancy-specific protein B are significantly reduced in high intake dams with growth restricted placentae (Wallace et al 1997 a,b). For newborn lambs, the ingestion of adequate quantities of nutrient dense colostrum is essential to provide fuel for heat production and to ensure absorption of maternal antibodies to give immunological protection against infection. The objective of the present study was to examine the effect of nutritionally-mediated placental growth restriction on colostrum yield, nutrient composition and immunoglobulin content.
The effect of the pea to wheat ratio and harvest date on the voluntary feed intake,in vivodigestibility and nitrogen retention of pea-wheat bi-crop silages by sheep
Authors: Adesogan A.T. , Salawu M.B. , Deaville E.R.
Published: June 2019

Pea-wheat bi-crop silages were reported to have moderate nutritive value when the proportion of peas in the sward was less than 200 g/kg (Adesoganet al., 1999). These authors also suggested that improvements in the digestibility, intake and nitrogen (N) balance of the forages may result from increasing the proportion of peas in the sward. This experiment was designed to examine this theory by determining thein vivoapparent digestibility, N retention and voluntary feed intake (VFI) in sheep of pea-wheat bi-crop silages containing different ratios of peas to wheat and harvested at two stages of growth.
Growth and carcass characteristics of three lamb genotypes finished on the same level of feeding
Authors: Carson A.F. , McClinton L.O.W.
Published: June 2019

Improving the efficiency of lean meat production is of major importance to the UK sheep industry. Compared to a range of other breeds, Texel-sired lambs have been found to contain a higher proportion of carcass lean content. Carson et al. (1999) found that Texel X Greyface (Border Leicester X Scottish Blackface) lambs contained 38 g/kg more lean than Rouge de l'Ouest (Rouge) X Greyface lambs. The aims of the present experiment were (a) to investigate the efficiency of liveweight and carcass gains in Greyface, Rouge and Texel lambs at equal dry matter intakes of a standard diet (b) to test the hypothesis that carcass chemical composition would be similar in Greyface, Texel and Rouge lambs when finished on the same level of feeding.
Somatic cell count and reduction in antibiotic use in dairy cows by dietary supplementation with trace elements and vitamins given as a ruminal bolus system
Authors: Hemingway R.G. , Parkins J.J. , Ritchie N.S. , Taylor D.J.
Published: June 2019

Many references (review, Hemingway, 2000) indicate that giving supplementary dietary selenium (Se) and vitamin E during the dry period in amounts greater than accepted nutritional requirements can decrease the incidence, duration and severity of high somatic cell counts (SCC) and mastitis in dairy cows. Low dietary Se intakes and plasma Se concentrations are more frequent than those for vitamin E. As one example, Erskine et al. (1987) investigated two groups each of 16 herds each having either > 700 x 103 SCC /ml (High) or < 150 x 103 SCC /ml (Low). Mean contrasting plasma concentrations (μg /ml) were respectively 0.074 and 0.138 (P < 0.01) for Se with 4.2 and 4.8 (NS, adequate) for vitamin E. Supplementary dietary Se and vitamin E were given more frequently to the Low SCC herds. The present experiment investigated the effect of two multi-trace element/vitamin boluses (‘All-Trace’, Agrimin Ltd. DN20 0SP) which, inter alia, release 2 mg Se and 9 i.u. vitamin E /day giving a significant increase in glutathione peroxidase activity over an 8-month period (Allan et al., 1993).
An evaluation of the effects of rate of nitrogen fertilisation and stage of maturity on degradability of grass in the rumen
Authors: Keady T.W.J. , Mayne C.S. , Fitzpatrick D A
Published: June 2019

Grass forms the basal forage for the majority of ruminant livestock in Ireland and the UK. Level of nitrogen (N) and harvest date are the two major factors affecting the yield of herbage. In a concurrent study, Keady et al. (1999) concluded that herbage dry matter (DM) yield of the primary growth of a perennial ryegrass sward is increased by 7.9 kg DM/ha/kg N and by 152 kg DM/ha/day delay in harvest respectively. However as herbage yield increases, particularly as a result of delayed harvest, digestibility declines. The present study was undertaken to evaluate the effects of rate of N fertilisation application and harvest date on the degradation characteristics of grass.
The nutritive value of wheat for ruminants: Factors affecting starch content and availability to the rumen
Authors: Moss A. R. , Givens D.I. , Froment M
Published: June 2019

The current UK Recommended Lists For Cereals (Anon., 1997), include grain quality information on each variety outlining its potential value to the miller, baker or maltster. These grain quality measures are used as a basis for premiums paid to producers. However, no such standards exist for feed grains with the exception that contracts often indicate a minimum specific weight. This is in spite of the fact that feed grains account for 41% of wheat and 50% of barley sales from UK produced cereals. Usage may be increased if its nutritive value was better defined to include information such as the proportion of the starch that is rumen degradable and the rate of degradation of this starch in the rumen. It is vital to know the quantity of starch available to the rumen since it is a major source of energy for microbial protein synthesis (see Reynolds et al., 1997). This study aimed to use the in vitro automated gas production (GP) technique to estimate rate and extent of starch degradation from a large population of wheat grains obtained from wide ranging agronomic conditions and relate this to chemical and quality parameters.
Effects of the addition of polyunsaturated fatty acids on rumen degradation of dry matter and neutral detergent fibre of Guinea grass (Panicum maximum) in Pelibuey sheep
Authors: Herrera–Camacho J. , Ku-Vera J.C. , Quintal-Franco J.A. , Williams L.G. , Quijano-Cervera R.
Published: June 2019

Fat is often fed to sheep and cattle as a means to increase dietary energy concentration. There is increasing interest in the supplementation of ruminant diets with fats and oils. However feeding fat may reduce dry matter digestibility, and feeding ruminant animals large quantities of fat (>5% of total dry matter intake) can result in a marked negative effect on fibre and dry mater intake. The aim of the present study was to investigate the effect of fat supplementation on ruminal degradation of dry matter (DM) and neutral detergent fiber (NDF) of sheep fed a tropical hay.
Intake and apparent digestibility of hay, haylage, big bale and clamp silage by ponies
Authors: Moore-Colyer Meriel , C Longland Annette
Published: June 2019

Grass hay is the traditional conserved fodder fed to horses in the UK, yet good quality hay is often scarce and expensive. Working or breeding equines often require a higher plane of nutrition than that provided by hay, yet feeding high levels of concentrates can lead to a number of metabolic disorders such as colic and laminitis. Furthermore, the high dust content of hay can elicit the onset of the debilitating disorder, chronic obstructive pulmonary disease. Thus, there is increasing interest in feeding horses forage-based diets which are both low in dust and have enhanced nutritive values. The aim of this experiment was to determine the intakes and digestibility of four types of conserved forage by ponies.
Supplement containing immunoglobulins fed post weaning promotes nursery pig performance
Authors: Miller H.M. , Toplis P.
Published: June 2019

Post weaning performance is determined by weaning weight and week one growth rate (Miller, et al., 1999). Strategies which increase feed intake in the immediate post-weaning period would be expected to increase overall post-weaning performance through better week one growth rate. Top dressing normal pelleted feed following weaning with a palatable nutrient dense supplement should increase nutrient intake and hence week 1 growth rate. This strategy might be particularly beneficial for low weaning weight pigs. Inclusion of ingredients containing immunoglobulins (Ig) in immediate post-weaning diets have been shown to increase post weaning performance (Coffey and Cromwell, 1995). We hypothesise that the use of a palatable nutrient dense supplement containing bovine Igs will improve feed intake and growth rate post weaning. The aim of this experiment was to investigate this hypothesis using low weaning weight piglets.
Estimation of lactation curve parameters for Iranian Holstein dairy cows using non-linear models
Authors: Farhangfar H. , Rowlinson P. , Willis M.B.
Published: June 2019

In dairy cattle breeding programmes the knowledge of cow's lactation curve could be an effective tool to make selection decisions. In order to obtain an accurate shape of lactation curve a variety of mathematical models have been used in which parameters of production peak, inclining and declining phases of milk production over the course of lactation have been estimated by linear or non-linear techniques. The main purpose of this research was to compare four non-linear functions for the estimation of first lactation curve of Iranian Holstein dairy cows.
Sensitivity of genotypes to feeding systems for production, weight and feed intake in dairy cattle
Authors: Pryce J.E. , Veerkamp R.F.
Published: June 2019

Getting reliable genetic parameter estimates for dry matter intake is difficult because recording it is expensive, hence it is tempting to combine data from research herds. However, there are large differences in feeding and management systems, which causes differences in means across herds. Furthermore, variances or heritabilities may differ and genetic correlations may be less than one between herds. This is one of the reasons why it is important to investigate effects of genotype by environment interaction (GxE). Another reason is that it is important to understand how high genetic merit cows perform in different feeding systems. The objective of this study was to estimate the effect of GxE for three feeding systems at two research herds belonging to ID-Lelystad (ID) and to SAC/University of Edinburgh (Langhill).
Changes in the relationship between porcine fetal size and organ development during pregnancy
Authors: Silva P. F. N. , Finch A. M. , Antipatis C. , Ashworth C. J.
Published: June 2019

Individual piglet birthweight is a major determinant of subsequent survival and weaning weight of the litter. Low birthweight piglets are more likely to die from starvation and thermoregulatory stress than their heavier littermates, while those that do survive grow more slowly and reach a lower mature body weight with a higher body fat to muscle ratio. Inadequately grown porcine fetuses are often characterised by assymetrical organ development although it is not clear when this difference in relative organ size arises and whether this is a consequence of changes in cell size or cell number. The objectives of this study were to assess a range of determinants of fetal growth at stages of gestation and to determine when changes in the relationship between fetal size and organ development occur.
An examination of factors affecting the dirtiness of housed finishing beef cattle
Authors: O'Hagan J.C. , Steen R.W.J.
Published: June 2019

Cattle presented for slaughter must now attain a very high level of cleanliness. The objective of this on farm study was to investigate the factors that affect the cleanliness of housed beef cattle in order to provide sound scientific information on the relative importance of these factors and to provide a basis for advice to the industry on producing cleaner cattle.
Individual differences in sociability and their consequences for foraging behaviour in sheep
Authors: Sibbald A.M. , Smith D.J.F. , Hooper R.J.
Published: June 2019

The spatial distribution of grazing sheep is influenced by the distribution of vegetation and by social behaviour. Where there are conflicts between grazing preferred vegetation and maintaining normal inter-individual distances, animals may have to make trade-offs based on the relative strengths of their motivation to feed or to be social. Social motivation, or sociability, has been assessed in chickens by measuring the rate at which isolated individuals move towards their companions (Suarez and Gallup, 1983) and in sheep by studying nearest neighbours (Sibbald et al, 1998). The aim of this experiment was to test whether individual differences in sociability affect the foraging behaviour of sheep, when animals have to choose between grazing or remaining close to their companions.
Reproductive behaviour and performance of gilts bred at the same age but at different post pubertal heat in a dynamic service system
Authors: Grigoriadis D. F. , Edwards S. A. , English P. R. , Davidson F.
Published: June 2019

The heat period at which gilts are bred affects first reproductive performance and overall sow productivity. However, most studies which have examined this subject have confounded chronological age (i.e. days) with physiological age (i.e. number of heat periods experienced) and the importance of each factor remains unclear. The Dynamic Service System (DSS) is a recently developed variant of group mating and the optimum heat period at which gilts should be bred has never been established. This study tested the hypothesis that the physiological age at which gilts are first mated in a DSS will affect their first reproductive behaviour (i.e. mating frequency and quality) and performance.
Effect of dietary energy intake during pregnancy on grazing behaviour of primiparous sows kept in an outdoor system under tropical conditions
Authors: Santos Ricalde R. H. , Lean I. J.
Published: June 2019

Grazing activity observed in sows kept outdoors is influenced by different factors such as their nutritional status and reproductive stage. Reduction in concentrate feed intake and pregnancy development in sows kept outdoors resulted in an increase in time spent by them in grazing under temperate conditions (Robert et al., 1997). Little information is available about behaviour of sows kept outdoors under tropical conditions. The aim of the present study was to investigate the effect of three planes of energy at three points in pregnancy on grazing behaviour of sows kept outdoors under tropical conditions.
Assessment of hypothermia in outdoor newborn piglets and comparison with an indoor system
Authors: Riart G.R. , Edwards S.A. , English P.R.
Published: June 2019

In the last few years, there has been an increase in outdoor pig production in many countries. Outdoor herds, on average, are still less productive than indoor herds, often due to higher pre-weaning piglet mortality. Hypothermia is one of the most important underlying causes of piglet mortality in early post-natal life (English and Morrison, 1984). Although the extent of hypothermia suffered by the new-born piglet in an indoor system has been demonstrated (Pattison et al, 1990), no data of this kind are available regarding the outdoor situation. The objectives of this study were to evaluate the extent of hypothermia suffered by outdoor piglets at 30 and 60 minutes after birth, and to compare this with piglets born indoors.
Development of a model to predict dry matter intake of individual dairy cattle on commercial farms
Authors: Wicks H.C.F. , Leaver J.D.
Published: June 2019

Nutritional research on commercial farms is difficult to carry out due to the problems associated with measuring individual animal dry matter intake (DMI). This research was aimed at developing a satisfactory method of estimating DMI from routine farm records, supplemented by cow body condition score and height at withers of the cow.
The effect of slurry application timing on grass silage fermentation and intake by dairy cattle
Authors: Allison R.D. , Lane S.J. , Smith K. , Laws J.A.
Published: June 2019

Many farmers apply slurry to grassland as a fertiliser or a means of waste disposal. There is evidence that winter slurry application leads to higher losses of nitrogen due to leaching subsequently reducing the efficiency of slurry N utilisation when compared with spring applications (Smith et al 1995). This suggests that slurry applications should be undertaken in spring, but the effect of timing on the extent of grass contamination is unknown. When grassland is used for silage production, contamination of the sward can lead to reduced silage fermentation and acceptability (Boxem and Remmelink 1987). A study was conducted to investigate the effect of timing of slurry application on fermentation and dry matter intake of first and second cut grass silage.
Milk production from dairy cows offered pea-wheat bi-crops containing different ratios of peas to wheat and harvested at two maturity stages
Authors: Salawu M.B. , Adesogan A.T. , Dewhurst R.J.
Published: June 2019

As more farmers try to improve the efficiency of their production systems by sourcing safer and cheaper dietary energy and protein from home grown feeds, the importance of cereal-legume bi-crops for winter-feeding of UK livestock may increase. However, little is known about the production, conservation, feeding value and animal performance from such bi-crops in the UK. This study measured the feed intake and milk production from dairy cows fed pea-wheat bi-crop silages.
Effects of silage fermentation on milk protein and fat content and yield
Authors: Khalili H. , Nousiainen J.I. , Jaakkola S. , Heikkilä T. , Huhtanen P.
Published: June 2019

The extent and type of in-silo fermentation has a profound influence on the composition of nutrients absorbed from the digestive tract of dairy cows (Choung & Chamberlain, 1993; van Vuuren et al. 1995). The amount of amino acids absorbed from the small intestine decreases when the extent of in-silo fermentation is increased due to reduced efficiency of microbial protein synthesis. The ratio of lipogenic to glucogenic VFA increases when in-silo fermentation is restricted, since silage lactic acid generally increases propionate in rumen VFA, whereas WSC in silage increases acetate, butyrate or both. The purpose of this study was to estimate quantitative relationships between silage fermentation characteristics and milk production using data based on mean treatment values of production parameters and silage fermentation characteristics.
The effect of steer sera generating low or high concentrations of ammonia in culture on bovine embryo development and cell number in vitro
Authors: Kuran M. , Staines M.E. , McCallum G.J. , Onal A.G. , McEvoy T.G.
Published: June 2019

Ovine embryos produced in synthetic oviduct fluid (SOF) medium or in coculture with granulosa cell monolayers supplemented with low (A; 120 μmol/l) and high (B; 190 μmol/l) ammonia-producing steer sera caused different degrees of fetal oversize (Carolan et al., 1998). The objective of the present study was to determine whether the effects on fetal growth induced by these sera were associated with alterations in early embryo development.

A total of 911 bovine oocytes, used in 8 replicates to test the effect of three culture treatments on embryo development, were matured and fertilized in vitro (IVF= Day 0). Presumptive zygotes were allocated on Day 1 to culture in SOF supplemented with 10% v/v steer serum (SOF+A, n=308; SOF+B, n=302) or with amino acids plus 0.4% w/v crystalline BSA (SOFaaBSA, n=301). All cultures were in 20 μl droplets under oil (38.5°C; 5% CO2, 5% O2; 4 zygotes per drop) and droplets were renewed every 48 h. Cleavage rate was recorded on Day 3. On Days 7 and 8, blastocyst yields, grade 1 and 2 blastocysts, their cell numbers (by staining with Hoechst 33342) and their stage and diameter were determined.
Effects of different energy sources on metabolic state and production performance of lactating sows
Authors: Jones G. , Edwards S.A. , Sinclair A.G. , Gebbie F.E. , Jagger S. , Hoste S.
Published: June 2019

Starch and fat are the two major energy sources available for sow lactation diets. Fat is more energy dense and can be used to maximise energy intakes, particularly in sows with low appetite. However, the quantity of milk produced in sows has been associated with milk lactose production and the main precursor for lactose is glucose, for which dietary starch is the major source. It is therefore important to know the consequences of using a glucose deficient energy source, such as fat, compared to starch in lactation diets. The following experiment was designed to assess energy sources in lactation diets at an isocaloric level in determining sow and piglet performance, in association with the effects of dietary glucose availability on the metabolic state of the sow around peak lactation.
The effect of feed restriction prior to slaughter on performance and meat quality of pigs
Authors: Beattie V.E. , Weatherup R.N. , Moss B W
Published: June 2019

Feed restriction prior to slaughter may reduce live and carcass weight gain (Murray and Jones, 1994) and meat quality (Warriss, 1982) but can reduce carcass contamination and the amount of waste to be disposed of at the slaughter house (Eikelenbloom et al., 1991). Most literature studies are however based on a single feed restriction while group housed pigs may be slaughtered over a period of time and can therefore be subjected to several periods of feed restriction. This study was conducted to examine the effects of feed restriction prior to slaughter on the production performance and meat quality of group housed finishing pigs.

There were three experimental treatments (1) control - ad libitum access up to point of transport, feeders closed off for 12 hours (Treatment 2) and feeders closed off for 20 hours (Treatment 3) prior to transport to the slaughter house. All pigs had unrestricted access to water. Four hundred and eighty six, 35 kg crossbred pigs, housed in groups of 18, were randomly allocated to 9 replicates of the three treatments. Pigs were slaughtered when a target live weight of 102 kg was reached. Production performance was recorded on a weekly basis when the first pig in any treatment approached 95 kg live weight until all pigs were slaughtered.
Effects of metabolizable protein on performance and faecal egg count of the parasitized ewe
Authors: Houdijk J.G.M. , Kyriazakis I. , Coop R.L. , Jackson F.
Published: June 2019

The periparturient relaxation (PPR) in acquired immunity in ewes has been ascribed to various factors, including poor nutrition (Barger, 1993). Clinically, the faecal egg count (FEC) may increase during PPR when the ewe is continuously infected with gastrointestinal parasites. As such, the periparturient ewe plays an important role in the epidemiology of parasitic infections. The nutritional basis of PPR probably includes metabolizable protein (MP), since host's responses, in terms of immunity and resilience, are highly proteinaceous by nature. We propose that the PPR directly results from less MP being available to maintain acquired immunity and resilience, since an increasing amount of MP is directed to bodily functions with higher priority (reproduction). It is hypothesized that the increased FEC in the parasitized periparturient ewe reduces if her MP-intake exceeds her assumed MP-requirement (AFRC, 1993).
Trade-offs between sward nitrogen intake and faecal avoidance in sheep foraging decisions: the effect of parasitic status and level of feeding motivation
Authors: Hutchings M.R. , Kyriazakis I. , Anderson D.H. , Gordon I.J. , Jackson F.
Published: June 2019

The deposition of dung on pasture may create a trade-off between the benefit of increased nutrient intake due to the leaching of nutrients and the risk of parasitism due to migration of helminth parasite larvae (Sykes, 1987), from the faeces to the sward. Physiological state can affect herbivore foraging decisions in relation to this trade-off. Our objectives were to determine whether such a trade-off exists in a grazing situation for sheep and whether level of feeding motivation and parasitic status affect the grazing behaviour of sheep faced with this trade-off.

Texel x Greyface lambs were presented pairs of swards (36 x 21cm) which varied in nitrogen content (high=N+; low=N-) and level of contamination with faeces from sheep infected with Ostertagia circumcincta (Ost.) (20g faeces per sward=F+; no faeces=F-) and allowed to graze for short periods (60 bites or ten minutes). We defined ‘taking the trade-off’ as taking more bites from an N+F+ sward compared to an N-F- sward, when presented together as a choice.
The effects of feeding compound concentrate supplements with either a low or high level of true methionine digested in the small intestine (DVmet) to dairy cows
Authors: Zom R.L.G. , Kamerman E. , Remmelink G. , Duinkerken G. van
Published: June 2019

The Dutch DVE/OEB protein evaluation system (Tamminga et al., 1994) gives predictions for the concentration of whole true protein digested in the small intestine (DVE) in cattle feeds, but not for the concentration of single amino acids. Therefore, new standard methods has been introduced for the prediction of true methionine and lysine digested in the small intestine (DVmet and DVlys, respectively) in cattle feeds based on the principles of the calculation of DVE (van Duinkerken and Blok, 1998). These methods give the opportunity to select particular feeds and concentrate ingredients in order to manipulate the concentration of DVmet and DVlys in diets and compound concentrates. However, in the Netherlands, there are no recommendations for DVmet and DVlys in dairy cow rations established yet. An experiment was therefore conducted to study the effects of feeding compound concentrate supplements with either a low (L) or high (H) level of DVmet on feed intake and milk production in dairy cows fed a grass and maize silage mixture ad libitum
Cumulative protein intake of pig genotypes, selected for high or low lean growth, when fed diets differing in protein content
Authors: Cameron N.D. , McCorquodale C.C. , Welham S. , Thompson R.
Published: June 2019

Testing several genotypes on one diet may impose nutritional constraints on growth for particular genotypes. In the study, three genotypes were tested on four isoenergetic dietary regimes to determine if a genotype with diet interaction existed for the pattern of cumulative protein intake and total protein intake.

There were 150 Large White pigs from the lean, control and fat lines, with divergent selection for lean growth rate over seven generations. In each line, there were 10 full-sib groups and within each full-sib group, one pig was allocated to each of the high (H : 220 g crude protein (CP)/kg) or low (L : 120 g CP/kg) protein diets, a standard test diet (S : 195 g CP/kg) and the two remaining pigs were tested using the diet-choice procedure (DC), using the H and L diets. Pigs were performance tested from 30 to 85 kg, with individual penning.
The effect of diet and condition score on fasting heat production of non-producing dairy cows
Authors: Birnie J.W. , Agnew R.E. , Gordon F.J.
Published: June 2019

The metabolisable energy (ME) requirement for maintenance (MEm) has been derived from measurements of fasting heat production (FHP) with non-lactating cattle, with, for example, ARC (1980) using published data on steers to develop equations to calculate the MEm of dairy cattle. Recent studies at this Institute (Yan et al. 1997 a&b) have produced estimates of MEm, through either direct measurement of FHP, or the use of regression techniques for producing animals and concluded that MEm was higher than those in published feeding standards (ARC, 1980; AFRC, 1993). The objective of the present experiments was to explore possible reasons for the differences, such as the effect of cow body condition score (CS) on FHP and the effect of level and type of diet given during the pre-fasting period on FHP.
The use of the in vitro gas production technique to investigate the effect of substrate on the partitioning between microbial biomass production and the yield of fermentation products
Authors: Rymer C. , Givens D.I.
Published: June 2019

The in vitro gas production technique has been developed as a means of predicting the degradability of feeds. However, it was pointed out by Blümmel et al. (1997) that attention should be given to the other products of the incubation as well. Degraded feeds may be incorporated directly into microbial biomass, or they may be fermented to produce VFA and gas. One of the objectives of this experiment was to determine whether the proportion of degraded substrate that was partitioned to gas production varied with different feeds. Blümmel et al. (1997) observed a negative relationship between gas yield (ml gas produced/g substrate degraded) and microbial biomass yield (mg biomass/g substrate degraded) when poor quality forages were incubated. A second objective of this work was to determine whether this relationship was also observed when higher quality feeds were used.
The effect of acrylate and fumarate on fermentation and methane production in the rumen simulating fermentor (Rusitec)
Authors: Ouda J. O. , Newbold C. J. , Lopez S. , Nelson N. , Moss A .R. , Wallace R. J. , Omed H.
Published: June 2019

Methane formation in the rumen represents a substantial loss of energy to the animal and is also a major source of greenhouse gas emissions from agriculture. Methanogenesis is the main means of disposal of hydrogen during rumen fermentation. The formation of propionate represents an alternative route of hydrogen disposal, providing sufficient propionate precursors are available. Theoretically, adding propionate precursors should stimulate propionate production and decrease methane production. In the present experiment, the effects of two potential precursors of propionate, fumarate and acrylate, on rumen fermentation and methane production were investigated in a rumen simulating fermentor.
Impact of variation in yield of gas during incubation on simulated gas production and extent of ruminal degradation
Authors: Dijkstra J. , France J. , Lopez S. , Dhanoa M.S.
Published: June 2019

To calculate the extent of ruminal degradation based on the gas production technique, equations were derived to describe gas production profiles from substrate degradation (France et al. submitted). This derivation demonstrated that if the yield of gas (Y; ml/g degradable OM) produced during the course of incubation varies significantly, then the calculated extent of degradation is not correct. Variation in Y may occur due to variation in the yield of individual volatile fatty acids (VFA) produced. The objective of this simulation study was to examine the impact of variation in individual VFA production and consequently in yield of gas on the extent of ruminal degradation.

Gas production profiles were simulated based on a generalized Mitscherlich (GM) equation (see France et al. submitted) for three substrates (soluble sugars, starch, fibre) that differ in degradation rate and VFA production profile (see Table 1).
Estimation of efficiency of microbial growth in rumen fluid with the gas production technique
Authors: Cone J.W. , Gelder A.H. van
Published: June 2019

In the Dutch feed evaluation system for ruminants, it is assumed that each 1000 g of rumen fermented organic matter (FOM) produces 150 g of microbial protein. However, this is a simplification of the real in vivo processes. Demeyer and Van Nevel (1986) concluded that the efficiency of microbial growth depends on several factors, such as chemical and physical properties and intake. They concluded that feeding low quality roughage would show lowest efficiency and feeding highly degradable starch would show highest efficiency. We investigated the possibilities to estimate differences in efficiency of microbial growth in rumen fluid with the gas production technique.
Effects of selection for production on maiden heifer fertility traits
Authors: Pryce J.E. , Wilson L.A. , Visscher P.M.
Published: June 2019

There is evidence from UK field data to suggest that selection for milk yield has led to a deterioration in the fertility of lactating dairy cows (Pryce et al., 1997). As cow fertility may be affected by metabolic load and lactation effects, it is important to investigate the fertility of non-lactating heifers. Since 1973 selection line (S) cows at the Langhill Dairy Cattle Research Centre have been bred to bulls with the highest predicted transmitting abilities for weights of fat plus protein (PTA F+P) available in the UK, while the control line (C) are of about UK average genetic merit for PTA F+P. Results using data from lactating Langhill cows show that S cows have calving intervals that are, on average, 12 days longer than C cows, which is a combination of poorer conception rates and a delay in first observed oestrus (Pryce et al., 1999). The objective of this study was to investigate the effect of selection for PTA F+P on the fertility of maiden heifers at Langhill.
Phospholipid fatty acids and meat quality in cattle breeds fed different diets
Authors: Vatansever L. , Kurt E. , Richardson R.I. , Nute G.R. , Enser M. , Scollan N. , Wood J.D.
Published: June 2019

The aim of future beef production is healthier, tastier products which consumers will find attractive. Combinations of breed and feeding system are required to fulfil these aims. In this project we compared the Holstein- Friesian (HF) breed, an allegedly inferior beef producer, with Welsh Black (WB), a traditional beef breed. Of particular interest was the role of polyunsaturated fatty acids (PUFA) in flavour development.

Thirty six steers, 18 HF and 18 WB, were reared on grass silage plus one of three concentrates. The concentrates contained different fat sources at 0.03 of intake: 1. megalac (control, C16:0); 2. formaldehyde-protected whole linseed (Lin, C18:3 n-3); and 3. an equal mix on a fat basis of protected linseed and fish oil (Lin/fish, C20:5 and C22:6 n-3). The animals were slaughtered after 90 days consumption of the diets. Fortyeight hours after slaughter, three forequarter muscles (M. supraspinatus, M. infraspinatus and M. triceps brachii caput longum) were trimmed of fat, minced and displayed in modified atmosphere packs (0.8 02:0.2 CO2, 4°C in 1000 Lux) for 3 or 10 days.
Effect of calf isolation and restricted suckling on LH secretion in postpartum suckler cows
Authors: Mackey D.R. , Roche J.F. , Sreenan J.M. , Diskin M.G.
Published: June 2019

In suckler cows follicular development resumes early in the postpartum period, but failure of successive dominant follicles to ovulate results in a prolonged interval from calving to first ovulation (postpartum interval, PPI). Calf isolation and restricted suckling induce ovulation of either the current or subsequent dominant follicle (DF), probably due to changes in LH pulsatility, but this ovulation is generally silent and followed by an 8-10 day cycle due to lack of progesterone priming. The aim of this study was threefold: 1) to examine the acute effects of calf isolation and restricted suckling on LH pulse frequency and PPI, 2) to determine if progesterone priming would eliminate silent heats and short cycles, and 3) to determine if oestradiol treatment would cause atresia of the current dominant follicle and induce new wave emergence providing a “fresh” dominant follicle at progesterone withdrawal.
The effects of melatonin treatment and recent sexual experience on the ability of rams to induce ovulation in seasonally anoestrous ewes
Authors: Rosa H.J.D. , Bryant M.J.
Published: June 2019

Rosa and Bryant (1997) have described how sexual experience increased the amount of time that rams spent in courtship of seasonally anoestrous ewes. There was a non-significant trend for a greater proportion of ewes to respond to increased ram stimulation in early July, indicating that efforts to enhance the cues provided by rams at this time may be effective in increasing the incidence of ovulation. The objective of this experiment was to establish if advancing the seasonal changes associated with the rams by treatment with exogenous melatonin and allowing the rams prior sexual experience would induce ovulation in anoestrous ewes in early July.
The effect of cutting height at harvest on the aerobic stability and digestibility of fermented whole crop wheat silage offered to sheep
Authors: Wilkinson R. G. , Sinclair L. A.
Published: June 2019

Previous work with fermented whole crop wheat (WCW) silage has focussed on the effects of stage of maturity on nutritive value and milk production (Sinclair and Wilkinson 1998). An alternative means of manipulating nutritive value may be to alter the relative proportions of grain to straw by changing the cutting height at harvest. The objectives of the current experiment were to determine the effects of two cutting heights on the aerobic stability and whole tract digestibility of fermented WCW silage offered to sheep.

Winter wheat (variety Hunter) was grown as a conventional crop and harvested at a dry matter (DM) content of 450 g/kg and a Zadock growth stage of approximately 85 (soft dough). The crop was cut to leave a stubble length of either 17.9 cm (long straw, LS) or 38.2 cm (short straw, SS) prior to ensiling in separate ag-bags.
The effect of stage of maturity and endosperm type on the in situ dry matter degradability of fermented whole crop wheat silage
Authors: Southworth J.E. , Gilman K.M. , Raeside A.J. , Wilkinson R.G. , Sinclair L.A. , Huntington J.A.
Published: June 2019

Whole crop wheat (WCW) silage is potentially an important complementary forage to grass silage grown in the UK and recent studies suggest that although partial replacement of grass silage with either urea treated or fermented WCW increases forage intakes, responses in terms of milk yield and composition are poor. For urea treated WCW this has been attributed to the fact that mature intact grains are poorly digested in the rumen. (Abdulla et al. (1996). However, the rumen degradation characteristics of fermented WCW are unclear. The objective of this experiment was to investigate the effect of crop maturity (Mat) and endosperm type (Endo) on the in situ dry matter (DM) degradability characteristics of fermented WCW silage.
Influence of different energy supplements on nitrogen utilisation by dairy cows fed grass silage diets
Authors: Castillo A.R. , Barbi J.H. , Beever D.E. , Sutton J.D. , Humphries D.J.
Published: June 2019

The efficiency of nitrogen (N) utilisation in dairy cows fed grass silage diets is normally low and is related to an impaired utilisation of N in the rumen. Choice of carbohydrate type may affect this efficiency, influencing milk production and composition, and changing the output of N in faeces or urine. This experiment was undertaken to examine the effect of different iso-energetic supplements containing contrasting energy sources on N utilisation and milk production in early/mid lactation dairy cows fed early cut partially wilted grass silage.

Six iso-energetic supplements were formulated as treatments; four to contain 160 g CP/kg DM and contrasting carbohydrate sources, viz.: neutral detergent fibre (NDF; wheatfeed, 350 g/kg, molassed and unmolassed sugar beet pulp 412 g/kg); low degradability starch (LDS; maize grain 500 g/kg, wheat 237 g/kg); high degradability starch (HDS; wheat and barley grain 812 g/kg); and soluble sugars (SS; molasses, 525 g/kg, citrus pulp, 125 g/kg).
The production response by dairy cows to four levels of straw inclusion in grass silage based diets
Authors: Ferris C.P. , Patterson D.C. , Gordon F.J. , Kilpatrick D.J.
Published: June 2019

High concentrate feed levels, with a consequent fall in the fibre content of the diet, are increasingly being offered to high genetic merit dairy cows. To improve fibre intake, small quantities of straw are often incorporated into the diet. This study was undertaken to examine the production response of dairy cows, offered a medium quality grass silage based diet together with relatively high levels of concentrate supplementation, to straw inclusion in the diet.

Forty high genetic merit dairy cows, 20 multiparious and 20 first lactation animals (PTA95 fat + protein = 41.4 and 39.7 kg respectively) were used in this study. The study consisted of four treatments, arranged in a two period (4 week duration), partially balanced change-over design trial, with first lactation and multiparious animals being blocked separately. The experimental treatments consisted of grass silage mixed with one of four levels of straw, and offered ad libitum in the form of a mixed diet.
A comparison of two contrasting milk production systems for high genetic merit autumn calving dairy cows in a grassland based production environment
Authors: Ferris C.P. , Gordon F.J. , Patterson D.C. , Mayne C.S.
Published: June 2019

In a previous short term study, Ferris et al. (1997) demonstrated that similar levels of nutrient intake and animal performance could be obtained by either increasing silage feed value and reducing concentrate feed level, or by reducing silage feed value and increasing concentrate feed level. The principles established in this study were incorporated into this trial to examine two systems of milk production over a full lactation, including both the winter and grazing periods.

Forty high genetic merit dairy cows (PTA95 fat + protein = 38.2 kg), in their second or subsequent lactation, were used in a continuous design full lactation study. Animals had a mean calving date of 1 November and were allocated to one of two systems of milk production, HF or HC, within 36 hours of calving. During the winter, animals on system HF were offered a silage with high feed value characteristics, supplemented with 5.5 kg of concentrate (crude protein concentration of 280 g/kg DM) through an out-of-parlour feeding system.
The effects of replacing maize silage by triticale whole crop silage in a roughage mixture with grass silage on feed intake and milk production by dairy cows
Authors: Duinkerken G. van , Zom R.L.G. , Bleumer E.J.B.
Published: June 2019

In the Netherlands, grass and forage maize are the most important fodder crops. However, on drought prone sandy soils, and in years with insufficient rainfall the yield of maize is very low (7 to 8 tons DM/ha). Therefore, sprinkle irrigation is often applied to overcome problems with drought. However, in some regions sprinkle irrigation is not possible because of a lack of suitable water or due to legislative restrictions on the use of water for irrigation. In situations where water is a limiting factor for growing maize, triticale may be an alternative fodder crop. Triticale grows mainly during the early spring when there usually is a precipitation surplus and so, water is not a limiting factor for growth. When triticale is harvested as triticale whole crop silage the DM yield ranges between 9 and 11 ton of dry matter per hectare. Therefore, under water limiting conditions it may be attractive to replace forage maize by triticale whole crop silage.
The effect of fermented whole crop cereal species on botanical composition, chemical composition, in vivo digestibility and liveweight change in sheep
Authors: Adesogan A T , Jones G J
Published: June 2019

In the wetter parts of the UK where maize production is marginal, whole crop cereals can be used to boost milk yield from home grown forages, and thereby maintain profitability in the current climate of falling milk prices. In spite of the fact that barley and oat production are more suited to such wetter, marginal areas of the UK (Lockhart and Wiseman, 1978), most of the nutritional studies on whole crop cereals have been conducted on wheat. In Denmark which has a more established tradition of producing whole crop cereals, barley is the cereal of choice (Kristensen, 1992). This study therefore evaluated the chemical composition, in vivo digestibility and animal performance from fermented whole crop barley (WCB) and whole crop oats (WCO) to determine their potential as winter feeds in marginal areas of the UK.
An alternative method of administering alkane markers for estimating intake in dairy cows
Authors: Unal Y. , Garnsworthy P.C.
Published: June 2019

Alkanes have been used for a number of years to estimate food intake in ruminants. The technique requires animals to be dosed with synthetic even-chained alkanes, usually C32 and C36; faecal concentrations of these are then compared with naturally-occurring alkanes, e.g. C33, to estimate intake. Mayes et al. (1986) prepared capsules containing alkanes on shredded paper; Dove et al. (1988) used hard-shell gelatine capsules to administer dosed alkanes. Both methods required animal handling, extra material, like gelatine capsules or paper, and also some laboratory work for preparing alkane solutions, papers and capsules. We report here a less time-consuming method that can be used with dairy cows or other animals offered concentrates separately from a basal ration. The objective of the study was to see how accurately food intake in dairy cows could be estimated when dosed alkanes are administered via a compound feed.
Determination of nitrogen degradability of some different protein sources by in situ techniques
Authors: Gorgulu M. , Baykal L. , Kutlu H.R. , Atasoglu C.
Published: June 2019

The rate and extent of protein degradation in the rumen is very crucial, as it determines the availability of nitrogen to microorganisms and amino acids in the small intestine to the host animals. The protein consumed by the animal should be partly degradable in the rumen, as peptides and amino acids derived from proteolysis are thought to stimulate microbial growth and rumen fermentation under certain conditions. It is, therefore, very important to determine the degradability of different feed ingredients which are grown and used in different regions of the world. The present study was undertaken to assess the degradation characteristics of different protein sources grown and used in Turkey.
Evaluation of the potential of short term intake rate (STIR) to predict effects of chop length on in vivo parameters in sheep
Authors: Hurst D. , Romney D. L. , Murray A. H.
Published: June 2019

Parameters from in vitro gas production and in situ degradability are often used to predict digestibility and intake in vivo. However, these methods use dried ground feed samples and cannot be expected to estimate the effect of changes in physical form or particle size. Previous work (Romney and Gill 1998) has indicated that short term intake rate (STIR) values showed potential to rank a variety of feeds in terms of their ad libitum dry matter intake, rate of passage and digestibility. Since STIR values are determined on feeds “as offered” it is likely they will reflect the effects of physical structure on in vivo parameters. The present work examines whether measurement of STIR values can be used to predict in vivo responses to changes in particle size distribution in chopped forages.