scholarly journals The alleviation of chronic copper toxicity in sheep by ciliate protozoa

1986 ◽  
Vol 55 (2) ◽  
pp. 361-367 ◽  
Author(s):  
M. Ivan ◽  
D. M. Veira ◽  
C. A. Kelleher

1. Rams, fauna-free from birth and initially of 48–65 kg live weight, were allocated to two groups of ten each and given a diet containing 14 μg copper/g dry matter; five additional rams were killed and their livers were analysed for Cu.2. One group (faunated) was inoculated with a mixed population of ciliate protozoa, and contained between 60x105and 195 x 105protozoa/ml rumen fluid throughout the 184 d experiment. The other group remained fauna-free. Following blood sampling, three rams in each group were killed on day 63, two on day 125 and four on day 184. One sheep in each group died during the experiment.3. Faunated rams showed higher weight gains and feed consumption than fauna-free rams.4. Plasma Cu concentration (μg/ml) increased from an initial 0.82to a final 1.00 in faunated and 1.36 in fauna-free rams. Liver Cu concentration (μg/g dry matter) increased from an initial 745 to a final 962 and 1684 in faunated and in fauna-free sheep respectively, representing a 4.3-fold greater increase in the fauna-free than in the faunated group. The absorption and retention of Cu was 38–50% higher in the fauna-free than in the faunated rams.5. It was suggested that rumen ciliate protozoa increased rumen production of sulphide (through increased breakdown of soluble proteins) which complexed part of the Cu, making it unavailable for absorption and utilization. Therefore, ciliate protozoa could determine susceptibility to chronic Cu toxicity in sheep.

2001 ◽  
Vol 137 (2) ◽  
pp. 205-220 ◽  
Author(s):  
A. F. CARSON ◽  
B. W. MOSS ◽  
L. E. R. DAWSON ◽  
D. J. KILPATRICK

The study investigated the effects of lamb genotype produced from hill flocks on feed efficiency, carcass characteristics and meat quality in animals finished on either a high forage:concentrate ratio diet (HFC) or a low forage:concentrate ratio diet (LFC). Purebred Scottish Blackface (BXB) lambs were compared with Blue-Faced Leicester×Scottish Blackface (BLXB) and Texel×Scottish Blackface (TXB) lambs. Purebred Cheviot (CXC), Suffolk×Cheviot (SXC) and Texel×Cheviot (TXC) lambs were also investigated. Lambs on the LFC diet were offered grass silage and concentrates mixed in the proportion of 0·80 silage and 0·20 concentrates on a dry matter basis. The LFC diet consisted of 0·20 grass silage and 0·80 concentrates on a dry matter basis. Representative lambs were slaughtered at the start of the experiment and on reaching 38 and 46 kg live weight. Averaged over the two slaughter weights, within the Blackface cross lambs, BXB had a lower liveweight gain (P < 0·01) than either BLXB or TXB (138, 207 and 203 (S.E. 11·1) g/day, respectively). Within the Cheviot cross lambs, CXC had a lower liveweight gain (P < 0·05) than SXC (188 v. 220 (S.E. 11·1) g/day), while SXC and TXC (204 g/day) had similar liveweight gains. Lambs on the LFC diet had a higher dressing proportion (P < 0·001) compared with lambs finished on the HFC diet (0·466 v. 0·434 (S.E. 0·0018) kg carcass per kg live weight). Averaged over the two slaughter weights BXB lambs had a lower (P < 0·05) dressing proportion than the other genotypes. Carcass conformation classification (assessed on a five-point scale) was higher (P < 0·001) in lambs finished on the LFC diet (3·0 v. 2·4 (S.E. 0·04)). Conformation classification was higher in lambs produced from Cheviot compared with Blackface ewes (P < 0·05). Within the Blackface cross lambs, BXB and BLXB lambs had a lower conformation classification (P < 0·001) than TXB lambs (2·4, 2·4 and 2·9 (S.E. 0·08) respectively). Within the Cheviot ewes, TXC lambs had a higher (P < 0·001) classification than either CXC or SXC (3·1, 2·7 and 2·7 (S.E. 0·08) respectively). Lambs finished on the LFC diet had a higher fat classification score compared with lambs on the HFC diet (P < 0·001) (3·4 v. 2·8 (S.E. 0·04)). Fat classification was similar across all genotypes. Lambs finished on the LFC diet had a lower ash content in the carcass than lambs finished on a HFC diet (P < 0·01) (44 v. 47 (S.E. 0·8) g/kg). Lamb genotype and dietary forage:concentrate ratio had no significant effect on cooking loss, sarcomere length, Warner–Bratzler shear force and L* values. Ultimate pH (pHU) was not influenced by dietary forage:concentrate ratio, but was significantly (P < 0·01) higher in BXB lambs compared with BLXB, TXB, CXC and TXC lambs. Lambs offered the LFC diet during the finishing period had significantly higher values for a* (P < 0·05), b* (P < 0·001), C* (P < 0·001) and H0 (P < 0·05) than lambs offered a HFC diet. Of these parameters only b* was significantly affected by lamb genotype, with BXB lambs having a lower value (P < 0·05) than the other genotypes.


1993 ◽  
Vol 69 (2) ◽  
pp. 467-479 ◽  
Author(s):  
E. J. Van Weerden ◽  
J. Huisman

In a study with ten pigs of 60–70 kg live weight, provided with a re-entrant cannula at the end of the ileum, and sixteen intact, non-cannulated pigs, the digestion and absorption of a dietary dose of 100 g isomalt/kg, and isomalt given between the meals as a ‘sweet’on the basis of 50 and 100 g/kg feed consumption, were examined. In all three isomalt treatments slightly less than 0.40 of the isomalt consumed was digested in the small intestine when the calculations were based on ileal sugar passage. However, when basing the calculations on energy contents of ileal chyme, only approximately 0.10 was digested in the small intestine. The bacterial fermentation of the isomalt flowing into the large intestine was indicated by a decreased faecal energy digestibility and a slight reduction in faecal dry matter and nitrogen digestibility. The retention of the minerals sodium, potassium, magnesium, calcium and phosphorus was not influenced to any measurable extent when isomalt was fed.


2010 ◽  
Vol 55 (No. 11) ◽  
pp. 468-478 ◽  
Author(s):  
K. Poláková ◽  
V. Kudrna ◽  
A. Kodeš ◽  
B. Hučko ◽  
Z. Mudřík

The main aim of this study was to investigate experimentally the effect of different composition of non-structural carbohydrates (NFC) in prepartum feed rations administered to high-yielding dairy cows at a high concentration of NFC in the diet on dry matter intake both before and after parturition and on subsequent milk performance, body condition and physiological traits of rumen fluid and blood. Thirty-six high-yielding dairy cows were allocated into one of the three well-balanced groups (K, O, and C), and each group received a different feeding rations. Feeding rations differed in non-structural carbohydrate (NFC) structure. The "K" (control) group received a feeding ration with NFC in the form of maize starch in particular, while the feeding rations of the other two (experimental) groups contained either (besides maize starch) saccharose from dried sugar beet (the "O" group) or a dominant amount of NFC was in the form of saccharose (the "C" group). After calving, all dairy cows were given the same feeding ration from the first day after parturition. The experiment was conducted for 21 days before and 50 days after calving. FR in the form of total mixed ration was offered ad libitum. Dry matter intake, milk performance, body condition, live weight, and blood and rumen parameters were recorded for the duration of the experiment. Average daily dry matter intake before calving was highest in the "K" group (14.32 kg per head). Differences among groups were statistically significant (P &lt; 0.05). Prepartum dry matter consumption dropped as the rate of saccharose in the diet of cows increased. Dry matter consumption levelled off after calving. Milk yield was also highest in the "K" group (43.71 kg/head/day), but fatness of milk and thus the production of fat corrected milk were lowest in this group. The highest milk fat content (4.10%) and fat corrected milk production (44.03 kg/head/day) were recorded in the "C" group, whereas the highest milk protein concentration was found in the milk of the "O" group. The composition of NFC affected dry matter intake before parturition, but these concentrations did not significantly affect dry matter intake, milk yield, milk composition, live weight, body condition or blood serum and rumen fluid parameters after calving


1998 ◽  
Vol 130 (2) ◽  
pp. 199-204 ◽  
Author(s):  
H. PEIRIS ◽  
R. ELLIOTT ◽  
B. W. NORTON

Sorghum grain was included in a basal diet of molasses (molasses 505, urea 21, sunflower meal 191, pangola grass hay 250, minerals 31 g/kg as fed) at rates of 0, 202, 391 and 707 g/kg, generating diets in which grain replaced 0 (diet A), 33 (diet B), 66 (diet C) and 100% (diet D) of the molasses and hay. The four diets were fed to groups of four Hereford steers (293–334 kg liveweight) over a 96-day period. One half of each treatment group was implanted with a growth promotant (zeranol), and all were slaughtered at a commercial abattoir at the end of the trial. The inclusion of 33% grain increased voluntary feed consumption, digestible dry matter (DM) intake (from 57·6 to 82·0 g digestible DM/kg0·75 per day and significantly increased liveweight gain from 592 to 900 g/day. Zeranol implantation also increased liveweight gain but not feed intake. Steers given only grain (diet D) had the highest liveweight gains (1127 g/day). The addition of grain to molasses diets decreased urinary N excretion and increased ammonia and volatile fatty acid (VFA) concentrations in rumen fluid. Molar proportions of propionic acid in total VFA increased from 0·15 to 0·20, and butyric acid decreased from 0·36 to 0·29 when 33% of the molasses was replaced by sorghum grain. The fat content (depth at sacral position) of the carcasses of steers given grain only (diet D) was significantly greater (14 mm) than that of steers given the basal diet of molasses (4 mm), and carcass fat contents were intermediate (10 and 11 mm) for steers given diets B and C respectively. It was concluded that the inclusion of small amounts of grain in molasses-based diets increased cattle growth principally by increasing digestible energy intake without decreasing molasses intake, thus improving the efficiency of utilization of molasses in molasses-based diets.


1997 ◽  
Vol 65 (2) ◽  
pp. 305-310 ◽  
Author(s):  
J. R. Webster ◽  
I. D. Corsor ◽  
R. P. Littlejohn ◽  
J. M. Suttie

AbstractThe growth of male red deer slows during the first winter of life before increasing again during spring. This study aimed to determine if this period of slow growth could be minimized using artificial photoperiods during autumn and winter (10 April (week 1) to 11 September (week 23), southern hemisphere). Four groups of deer (no. = 10) were housed indoors as follows. Two groups were placed on a winter solstice photoperiod (8·5 light (L): 15·5 dark (D)) and given either a natural increase in photoperiod to 11·25L: 12·75D (WSN) or held on 8·5L: 15·5D for 7 weeks followed by an abrupt increase to 11·25L: 12·75D (WSH). One group was exposed to a summer solstice photoperiod of 16L: 8D (SS) and one group exposed to a natural photoperiodic pattern (IC). A fifth group of deer (no. = 10) was maintained outside on a gravelled enclosure under natural changes in photoperiod (OC). All groups were given a diet containing 160 g protein per kg and 11·0 MJ metabolizable energy per kg dry matter (DM) ad libitum. All animals were weighed weekly and group food intake recorded daily. Metatarsal length was measured at weeks 3,17 and 22 from the start of treatments.The major differences occurred between SS and the other groups. After a period of slower growth (weeks 1 to 5, SS = 88 g/day v. 168 g/day other groups, s.e.d. 31·2, P < 0·05), SS grew more rapidly from week 10 (P < 0·01). As a result, SS was heaviest from week 17 (P < 0·05) until the end of the experiment (P < 0·01). The mean growth rate of SS animals from weeks 10 to 23 was 346 g/day compared with 173 g/day (s.e.d. 15·3; P < 0·001) for the other groups. Over the whole experiment, SS animals gained 42·3 kg live weight, compared with 31·1 kg for WSN, 26·6 kg for WSH, 25·1 kg for OC and 23·7 kg for IC (s.e.d. 2·08 kg P < 0·01). The DM intake of SS from week 9 until the end of the experiment averaged 2·04 kg DM per head per day compared with 1·48 (s.e. 0·041) kg DM per head per day for the mean of the other groups. Metatarsal length increased more in SS than the other groups (P < 0·001) between weeks 3 and 17 and was longest in SS at weeks 17 and 22 (P < 0·01). Exposure to a 16L: 8D photoperiod during winter advanced the rapid growth of red deer calves normally associated with spring and summer. This response may be used to advance slaughter dates for venison production.


1954 ◽  
Vol 44 (4) ◽  
pp. 383-393 ◽  
Author(s):  
T. L. Dodsworth

1. A feeding trial is described including four groups of cattle fed on silage only, two mixtures of silage and roots, and roots, straw, hay and oats.2. The live-weight gains made are recorded together with the rate of dry-matter intake.3. The efficiency of the dry matter of the diets was calculated.4. Silage fed alone produced a significantly greater rate of fattening than the other three diets.5. Cattle receiving roots in the morning and silage at night consumed 10·78% more dry matter and made greater live-weight gains than cattle fed on silage in the morning and roots at night.6. Calculation of the starch values of the roots and silage showed that these are higher when fed together than when silage is fed alone or when roots are fed with straw, hay and oats.7. An experiment is described designed to determine the effect of the dry-matter percentage of the diet on dry-matter intake in ruminants and of sudden changes in dry-matter content on digestibility.8. Sheep receiving 19·46% dry-matter silage consumed 16·7% more dry matter and 19·8% more starch equivalent than sheep eating 15·85% dry-matter silage.9. When the dry-matter percentage of the silage fell from 19·46 to 15·77 the digestibility of the dry matter fell by over 10%.10. The starch equivalent of the silage when fed alone was determined from the results of a digestibility trial and according to the performance of the cattle in the feeding trial. The values found were 65·88 and 66·15% respectively.11. The losses suffered in silage-making in twentyfive silos are recorded and discussed. The loss of dry matter and crude protein both average approximately 40% of that ensiled. The need for finding methods of reducing these losses is again stressed.


1982 ◽  
Vol 99 (1) ◽  
pp. 153-161 ◽  
Author(s):  
D. A. Davies ◽  
T. E. H. Morgan

SUMMARYHerbage characteristics of perennial ryegrass (Lolium perenne L.), cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.) and timothy (Phleum pratense L.) pastures were obtained whilst rotationally grazed by ewes and their single lambs at a fixed stocking rate of 25/ha on an upland site (305 m O.D.) in mid-Wales. Drymatter production of cocksfoot averaged 32·1 kg/ha/day over the 3-year duration of the trial (1975·7) and was 13·3 kg/ha/day lower than that of the other three grass species. This resulted in a 8 kg/ha/day reduction in dry-matter intake on cocksfoot; this was significantly lower (P < 0·05) than that achieved on the other grasses, which were similar to one another around 36 kg/ha/day.In vitro digestibility of the herbage ranked in the order perennial ryegrass > timothy = cocksfoot > tall fescue. Intake of digestible organic matter (DOMI) was lower on cocksfoot than on perennial ryegrass and timothy. Differences were also detected in crude protein, water-soluble carbohydrates and sodium composition between species.Dry-matter intake was positively correlated with herbage growth rates (r = 0·95, P < 0·001) but not to digestibility of herbage on offer (r = 0·18). Both ewe and lamb live-weight gains were positively related to intake of dry matter and DOMI.Reference is made to comparative yield data between the grasses obtained under cutting trials. In the 2nd and 3rd harvest years (1967–1967) growth rates in the grazing experiment were 76, 61, 81 and 80% of the 66·2, 66·7, 67·8 and 65·0 kg D.M./ha/day obtained under a cutting regime on perennial ryegrass, cocksfoot, tall fescue and timothy swards respectively. This illustrates the danger involved in assessing the potential of grasses based on such information.The results are discussed in relation to the value of the species for use under grazing in the uplands.


1984 ◽  
Vol 52 (2) ◽  
pp. 261-275 ◽  
Author(s):  
F. G. Whitelaw ◽  
J. Margaret Eadie ◽  
L. A. Bruce ◽  
W. J. Shand

1. Twelve steers fitted with rumen cannulas were used in three separate experiments to investigate the effects of the presence or absence of rumen ciliate protozoa on methane production. The diet consisted of 850 g barley and 150 g protein supplement/kg, and was given in three feeds daily at a restricted level of 61 g/kg live weight0.75. Animals were defaunated initially by allowingad lib. consumption of this diet and were then maintained ciliate-free by isolation or were faunated by inoculation with a mixed ciliate suspension. Samples of rumen fluid were taken routinely for the assessment of microbial populations and for volatile fatty acid (VFA) analysis and energy and nitrogen balances and digestibility measurements were made at intervals while animals were confined in respiration chambers.2. In each experiment the rumen VFA proportions changed from a high-propionate pattern under ciliate-free conditions to a low-propionate, high-butyrate pattern in the presence of ciliates: differences between treatments were highly significant (P < 0.001). There were also marked differences between treatments in CH, production but a reliable comparison was possible only in Expt 3, in which CH4was significantly higher (P < 0.001) in the presence of a rumen ciliate population. In Expt 3 the increased loss of energy as CH4in the faunated animals amounted to 44 MJ/100 MJ energy intake.3. Stoichiometric estimates of CH4production derived from the observed VFA proportions showed good agreement with CH4production as measured in respiration chambers. On average, the stoichiometric CH4values overestimated CH4production by a factor of 1.08.4. Highly significant linear relationships (P < 0.001) were observed between the molar proportion of each major VFA and the quantity of CH4produced: the proportion of propionic acid was inversely related to CH4and showed the lowest residual standard deviation of all the relationships examined.5. The losses of energy in faeces and urine did not differ between treatments hence the increased loss of energy as CH4in the faunated animals resulted in a significant reduction in the metabolizability of the diet from 0.73 to 0.69 (P < 0.05). No significant differences were detected between treatments in heat production, apparent digestibility coefficients or N balance.6. It is suggested that the rumen ciliates, by modifying the rumen VFA proportions, are directly responsible for the increased CH4production in faunated animals.


1994 ◽  
Vol 58 (3) ◽  
pp. 381-387 ◽  
Author(s):  
G. R. Iason ◽  
D. A. Sim ◽  
E. Foreman ◽  
P. Fenn ◽  
D. A. Elston

AbstractVoluntary food intake (VFI) of chopped timothy hay and metabolic rate were each measured in each month of the year in six non-breeding ewes of each of three breeds. Metabolic rate was measured using indirect calorimetry over a range of food intakes and adjusted for intake to an estimated maintenance metabolic rate (MMR). The breeds compared were the Dorset Horn (DT), Scottish Blackface (BF) and Shetland (SH), the first being less seasonal in reproductive and other characteristics than the other two which are hill or northern latitude breeds. There was significant overall variation between months in VFI which was higher in the summer (July to September) than in the winter (December to February) months (P < 0·001). There was a significant breed × month interaction (P < 0·01), the seasonal effect being most strongly observed in the BF and SH ewes, whose VFI in summer was proportionately 0-1 greater than the year-round mean but was 0-1 lower in the winter. The DT ewes showed much less seasonal variation in VFI. There was no overall difference in VFI between breeeds (DT: 43-7; BF: 49-5; SH: 48-1 g dry matter per M075 live weight per day, P > 0·1). Although MMR varied significantly between months (P < 0·001), there was no systematic variation between summer and winter. There was no significant breed × month interaction, but the MMR differed significantly (P < 0·001) between breeds giving a high overall MMR in BF (DT: 322-7; BF: 356-6; SH: 324-5 kf/kg M0·75 per day). No significant correlation existed (P > 0·05) between the monthly mean MMR and VFI in any of the breeds. The causal relationship between seasonal cycles of basal metabolic rate and VFI is questioned.


1973 ◽  
Vol 53 (2) ◽  
pp. 273-278 ◽  
Author(s):  
H. R. SHARMA ◽  
J. R. INGALLS

Twenty-four Holstein calves were fed three experimental rations containing either 14% soybean meal, 20% rapeseed meal, or 20% formaldehyde-treated (0.7 g formaldehyde/100 g protein) rapeseed meal from 8 to 22 wk of age. No significant differences (P > 0.05) were observed in feed consumption, dry matter intake, liveweight gain, and feed conversion among the three groups. There was a significant (P < 0.05) reduction in rumen ammonia levels in calves receiving the treated rapeseed meal compared with the untreated rapeseed meal rations. Plasma urea levels and rumen fluid volatile fatty acids (mmol/100 ml and molar percent) did not differ significantly (P > 0.05) among treatments. There were no significant differences in the digestibilities of dry matter, nitrogen, acid detergent fiber, and gross energy among treatments, although treating the rapeseed meal with formaldehyde tended to reduce dry matter, nitrogen, fiber, and energy digestibility.


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