15 results on '"B. M. L. McLean"'
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2. Relationship between water holding capacity and fibre concentration in equine feeds
- Author
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J J Hyslop, B M L McLean, and M J S Moore-Colyer
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Polymers and Plastics ,food and beverages - Abstract
The water content of feedstuffs is an important factor when considering both the nutritive value of a feed for dietary rationing purposes and when assessing the functional properties associated with the practical inclusion of a feedstuff in animal diets. Water is a vital nutrient in its own right and must be supplied on a daily basis. Feed associated water provides one source of this obligatory requirement. In addition, the water holding capacity (WHC) of a feedstuff and its relationship with other constituents of the feed may have important effects. Water can be associated with feedstuff in one of three ways (Robertson and Eastwood, 1981b). Firstly, water can be bound by the hydrophilic polysaccharides of the fibre component of feeds. Secondly, water can be held within the structural fibre matrix of feeds and finally, water can be associated with feedstuff fibre other than bound or matrix water and is usually considered as water trapped within the cell wall lumen.
- Published
- 2004
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3. Physical processing of barley and its effects on intra-caecal fermentation parameters in ponies
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B M L McLean, J J Hyslop, Annette Longland, D Cuddeford, and T Hollands
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chemistry.chemical_classification ,food and beverages ,Horse ,Straw ,Biology ,biology.organism_classification ,Caecum ,Animal science ,Biochemistry ,Fodder ,chemistry ,Propionate ,Hay ,Animal Science and Zoology ,Fermentation ,Dry matter - Abstract
Intra-caecal fermentation parameters in caecally-fistulated ponies offered barley based diets in which the barley had been physically processed by either rolling (RB), micronising (MB) or extruding (EB). Three ponies were offered 4 kg dry matter (DM) per day of either 100% hay cubes (HC), or one of three diets consisting of a 50:50 barley:HC mix. Due to small refusals of HC, the actual DM intakes (kg per day) were 3.74, 3.67, 3.57 and 3.52 (S.E.D. 0.18) for the HC, RB:HC, MB:HC and EB:HC diets, respectively. With the exception of butyrate, all intra-caecal fermentation parameters 4-8 h post feeding in ponies given diet RB:HC were significantly (P
- Published
- 2000
- Full Text
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4. In situ incubation sequence and its effect on degradation of food components when measured in the caecum of ponies
- Author
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D Cuddeford, J J Hyslop, Annette Longland, B M L McLean, and G J Stefansdottir
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In situ ,biology ,Chemistry ,Starch ,0402 animal and dairy science ,04 agricultural and veterinary sciences ,biology.organism_classification ,040201 dairy & animal science ,Caecum ,chemistry.chemical_compound ,Animal science ,040103 agronomy & agriculture ,Hay ,0401 agriculture, forestry, and fisheries ,Animal Science and Zoology ,Dry matter ,Digestion ,Beet pulp ,Incubation - Abstract
Three experiments were conducted to investigate the effect of bag incubation sequence on the degradation of food components in situ in the caecum of mature, caecally fistulated Welsh-cross pony geldings (mean live weight 278 kg) offered hay ad libitum. In experiment 1 a fibre-based commercial horse concentrate was incubated in situ using a forward (3, 5, 16, 8, 24, 48 h) or reverse (48, 24, 8, 16, 5, 3 h) incubation sequence. Dry matter (DM), crude protein (CP), neutral-detergent fibre (NDF) and acid-detergent fibre (ADF) degradation coefficients and calculated effective degradability (ED) values were determined. In experiment 2 unmolassed sugar-beet pulp (USBP), hay cubes (HC), soya hulls (SH) and a 2: 1 mixture of oat hulls: naked oats (OHNO) were incubated in situ as for experiment 1. In experiment 3 unprocessed barley (UB), micronized barley (MB), extruded barley (EB) and dehydrated grass (DHG) were incubated in situ according to slightly different forward or reverse incubation sequences of (2, 4, 6, 12, 8, 24, 48 h) and (48, 24, 8, 4, 12, 6, 2 h) respectively. In experiments 2 and 3 only DM degradation parameters were studied. Of the three starch-based foods studied in experiment 3 (UB, MB and EB), incubation sequence did not significantly P > 0·05) affect any of the degradation parameters examined. Conversely however, of the six fibre-based foods which were examined across the three experiments, incubation sequence did significantly P < 0·05) affect in situ degradation parameters in the commercial horse concentrate in experiment 1, the SH food in experiment 2 and the DHG food in experiment 3. Depending on the food or food constituent studied (i.e. DM, CP, NDF or ADF) degradation coefficients a, b, c and a + b along with ED values calculated at fractional outflow rates of 0·05 and 0·025 could all be statistically different CP < 0·05) according to whether a forward or reverse incubation sequence was used. It is postulated that this effect is related to the basic digestive physiology of the equine caecum which is small, digesta passage rate through it is fast and digesta volumes can vary considerably. These factors may interact to create a considerable degree of non-uniformity within the caecal digesta pool in which in situ bags are incubated. Consequently, it is recommended that in future in situ experiments in the equine hindgut, animals are offered ad libitum diets in an attempt to minimize variation within the caecum. It is also recommended that in situ experimental protocols incorporate more than one incubation sequence when the degradation parameters of fibrous foods are studied in equids.
- Published
- 1999
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5. Performance of crossbred Welsh Mountain ewes in the hill environment
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B. M. L. McLean, J. B. Griffiths, B. T. Wolf, and O. D. Davies
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Engineering ,Welsh ,Animal science ,business.industry ,language ,General Medicine ,business ,Crossbreed ,Agricultural economics ,language.human_language - Abstract
The Welsh Mountain sheep is a numerically important breed in the UK, but its lambs are characterised by low slaughter weights and poor carcass conformation. The reduction in stocking rates that is often associated with environmental conservation schemes, offers the potential for the use of larger ewes. Crossbreeding allows more rapid genetic change to be undertaken than would be possible from selection within breeds, and affords the potential to utilise heterosis and improve the quality of subsequent crosses with the Bluefaced Leicester. This work compared the survival and productivity of purebred Welsh Mountain ewes with a range of crossbred ewe types maintained in a hill environment.
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- 2009
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6. Short-term impact of grazing prescriptions on cattle performance
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A. Clarke, O. D. Davies, B. M. L. McLean, D. E. Evans, and J. B. Griffiths
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geography ,geography.geographical_feature_category ,biology ,Agroforestry ,Molinia caerulea ,General Medicine ,biology.organism_classification ,Pasture ,Habitat ,Mire ,Grazing ,Moorland ,Dominance (ecology) ,Flock - Abstract
Livestock farming is a traditional and important contributor to the rural economy in the hills and uplands of the UK. However, significant areas of the uplands have seen a decline in the condition of heath and mire habitats and the loss of dwarf shrubs as a result of over-grazing. Attempts to halt the decline and improve the condition of upland heath and mire habitats have been undertaken by the introduction of agri-environment schemes. In the main, such schemes rely on the reduction of sheep numbers. However, recent Defra funded research (LS1508) has indicated that this can result in dominance by competitive and/or unpalatable species such as purple moor-grass (Molinia caerulea ) or mat-grass (Nardus stricta ), leading in time to a reduction in the physical and financial performance of the flock. The objective of this study is to assess the impact of cattle grazing on Nardus stricta dominated pasture on sheep and cattle performance. It is being carried out as part of a wider project to determine environmentally sustainable and economically viable grazing systems for heather moorland.
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- 2005
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7. Improving lamb performance from Welsh Mountain Sheep breeding groups
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O D Davies, D. E. Evans, and B M L McLean
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Local type ,biology ,biology.animal_breed ,General Medicine ,Popularity ,language.human_language ,Welsh Mountain sheep ,Mid wales ,Welsh ,Geography ,Work (electrical) ,language ,Cooperative group ,Socioeconomics - Abstract
Sheep group breeding schemes have gained in popularity in recent years. The objectives of group breeding schemes are to improve desirable traits such as carcass conformation, weight and maternal ability whilst maintaining local type. However, if group breeding schemes were to work together then a larger genetic pool of performance recorded animals would be available to facilitate improvements. The objectives of this project were therefore twofold, 1.) was to improve traits such as weight and carcass conformation and 2.) to demonstrate the benefits of cooperative groups working together. In this project, group breeding schemes from North and Mid Wales have been working together with ram performance testing groups from North, South and Mid Wales to improve results from Welsh Mountain breeding schemes.
- Published
- 2001
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8. Development of the mobile bag technique to determine the degradation kinetics of purified starch sources in the pre-caecal segment of the equine digestive tract
- Author
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J J Hyslop, T Hollands, Annette Longland, B M L McLean, and D Cuddeford
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chemistry.chemical_compound ,Degradation kinetics ,Chemistry ,Starch ,Digestive tract ,General Medicine ,Food science - Abstract
Previous work has shown that the mobile bag technique (MBT) can be used to study the dynamics of digestive processes in the whole tract of ponies (Hyslopet al, 1998). This experiment further develops the MBT as a method to study feed degradation dynamics over time in the pre-caecal segment of the digestive tract of ponies.Two caecally-fistulated mature Welsh-cross pony geldings (LW 270kg) were offered 4kg of dry matter (DM) per day of a 1:3 rolled barley:hay cube mix plus minerals, in 2 equal meals per day at 09:00 and 17:00h. Grass hay was also offeredad libitumbetween 17:00 and 09:00h. Two sizes of mobile bag (6 x 1 cm Ø-large and 4 x 1 cm Ø- small) made from monofilament polyester with a 7 μm pore size were used.
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- 1999
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9. Effect of physical processing on in situ degradation of maize and peas in the caecum of ponies
- Author
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T Hollands, D Cuddeford, J J Hyslop, Annette Longland, and B M L McLean
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biology ,Chemistry ,Pony ,Starch ,General Medicine ,biology.organism_classification ,Processing methods ,Caecum ,chemistry.chemical_compound ,Animal science ,biology.animal ,Hay ,Dry matter ,Incubation ,In situ degradation - Abstract
Maize and peas that have undergone physical processing are used routinely in cereal mixes for equines. However, little information is available on how physical processing of maize and peas affects degradation dynamics in equines. This experiment examines the effect of two physical processing methods (micronisation and extrusion) on in situ degradation of maize and peas in the caecum of poniesTwo caecally-fistulated mature Welsh-cross pony geldings (approx. LW 270kg) were offered ad libitum grass hay plus minerals. Incubation bags (monofilament polyester 6.5 x 20cm, 41? m pores, 16mg/cm2 sample size) containing either unprocessed maize (UM), micronised maize (MM), extruded maize (EM), unprocessed peas (UP), micronised peas (MP) or extruded peas (EP) were incubated in the caecum for fixed times according to both a forward (0, 2, 4, 6, 12, 8, 24, 48h) and reverse (48, 24, 8, 4, 12, 6, 2, 0h) incubation sequence. For each feedstuff residues from each time were bulked within pony and across incubation sequence for subsequent analysis of dry matter (DM) and starch (STC).
- Published
- 1999
- Full Text
- View/download PDF
10. In vivo apparent digestibility in ponies given rolled, micronised or extruded barley
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D Cuddeford, B M L McLean, Annette Longland, J J Hyslop, and T Hollands
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Animal science ,In vivo ,Pony ,Latin square ,biology.animal ,Hay ,Dry matter ,General Medicine ,Biology ,Processing methods - Abstract
Processed cereals are used routinely in diets for equines but little information is available on how physical processing affects the digestibility of cereals in equines. This study examines the effects of three physical processing methods (rolling, micronisation and extrusion) on the in vivo apparent digestibility of barley fed to ponies.Three mature caecally-fistulated Welsh-cross pony geldings, (LW 284kg ± 3.8kg) were used in a 3 x 4 incomplete latin square changeover design experiment consisting of four 21 day periods. Each period comprised a sixteen day adaptation phase and a five day recording phase when apparent digestibility in vivo was determined. Ponies were offered 4kg dry matter (DM) per day of either 100% hay cubes (HC) or one of three diets consisting of a 50:50 barley:hay cubes mix. The barley in the mixed diets was either rolled barley (RB), micronised barley (MB) or extruded barley (EB). Diets were offered in 2 equal meals per day fed at 09:00 and 17:00 hours respectively.
- Published
- 1999
- Full Text
- View/download PDF
11. In situ degradation of crude protein in physically processed barley, maize and peas in the caecum of ponies
- Author
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T Hollands, J J Hyslop, B M L McLean, D Cuddeford, and Annette Longland
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Caecum ,Animal science ,biology ,Pony ,Chemistry ,biology.animal ,Hay ,Extrusion ,General Medicine ,biology.organism_classification ,Incubation ,Processing methods ,In situ degradation - Abstract
Little information is available on how physical processing of cereals affects crude protein (CP) degradation dynamics in equines. In two experiments the effects of two physical processing methods (micronisation and extrusion) on in situ degradation of CP in barley, maize and peas in the caecum of ponies were investigated.In experiment 1, three caecally-fistulated mature Welsh-cross pony geldings (approx. LW 270kg) were used whilst two of these ponies were used in experiment 2. In both experiments ponies were offered ad libitum grass hay plus minerals. Incubation bags (monofilament polyester, 6.5 x 20cm, 41μm pores, 16mg/cm2 sample size) contained either unprocessed barley (UB), micronised barley (MB) or extruded barley (EB) (experiment 1) and either unprocessed maize (UM), micronised maize (MM), extruded maize (EM), unprocessed peas (UP), micronised peas (MP) or extruded peas (EP) (experiment 2).
- Published
- 1999
- Full Text
- View/download PDF
12. Gas production in vitro from purified starches using equine faeces as the source of inocula
- Author
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D Cuddeford, Annette Longland, J J Hyslop, B M L McLean, and T Hollands
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Chromatography ,Fermentation kinetics ,Starch ,Sodium ,food and beverages ,chemistry.chemical_element ,General Medicine ,In vitro ,Incubation period ,Wheat starch ,chemistry.chemical_compound ,chemistry ,Hay ,Feces - Abstract
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.
- Published
- 1999
- Full Text
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13. Measurement of caecal outflow rate in ponies using Chromium mordanted feeds
- Author
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T Hollands, J J Hyslop, Annette Longland, D Cuddeford, M. J. S. Moore-Colyer, and B M L McLean
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Chromium ,Animal science ,Outflow rate ,Chemistry ,chemistry.chemical_element ,General Medicine - Abstract
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.
- Published
- 1999
- Full Text
- View/download PDF
14. Effect of physical processing on in situ degradation of barley in the caecum of ponies
- Author
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B M L McLean, J J Hyslop, Annette Longland, and D Cuddeford
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biology ,Pony ,Starch ,General Medicine ,biology.organism_classification ,Processing methods ,Caecum ,chemistry.chemical_compound ,Animal science ,chemistry ,biology.animal ,Hay ,Dry matter ,Incubation ,In situ degradation - Abstract
Cereal grains are often subjected to physical processing before being fed to equids. However, little information is available on how physical processing of cereals affects degradation dynamics in equids. This experiment examines the effect of two physical processing methods (micronisation and extrusion) on in situ degradation of barley in the caecum of poniesThree caecally fistulated mature Welsh-cross pony geldings (approx. LW 270kg) were offered ad libitum grass hay plus minerals. Incubation bags (monofilament polyester 6.5 x 20cm, 41μm pores, 16mg/cm2 sample size) containing either unprocessed barley (UB), micronised barley (MB) or extruded barley (EB) were incubated in the caecum for fixed times according to both a forward (0, 2, 4, 6, 12, 8, 24, 48h) and reverse (48, 24, 8, 4, 12, 6, 2, 0h) incubation sequence. For each feedstuff residues from each time were bulked within pony and across incubation sequence for subsequent analysis of dry matter (DM) and starch (STC). Degradation profiles were fitted to the DM and STC disappearance data according to Ørskov and McDonald (1979).
- Published
- 1998
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15. The Use of N-alkanes for Estimating Intake and Passage Rate in Horses
- Author
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F.D.DeB. Hovell, B M L McLean, and R.W. Mayes
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Alkane ,chemistry.chemical_classification ,Carbon chain ,N alkanes ,Animal science ,Chemistry ,food and beverages ,General Medicine ,Long chain ,Feces ,Forage crop - Abstract
Alkanes occur naturally in all plants, although forage crops tend to have higher alkane contents than cereals. N-alkanes have odd-numbered carbon chains. They are ideal for use as markers in feed trials, because, they are inert, indigestible and naturally occurring, and can be recovered in animal faeces. Synthetic alkanes (even-numbered carbon chains) are available commercially and can also used as external markers. Dove and Mayes (1991) cite evidence indicating that faecal recovery of alkanes in ruminants increases with increasing carbon-chain length. Thus the alkane “pairs” (e.g. C35 & C36, and C32 & C33) are used in calculating intake and digestibility because they are long chain and adjacent to each other. However, recent work by Cuddeford and Mayes (unpublished) has found that in horses the faecal recovery rates are similar regardless of chain lengths.
- Published
- 1996
- Full Text
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