The use of sheep fitted with oesophageal fistulas to measure diet quality

1964 ◽  
Vol 4 (12) ◽  
pp. 71 ◽  
Author(s):  
GW Arnold ◽  
WR McManus ◽  
IG Bush ◽  
J Ball

Ewes and wethers with oesophageal fistulas were compared with normal sheep in several experiments over three years. The grazing behaviour, herbage intake, liveweight changes, and ability to bear and rear lambs were altered little by fistulation, provided fistulas were less than 5 cm in length and closure of the fistulas was good. This was so even at a relatively high stocking rate of G ewes to the acre. These findings infer that studies with fistulated sheep provide information validly applicable to normal sheep. Fistulas that allowed good closure control (<5 cm in length) did not always allow complete recovery of ingested material. However, with incomplete recovery representative diet samples were obtained. Sampling procedures for obtaining adequately representative diet samples for individual sheep, and for obtaining estimates of diet composition for flocks of sheep on different pastures were established. The routine that must be followed to avoid obtaining untrue diet samples is to sample sheep when they are accustomed to a pasture, without prior fasting, and at the time(s) of the day when sheep are normally grazing. An hour's sampling period will collect about l/l0th of the total daily intake and longer periods may cause rumen dysfunction. Pooling data from once-a-day samples for two successive days for an individual sheep seemed to give accurate values for the whole diet over those two days for sheep set stocked on pasture. Variation between-sheep, between-days, and within-days in the nitrogen and soluble carbohydrate content and botanical composition of extrusa samples was studied. The contribution of these sources of variation to total variation differed for different diet constituents. For nitrogen, between-sheep variation was greater than between-day variation but for soluble carbohydrates the position was reversed. Within-day variation was much the same as between-day variation in a constituent. The standard deviations of nitrogen and soluble carbohydrate contents and botanical composition were large and a true mean value for any of these parameters for a flock of sheep, could only be obtained by pooling data for several sheep on several successive days.

1991 ◽  
Vol 42 (6) ◽  
pp. 913 ◽  
Author(s):  
H Dove ◽  
RW Mayes

This review discusses the potential use of plant wax components, especially n-alkanes, as markers for estimating herbage intake, estimating the botanical composition of consumed herbage and studying digesta kinetics. Previous approaches to making these measurements are discussed briefly. Attention is drawn to the fact that current methods for estimating intake do not adequately allow for differences between individual animals. It is also suggested that the markers currently used to estimate botanical composition or study digesta kinetics are inadequate. The nature of the chemical constituents of plant waxes is briefly discussed and the concept of using alkanes to estimate intake is introduced. Particular emphasis is given to the fact that although the recovery of alkanes in faeces is not complete, intake can still be estimated using a pair of alkanes (one natural, one dosed) provided these have similar faecal recoveries. The accuracy of estimation of intake is discussed in terms of: obtaining a representative sample of herbage; alkane dosing and faecal sampling procedures; validity of the assumption of similar recoveries for the natural and dosed alkanes; sample preparation and analysis. Published comparisons of estimated and actual intakes are presented, with the conclusion that satisfactory results are obtained if intake is estimated using natural C33 alkane and dosed C32 alkane. The use of the different patterns of alkanes in herbage species, as a means of estimating botanical composition, is then discussed. Results are presented showing this can be done successfully with herbage mixtures or oesophageal extrusa. Procedures are then described for making the corrections for incomplete faecal alkane recovery, necessary to estimate the botanical composition of the herbage consumed by the free-grazing animal. This allows the quantification of the intake of individual plant species by individual animals, and it is suggested that this can be achieved without the need for oesophageally-fistulated (OF) animals. Differences in alkane levels between plant parts within a species are then discussed. It is suggested that these can lead to error in the estimation of intake, if OF animals should consume plant parts different from those consumed by the test animals. However, it is also suggested that differences in alkane levels between plant parts can be used to quantify the intake of these parts, in a manner analogous to the estimation of the intake of individual plant species. The usefulness of alkanes in studies of digesta kinetics is then discussed, principally in relation to the natural alkanes, which remain intimately associated with plant particles in the gut. It is suggested that natural alkanes could prove excellent markers for studies of particle breakdown and digesta flow. The preparation of natural 14C-labelled alkane, for use as a pulse dose in mean retention time studies, is also discussed.


1999 ◽  
Vol 50 (4) ◽  
pp. 465 ◽  
Author(s):  
B. J. Leury ◽  
C. Siever-Kelly ◽  
R. J. Simpson ◽  
K. L. Gatford ◽  
H. Dove

The treatment of annual ryegrass–silver grass pasture with the herbicide glyphosate at seed head emergence delayed the loss of soluble carbohydrates and improved herbage digestibility. The present study investigated whether this improvement in nutritive value had any influence on the diet preference, intake, and performance of housed sheep. Since the effects of glyphosate on digestibility were most marked in stem tissue, preference was examined not only in relation to sprayed v. unsprayed herbage, but also in terms of preference for individual plant parts. In the preference testing, sheep showed a marked preference for sprayed rather than unsprayed herbage. They also consumed more of it, such that their digestible dry matter intake from sprayed herbage was nearly twice that from unsprayed herbage. When sheep were offered different plant fractions from the control herbage, they selected against stem material and preferred leaf or seed head. By contrast, when offered fractions from the sprayed material, they preferred stem to leaf, but showed no strong preference for stem over seed head. Preference was related more to the soluble carbohydrate content of a plant part than its digestibility, and only when soluble carbohydrate contents were similar was there preference for the more digestible material. The consumption of sprayed herbage, compared with control herbage, led to higher concentrations of rumen volatile fatty acids in the period 4 h after feeding. Moreover, the feeding of these herbages over a 6-week period resulted in significant reductions in pre-feeding plasma urea and β-hydroxybutyrate concentrations. When control herbage was fed with supplements of fructose, urea, or fructose+urea, in an attempt to mimic the possible differences in nutritive value between control and sprayed herbage, the responses in rumen and blood metabolites were less marked than when sprayed herbage was fed. As a consequence of the higher nutritive value of the sprayed herbage and the higher intakes by the animals fed this material, sheep fed sprayed herbage were able to maintain weight over the feeding period, whereas those offered the control herbage lost weight at 130–150 g/day


1966 ◽  
Vol 66 (3) ◽  
pp. 351-357 ◽  
Author(s):  
W. Ellis Davies ◽  
G. ap Griffith ◽  
A. Ellington

The primary growth of eight varieties of three species–white clover (3), red clover (4) and lucerne (1)–was sampled at fortnightly intervals and the percentage dry matter, in vitro digestibility, crude protein, water soluble carbohydrates, P, Ca, K, Na and Mg were determined.Differences between species were nearly always significant and the general order of merit was white clover, red clover and lucerne. The exceptions were for dry-matter percentage where this order was reversed, and red clover had the lowest Na and highest Mg content.


2016 ◽  
Vol 2 (1) ◽  
pp. 61-65 ◽  
Author(s):  
V. Melo-Ruíz ◽  
K. Sánchez-Herrera ◽  
H. Sandoval-Trujillo ◽  
R. Díaz-García ◽  
T. Quirino-Barreda

Escamoles, ant eggs (Liometopum apiculatum M), are edible insects consumed in great numbers and appreciated for their sensory characteristics, but not for their nutritional value. In Mexico, they reproduce in arid and semi-arid zones of Mexico and several states (Puebla, Tlaxcala, Hidalgo). Samples were gathered to determine reproduction conditions and perform an insect analysis to generate data composition in macronutrients, on dry basis, according to AOAC methods. The obtained data were: proteins: 42.12-50.63%; lipids: 30.27-34.96%; minerals: 6.53-7.85%; fibres: 1.91-2.56%; and soluble carbohydrates: 6.80-18.27%. Entomological material was collected in spring 2014, 3 nests for each zone, all from different altitudes and agroclimatic regions. Samples were representative for the insect supply in the areas studied. Insects are high in proteins and lipids, compared with most of the commonly consumed food, due to their high content of fatty acids; they must be refrigerated for later consumption. Minerals are moderated. Fibre and soluble carbohydrate levels are low, but an excess of proteins can be converted into carbohydrates via gluconeogenesis. Escamoles reproduce once a year in the spring, but sometimes one nest can provide escamoles eggs twice in the same season, once at the beginning and again at the end, depending on the biotic and abiotic conditions of their environment. Escamoles are a good source of nutrients; however, some rural people sell them to obtain extra income rather than consume them to improve their nutritional condition and welfare.


2019 ◽  
Vol 12 (4) ◽  
pp. 527-534 ◽  
Author(s):  
Suzanne Kabrite ◽  
Christelle Bou-Mitri ◽  
Jessy El Hayek Fares ◽  
Hussein F. Hassan ◽  
Jocelyne Matar Boumosleh

Background and Aim: The safety and quality of dairy products are considered to be of significant importance to human health. Although antimicrobial drugs are essential for disease treatment in modern medicine, the use of these drugs can have undesired consequences for human and animal health. This study aimed to investigate the presence of tetracycline and penicillin residues in raw, pasteurized, and UHT cow's milk of different fat contents, as well as in the dairy products yogurt and labneh, a traditional Lebanese product. Materials and Methods: A total of 44 samples, 4 raw, 9 UHT, 9 pasteurized milk, 10 yogurt, and 12 labneh samples from common local brands available in the Lebanese market were collected from Keserwan regions in May 2016. Tetracycline and penicillin residues were determined using a competitive enzyme-linked immunosorbent assay (ELISA) technique. Results: The mean values for tetracycline and penicillin were all below the limit of detection (LOD) of the ELISA kit of a maximum standard concentration of 1.80 μg/kg and 4.00 μg/kg, respectively. All samples tested positive for antibiotic residues. The detection rate for tetracycline in milk (n=22) samples was 86.4% with a mean residues value of 1.16±0.70 μg/kg. The detection rate of tetracycline in labneh (n=12) and yogurt (n=10) samples was 50% for each with a mean value of 1.76±0.40 μg/kg and 0.63±0.12 μg/kg, respectively. As for penicillin residues, 90.9% of the milk (n=22) samples tested positive with a mean value of 0.52±0.25 μg/kg. The detection rate in labneh (n=12) and yogurt (n=10) samples was 0% for penicillin residues, where mean values were all below the LOD (<1.25 μg/kg) for these dairy products. None of the samples exceeded the maximum residue levels. The estimated dietary intake (EDI) for tetracycline and penicillin residues for all dairy products is 2.09 ng/kg body weight (BW)/day resulting in 0.007% of the acceptable daily intake (ADI) and 1.83 ng/kg BW/day resulting in 0.006% of the ADI, respectively. Conclusion: All EDI values were below the ADI set for each antibiotic residue and do not exceed relevant toxicological reference values. However, concerns might still be present from consumption of other animal food products containing residues. Moreover, the long-term exposure to such residues is still unknown as a result of bioaccumulation; it is a challenging process to determine the actual dietary consumption of foods containing antibiotic residues; hence, the human health risk cannot be easily predicted.


2019 ◽  
Vol 50 (3) ◽  
pp. 155-163 ◽  
Author(s):  
B. Talebi ◽  
M. Heidari ◽  
H. Ghorbani

Abstract The elevation of arsenic (As) content in soils is of considerable concern with respect to its uptake by plant and subsequent entry into wildlife and human food chains. The treatment of sorghum seedlings with As as NaH2As4O. 7H2O at various concentrations (A1 = 0, A2 = 20, A3 = 40 and A4 = 60 mg As kg−1 soil) and salinity at four different levels (S1 = 0, S2 = 3, S3 = 6 and S3 = 9 dS m−1) reduced fresh and dry weights of sorghum plants. The co-application of As and salinity increased the guaiacol peroxidase (GPX) activity in shoot and root tissues. The highest GPX activity in shoot and root tissues was obtained at S2A4 and S3A3 treatments, respectively. The activity of catalase (CAT) in shoot was not changed, but unlike the GPX activity, salinity and As decreased the CAT activity in root tissues. Concerning the photosynthesis pigments, salinity had no effect on the chlorophyll ‘a’, chlorophyll ‘b’ and carotenoid content in leaves, but the As treatment significantly decreased the content of both chlorophyll types. Salinity increased the anthocyanin content in leaves. There were negative correlation between soluble carbohydrates (r2 = −0.78**) and stomata conductance (r2 = −0.45**) and dry weight of the plant biomass in this study. By increasing the salinity and As concentration in root medium, soluble carbohydrate in leaves increased but salinity decreased the leaf stomata conductance.


HortScience ◽  
2019 ◽  
Vol 54 (12) ◽  
pp. 2169-2177 ◽  
Author(s):  
Karen Mesa ◽  
Sara Serra ◽  
Andrea Masia ◽  
Federico Gagliardi ◽  
Daniele Bucci ◽  
...  

Annual accumulation of starch is affected by carbon reserves stored in the organs during the growing season and is controlled mainly by sink strength gradients within the tree. However, unfavorable environmental conditions (e.g., hail events) or application of management practices (e.g., defoliation to enhance overcolor in bicolor apple) could influence the allocation of storage carbohydrates. This preliminary research was conducted to determine the effects of early defoliation on the dry matter, starch, and soluble carbohydrate dynamics in woody organs, roots, and mixed buds classified by age and two levels of crop-load for one growing season in ‘Abbé Fétel’ pear trees (Oct. 2012 to mid-Jan. 2013 in the northern hemisphere). Regardless of the organs evaluated (woody organs, roots, and mixed buds), an increase of soluble carbohydrate concentration was observed in these organs in the period between after harvest (October) and January (dormancy period). Among all organs, woody short-old spurs showed the highest increase (+93.5%) in soluble sugars. With respect to starch, woody organs showed a clear trend of decreasing in concentration between October and January. In this case, short-old spurs showed the smallest decline in starch concentrations, only 6.5%, whereas in other tree organs starch decreased by 34.5%. After harvest (October), leaves showed substantially higher starch and soluble sugar concentrations in trees with lower crop-loads. These results confirm that in the period between October and January, dynamic interconversions between starch and soluble carbohydrates occur at varying magnitudes among organs in pear trees.


1996 ◽  
Vol 47 (2) ◽  
pp. 257 ◽  
Author(s):  
H Dove

The interaction of grazing animals and their pasture generates substantial income for Australia, so that an interest in modelling the processes involved can be justified readily. Based on a brief review of the factors influencing diet selection, it is suggested that, from the point of view of modelling the process, a major constraint has been the availability of accurate and convenient methods for estimating the botanical composition of the consumed diet. It is also suggested that there is a need in future work to define more adequately the available herbage in botanical, physical, chemical and spatial terms, and to conduct experiments in which factors influencing selection are examined in an unconfounded way. It is further suggested that, while the idea of fixed preference or selection coefficients for particular species is attractive from a modelling standpoint, available evidence does not support the concept. Factors influencing herbage intake are then discussed, particularly in relation to the interaction between the degree of rumen fill and the animal's capacity to use energy. The manner in which this interaction has been used in the modelling of intake is then described briefly and the modeling of diet selection and intake within the decision-support system GrazFeed is presented by way of example. Finally, the constraints associated with model validation are discussed briefly, especially in relation to the need in future work to define more adequately the characteristics of the pasture on offer.


2002 ◽  
Vol 75 (1) ◽  
pp. 153-167 ◽  
Author(s):  
M. J. Gibb ◽  
C. A. Huckle ◽  
R. Nuthall

AbstractTwo 4-week experiments were conducted to examine the effect of type of supplement, offered through automatic feeders at pasture, on supplement intake and grazing behaviour by multiparous spring-calving Holstein-Friesian cows grazing continuously stocked grass pastures. Four supplement formulations were used: a dairy concentrate containing 180 g crude protein per kg fresh weight (treatment DC), a high digestible undegraded protein supplement (treatment HP), a high starch, low protein supplement (treatment HS) and a high fibre supplement (treatment HF). In experiment 1, groups of eight cows were provided with access to one of diets DC, HP or HS, with a maximum of 4 kg being available during each of two periods, between 16:00 and 03:30 h and between 03:30 and 14:30 h. During experiment 2, groups of eight cows were provided access to diet DC, HP, HS or HF, up to a maximum of 8 kg between 16:00 and 14:30 h the following day. Detailed measurements of grazing, ruminating and supplement eating behaviour were made using jaw movement recorders and the transponder-controlled out-of-parlour feeder software. Treatment had no effect on intake rate per min or daily intake of supplement in either experiment, but did affect the temporal pattern of concentrate meals. Treatment did not affect grazing bite mass, bite rate or intake rate in either experiment. During experiment 1, compared with treatment DC, treatment HS reduced total eating time, total grazing jaw movements and daily herbage intake and increased ruminative mastications per bolus and ruminative mastications per kg grass OM intake. In experiment 2, compared with treatment DC, only treatment HS reduced total eating time, total grazing jaw movements and daily herbage intake. Treatments HS and HF both increased ruminative mastications per bolus. The results indicate that when supplements are available at pasture there is a conflict between the time required to consume supplements and herbage and that supplement type can affect both the temporal pattern of supplement intake and subsequent grazing activity.


Weed Science ◽  
1995 ◽  
Vol 43 (4) ◽  
pp. 604-611 ◽  
Author(s):  
Gregg A. Johnson ◽  
David A. Mortensen ◽  
Linda J. Young ◽  
Alex R. Martin

Intensive field surveys were conducted in eastern Nebraska to determine the frequency distribution model and associated parameters of broadleaf and grass weed seedling populations. The negative binomial distribution consistently fit the data over time (1992 to 1993) and space (fields) for both the inter and intrarow broadleaf and grass weed seedling populations. The other distributions tested (Poisson with zeros, Neyman type A, logarithmic with zeros, and Poisson-binomial) did not fit the data as consistently as the negative binomial distribution. Associated with the negative binomial distribution is akparameter.kis a nonspatial aggregation parameter related to the variance at a given mean value. Thekparameter of the negative binomial distribution was consistent across weed density for individual weed species in a given field except for foxtail spp. populations. Stability of thekparameter across field sites was assessed using the likelihood ratio test There was no stable or commonkvalue across field sites and years for all weed species populations. The lack of stability inkacross field sites is of concern, because this parameter is used extensively in the development of parametric sequential sampling procedures. Becausekis not stable across field sites,kmust be estimated at the time of sampling. Understanding the variability in it is critical to the development of parametric sequential sampling strategies and understanding the dynamics of weed species in the field.


Sign in / Sign up

Export Citation Format

Share Document