摘要:

AbstractThe origins and development of in‐vitro techniques for the determination of the apparent digestibility of ruminant feedstuffs are critically reviewed. Special attention is given to the effect of the pH used for the pepsin digestion stage, its optimum value, and its solubilising effect upon various mineral compounds and protein‐ and mineral‐tannin complexes formed in the ruminant digestive system. New experimental evidence is presented concerning the latter effect. Comparisons are made with the Tilley and Terry method in widespread use at the present

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350802

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe effects of crusning and of heat‐treatment of high‐glucosinolate rapeseed (cv. Jet Neuf) by infrared, microwave or hot‐air oven upon the utilisation of protein and upon the anti‐thyroid activity, measured in terms of thyroid weight and plasma tri‐iodothyronine (T3) and thyroxine (T4) concentrations, were studied and comparisons made with crushed and untreated low glucosinolate rapeseed (Canola) and also with extruded soya bean. All treatments of Jet Neuf reduced net protein utilisation; crushing Jet Neuf produced the most severe deterioration. Jet Neuf also had greater anti‐thyroid activity. However, anti‐thyroid activity and protein utilisation were not highly correlated. None of the treatments applied to Jet Neuf produced improvements in protein utilisation or diminished anti‐t

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350803

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe weight of ‘dhal’ (the edible part of the seed) from 100 whole seeds, and the hull, protein, fat, starch and soluble carbohydrate contents of 12 pigeonpea (Cajanus cajan) cultivars and the F1crosses were determined. The mean values for cultivars and the F1crosses differed in 100‐seed wt, hull content (%) and protein and starch contents. Whereas 100‐seed wt showed a high positive correlation with the weight of dhal, its correlation was significantly negative with hull content (%) in cultivars and protein content in the F1

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350804

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractA detailed description is given of the construction and operation of a system of small wind‐tunnels used in the measurement of ammonia volatilisation from grass swards. In the design of the system, emphasis was placed on the requirements that (i) natural sward conditions should be influenced as little as possible, and (ii) airspeed through the tunnels should be controllable in the range normally encountered in the field. An analyser is described which incorporates an ammonia‐sensing probe; it was used to monitor automatically and continuously the concentration of ammonia in air entering and leaving the tunnels. The tunnels were found to have only small effects on sward conditions. Differences between simultaneous measurements of temperature made inside and outside the tunnels were rarely more than 1°C for air temperature and 2°C for soil temperature at 3 cm depth. The potential of the system was examined in a study comparing the loss of ammonia through volatilisation from swards treated with natural urine or an artificial urine. There were marked differences in the rates of volatilisation from the two urines although the total loss of nitrogen was similar from both, amounting to about 3% of the nitrogen ap

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350805

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350806

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350807

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThirty British Friesian bulls (12 months old), in groups of 6 or 12, were mixed with unfamiliar animals for 16 h preslaughter. Before and during mixing, blood samples were collected and behaviour was monitored. The ultimate pH (pHu) was measured in them. Longissimus dorsi(LD) 24 h after slaughter. Thirteen carcasses were dark cutting (DC, pHu≧6) and 17 were normal (pHu<6). DC carcasses came from animals which exhibited over twice the total number of agonistic interactions (P<0.001) and showed more dominant behaviour (P<0.001) than animals producing normal carcasses. There was no difference in the blood profile of DC and normal bulls before mixing. However, DC bulls had higher levels of creatine phosphokinase (P<0.001), free fatty acids (P<0.001) and β‐hydroxybutyrate (P<0.01) in the blood samples collected after mixing. Overall, pHu was correlated with total activity (r=0.71,P<0.001) and dominance scores (r=0.70,P<0.001). The conclusion is that the cause of DC in mixed groups of bulls is primarily behavioural. Muscle glycogen stores are depleted when blood‐borne metabolites are inadequate to fuel the intense or prolonged muscular activity associated with agonistic beh

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350808

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractSteers fitted with simple rumen and abomasal cannulas were given isoenergetic diets of approximately equal amounts of untreated (UT) barley straw and concentrates (flaked maize + tapioca) alone (BS) or with urea (BSU) or fishmeal (BSF). Similar diets were also given in which the barley straw had been treated (AT) with NaOH (BSA, BSAU and BSAF respectively). The diets were given in a 6 × 6 Latin square design. Feed components and abomasal digesta samples were analysed for neutral (NDF) and acid (ADF) detergent fibres and for monosaccharide constituents of structural polysaccharides. Hemicellulose contents were estimated as the sum of xylose + arabinose (X + A) and by the difference between ash‐free NDF and ash‐free ADF (NDF‐ADF). Cellulose was estimated as β‐linked glucose (C) and by the difference between ash‐free ADF and lignin (ADF–L).103Ruthenium and PEG were given as flow markers and flows (g24h−1) at the abomasum of carbohydrate components estimated in these ways were calculated. Approximately 98% (by wt.) of the cellulose (C) found in original feed and digesta samples was recovered in both NDF and ADF. Recoveries of hemicellulose (X + A) in NDF from UT straw, AT straw and abomasal digesta were approximately 92, 48 and 50%, respectively. The ADF fraction of feeds and digesta contained 3–6 and 10–17% of the nitrogen and xylose, respectively, present in the original samples. Mouth to abomasum digestibilities of hemicellulose (NDF– ADF) for diets BS, BSU, BSF, BSA, BSAU and BSAF were 39, 62, 67, 29, 61 and 76%, respectively. Corresponding values for cellulose (ADF–L) were 37, 34, 50, 45, 48, and 63%, respectively. The use of NDF–ADF and ADF–L as measures of hemicellulose and cellulose contents, respectively, of feeds and digesta, and the digestibility of these carbohydrate fractions between mouth and aboma

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350809

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractBothriochloa bladhi(Retz.) S. T. Blake, an aromatic fodder grass in the Himalayan region yielded 0.2% essential oil. Thirteen monoterpenoids and 14 sesquiterpenoids were identified in the oil, with sesquiterpenoids being the major constituents of the oil. The composition of this oil differs from reports on the essential oils from otherBothriochloaspecies with respect to major constituents, especially in the absence of acorenone‐

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350810

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractA method is described for the simultaneous determination by reversed‐phase h.p.l.c. of proline, glycinebetaine, trigonelline and stachydrine. The mobile phase was water containing 0.02Mdibutylamine phosphate at pH 3.0. The compounds were separated in a Dextropak Radial‐PAK Cartridge and were detected by a differential refractometer. Total time of elution was 8 min. The method was applied to the analysis of leaves of two tropical grasses and a tropical legume which had been subjected to water str

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350811

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY