The effect of concentrates on the rate of disappearance of digesta from the alimentary tract of cows given hay

1966 ◽  
Vol 33 (1) ◽  
pp. 13-23 ◽  
Author(s):  
R. C. Campling

SummaryTwo experiments were conducted with non-lactating cows to examine the effect of adding concentrates to a diet of hay on the rate of disappearance of digesta from the alimentary tract. The addition of large amounts of concentrates to the diet of cows offered hay ad lib. decreased the voluntary intake of hay, increased slightly the digestibility of the organic matter and decreased markedly the digestibility of the crude fibre of the diet. Also, the addition of concentrates increased the mean time of retention of stained hay residues in the alimentary tract and increased the time/kg hay the cows spent ruminating. At the end of a meal the amount of digesta in the reticulo-rumen of the cows offered hay ad lib. with restricted amounts of concentrates was about the same as that found when offered hay ad lib. as the only food. The results are discussed in relation to the regulation of the voluntary intake of hay by the cow.

1969 ◽  
Vol 11 (1) ◽  
pp. 11-18 ◽  
Author(s):  
J. D. Leaver ◽  
R. C. Campling ◽  
W. Holmes

SUMMARY1. In the first experiment, the digestibility of diets containing ratios of 1:1 and 1:4 hay to concentrates was determined at five levels of feeding in castrated male sheep. With diet 1.1, increasing the daily dry matter intake from 600 to 1400 g resulted in a linear decline in organic matter digestibility from 74·4 to 68·6%. The same increase in level of feeding led to a curvilinear decline in the organic matter digestibility of diet 1.4 from 83·0 to 75·9%.2. In a similar way the crude fibre digestibility of the diets declined as food intake increased. Also the increase in level of feeding caused a decrease in the mean retention time of stained hay in the alimentary tract.3. In a second experiment the digestibility of long dried grass offered ad libitum to eight dry and eight lactating cows was measured and compared with the digestibility of similar dried grass offered at maintenance level and ad libitum to eight castrated male sheep.4. On a metabolic live-weight basis (kg W0·73), the lactating cows ate 34% more organic matter than the dry cows and the mean voluntary intake of sheep was only 54% of the intake of dry cows.5. The organic matter digestibility for the dry cows was 1·9 units higher than that of the lactating cows and at ad libitum intake the organic matter digestibility for the sheep was 5·6 and 3·7 units lower than that of the dry and lactating cows respectively. The results are discussed in relation to the validity of extrapolating results obtained with sheep to cattle, and with non·lactating to lactating animals.


1975 ◽  
Vol 85 (2) ◽  
pp. 337-343 ◽  
Author(s):  
V. A. Oyenuga ◽  
F. O. Olubajo

SUMMARYThe organic-matter intake and the digestibility of grazed tropical pasture mixtures were assessed by the chromic oxide-faecal organic matter-nitrogen technique in five digestion trials. The pasture treatments were designated as: H, Cynodon nlemfuensis var. robustus in a mixture with the legumes Centrosema pubescens and Stylosanthes gracilis; J, Pennisetum purpureum in a mixture with the two legumes in H; K, treatment J plus Panicum maximum; L, a mixture of all the grass and legume species in treatments H, J and K.The mean organic-matter digestibility of the herbages was determined in indoor digestion trials during the experimental period and varied from approximately 60·0 ± 1·73% to 62·7 ± 4·18% in treatments K and H respectively, with treatments J and L falling between these two values. The mean digestibility of the herbage as grazed, however, was approximately 66·8 ± 1·72, 69·7 ±7·68, 67·1 ± 4·40 and 67·4 ± 4·15 % for treatments, H, J, K and L respectively.The estimated mean intake of organic matter was somewhat lower, while that of the digestible organic matter was appreciably lower than those reported for animals of corresponding live weights in temperate countries. Grazed pastures were better digested by 4·1 digestibility units in treatment H, by 7·1 in both J and K, and by 5·3 units in L, compared with the indoor digestion trials.More intensive studies are still needed to warrant any justifiable conclusion as to whether the low intake of herbage by tropical cattle is due primarily to the high crude fibre and the low nutritional values of the pastures, or to the inherent capacity of the animals conditioned to grazing poor·quality pastures.


1966 ◽  
Vol 20 (2) ◽  
pp. 229-244 ◽  
Author(s):  
R. C. Campling ◽  
M. Freer

1. Two experiments were conducted to examine the effect of grinding and pelleting roughages on the voluntary intake of food, digestibility, time of retention of food in the digestive tract, amounts of digesta in the recitulo-rumen and eating and ruminating behaviour of adult, non-lactating, non-pregnant cows. The first experiment was with artificially dried grass and the second with oat straw; also, with a diet of ground, pelleted oat straw the effect was studied of giving a daily intraruminal infusion of 150 g urea. The size of the particles of the ground roughages are given. 2. The mean voluntary intakes of long and ground dried grass were similar, the voluntary intake of ground, pelleted oat straw was 26% greater than that of long straw and the daily infusion of urea increased the voluntary intake of ground, pelleted oat straw by 53%. 3. The digestibility of the ground roughages was lower than that of the long roughages, the lower digestibility of the ground roughages was due mainly to the poor digestibility of crude fibre in the reticulo-rumen. The rate of disappearance of cotton thread placed in the ventral sac of the rumen was slower with ground than with long roughages. 4. The mean times of retention of ground roughages were shorter than those of long roughages when equal and restricted amounts of each food were given; with food offered ad lib. there was little difference between the mean times of retention of long and ground roughages in the alimentary tract. 5. On average, the mean amounts of digesta dry matter in the reticulo-rumen immediately after a meal were about the same with long and ground dried grass, with long and ground oat straw the amounts of dry matter were similar, but when the intraruminal infusion of urea was given the amount of dry matter increased by 49%. 6. The rate of eating (min/kg food) ground, pelleted roughages was much faster than that with long roughages; when the cows received ground roughage rumination did not occur but during short periods triple reticular contractions were seen. 7. The relationship between the voluntary intake of food, the amount of digesta in the reticulo-rumen and the rate of disappearance of digesta from the alimentary tract is discussed.


1989 ◽  
Vol 48 (3) ◽  
pp. 503-511 ◽  
Author(s):  
M. N. McLeod ◽  
B. R. Smith

ABSTRACTA study was made of the effect of fibre level in forages on eating and rumination behaviour. Eight forage diets were prepared from the leaf and stem fractions of two grasses and two legumes and were given at hourly intervals to four steers under steady-state conditions. Eating and rumination behaviour were measured automatically by recording changes in intra-oesophageal pressure.Mean voluntary intake of leaf was higher than that of the stem fractions (9·9 v. 5·6 kg/day; P < 0·001). This was associated with a shorter mean retention time in the rumen of the leaf than that of the stem fractions (21·4 v. 30·6 h; P < 0·001) and a lower concentration (g/100 g dry matter (DM)) of fibre (52-0 neutral-detergent fibre (NDF) and 30·5 acid-detergent fibre (ADF) v. 68·2 NDF and 45·3 ADF). Similar values (P > 0·05) between diets were found for both the water and DM contents of the rumen (60·1 kg, 7·8 kg). Voluntary intake was not related to either.No difference was found between forage diets in the mean time (132 min) and number (18·7) of periods spent eating each day (P > 0·05). Legume leaf fractions were eaten at a faster rate (g/min) than either the grass leaf or the stem fractions. Voluntary intake was related to the rate at which food was eaten (r = 0·89; P < 0·01) but no relationship was found with the time taken to eat food (r = –0·14; P>0·05). Eating rate was related to the level of both NDF (r = –0·91; P < 0·01) and ADF (r = –0·96; P < 0·001).Differences between diets were found in rumination times (mean 425 min; P < 001), the number of boluses regurgitated during each period (27·6; P < 0·05) and during each day (485; P < 0·001), and in the weight of boluses (455 g; P < 0·05). No differences (P > 0·05) were found between diets in the mean number of rumination periods each day (17·6), the mean time spent ruminating during each period (24·3 min), the mean rate at which boluses were regurgitated (53·2 s per bolus), the interval between boluses (5·1 s), and the DM in a bolus (27·5 g). Rumination time and the number of boluses regurgitated either per period or per day were not related to the fibre content of the diet (P > 0·05).The regurgitated boluses from leaf fractions were chewed less than the stem fractions (43·7 v. 54·7 chews per bolus). The regurgitated boluses of lucerne leaf were chewed at a faster rate (1·13 chews per s; P > 0·05) than regurgitated digesta of the other diets which were chewed at similar rates (0·97 chews per s; P > 0·05). The total number of rumination chews made each day by animals given lucerne leaf (12 300) was much lower (P < 0·001) than that by animals given the other fractions (25 300). The number of chews made on each bolus was related to fibre levels in the diets (NDF, r = 0·78, P < 0·05; ADF, r = 0·91, P < 0·01).It is concluded that the voluntary intake of high-fibre diets is not always restricted by rumen fill or rumination. The ease with which forage is eaten should be investigated as a factor influencing intake of fibrous forages.


1966 ◽  
Vol 20 (1) ◽  
pp. 25-39 ◽  
Author(s):  
R. C. Campling

1. Monozygotic twin cattle were used in a preliminary study of the effect of pregnancy and of lactation on the voluntary intake of food and water, and on eating and ruminating behaviour. Also, results are reported of an experiment with five pairs of monozygotic twin heifers to examine the variation within pairs of twins in voluntary intake of food and water and eating and ruminating behaviour.2. Voluntary food and water intakes were measured during the last few weeks of pregnancy and during early lactation. Within each twin pair one twin was pregnant or lactating and the other non-lactating and not pregnant, and the food and water intakes of a pair of twins were measured simultaneously.3. On average the variation in voluntary intake of hay within pairs of non-pregnant, monozygotic twin heifers was 0.2 kg or 3 % of the mean daily hay intake.4. The effect of pregnancy was observed in six pairs of twins and in five of the pairs the pregnant animal ate iess hay than its non-pregnant twinmate; in four of these five pairs the effect was small (13 % ). Changes in eating and ruminating behaviour associated with pregnancy were small; the pregnant animals ate concentrates and hay more slowly and ruminated longer than the non-pregnant animals.5. Lactation was associated with a mean increase of 29 % in hay intake in eight out of the nine pairs studied. In four pairs of twins given a diet of concentrates alone the lactating animal ate on average 8 % more than the non-lactating animal. The lactating cows tended to eat concentrates and hay more quickly than the non-lactating cows; because of differences in the ratio of hay to concentrates it was not possible to interpret the changes in rumination that occurred with lactation.


1978 ◽  
Vol 40 (2) ◽  
pp. 347-357 ◽  
Author(s):  
J. A. Milne ◽  
J. C. Macrae ◽  
ANGELA M. Spence ◽  
S. Wilson

1. Comparisons were made between castrated male Scottish Blackface sheep and red deer (Cervus elaphus) of voluntary forage intake (VFI), digestibility and the mean retention time (MRT) of a particulate-phase marker (103Ru-phenanthroline) in the alimentary tract, when a range of forages: dried-grass pellets, chopped dried grass, fresh-frozen Agrostis-Festuca spp. and heather (Calluna vulgaris, L. Hull) were given at different times of the year.2. On both the dried-grass-pellet and chopped dried-grass diets the red deer and sheep ate similar quantities. Both species had a higher VFI of dried-grass pellets in July than in November. The sheep digested the dried-grass-pellet diet better than the red deer and this was associated with a longer MRT of the particulate-phase marker in the alimentary tract.3. The VFI of Agrostis-Festuca spp. and heather by the red deer was twice that of the sheep. The VFI of heather by the sheep increased by 32 % between January and April, and the VFI of both the Agrostis-–Festuca spp. and heather diets by the red deer increased by 65–70 %. The sheep digested the Agrostis–Festuca spp. better than the red deer but the red deer digested the heather slightly better than the sheep. MRT of the particulate-phase marker was greater for the sheep than for the red deer on both diets. The digestibility and MRT of both diets in the red deer did not decrease with the seasonal increase in VFI, suggesting a possible hypertrophy of the alimentary tract.


1977 ◽  
Vol 24 (2) ◽  
pp. 227-235 ◽  
Author(s):  
W. A. McIlmoyle ◽  
J. C. Murdoch

SUMMARYTwo 7 × 7 Latin square experiments were carried out with British Friesian steers (mean initial live weight 360 kg). In Experiment 1 the effects of different levels of dried grass or concentrate on the intake of silage dry matter (DM) were compared, and in Experiment 2 the effect of a supplement containing various proportions of dried grass: concentrate on the intake of silage DM was examined. In both experiments the digestibility of the ration and the rate of passage of digesta were measured.In Experiment 1, supplementation depressed intake of silage DM, the difference being significant (P<0·05) at 5·0 and 7·5 kg/day, but there were no significant differences in silage intake between supplements given at the same level. Intake of silage was also significantly lower (P<0·05) in Experiment 2 when a supplement was offered, but differences between supplements were not significant. Total DM intake was increased significantly (P<00·5) by supplementation in both experiments. Supplementation increased energy digestibility but decreased crude fibre digestibility. In Experiment 1 nitrogen digestibility was significantly lower (P<0·05) with dried grass than with concentrate supplementation, but in Experiment 2 supplementation increased the digestibility of nitrogen. In both experiments the mean retention time was shorter, the time for the highest rate of excretion of stained particles was lower, and the maximum rate of excretion higher for dried grass than for silage.


1972 ◽  
Vol 12 (54) ◽  
pp. 21 ◽  
Author(s):  
DJ Minson

The digestibility and voluntary intake of Chloris gayana, Digitaria decumbens, Panicimum maximum var tricboglume, Paspalm dilatatum, Pennisetm Clanhtinum, and Setaria splendih were measured with sheep in metabolism pens. All grasses were grown under the same conditions and cut at the same time. Each grass was cut after growing for 28, 70, and 98 days in the summer and then again (except for P. dilatatum) after 42, 70, and 105 days in the following autumn. Four successive 28-day regrowths of each grass (two cuts only for P. dilatatum) were also harvested during the summer. All 55 cuts were artificially dried and fed at the same time, each cut being fed to eight sheep. Differences in dry matter and organic matter digestibility between grass species were relatively small with a maximum mean difference of six digestibility units between S. splendida and P. clandestinzrm. For the 28-day regrowths S. splendida was 5.1 digestibility units higher but with the more mature regrowths the difference was 6.8 digestibility units. The mean voluntary intake of dry matter of S. splendida and P. clandestinum was 9 and 11 per cent lower than that of D. decmbens (P<0.01) with the largest differences in voluntary intake between grasses occurring at the mature stages of growth. Large differences were found between grass species in both the slope and intercept of regressions relating voluntary intake to dry matter digestibility.


1962 ◽  
Vol 4 (1) ◽  
pp. 97-116 ◽  
Author(s):  
L. E. Harris ◽  
A. T. Phillipson

1. A comparison of the performance of Scottish Blackface ewe hoggets with and without an exteriorised flow to the duodenum was carried out while the animals were fed on hay with a low nitrogen content and added salt. No evidence was found from the food and water consumed, from the weight changes or from a comparison of the organic matter, nitrogen and ash contents of the food and the faeces that the operation caused any permanent disturbance to digestion.2. Regular measurements of the flow of abomasal contents to the duodenum established a pattern of flow that was influenced by feeding. A relationship between the quantities passed per hour from the abomasum and the time devoted to rumination was found, but the relationship appeared to be dissociated in time so that increased rumination preceded the increased passage of contents.3. The mean quantity of abomasal contents passed from four animals was 398 ml./hour. According to the quantities of chromium sesquioxide administered by mouth, passed from the abomasum, and excreted in the faeces this value represents not more than 90% and not less than 86% of the flow that can normally be expected.4. The quantities of organic matter that disappear in the stomach were calculated and represent about half or more of the total disappearance in the alimentary tract.5. Substantially more nitrogen left the abomasum than was eaten in the food daily. Of the nitrogen passing to the duodenum the greater part disappeared in the intestines.6. About twice as much ash left the stomach as was present in the food and about two-thirds of the ash entering the duodenum disappeared in the intestines.


Sign in / Sign up

Export Citation Format

Share Document