bluuebunny/crossref_metadata_2025_split huggingface dataset:
Embryo mortality and its prevention
Authors: Peters A R 
Published: November 2021

The economic and biological significance of embryo mortality in cattle is well recognised. About 90% or more ova are fertilised at oestrus but only about 55% of dairy cows calve to first insemination (reviewed by Sreenan and Diskin, 1985). Of this 35% post fertilisation loss, most (25-30%) occurs within a cycle length therefore not affecting the time of return to the subsequent oestrus. It is also accepted that the maintenance of early pregnancy requires the secretion of progesterone by a viable corpus luteum and that premature luteolysis is the major cause of embryonic loss during these early days of pregnancy.The corpus luteum forms after ovulation from the cells of the granulosa and theca interna layers of the ovarian follicle. These are thought to differentiate into the large and small luteal cells respectively (Smith et al., 1994). The large cells secrete progesterone and oxytocin and are responsive to prostaglandin E whilst the small ones secrete progesterone and are responsive to LH (reviewed by Wiltbank, 1994).
The effect of feeding supplementary mixtures of tree leaves on nitrogen utilisation in sheep
Authors: Powell C J , Lascano C E , Romney D L , Gill M 
Published: November 2021

The potential benefits of mixing leaves containing high and low levels of condensed tannin (CT) on N utilisation in sheep was studied at the Centro Internacional de Agricultura Tropical (CIAT), Colombia.Supplements of Cratylia argentea (Ca) (tannin free), replaced with 0, 25, 50 or 100% Flemingia macrophylla (Fm) (25.1 g CT/kg DM) were fed as 40% of total ration DM (85g/M0Â·75), the remainder coming from Brachiaria dictyoneura (Bd). Treatments were offered in a replicated 4x4 latin square to eight male African Hair sheep (mean liveweight 23 (s.e. 1.5) kg), fistulated at the rumen and proximal duodenum (T-piece). Total collections of urine and faeces were used to estimate apparent N retention. Ammonia concentration was measured in rumen liquor samples taken hourly over 24 hours, while duodenal flows were estimated from spot samples using Ytterbium chloride as a single phase marker.
The application of an oral zinc tolerance test to assess zinc absorption from three different dietary sources in the dog
Authors: Lowe J.A. , Wiseman J. 
Published: November 2021

Zinc (Zn) is a key nutrient for dogs, playing an important role in many metabolic functions. It has been estimated that 91% of the minimum maintenance requirement for Zn is needed to support hair growth. Coat condition is perceived as being important by pet owners and is thus of fundamental concern when evaluating the adequacy of a diet for dogs.Zn absorption has been shown to vary as a function of the amount and source of the Zn in the diet and as a function of the presence of elevated calcium and / or phytate levels in the diet.It has been suggested that when dietary Zn is supplied in the form of a chelate with amino acids, rather than from inorganic sources, a greater proportion of Zn is absorbed an is thus available to the animal. Further, the undesirable effects that dietary antagonists, such as calcium, exert on Zn absorption may be negated
Selecting terminal beef sires on their estimated breeding values for economic efficiency
Authors: King Margaret E , Broadbent P J 
Published: November 2021

The selection objective of the SAC Simmental MOET Project, is to improve the economic efficiency of lean, or saleable, meat production in crossbred beef production systems.The factors which contribute to the selection objective are the yield of saleable meat, feed intake and calving difficulty. These goal characteristics are combined into an index by taking into account their respective financial values and costs. Calves generated by multiple ovulation and embryo transfer (MOET) are weaned from their recipient dams at 10 weeks old and placed in performance test from 5 to 11 months of age. At the end of the performance test, saleable meat yield is estimated from liveweight at end of test, ultrasonic fat depth measurements and muscling score. Calving difficulty is predicted from the birthweight and gestation length of the animal on test whilst feed intake is measured directly by recording individual food intakes during performance testing. The estimated breeding value for the selection index of an animal is expressed in Â£'s (pounds sterling) as deviations from a mean of zero for the SAC population of Simmentals. It is calculated using the information for each animal plus that of all its relatives in its own and other performance tests by means of BLUP procedures.The objective of the work described here was to evaluate the effectiveness of the selection index in identifying sires of superior genetic merit for use in crossbred beef production systems.
Within litter effect of halothane genotype on performance and conformation
Authors: Grundy B. , Webb A.J. , Kitchin P. 
Published: November 2021

A DNA test is now available for use in pigs to identify halothane genotype (Fujii et al, 1991; Otsu et al 1991). It has been established that the positive phenotype (nn) at the halothane locus shows advantages in lean yield accompanied by disadvantages in meat quality and stress susceptibility (Webb et al, 1987). The aim of this study was to accurately estimate the relative performance of the halothane heterozygote (Nn) within litters for both production and conformation traits in two breeds of pig.Halothane genotype was determined for 1131 entire boars and gilts from 389 litters, 145 sires and two lines (Table 1). Line A was derived from a single breed, and selected on rate of lean growth for over 10 generations as a closed population. Line B was a closed synthetic population containing Pietrain and Hampshire.
The effect of agonistic social interactions on the heart rate of group-housed sows
Authors: Marchant J.N. , Broom D.M. , Rudd A.R. , Mendl M.T. 
Published: November 2021

A major problem reported by many commercial producers keeping sows in group housing systems, is that of inter-sow aggression and bullying, due to the establishment and maintenance of a social hierarchy. Even in stalls and tethers, inter-neighbour aggression can be high but the physical consequences for the sow receiving the aggression are negligible, due to the lack of opportunity for physical contact. In a group situation, an inability to prevent attack by another sow can itself lead to poor welfare, in addition to any effects of injury or pain caused by the attack. A sow's ability to control its social environment can not only affect its access to resources (Edwards et al., 1993), but also its physiological state and productivity (Mendl et al., 1992).The aim of this experiment was to determine the effects that different intensities and degrees of success of agonistic social interaction have on the heart rate of sows, which can be a useful measure of the emotional response of an individual to short-term problems such as social challenge.
Choice feeding to characterise genotypes in pigs
Authors: Wilson J.M.F. , Southwood O.I. , van der Steen H.A.M. 
Published: November 2021

The choice feeding of pigs has been shown in many experiments to allow the individual pig to express its own needs and thereby grow more efficiently and show its full potential.The objective of this experiment was to test whether pigs representing 7 distinct genotypes, including Large White, Landrace, Pietrain, Duroc and Meishan, were able to select their dietary crude protein (CP) in relation to energy requirements under a choice feeding regime, and whether these differences were related to growth and performance.
Use of seeds as delivery vehicle for enzymes
Authors: Pen Jan 
Published: November 2021

Crops are presently exploited for the economic production of materials like carbohydrates, lipids and proteins for e.g. food, feed, or processing industries. The designed modification of plants by genetic engineering has opened up the possibility to broaden this range of products. The number of novel compounds successfully produced in plants using this “molecular farming” approach is steadily increasing, and includes carbohydrates, fatty acids, biodegradable plastics, high-value pharmaceutical (poly)peptides and industrial enzymes.The technical feasibility of producing active industrial enzymes in plants at a relatively high level has been demonstrated. The use of seeds as the formulation and delivery vehicle for the enzymes greatly enhances the economic competitiveness of plants as a source of industrial enzymes. This novel concept exploits the fact that many plants and plant organs are or can be a component in industrial processes, animal feed and human food.
Responses in gilt post-farrowing traits and pre-weaning piglet growth to divergent selection for components of efficient lean growth rate
Authors: Kerr J. C. , Cameron N. D. 
Published: November 2021

Responses in sow traits at farrowing and during lactation and in pre-weaning piglet growth rate were determined in a population of Large White pigs, after seven generations of divergent selection for components of efficient lean growth rate. Information on the factors influencing preweaning piglet growth rate is required for a comprehensive evaluation of alternative selection strategies.There were four selection groups: daily food intake (DFI), lean food conversion (LFC), lean growth rate (LGA) on ad-libitum feeding and lean growth rate on scale feeding (LGS). There were 242 gilts in the study, with 20 gilts in the high, low and control lines of each selection group. Pigs in the ad-libitum selection groups were performance tested over a fixed weight range of 30 to 85 kg. Pigs fed on scale feeding were performance tested for a fixed time period of 84 days from 30 kg with food intake equal to 0.75 g/g of daily ad-libitum food intake. Matings were unsupervised and took place in outside paddocks.
Evaluation of genetic markers for litter size in Meishan synthetic and Large White pigs
Authors: Southwood O.I. , Hoste S. , Short T.H. , Mileham A.J. , Cuthbert-Heavens D. 
Published: November 2021

A significant relationship between the oestrogen receptor gene (ESR) and litter size has been detected in USA populations of Large White and a synthetic comprising 50% Meishan (Rothschild et al., 1995). Animals carrying two copies of the favourable allele (B) had an extra pig born per litter than those that did not have the allele. This paper reports on results observed in a UK 50% Meishan synthetic and four UK Large White lines.Litter size data from 50% Meishan synthetic (L93) full-sib females where more than one ESR genotype was segregating. Data were analysed using a mixed model with full relationships and including the fixed effects of season of farrowing, parity, ESR genotype (AA, AB or BB) and service type (AI or natural service). Heritiability and permanent environmental effects for litter size were assumed as 0.09 and 0.11, repectively. A total of 27 full-sib families were represented and included 62 sows and 139 litter records. Hypothesis testing used the option in PEST under a mixed model (Groeneveld et al., 1991).
Annual variation in the balance between winter fodder production and requirements in beef cow systems
Authors: Wright I.A. , Maxwell T.J. , Russel A.J.F. , Sibbald A.R. 
Published: November 2021

Herbage intake by beef cows is highly correlated with sward height and therefore intake can be managed in a predictable manner by controlling sward height. For beef cows this requires adjustment of the grazing area and conservation of herbage which is not grazed, with the silage aftermath subsequently grazed later in the summer. Year-to-year variation in herbage growth rate will result in variation in the amounts of silage produced. Most grazing experiments do not consider this year-to-year variation, but it constitutes one of the major features which has to be accommodated in the operational management of beef cow systems which are based on pastoral resources.During three consecutive summers, 40 spring-calving Hereford x Friesian beef cows and their Charolais-cross calves grazed perennial ryegrass-dominated swards receiving 200 kg N/ha at one of two annual stocking rates (2.0 or 2.5 cows/ha) at one of two sward heights (4 to 5 (short) or 7 to 8 cm (tall)) in a 2x2 factorial experiment, replicated twice.
Options for housing the sow and litter
Authors: Edwards S A , Fraser D 
Published: November 2021

Following on from the previous paper, this paper could be subtitled 'The welfare of the sow, her litter, the stockperson, the farmer and the bank manager'. There are many different considerations involved in assessing a farrowing system and, in some cases, these can lead to conflicting conclusions.As reviewed in the previous paper, the animals have a set of requirements for optimal welfare. For the sow, these include the ability to exhibit certain hormonally regulated behaviour patterns including pre-farrowing ambulation and nest building. For the piglet, although longer term issues of behavioural development exist, the immediate welfare challenge is to stay alive and healthy in a situation fraught with dangers (Fraser, 1990). This requires environmental measures which reduce the likelihood of crushing, hypothermia, starvation and infection. Increasingly, as sow prolificacy has become a goal of genetic selection, it is also dependant on inputs of skilled stockpeople (English, 1993).
Gaseous emissions of slurry from pigs offered low crude protein diets
Authors: Hobbs P.J. , Pain B.F. , Misselbrook T.H. , Kay R.M. , Lee P.A. 
Published: November 2021

Increasingly emissions from livestock production has caused problems for the industry. If the problem can be reduced at source by a change of diet this could be the simplest solution, requiring the minimum of effort.Reducing nitrogen excretion by pigs offered low crude protein (CP) diets may not only reduce nitrogen polluting potential of slurry, but also change gaseous and odorous emission characteristics.Slurry was collected from beneath slatted pens at the end of the fmishing period (65 to 90 kg live weight) of groups of pigs offered either a commercially available finisher diet (F-com), slurry A, or a low CP diet (F-lc) formulated using a commercial least cost database which has been shown to reduce the nitrogen concentration of the slurry, slurry B. Slurry samples were placed in a closed odour emission chamber and air samples taken after 0, 15, 40, 65, 95, 155 and 225 minutes. Odour concentration (OC) was determined by dynamic dilution olfactometry.
Diet selection in dairy cows: effect of training on choice of dietary protein level
Authors: Tolkamp B.J. , Burger M. , Kyriazakis I. , Oldham J.D. , Dewhurst R.J. , Newbold J.R. 
Published: November 2021

An experiment was carried out to determine the ability of lactating cows to select a diet from two similar feeds differing in the ratio of metabolisable protein to energy (MP/ME) content and to investigate the effect of training through previous access to feeds separately on diet choice.Holstein-Friesian cows (n=36), 1-5 months in lactation, yielding 37 (s.d.=5) kg of milk were housed in a cubicle shed equipped with 28 computer linked Hokofarm feeders which can be programmed to give or deny specific animals access and record intake, meal size and meal duration. All feeds were mixtures of grass silage and pelleted concentrates. Approximately 75 % of daily offer was given in the morning and topping up occurred during afternoon milking. After adapting to feeders and feed for at least two weeks, intake was recorded in week 1 when all feeders contained a standard mixed feed calculated to contain 8.3 g MP/MJ ME. In weeks 2-7 a low protein (lp) and a high protein (hp) feed were offered in 14 feeders each (in the order 7 lp, 7 hp, 7 lp, 7 hp).
Effects of inoculant treatment on silage fermentation and digestibility and on rumen fermentation, dry matter intake and performance of lactating dairy cattle
Authors: Keady T.W.J. , Murphy J.J. 
Published: November 2021

Recent studies have shown that the use of an effective bacterial inoculant as a silage additive results in improvements in animal performance of dairy and beef cattle. Treatment with an inoculant based on a single strain of L. plantarum has increased silage digestibility and altered the composition of rumen fluid in beef cattle (Keady and Steen, 1994 and 1995). Inoculant products vary in composition, containing different bacteria species and numbers, possibly with the addition of enzymes, clostridiaphages and rumen enhancers. The present study was designed to evaluate an inoculant containing mixed strains of bacteria, enzymes, bacteriophages and a rumen enhancer through lactating dairy cattle and to study its effects on diet digestibility and rumen fermentation patterns.Herbage was harvested from the primary regrowth of a predominantly perennial ryegrass sward, which had received 99 kg nitrogen (N) per ha after the previous harvest, after a fifty-one day regrowth interval. Herbage was mown down using a mower conditioner and picked up immediately, unwilled, using a precision chop harvester.
The effect of treatment with a gonadotrophin releasing hormone on the fertility of beef cows
Authors: Pullar Duncan , Wrathall Anthony 
Published: November 2021

Use of the gonadotrophin releasing hormone (GnRH) analogue, buserelin has been shown to be effective reducing embryo mortality, by a luteoprotective mechanism, in reproductively normal dairy cows. Drew and Peters, (1991) increased mean pregnancy rates to AI from 53.4 to 65.4% in dairy herds by a buserelin treatment, given 10-12 post service. The objective of this experiment was to determine whether buserelin can also have a beneficial effect on pregnancy rate, in normal and known problem suckler cows.Seventy-eight Hereford x Friesian cows (from 0-4 parities) were used. Forty were considered reproductively normal ('normal' cows) having calved each year from their first season and currently with a 10 week old calf at-foot; while 38 had a history of reproductive disorders ('suspect' cows) and had not calved in the previous 15 months (May 1994 to July 1995).
Effect of undegradable protein given for six weeks before calving on the performance of dairy cows in the subsequent lactation
Authors: Dewhurst R.J. , Davies D.W.R. , Fisher W.J. , Aston K. 
Published: November 2021

Previous studies (Moorby et al, 1994) have shown increased yields of protein and lactose in the subsequent lactation as a consequence of feeding additional undegradable dietary protein (UDP) and restricting energy intake during the dry period. This experiment was undertaken to investigate the effect of supplementary UDP in the dry period diet of Holstein-Friesian cows given unrestricted access to grass silage and 1.5 kg of barley per day.Sixty-one cows received diets based on ad libitum access to grass silage with either (a) 1.5 kg barley / day or (b) 1.0 kg barley and 0.5 kg Maize Gluten Meal / day. After calving, cows had ad libitum access to grass silage (Metabolisable Energy (ME)=11.3 MJ/kg DM; crude protein (CP)=181 g/kg DM) and received 5 kg/day of concentrates (ME=13.0 MJ/kg DM; CP=250g/kg DM).
Composition, intakes and apparent digestibility of 3 grass silages offered to horses
Authors: Istasse L. , Van Eenaeme C. , Hornick J.L. , Van Calster P. , Huet D. 
Published: November 2021

Hay is an usual component of horse diet. Nevertheless, it is suspected to provide some spores causing chronic obstructive pulmonary disease. Grass silage has been suggested as forage in the diet to overcome the problem. It was therefore of interest to assess the nutritive value of grass silage in horses.Three silages with different dry matter (DM) content were compared. Since horses dislike grass silage with a low DM content, wilted silages only were compared. The first two were first cut grass silages with a low DM content at 427.3 g/kg (LGS) or a medium DM content (661.7 g/kg - MGS). They were compared with a second cut silage from grass grown under very dry conditions (HGS - 787.5 g/kg). The grass was ensiled in square big bales. The 3 silages were offered alone and ad libitum to 4 sport horses in 3 consecutive periods,each silage being offered during one period.
The inheritance of faecal egg count following natural Ostertagia circumcinctainfection in Scottish Blackface lambs
Authors: Bishop S.C. , Bairden K. , McKellar Q.A. , Park M. , Stear M.J. 
Published: November 2021

The use of genetic selection as a means of reducing the welfare and production losses caused by gastrointestinal parasites has hitherto been ignored by the UK sheep industry. The aim of this study is to assess the potential for selection for reduced faecal egg count, as an indicator of parasitism, and to establish relationships with live weight.Faecal egg counts and live weights were measured on approximately 200 predominantly twin born Scottish Blackface lambs each year for three years following natural, predominantly Ostertagia circumcincta , infection on pasture. Measurements were made from one to six months of age, at four week intervals, following anthelmintic treatment. Heritabilities, maternal common environment effects, genetic and phenotypic correlations were calculated using Residual Maximum Likelihood techniques.
The effect of supplementing grass silage with molasses and/or a mineralised fishmeal on performance and carcass characteristics of finishing beef cattle
Authors: Chapple D. G. , Grundy H. F. , Wheeler K. P. A. , Marsh S. P. 
Published: November 2021

In forage-based intensive beef production systems supplementary feedingstuffs are generally required to optimise live-weight gain and to ensure adequate finish. Information on the feeding of molasses alone or molasses in conjunction with supplementary protein, in grass silage-based beef cattle diets is limited.To evaluate the effect of replacing barley with molasses and/or mineralised fishmeal when fed with ad libitum grass silage to finishing beef cattle.Daily supplements of 2.0 kg of rolled barley + 50 g minerals (B), 0.5 kg mineralised fishmeal (F), 2.0 kg cane molasses + 0.5 kg mineralised fishmeal (MF) or 2.5 kg cane molasses + 50 g minerals (M).
The potential for improving soya-bean meal in diets for weaned piglets by protease treatment: comparison with other protein sources
Authors: Rooke J.A. , Fraser H. , Shanks M. , Morgan A 
Published: November 2021

Vegetable proteins, including soya-bean meal (SBM), can only be included in diets for newly-weaned piglets in restricted amounts as they can induce a transient local gut hypersensitivity. This hypersensitivity may be a causative factor in post-weaning diarrhoea. The object of the current experiment was to assess whether protease treatment of SBM could reduce in vitro antigenicity of SBM and improve its nutritional value when fed to newly weaned piglets.Soya-bean meal was treated for 3 h at 50Â°C at 800 g water / kg. Treatment was carried out at pH 4.5 without and with lg protease P2 (Finnfeeds International Ltd) / kg soya-bean meal dry matter (DM). Treated SBM was neutralised and dried at 65Â°C before inclusion into diets. The diets were formulated to contain 14.5 MJ Digestible Energy (DE), 190 g crude protein (CP) and 12 g total lysine / kg.
Response of weaned pigs to diets containing spray dried plasma protein and spray dried blood cells
Authors: Lynch P.B. , Weaver E. , Russell L. E. 
Published: November 2021

Spray dried plasma protein (SDPP) has been used as a replacement for expensive milk based ingredients in starter diets in the US over the past few years. The objective of this trial was to assess dried blood products as a replacement for dried milk products and fish meal in diets fed to pigs for four weeks after weaning.Thirty six mixed sex groups of 16 pigs, weaned at 22-28 days of age and weighing 7.6 (s.e. 0.1) kg, were used in this trial in a factorial design of two starter diets (control and 10% SDPP (AP920) - American Protein Corp., Ames, Iowa) for 14 days from weaning, followed by two link diets (control and 2.5% spray dried blood cells - SDBC (AP301)) for 12 days. Composition of diets is shown in Table 1. All pigs received a common weaner diet from day 26 to day 49 (34 kg liveweight approx).