bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship between plasma ammonia and the urea concentration of milk and plasma in the lactating dairy cow
Authors: Biggadike H. J. , Allison R.D. , Laven R.A. , Collins C.A. , Drew S.B. , Mansbridge R.J.
Published: June 2019

The objective of this study, which formed part of a larger project, was to investigate the effect of feeding high levels of urea on the reproductive function of the lactating dairy cow. Increasing dietary protein intake can increase milk production, but may reduce reproductive performance (Laven and Drew 1999). McEvoy et al (1997), based on work which fed urea to sheep, suggested that this effect on fertility may be caused by ammonia. However, there is little information on the effect of feeding quickly degradable nitrogen (QDN) on the concentration of plasma ammonia in the dairy cow and the accurate measurement of plasma ammonia is difficult. The measurement of a more stable metabolite, such as urea, may be more useful, if it can be shown to be correlated with plasma ammonia.
Effects of body condition at calving, post-partum nutrition and calf access on the interval from calving to first ovulation in beef cows: Cow performance and metabolism
Authors: Sinclair K. D. , Molle G. , Revilla R. , Roche J. F. , Quintans G. , San Juan L. , Sanz A. , Mackey D. R. , Diskin M. G.
Published: June 2019

The prolonged interval from calving to first ovulation in beef cows is primarily due to the suckling-mediated inhibition of pulsatile LH release. Undernutrition both before and after calving also suppresses LH release, reduces ovarian follicular growth and delays ovulation. The interactive effects of these factors on the interval from calving to first ovulation in beef cows were quantified by studying the incidence of ovulation, following acute calf isolation and once-a-day suckling (restricted access), after emergence of the fourth follicular wave post partum in cows in differing body condition at calving and offered low or high planes of nutrition after calving.

The experiment was a 2 x 2 x 2 factorial design, in which the factors were body condition score at calving (Low v. Moderate), feeding level after calving (0.6 v. 1.0 MJ ME/d/kg M0.75), and restricted (once-a-day) v. ad libitum access and suckling. The experiment, duplicated at each of the four participating sites, involved 16 Simmental, 16 Sarda, 16 Brown Swiss and 16 Hereford x Friesian multi-parous cows. Follicle growth was monitored daily from day 21 post partum until the earlier of second ovulation or Day 90 post partum using transrectal ovarian ultrasonography.
Effects of body condition at calving, post-partum nutrition and calf access on the interval from calving to first ovulation in beef cows: Ovarian folliculogenesis and gonadotrophin secretion
Authors: Diskin M. G. , Mackey D. R. , Sanz A. , Marongiu L. , Quintans G. , Roche J. F. , Revilla R. , Branca A. , Sinclair K. D.
Published: June 2019

The interval from calving to first ovulation is a major factor affecting reproductive and productive efficiency in beef cows. While this interval is affected by pre- and post-partum nutrition, the maternal-offspring bond is generally considered to be the major cause of delayed ovulation in beef cows. The endocrine and physiological mechanisms by which these factors either singularly or interactively control the duration of the post-partum anovulatory period are not well established, although they most likely involve the regulation of pulsatile LH release. The present study sought to examine the interactive effects of pre- and post-partum nutrition on LH secretion and follicle wave dynamics following acute calf isolation and once-a-day suckling (restricted access), after emergence of the fourth follicular wave post partum.
Effect of Protein accretion rate on reproductive function in the gilt between 50kg and 3rd oestrus
Authors: Cameron J. , Wiseman J. , Webb R. , Hunter M.G.
Published: June 2019

Recent MLC survey data (Pig Year Book, 1995) reports that approximately 0.5 of annual first parity gilt cullings are due to reproductive failure. This high culling rate may be attributed to recent genetic selection for increased lean tissue accretion rates, and as a result a greater mature body weight. However, the gilt attains puberty and is thus mated at a lower age and as a consequence has not reached the target threshold of 35kg body protein mass at farrowing, suggested by Everts (1994),to be necessary for optimal reproductive performance. This, confounded with excessive tissue catabolism over lactation results in the attenuation of the gilt's potential protein accretion curve and hence reproductive failure (Foxcroft et al. 1995). The aim of this experiment was to study the effect of two protein accretion rates (maximum and 0.8 of maximum) on reproductive function in the gilt from 50kg liveweight to 3rd oestrus.
Body weight and P2 measurements as estimates of body tissue losses of lactating primiparous and multiparous sows
Authors: Probert L.D. , Wiseman J. , Jagger S.
Published: June 2019

Reproductive failure, especially in young sows, is the major contributor to the steady rise in sow culling and mortality rates in recent years. There is now considerable interest in the nutrition of the gilt and its effect on production characteristics and subsequent reproductive performance. Both fat, and more recently lean tissue, have been postulated to play singularly important roles. The objective of the current study was to use production performance criteria of both primiparous and multiparous animals to estimate the proportions of fat and lean tissue mobilised during lactation.

Ninety two animals, forty five gilts and forty seven third parity sows, based at the University commercial pig unit, were used in this study. All animals were weighed and monitored for P2 backfat depth on entry to the farrowing house, during lactation and, finally, at weaning. The data for each individual animal was then used to calculate, by linear regression, the daily rate of loss of both body weight and P2 backfat depth during lactation. These responses were then utilized to calculate the weight and P2 backfat level of each animal on days 1 and 28 of lactation.
A computer model of cadmium metabolism in the sheep with regard to the human food chain
Authors: Prankel S.H.
Published: June 2019

Cadmium (Cd) is a non-essential toxic heavy metal which is added to soil in phosphorous fertilizers and sewage sludge. Cd enters the human food chain via animals fed on crops from these soils, food of vegetable origin and smoking. In chronic exposure situations Cd accumulates in the liver and kidney of animals and man. Intake resulting in a Cd concentration of over 200μg/g wet weight in the kidney cortex results in kidney damage in humans (Friberg et al., 1974). With the prohibition of disposal of sewage sludge at sea in 1998, it is likely that more Cd will be deposited on soils. Current limits for Cd in animal feed are intended to prevent food from animal origin from exceeding legal Cd limits. This work examines the behaviour of Cd in the ovine body and models organ Cd from given intakes to investigate whether current limits in feed are safe and result in animal products fit for human consumption.
The viability of ovine embryos recovered transcervically and transferred by laparoscope
Authors: Mylne M J A , Dingwall W S , King M E , McKelvey W A C , Robinson J J
Published: June 2019

In previous studies (Mylne et al, 1992; McKelvey et al, 1997)) we have shown that the recovery of sheep embryos via the cervix can be facilitated by combining topical application of prostaglandin E2 (PGE2) to the external os cervix with systemic oestradiol treatment (E2) to dilate the cervix. The combined PGE2 and E2 treatment did not inhibit early embryo development (McEvoy et al, 1996) but conceptus viability was not determined. The objective of the present study was to test the viability of embryos recovered transcervically following dilation of the cervix with exogenous hormones and provide quantative data on their subsequent ability to establish normal pregnancies.
The response of net milk protein output to metabolisable protein supply in dairy cows
Authors: Mansbridge R.J. , Metcalf J.A. , Oldham J.D. , Blake J.S , Newbold J.R.
Published: June 2019

The UK Metabolisable Protein (MP) system (AFRC, 1993) assumes that MP intake is converted to milk net protein with an efficiency of 0.68 and that MP for maintenance is 2.30*liveweight0.75. Previous work has indicated that the efficiency of MP use for milk production may be too high or that the amount of MP required for maintenance may be too low (Newbold et al, 1994). This experiment was designed to investigate the relationship between MP supply and net protein output in diets of differing MP to Metabolisable Energy (ME) ratios.

Four‘cornerstone’ diets based on grass and maize silage (0.33:0.67 dry matter basis), were formulated to meet ME requirements and either 0.25 above or below MP requirements for either 46 or 24 kg milk/d. A total of 72 multiparous Holstein cows, on average 46 days post calving at the start of the study, were grouped into blocks of 4 cows on the basis of milk energy output in the covariance period. ME and MP requirements for each block of cows were calculated from milk energy and milk protein yield in the covariance period.
An examination of the effect of level of concentrate supplementation during late gestation on subsequent milk yield and composition of lactating dairy cattle
Authors: Keady T.W.J. , Mayne C.S. , Fitzpatrick D A
Published: June 2019

The transition period (last four weeks of pregnancy and the first four weeks of lactation) is the most traumatic period in the annual cycle of the dairy cow. It is physiologically and nutritionally stressful, particularly as food intake is reduced, especially in the last few days prior to calving, whilst nutrient demands for foetal growth and initiation of milk synthesis are increased. As the genetic merit of the national herd has increased considerably in the last ten years, improved nutritional management of cows during the transition period may be more important in reducing or preventing the cumulative loss of body condition, particularly in early lactation. The present study was undertaken to evaluate the effect of level of concentrate intake in late gestation on subsequent milk yield and composition.
The effects of diets with reduced crude protein and digestible energy content on the performance of growing and finishing pigs and the characteristics of slurry produced
Authors: Lee P A , Armsby A
Published: June 2019

Formulating diets to match more closely the requirements of the pig for amino acids results in diets which are lower in crude protein (CP) than conventional commercial diets. The lower intake of nitrogen (N) which is concomitant with these diets results on lower N excretion. The excretion of excess N requires energy and previous nutrient balance work undertaken at Terrington (Lee and Kay, 1998) indicated that the ‘energy sparing’ effect of the reduced crude protein diets can be utilised by reducing the digestible energy (DE) content of reduced CP diets whilst at the same time maintaining the level of N retention. The objective of this work was to determine the performance carcass characteristics and slurry characteristics of growing/finishing pigs given reduced CP/DE diets.
The effects of sequence of feed allocation within the day on the growth and carcass characteristics of lambs fed barley based diets
Authors: Richardson J. M. , Sinclair L. A. , Wilkinson R. G.
Published: June 2019

Feeding lambs diets formulated to be synchronous for their hourly release of energy and nitrogen (N) in the rumen has been shown to increase growth rate and feed conversion efficiency (Wittet al.1997). However the diets used contained different feed ingredients and therefore the differences in performance may have been due to some aspect of the diet that was not characterised. The objectives of the current experiment were to supply the same quantity of feed ingredients over a 24h period but alter the sequence of allocation within the day to achieve different patterns of energy and N release in the rumen and investigate the effects on growth and metabolism of ram lambs when fed at a restricted level.
The fatty acid composition of solid- and liquid-associated rumen bacteria isolated from cows
Authors: Lee S.S. , Chang M.B. , Scollan N.D. , Merry R.J. , Dhanoa M.S. , Hobbs P.J. , Theobald V.J. , Maeng W.J. , Dewhurst R.J.
Published: June 2019

The distinctive (phospholipid or total) fatty acid profiles of the major classes of micro-organism have been used in microbial taxonomy as well as to act as microbial markers in soils. Our studies seek to identify the potential of this approach in rumen studies. One of the main distinctions is between solid- and liquid-associated bacteria (SAB and LAB) in the rumen, though it is not clear what relative contributions these make to microbial yield from the rumen. The objective of this work was to determine whether SAB and LAB have distinctive fatty acid profiles and if differences are affected by dietary fat supplementation.
Impaired deposition of vitamin E in lambs of two breeds fed a dry pelleted complete diet and its effects on meat quality
Authors: Enser M. , Demirel G. , Wood J.D. , Nute G.R. , Wachira A.M. , Sinclair L.A. , Wilkinson R.G.
Published: June 2019

Vitamin E is an important nutrient for lambs and low levels in tissues as a result of either low intake, poor absorption or excessive utilisation results in myopathy (pale muscle). The causes of deficiency are incompletely understood, especially as it can occur when lambs are consuming good quality grass containing high levels of vitamin E. We now report an occurrence of low tissue levels of vitamin E in lambs of two breeds raised on complete dry pelleted rations and its effect on meat quality and fatty acid composition.

96 male lambs, half Suffolk x Lleyn and half Scottish Blackface, with average live weights of 24 kg and 18kg respectively were individually penned and randomly allocated to one of 6 isoenergetic isonitrogenous diets based on dried grass, molassed sugar beet pulp, soya bean meal and molasses and containing two levels of vitamin E, 100 (low) and 500 (high) g/kg DM.
The effects of the ratio of silage to concentrates in the diet on the performance and carcass composition of continental bulls
Authors: Patterson D.C. , Steen R.W.J. , Moore C.A.
Published: June 2019

Continental bulls of high genetic potential for lean tissue growth (½ Blonde d’Aquitaine ⅜ Charolais genotype) have exhibited high rates of liveweight and carcass gain when grass silage based diets were offered with a moderate proportion of concentrates, i.e. concentrates comprising 0.40 of total dry matter intake (Patterson et al., 1994). It was the objective of the present experiment to examine the effect of forage to concentrate ratio in the diet on growth rate and carcass composition.

The experiment was a five treatment continuous design randomised block arrangement with five concentrate ratios in the total diet (DM basis) namely: 0.25, 0.40, 0.55, 0.68 and 0.75 and grass silage (D value 730 g/kg) as the sole forage. The diets were fed ad libitum. A total of 45 continental bulls (½ Blonde d’Aquitaine ⅜ Charolais) were used with mean initial and final live weights of 467 and 651 kg respectively.
In vivo estimation of body composition in Belgian Blue double-muscled bulls from urea space and fasted live weight
Authors: De Campeneere S. , Fiems L.O. , Vanacker J.M. , Cottyn B.G. , Boucqué Ch.V.
Published: June 2019

Urea is non-toxic, not foreign to the body and it shows an even and rapid distribution throughout the total body water without any physiological effect or toxic manifestation. For these reasons and for its easy and accurate measurement, urea is an ideal tracer to estimate body composition in vivo. Total body water volume (urea space) can be estimated by dividing the total amount of urea infused by the increase in plasma urea concentration between prior to infusion and 12, 18 or 24 min after mean infusion time (Preston and Kock, 1973). In this experiment the urea infusion technique was evaluated to estimate body composition of Belgian Blue double-muscled bulls.
Effect of supplementation with methionine during fattening of Belgian Blue cull cows of three different ages on animal performance, carcass composition and meat quality
Authors: Hornick J.L. , Evrard M. , Clinquart A. , Van Eenaeme C. , Istasse L.
Published: June 2019

By contrast to bulls, fattening cull cows deposite large amounts of fat in the carcass. Furthermore, the live weight gain are low. Methionine (M) is a limiting amino acid for muscle growth in Belgian blue cattle (Hornick et al., 1997). Supplementation with M in fattening diets for cattle could therefore improve weight gain or feed conversion ratio. An experiment was thus conducted in Belgian Blue cull cows in order to assess the effects of M in fattening diet on characteristics of tissue deposition.

Twenty four Belgian Blue females from double muscled type -8 heifers (H), 8 cows with 2 calving (C2) and 8 cows with 4 calving (C4)- were used. In each group, 4 animals received a control fattening diet (M0) based on maize silage complemented with cereals, sugar beet pulp and protein from vegetable origin (10.3 MJ ME and 160 g/ kg CP per kg DM), while 4 other received similar diet but with 3.5 g of rumen protected methionine (M1).
An evaluation of protein supplements and yeast culture with cereal fed beef bulls
Authors: Pullar D. , Marsh S. P. , Parker J
Published: June 2019

Intensive cereal based rations for beef cattle are typically formulated to contain 175 g/kg DM crude protein. Many different sources of protein have been successfully used to supplement cereals. In this study, the performance of bulls fed three different protein supplements were compared, namely rapeseed meal (R), urea (U) and a combination of urea and soya (S). The study also examined the performance of beef cattle fed a yeast culture (Diamond V ‘XP’ Yeast - Rumenco).

A total of 48 Limousin x (Hereford x Friesian) suckled bull calves at approximately 8 months old were allocated to one of three treatments with four replicates per treatment. Two replicates from each treatment were fed 40 g/head/day of yeast culture. Each diet was fed ad libitum with free access to barley straw and water. The feed ingredient inclusions in the rations were: R, 0.775 barley, 0.15 rape, 0.05 molasses, 0.025 minerals; U, 0.85 barley, 0.10 mineralised urea concentrate (Promol™ Rumenco), 0.05 molasses; S, 0.80 barley, 0.10 mineralised urea concentrate, 0.05 soya and 0.05 molasses. The R diet was used as the control. The bulls were slaughtered at fat class 4L. Statistical analysis was by ANOVA unless otherwise indicated.
Exposure of bovine zygotes to serum in a two-phase in vitro culture system adversely affects cleavage rate and cell number of embryos produced
Authors: Kuran M. , McEvoy T.G. , Sinclair K.D. , Broadbent P.J. , Robinson J.J.
Published: June 2019

The number of cells in bovine and ovine embryos is reduced when steer serum which can generate high concentrations of ammonia in vitro is included in the culture system (Kuran et al., 1998). Moreover, production of embryos in synthetic oviduct fluid (SOF) medium supplemented with this serum causes fetal oversize (Sinclair et al., 1998). The present study investigated the effect of the same high ammonia-producing steer serum in a two-phase culture system on bovine embryo development and blastocyst cell numbers.

The experimental design was a 2 x 2 factorial with 5 replicates and involved a total of 928 bovine oocytes that were matured and fertilized in vitro (IVF = Day 0). Presumptive zygotes were cultured in SOF supplemented with 10% v/v steer serum (SOF+SS; n=461) or with amino acids plus 0.4% w/v crystalline BSA (SOFaaBSA; n=467) for an initial period of 48 h following IVF.
The effects of exogenous progesterone supplementation in late pregnancy on gestation length and colostrum yield in ewes
Authors: Crosby T.F. , Quinn P.J. , O'Donnell A. P. , Nowakowski P. , O'Doherty J.V.
Published: June 2019

The importance of falling progesterone (P4) concentrations in the initiation of parturition and the onset of lactogenesis in many species has long been recognised (Thorburn, et al., 1972). O'Doherty and Crosby (1996) reported a negative linear relationship between P4 concentration at 1 hour post lambing and colostrum yield at 1 h and total yield at 18 h. The administration of progesterone failed to delay parturition when given at a daily dose of 80 mg for a week but larger doses of progesterone (160 mg/day) blocked term labour in most sheep (Bengtsson and Schofield, 1963). The objective of this experiment was to examine the effects of exogenous progesterone administration to ewes in late pregnancy on ewe serum progesterone concentrations, gestation length and colostrum yield and quality.
Placental steroids are involved in the late-gestation decrease in gonadotrophin secretion in the ovine fetus
Authors: Miller D.W. , Brooks A.N.
Published: June 2019

The mid-gestation peak in activity of the fetal gonadotrophic axis is thought to be crucial for normal reproductive development. It is clear that the increase to mid-gestation is a result of the concomitant rise in gonadotrophs (Thomas et al., 1993). The mechanisms responsible for the decrease after mid-gestation are unclear, but may involve feedback from the placental steroids (Challis et al., 1981; Gluckman et al., 1983). The aim was to determine the roles of the placental steroids, progesterone and oestradiol, in the late-gestation decline in fetal gonadotrophins using the oestradiol antagonist ICI 182,780 and the progesterone antagonist RU486.
Effects of concentrate acidogenicity on the performance of cows on maize silage-based diets
Authors: Wadhwa D. , Dhanoa M.S. , Fisher W.J. , Borgida L.P. , Dewhurst R.J.
Published: June 2019

Feeding of highly fermentable carbohydrates is often necessary to meet the energy requirements of high producing cows. Unfortunately, these diets can lead to reduced rumen pH and impaired productivity. Earlier work showed that maize silage intake was greatly reduced when concentrates producing a high rumen acid load (Acidogenicity Value (AV); Wadhwa et al., 1998) were included at 0.5 of feed DM intake (Dewhurst et al., 1998). This further experiment sought to define the level of concentrate feeding at which AV becomes important.

Sixteen Holstein-Friesian cows in the third month of lactation were used. After a covariance period, cows went onto a cyclical changeover design with four periods each lasting for 21 days. Maize silage was offered ad libitum, through Calan gates, along with a fixed allocation of one of 8 concentrates.
Effect of timing and level of protein supply on silage intake, feeding behaviour and milk yield of lactating dairy cattle
Authors: Romney D L , Blunn V , Leaver J D
Published: June 2019

Previous studies have shown that the timing of supplement distribution and supplement type can have implications on forage intake and/or production. For example, Robinson et al. (1997) showed that feeding a protein supplement at 00.30 h compared with 08.30 h increased fat yield through stimulation of rumen fermentation. The objective of the present trial was to test the hypothesis “that supplying a protein supplement either before or after silage was offered would affect feeding pattern and silage intake”.

Twelve multiparous cows, with average starting milk yield of 25.4 (s.d. 5.95) kg/day were allocated to one of six treatments in an incomplete Latin square with four periods of 21 days. Grass silage (219 g/kg DM, 151 g CP/kg DM) was fed ad libitum mixed with barley in the ratio 3:1 on a DM basis.
Effect of glucose sources on production and metabolic responses of dairy cows fed diets based on restrictively fermented grass silage
Authors: Vanhatalo A. , Huhtanen P. , Varvikko T.
Published: June 2019

Diets based on restrictively fermented grass silage do not provide sufficient gluconeogenic precursors in high-yielding dairy cows (Huhtanen 1998). In principle, manipulating the glucose supply of cows may be done either by increasing the proportion of propionate in rumen volatile fatty acids or by increasing glucose supply to the intestines. The objective of this experiment was to compare casein, glucose, propionic acid, and starch as glucose sources in dairy cows fed diets based on restrictively fermented grass silage.

Four rumen cannulated Finnish Ayrshire cows 15-16 weeks into their 4. or 5. lactation were used in an experiment designed as a 4 x 5 incomplete Latin square with 14-d periods. The five treatmens allocated to four animals were continuous infusions of 1) water (Control), 2) casein 300 g/d (Cas), 3) glucose 300 g/d (G), 4) propionic acid 247 g/d (P) and 5) barley starch 270 g/d (S). Substrates dissolved in water were infused either into the rumen (P) or the abomasum (other substrates).
Effect of abrupt and frequent changes in forage quality on digestibility and performance of crossbred cattle offered Napier grass (Pennisetum purpureum) and barley straw
Authors: Sanda I , Romney D , Tanner J , Thorne P , Leaver JD
Published: June 2019

Seasonal variation in feed supply, is recognised as an important constraint to animal production in the tropics. However, day to day fluctuations in quantity and quality of feed are also common in stall-fed animals on smallholder dairy farms. Opportunistic use of feeds available in small amounts, such as residues from food crops, weeds and purchased fodder is common. In addition, amounts of cut green fodder may be reduced or absent on some days. Ruminant animals require time to adapt to a given feed and it might be expected that frequent and abrupt changes of this type might have a negative effect on feed utilisation and animal performance. The objective of the experiment was to determine whether the way in which two fodders, with significantly different DM, CP and fibre contents, were offered, would influence digestibility and liveweight gain in cross-bred cattle.
Rumen digestibility in dairy cows of starch in near-isogenic lines of wheat
Authors: Garnsworthy P.C. , Wiseman J.
Published: June 2019

Wheat is a good source of carbohydrates for ruminants, and recent low prices in the UK suggest that usage is likely to increase. However, there is a shortage of information on the digestibility of wheat in the rumen. Such information is vital for predicting the relative value of wheat as a source of fermentable metabolisable energy or by-pass starch. Digestibility is likely to be affected by growing conditions and genetics. Genetic differences are found between wheat varieties, but comparisons of named varieties yield limited information because many characteristics vary simultaneously. This problem can be overcome by using near-isogenic lines of wheat that vary only in a limited number of known characteristics. The objective of this study was to determine the rumen digestion characteristics of different near-isogenic wheat lines grown under the same agronomic conditions.
Nitrogen utilisation by lambs offered red clover and lucerne silages harvested at two different stages of growth
Authors: Fraser M.D. , Speijers M.H.M. , Evans S.T. , Jones R.
Published: June 2019

Ensiled grass is presently the major source of winter feed for dairy cows and other livestock in the UK. However, the quality and quantity of protein in grass silage tends to limit its use for milk production, which means that bought-in concentrate supplements must be fed to maintain high production levels. Whilst forage legumes such as red clover and lucerne appear to have potential as home-grown, protein-rich feeds for livestock (Frame et al., 1998), there is very little information available regarding their nutritive value when ensiled. The aim of this study was to compare the N balance of lambs offered red clover and lucerne silages harvested at two different growth stages.
The effect of harvest date and inoculation on the voluntary intake and in vivo digestibility of kale silage by sheep
Authors: Fraser M.D. , Fychan R. , Evans S.T. , Speijers M.H.M. , Jones R.
Published: June 2019

Using new harvesting and ensiling technologies it is now possible to successfully ensile kale, thereby conserving the crop at the optimum time to achieve the best compromise between quality and quantity (Young et al., 1997). However, previous work with kale has concentrated on its value as a grazed crop, and consequently there is little information available regarding the optimum time for harvesting. The aim of this experiment was to compare the voluntary intake and in vivo digestibility by sheep of kale silage prepared at two different stages of growth, and to determine whether the use of an inoculant influenced nutritional quality.
The use of a soluble glass copper, cobalt and selenium bolus to supply selenium to sheep
Authors: Kendall N.R. , Farrar N.C. , Illingworth D.V. , Jackson D.W. , Telfer S.B
Published: June 2019

Many sheep may require supplementation with cobalt or selenium, whilst many also require copper for the prevention of swayback. Often more than one are in short supply and blanket supplementation is often the answer, but this could result in problems of toxicity especially with copper in sheep. This trial was carried out on a flock known to be copper sufficient to investigate the supplementation of extra copper in the form of a sintered soluble glass bolus being used to supply selenium and cobalt to the flock.

Two batches of Lleyn sheep were selected, the first were forty ewe lambs, whilst the second set were thirty gimmers. The ewe lambs were randomly split into two groups one being given a copper, cobalt and selenium bolus (Cosecure®, Telsol Ltd) with the other group remaining untreated as controls.
Assessment of energy status in hill sheep using computer tomography
Authors: Young M.J. , Leboulanger A. , McLean K.A. , Fraser J. , Conington J. , Simm G.
Published: June 2019

Breeding leaner sheep is a desirable goal provided reductions in fatness do not compromise survival and productivity, particularly in harsh environments. Whether some energy stores are more labile than others, the internal fat depots in particular, is not clear. Genetic variation in this trait could be usefully exploited in hill sheep where carcass fat is undesirable but energy reserves are important. Patterns of change in body energy stores need to be examined to determine when it is best to assess energy stores in animals. X-ray computer tomography (CT) provides a means to examine depletion and repletion of body energy but scans are not cheap. In order to use CT in a cost effective way, a number of variables need to be assessed from just a few scans. This report presents results of a study designed to define such a scanning approach in terms of which scans were most informative and which produced most accurate predictions of tissue size.
Growth and body composition of two breeds of sheep, and their cross, at similar proportions of mature size when given highly digestible or bulky feedsad libitum
Authors: Morrow S. E. , Emmans G. C. , Lewis R. M. , Donbavand J. E. , FitzSimons J
Published: June 2019

Differences in sheep management and breeding programmes lead to variations in carcass fatness. It is necessary to investigate the relationships between breed, growth and composition on different feeds in order that leaner carcasses may be produced. The purpose of this experiment was to investigate these relationships in two breeds of sheep, and their cross, when fed either a food considered non-limiting to growth or a food that was restrictive by virtue of its bulk.

Suffolk (S), Scottish Blackface (B) and reciprocal cross (X) lambs were born over a 4 week period beginning late February. The lambs were weaned at a weight (0.20 estimated mature size) or no later than 8 weeks of age and following an adjustment period, individually penned.
In vivo leucine oxidation in the gastrointestinal tract of lambs infected with nematode parasite Trichostrongylus colubriformis
Authors: Yu Feng , Bruce L.A. , Coop R.L. , Jackson F , MacRae J.C.
Published: June 2019

One major consequence of the presence of the nematode parasites in the gastrointestinal tract (GIT) of ruminants appears to be an elevated flow of endogenous N component from the small intestine, leading to adverse changes in host productivity (MacRae, 1993). However, many of these aspects have remained speculative because of a lack of appropriate methodology to quantify the influence of parasites on GIT protein metabolism. In the present study oxidation of leucine sequestrated from arterial blood and digesta-derived leucine during “first pass” metabolism in the GIT of lambs subjected to subclinical T. colubriformis infection were quantified directly, using trans-organ catheterisation procedures coupled with stable isotope tracer kinetics.
Effect of swath treatment and duration of field wilting of grass on chemical composition and feeding value of silage in sheep
Authors: Hill J.
Published: June 2019

The wilting of grass prior to ensiling is an effective method of reducing the moisture content of the grass and improving the fermentation quality of the silage (Wilkinson et al., 1996). The effects of wilting grass on voluntary intake, digestibility and animal performance are variable, potentially reflecting the losses of nutrients from the crop during the wilting period. Three methods of swath treatment to accelerate the loss of water from the mown crop are currently used in northern Europe, wilting in the swath, spreading the crop to 1.0 of ground area and tedding swaths. The aim of the experiment reported here was to investigate the effect of swath treatment and duration of field wilting on the voluntary intake and digestibility of wilted silage offered to lambs.
Effect of defaunation on utilisation of poor quality tropical feed by sheep
Authors: Teferedegne B. , Osuji P. O. , Odenyo A. , Wallace R. J. , Newbold C. J.
Published: June 2019

There are conflicting reports in the literature about the benefits of defaunation, the removal of ciliate protozoa from the rumen, in ruminant production. Ciliate protozoa are not essential for proper functioning of the rumen nor for the life of the host and that their contribution to microbial protein flowing to the lower gut is small (Williams and Coleman, 1992). Protozoa ingest and digest bacteria in the rumen decreasing the flow of microbial protein from the rumen, and inserting an energy wasting step in the net synthesis of bacterial protein in the rumen (Williams and Coleman, 1992). However, protozoa also play an active role in ruminal fibre digestion and up to 50% of ruminal carboxymethylcellulase activity is associated with the protozoal fraction (Williams and Colemans, 1992). Thus the effect of defaunation on animal productivity will be a balance between the increase in the supply of microbial protein leaving the rumen and any decrease in ruminal fibre digestion. The aim of this work was to determine the effect of defaunation on microbial protein supply and fibre digestion in sheep fed a poor quality tropical diet.
Performance of ewes selected to have four functional teats
Authors: Davies D.A.R.
Published: June 2019

Ewes with extra teats can be found in many breeds but the amount of milk produced from these is only occasionally substantial. The aim of the breeding project was to investigate the possibility of developing a ewe with four functional teats.

A group of 15 ewes and four rams, all with four teats, together with five two-teated Cambridge ewes formed the initial nucleus group. Subsequently five four-teated Cambridge rams were used. The following measurements were recorded: (a) number of teats, (b) length of front (FL) and rear (RL) teats measured at 5 months of age, (c) distance between the front teat (FT) and front perimeter line of the fore udder (FU) measured post partum, (d) milk production from front (FM) and rear (RM) teats recorded over a 3h period at 2 to 4 days post partum using oxytocin to ensure complete let down.
Genetic trends in linear type traits in the United Kingdom (UK) dairy herd
Authors: Lindberg C. M. , Swanson G. J. T. , Mrode R. A.
Published: June 2019

The Animal Data Centre (ADC) is responsible for producing linear type evaluations for the Ayrshire, Shorthorn, Jersey, Guernsey, Jersey Island and Guernsey Island breeds. Along with publication of breeding values (BV's), it is important to provide farmers and organisations in the industry with information on genetic trends in conformation to establish the effect of selection and determine future selection strategies. As selection goals in conformation are not as clear as in production traits, it is important to analyse each trait to find out how breeds are developing. The objective of the study was therefore to analyse linear type evaluations in order to determine the trends in the traits classified.
Assessing connectedness in across-flock genetic evaluations
Authors: Lewis R. M. , Crump R. E. , Simm G. , Thompson R.
Published: June 2019

With across-flock genetic evaluations, the extent of genetic links or connectedness between animals in separate flocks affects the reliability of selection decisions. As connectedness improves, error in comparing breeding values among flocks falls. Connectedness is thought more important when founder animals (i.e. unknown parentage) of separate flocks differ genetically. The prediction error variance (PEV) of differences in estimated breeding values (EBV) between animals is considered an appropriate measure of connectedness (Kennedy and Trus, 1993). In this study the level of connectedness, and its consequence, in breeding schemes that differ in the extent of ancestral relationships between flocks, and in which founder animals of these flocks differ genetically, was assessed by stochastic simulation.
Heritabilities of and phenotypic relationships between digestibility, dry matter food intake and production traits in grazing lambs
Authors: Vagenas D. , Bishop S.C.
Published: June 2019

Dry matter food intake (DMFI) and digestibility (DIG) of the forage are two important nutritional aspects contributing to lambs growth and subsequent meat production. However, there is a lack of literature describing their inheritance and their phenotypic correlations with production traits, e.g. ultrasonic muscle and fat depth and growth rate, in the grazing lamb. This study aimed to investigate and quantify these parameters for grazing lambs.

This study involved 90 male Texel-Oxford lambs in 1995 and 82 in 1996. The sires in 1996 were lambs in 1995, providing genetic links between these two generations. The lambs were split equally between two lines previously selected for increased or decreased carcass lean content. The lambs were born in a five week period in March-April each year, and they were reared on, and grazed, improved mixed- species pasture, typical of a Scottish upland farm.
Lactation in Improved Awassi sheep
Authors: Pollott G. E. , Gootwine E.
Published: June 2019

Few authors have reported on the complete lactation of sheep, without suckling, and most reports deal with ewes under experimental conditions or of non-dairy types (Groenwaldet al, 1995; Portolanoet al, 1996). In recent years, the commercial Awassi flocks in Israel have weaned their lambs once the lamb has received colostrum from the ewe and so are ideal for studying the complete lactation curves of sheep, under commercial conditions. The objective of this paper is to describe the complete lactation curve of sheep and the factors which affect it.

The records for this analysis were taken from the Improved Awassi flock belonging to the kibbutz Ein Harod. This flock of intensively managed milking sheep has been previously described by Gootwine, Bor, Braw-Tal and Zenou (1995).
Performance of ewes given maize silage during late pregnancy and lactation
Authors: Hill J. , Notman A.B. , Marsh S.P.
Published: June 2019

Maize silage is a popular feed for dairy and beef cattle in the United Kingdom, but its popularity for sheep production has never been great. Several reasons for the lack of interest in maize silage for ewes and lambs have been cited; the growth of an annual crop for silage on holdings with a predominance of long-term leys, the low requirement of ewes and lambs for conserved feed, the possibility of low voluntary DM intakes and the risk of a high degree of selection of dietary components of the diet (Brown and Thomas, 1989). The research reported here examines the use of maize silage for ewes in late pregnancy and early lactation.
Gas production in vitro from purified starches using equine faeces as the source of inocula
Authors: McLean B M L , Hyslop J J , Longland A C , Cuddeford D , Hollands T
Published: June 2019

In vitro techniques have been developed to study the fermentation kinetics of a wide range of animal feedstuffs but relatively few studies have been conducted specifically with purified feed constituents. This study uses the pressure transducer technique of Theodorou et al (1994) to record cumulative gas production (GP) when six purified starch sources were incubated in vitro.

Three replicates of six commercially available purified (98%) starch sources were incubated in vitro with an inoculum prepared from freshly voided faeces collected from six ponies fed hay ad libitum. The starches were a purified wheat starch (ABRA), four purified wheat starches that had been chemically modified with sodium tri-metaphosphate (V1, V21, V33 & V65) and a purified pea starch (PEA). GP was measured using the pressure transducer technique throughout a 72 h incubation period. At the end of the incubation period DM loss (DML) in vitro was determined by filtration.
Gas production in vitro from either unprocessed, micronised or extruded maize, peas, wheat, naked oats and barley using equine faeces as the source of inocula
Authors: McLean B M L , Hyslop J J , Longland A C , Cuddeford D , Hollands T
Published: June 2019

A wide variety of starch based feeds are available for inclusion in equine diets. These feeds may be subjected to physical processing (micronisation or extrusion) prior to inclusion. This experiment evaluates a range of starch based feedstuffs using an in vitro batch culture technique.

A total of 15 feedstuffs were incubated in vitro with an inocula prepared from freshly voided faeces which was collected from six ponies fed grass hay ad libitum. The feeds were five starch based feedstuffs; i.e: maize (M), peas (P), wheat (W), naked oats (NO) or barley (Ba) in one of three physically processed forms i.e: unprocessed (Unp), micronised (Mic) or extruded (Ext). All feeds were ground through a 1.0mm screen prior to incubation. Cumulative gas production (GP) was measured using the pressure transducer technique of Theodorou et al (1994) throughout a 72 h incubation period.
Measurement of caecal outflow rate in ponies using Chromium mordanted feeds
Authors: Hyslop J. J. , McLean B.M.L. , Moore-Colyer M. J. S. , Longland A. C. , Cuddeford D. , T. Hollands
Published: June 2019

Estimates of digesta passage through specific segments of the alimentary tract are a vital component of modelling approaches which attempt to quantitatively partition digestive processes in equines. This study reports results from three studies where digesta passage of Chromium (Cr) mordanted feeds was determined in the caecum of ponies.

Caecal outflow rates were determined during threein vivoapparent digestibility studies conducted using three caecally-fistulated ponies as described by Moore-Colyeret al, (1999) for studies 1 and 2; and McLeanet al, (1999) for study 3. Pony basal diets consisted of unmolassed sugar beet pulp (USBP), hay cubes (HC) or a 2:1 mix of oat hulls:naked oats (OHNO) in study 1; a 1:1 mix of USBP:HC (USHC) in study 2 and either 100% HC or one of 3 diets consisting of a 1:1 HC:barley mix where the barley was either rolled (RBHC), micronised (MBHC) or extruded (EBHC) in study 3.
The apparent digestibilities and rates of passage of two chop lengths of big bale silage and hay in ponies
Authors: Morrow H J , Moore-Colyer M , Longland A. C
Published: June 2019

A wide range of roughage foodstuffs is available for feeding to horses. Considerable variation exists in the quality of these feeds in terms of nutrient composition and freedom from dust, fungal and bacterial contamination and infestation by mites. Many horse-owners are now feeding forages such as haylage and baled silage to horses as opposed to hay. However, limited information is available regarding the effect of chop length on digestibility and thus the feeding value of chopped or long-cut silage to horses. More information on fodder type and preparation could help to provide the basis for improvements in the practical guidelines and recommendations for those involved with the production and feeding of forages to horses.
Comparison of inocula from sheep and cattle for thein vitrogas production technique under tropical conditions
Authors: Bueno I.C.S. , Abdalla A.L. , Cabral Filho S.L.S. , Vitti D.M.S.S. , Owen E. , Mauricio R.M. , Givens I. , Sutton J.D. , Mould F. L.
Published: June 2019

The use of small ruminants, such as sheep, in metabolism studies is more convenient as handling problems are reduced and their maintenance costs are lower, in comparison with cattle. However in vivo digestibility estimates obtained at maintenance are known to differ between these two species. With the increased use ofin vitrogas production techniques, to evaluate ruminant feedingstuffs, it is of great importance to identify whether the species from which the rumen fluid inoculum is obtained has a significant influence on the results obtained.

Rumen fluid samples were obtained from a non-lactating Holstein cow (C) and six wether sheep (S) offered the same diet (80 % tropical grass and 20 % dairy concentrate) and prepared so as to have similar dry matter (DM) contents and therefore potentially the microbial mass. Nine substrates (two tropical grasses 1-2, tropical alfalfa 3, barley straw 4, and five temperate grasses 5-9) were examined.
The influence of biotin on viability, pyruvate carboxylase activity and the response to malate concentration in vitro by isolated secondary hair follicles of the Angora goat
Authors: Tahmasbi A.M. , Galbraith H. , Scaife J.R.
Published: June 2019

Biotin is a prosthetic group for a number of enzymes involved in carboxylation reactions. Biotin deficiency has been associated with poor growth of integumental tissues by currently unknown mechanisms. Pyruvate carboxylase is a biotin-dependent enzyme which has an important anaplerotic role in intermediary metabolism, catalysing the formation of oxaloacetate from pyruvate and bicarbonate. It thus provides oxaloacetate for gluconeogenesis and replenishes Krebs cycle intermediates. Biotin deficiency may reduce pyruvate carboxylase activity and so oxaloacetate production. Malate is a Krebs cycle intermediate which can convert to oxaloacetate and reduce demand for oxaloacetate generated by pyruvate carboxylase. The aims of the study were to determine (a) the effect of biotin supplementation of the medium on hair follicle viability and pyruvate carboxylase activity and (b) the response to supplementation of the culture medium with malate.
Insulin stimulates phenylalanine uptake across the hind limb in fed lambs
Authors: Wester T.J , Lobley G.E. , Birnie L.M. , Lomax M.A.
Published: June 2019

Although insulin has been shown to stimulate muscle protein accretion in nonruminants (e.g., Wray-Cahen et al., 1998) evidence for this same effect in ruminants has been equivocal (e.g., Oddy et al., 1987; Wolff et al., 1989). Moreover, when insulin has been reported to have an anabolic effect in ruminants, the animal has been in the fasted state. In addition, Garlick and Grant (1988) have shown that branched-chain amino acids (BCAA) enhanced insulin-stimulated protein synthesis in fasted rats. The primary aim of the present study was to ascertain whether insulin increases phenylalanine (Phe) uptake (used as an index of skeletal muscle protein anabolism) across the hind limb of fed lambs. A secondary aim was to determine if infusion of BCAA, alone or in combination with insulin, would stimulate Phe uptake greater than insulin alone.