Effect of the liveweight of caged sheep and the amount of feed on offer on estimates of digestibility and ad libitum intake

1976 ◽  
Vol 16 (82) ◽  
pp. 656 ◽  
Author(s):  
H Jeffery

Three experiments were conducted in which the amount of feed offered to caged sheep was varied. Fresh kikuyu grass (Pennisetum clandestinum) was fed in one experiment and hays in the other two. Within each experiment a significant correlation between dry matter digestibility and liveweight occurred; no differences were detected between the slopes found with the various diets (slope = 0.34 per cent increase in digestibility per kg liveweight). Up to 60 per cent more kikuyu grass was offered to sheep than they could consume. Over this range a significant positive correlation was found between the ratio of the unconsumed to consumed feed and digestibility. This result indicates that great care should be exercised if the results of sheep digestibility experiments are used to interpret field data.

1982 ◽  
Vol 22 (116) ◽  
pp. 159 ◽  
Author(s):  
DJ Minson ◽  
D Ratcliff

To determine the effect of liveweight on the digestibility of dry matter, 29 grass cuts were each fed ad libitum to between five and ten sheep of the same age. In the complete experiment 255 different sheep were used. All 255 observations were used to calculate regressions relating digestibility to liveweight for each of the 29 grasses. When the data were divided into four digestibility groups (< 50, 50-55, 55-60, > 60%) the regression coefficient for grasses with a digestibility less than 50% was 0.373 (P < 0.01). The regression coefficient for the other three groups varied between -0.080 and 0.049 (P> 0.05). The data were also analysed by comparing the results obtained with the heaviest and lightest sheep on each of the 29 cuts. When the 29 cuts were divided into four groups, as described above, there was no significant difference in mean digestibility between heaviest and lightest groups for feeds having a digestibility greater than 50%. For cuts with less than 50% digestibility the heaviest sheep digested the grass 4.2 percentage units more efficiently than the lightest sheep (P < 0.05). There were no significant differences in the level of feed residues. It was concluded from both methods of analysis that any effect of liveweight on the digestive efficiency of sheep is limited to forages with a dry matter digestibility less than 50%.


1973 ◽  
Vol 53 (2) ◽  
pp. 257-263 ◽  
Author(s):  
G. PELLETIER ◽  
E. DONEFER

Three yearling Cheviot × Suffolk ewes and three Columbia wethers were confined in metabolic cages and fed ad libitum fresh and dried marrow-stem kale (Brassica oleracea var. acephala D.C.) harvested in mid- and late October. Chemical analyses of the forages indicated no marked effects on any of the plant constituents due to drying or advancing maturity. Digestibility measurements demonstrated that marrow-stem kale (MSK) was a highly digestible material with an average dry matter digestibility of 78%. The fresh forages had higher (P < 0.05) dry matter and gross energy digestibility values than the dried form. Dry matter digestibility coefficients were higher (P < 0.05) for late October as compared with the earlier harvest. A trend toward higher (P > 0.05) voluntary intake values due to drying maturity was observed with an average relative intake of 80%. The nutritive value index averaged 65, thus indicating a digestible energy intake similar to a high-quality (legume) forage.


1985 ◽  
Vol 36 (3) ◽  
pp. 483 ◽  
Author(s):  
JK Egan ◽  
PT Doyle

Six mature Merino sheep received three treatments in a randomized block design experiment. The treatments were: chopped oaten hay diet at 90% of ad libitum intake without urea (L); the ciet offered at the same level as for L with urea infused into the rumen at 11.5 g kg-1 dry matter intake (LU); and the diet offered at 90% of the ad libitum intake achieved with urea infused at 11.5 g kg-1 dry matter intake (HU). Sheep given HU consumed 37% more (P < 0.01) organic matter (OM) than those fed L or LU, but the apparent digestibility of OM did not vary (59.2-61.8%) between treatments. The addit onal food consumption was associated with c. 20% increase (P < 0.05) in the weight of OM in the reticulorumen and significantly higher (by 10-35%; P < 0.05) fractional outflow rates of most dietary and microbial constituents of digesta. The fractional digestion rate of potentially digestible plant cell walls was not affected by urea, but the flow of microbial non-ammonia nitrogen from the abomasum was enhanced (L, 7.0; LU, 8.2; HU, 12.5 g day-1; P < 0.05). The results of this study suggest that the stimulatory effect of urea upon food intake was associated with the provision of additional microbial protein for digestion in the intestines, rather than changes in the rate or extent of organic matter fermentation in the reticulorumen.


2008 ◽  
Vol 15 (3) ◽  
pp. 235 ◽  
Author(s):  
P. PURSIAINEN ◽  
M. TUORI

The effect of replacing wilted grass silage (GS) with pea-barley intercrop silage (PBS) on feed intake, diet digestibility and milk production was studied with 8 multiparous Ayrshire-cows in a replicated 4 × 4 Latin square experiment. Proportion of PBS was 0 (PBS0), 33 (PBS33), 67 (PBS67) or 100 (PBS100) % of silage dry matter (DM). The DM content was 559 and 255 g kg-1 for GS and PBS. Crude protein content was 131 and 170 g kg-1 DM, respectively. Pea-barley silage was more extensively fermented than GS with total fermentation acid content of 120 vs. 12 g kg-1 DM. Silage was fed for ad libitum intake and supplemented with on the average 13 kg concentrate per day. Silage DM intake was 9.2 (PBS0), 9.7 (PBS33), 9.0 (PBS67) and 7.1 (PBS100) kg per day (Pquadr. < 0.05). The energy corrected milk yield [30.3 (PBS0), 29.8 (PBS33), 30.3 (PBS67), 31.3 (PBS100) kg per day] was not significantly affected by the treatment. Milk protein concentration decreased linearly (P < 0.05) in response to feeding PBS. It is concluded that PBS can replace up to two thirds of wilted, moderate quality GS in the feeding of dairy cows because in this experiment pure pea-barley silage reduced silage intake.


1999 ◽  
Vol 50 (7) ◽  
pp. 1165 ◽  
Author(s):  
F. R. Dunshea ◽  
D. J. Kerton ◽  
P. J. Eason ◽  
R. H. King

Twelve Large White × Landrace sows nursing litters of 6 boars and 6 gilts were used in this study. Six litters suckled the sow only, whereas the other 6 litters received supplemental liquid skim milk (200 g/L) ad libitum from Day 10 until Day 20. On Day 20 the 4 heaviest pigs of each sex were allocated to 2 pairs and were weaned. Each pair was offered either pelleted or pelleted plus liquid feed. For the first 2 days post-weaning, each pair of liquid-supplemented pigs received liquid skim milk (250 g/L). On Day 23, pelleted feed was added to the milk. The ratio of liquid to pelleted feed was adjusted daily until, on Day 28, pigs were provided with pelleted feed only until 41 days of age. Supplemental skim milk increased growth (223 v. 291 g/day, P < 0.001) between Days 10 and 20 of age so that by weaning supplemented pigs were 10% (6.13 v. 6.74 kg, P = 0.038) heavier than unsupplemented pigs. Skim milk intake increased linearly from 190 to 600 g/day per pig over the 10 days of supplementation. Supplemental milk feeding did not alter sow liveweight change (−31.9 v. −30.3 kg for sows nursing litters with and without supplementation, respectively, P = 0.894) or change in P2 backfat thickness (−5.3 v. −4.2 mm, P = 0.279) between farrowing and Day 20 of age. Pigs weaned onto skim milk and pellets ate more (257 v. 30 g dry matter (DM)/day, P < 0.001) and grew better (213 v. −151 g/day, P < 0.001) over the first 2 days post-weaning than pigs weaned onto only pellets. Piglets provided with liquid feed after weaning continued to grow faster beyond Day 22, resulting in the benefit of weaning onto liquid feed being maintained until at least 41 days of age (14.1 v. 12.8 kg, P < 0.001). In conclusion, skim milk feeding before and after weaning can result in cumulative improvements in growth performance in the nursery.


1986 ◽  
Vol 26 (5) ◽  
pp. 527
Author(s):  
JC Spragg ◽  
RC Kellaway ◽  
TJ Kempton

Effects of cottonseed meal and cereal grain supplements on intake and utilisation of alkali-treated wheat straw were studied with 45 Friesian heifers (250 kg liveweight) in individual pens. Responses were measured in terms of feed intake and growth rate over 60 days. The basal diet fed ad libitum was coarsely milled wheat straw which was alkali-treated, sprayed with a solution containing urea, sulfur, copper and cobalt and sprinkled with dicalcium phosphate. Animals were also fed 800 g/day of 1 of 5 supplements: cottonseed meal (CSM), whole barley (WB), cracked barley (CB), ammonia-treated whole barley (NB) and extruded barley (EB). Intakes of the basal diet did not differ significantly between groups. Digestible organic matter in dry matter (%) was 53.1, 51.7, 47.2, 47.7, and 48.7 with supplements CSM, CB, WB, NB and EB, respectively; values for CSM and CB were significantly higher than for the other supplements (P< 0.05). Liveweight gains were 891,761,639, 657 and 784 g/day with the respective supplements, and did not differ significantly between CSM, CB and EB. We concluded that CSM did not stimulate intake of roughage more than supplements of barley grain, and that growth of the cattle was limited primarily by intake of energy.


1972 ◽  
Vol 79 (3) ◽  
pp. 493-499 ◽  
Author(s):  
G. J. Faichney

SUMMARYFistulated cross-bred sheep were given, by means of continuous feeders, concentrate diets containing chromic oxide (Cr2O3). Dry-matter digestibility coefficients predicted from the faecal concentration of Cr2O3 were compared with those obtained by total collection of faeces, and the concentration of Cr2O3 in spot samples of faeces taken at different times of day was compared with that in faeces bulked over an 8-day collection period. The rate of flow of digesta from the abomasum and the partition of digestion between the stomach and intestines, calculated from the concentration of Cr2O3 in samples of abomasal digesta, were compared with values obtained using two markers, one of which remained in solution while the other was adsorbed by particulate matter.Récovery of Cr2O3 in the faeces ranged from 91 to 101% and predicted dry-matter digestibilities were similar to those obtained by total collection. There was no diurnal variation but there was marked random variation in the concentration of Cr2O3 in spot samples of faeces. Cr2O3 was shown to behave independently of the particulate matter in digesta and, as a single marker, it significantly underestimated the flow of digesta from the abomasum relative to the double marker method. Cr2O3 thus overestimated digestion in the stomach and underestimated digestion in the intestines. It was concluded that Cr2O3 was not a satisfactory marker for studies of the flow of digesta and hence the partition of digestion within the gastro-intestinal tract when digesta samples are taken from a simple cannula.


1973 ◽  
Vol 24 (6) ◽  
pp. 939 ◽  
Author(s):  
SC Valentine ◽  
DC Brown

Formaldehyde-treated silage, formic acid-treated silage, formaldehyde-formic acid-treated silage, untreated silage, and lucerne hay were made from a lucerne sward and offered to Merino wethers. The formaldehyde was applied at a rate of 0.9 % of the weight of the dry matter and formic acid at 0.5 % of the fresh weight of the lucerne. Formaldehyde-treated silage and formaldehyde-formic acid-treated silage had significantly lower concentrations of ammonia nitrogen and total and individual organic acids than untreated silage. Formic acid-treated silage had a similar degree of fermentation to untreated silage, but more acetic acid and less lactic acid were produced than in untreated silage. However, when formic acid was applied in combination with formaldehyde, the ensiling fermentation was inhibited more than when formaldehyde was applied alone. There was some apparent protection of protein by the formaldehyde treatment. Treatment with formic acid significantly increased the in vivo digestibility of both nitrogen and dry matter, but did not increase ad libitum intake or wool growth by sheep offered this silage. Compared to untreated silage, treatment with formaldehyde significantly reduced the in vivo digestibility of nitrogen, produced a non-significant increase in intake, and significantly increased wool growth. The treatment of lucerne with both formaldehyde and formic acid significantly increased in vivo digestibility of dry matter, ad libitum intake, and wool growth compared with untreated silage. The treatment of lucerne with a mixture of formaldehyde (0.9% of the dry matter) and formic acid (0.5% of the fresh weight) was a suitable method of controlling the ensiling fermentation in order to increase the ad libitum intake of lucerne silage by sheep and their subsequent wool production. However, the intake and wool production of sheep offered such silage was still significantly less than that of sheep offered lucerne hay.


1974 ◽  
Vol 19 (1) ◽  
pp. 77-86 ◽  
Author(s):  
J. F. D. Greenhalgh ◽  
G. W. Reid

SUMMARY1. Four groups of eight castrated male lambs, weighing initially about 37 kg, were fed ad libitum for 18 weeks on: C, chopped dried grass throughout; P, pelleted grass throughout; C/P (or P/C), the two forms alternated every 3 weeks; or C + P, both forms on offer.2. Daily dry-matter intake (g/kg W0·75) was 58·2 for treatment C and 814 for treatment P; thus the long-term difference in intake was 40%. However, in the alternated sheep, dry-matter intake was 53·6 g/kg W0·75 for chopped grass and 86·5 g for pelleted; this short-term difference (61%) was significantly greater than the long-term difference. Dry-matter intake for treatment C+P was 84·9 g/kg W0·75; after the first week, chopped grass comprised only 10% of this. Dry-matter digestibility coefficients (%) were: C, 740; P, 61·4 and C+P, 62·0.3. The sheep were killed in week 19 and the dimensions of digestive organs and their contents were adjusted to an animal of 50 kg empty body weight. The weight of the reticulo-rumen was greater for C (1·30 kg) than for P (0·94) or C+ P (1·05), C/P and P/C being inter-mediate (1·15). The water-filled volume of the rumen was proportional to weight, except that C/P (alternated sheep finishing on pelleted grass) had low volumes. Reticulo-rumen fill was greater for C (7·28 kg) than for P (3·97) or C+ P (4·53), P/C (5·90) and C/P (4·34) being intermediate. There were no other significant differences in organs or contents.4. Gains in empty-body weight (g/day) were: C, 112; P, 181; C/P and P/C, 126; C + P, 195.


Author(s):  
R.A. Waned ◽  
E. Owen

The conventional method of measuring ad libitum intake of roughages involves offering sufficient (usually in chopped form) to ensure that 15 to 20% is left at the end of the feeding period (Blaxter et al 1961). Earlier experiments (Waned and Owen, 1986) with goats and sheep fed long roughages ad libitum (allowing 20% of feed offered to be refused) showed both species to be capable of selective feeding, in that refusals had a lower nutritive value than feed offered. The latter study and that of Glbb and Treacher (1976) with grazing sheep, suggested that selection and hence intake of roughage would increase if the amount offered (and hence refusal rate) was increased.To test this hypothesis two experiments were conducted with housed (16 hours light, 8 hours dark), individually penned Saanen castrate goats ranging in weight (15 to 65 kg) and age (6 to 30 months). Animals were fed restricted amounts of concentrates (15 g dry matter (DM) per kg M0.7S daily) and long barley straw ad libitum.


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