The nutritional value of four tropical grasses when fed as chaff and pellets to sheep

1968 ◽  
Vol 8 (32) ◽  
pp. 270 ◽  
Author(s):  
DJ Minson ◽  
R Milford

Pangola (Digitaria decumbens), kikuyu (Pennisetum clandestinum), setaria (Setaria sphacelata), and buffel grasses (Cenchrus ciliaris) were cut at different stages of growth and artificially dried to provide ten feeds with a range of leaf percentages (13-56), nitrogen contents (0.42-3.70 per cent), and acid detergent fibre percentage (26.3-43.3). Half of each cut was chaffed and the remainder pelleted. Both pellets and chaff were fed to Merino wethers in metabolism cages. Pelleting decreased the mean digestibility of dry matter by 6.8 percentage units, nitrogen by 2.2 percentage units, and ADF by 11.5 percentage units. Pelleting increased the mean voluntary intake by sheep 47 per cent for dry matter and 27 per cent for digestible dry matter with only minor differences in response to pelleting mature and young grass. The smallest increase from pelleting was 4.1 per cent for buffel grass containing 0.42 per cent N. In grass of the same age in which the nitrogen content had been increased to 0.75 by fertilizer nitrogen, pelleting increased intake by 26.6 per cent. It was concluded that with mature tropical grasses the response to pelleting may be limited by a low nitrogen content. Pelleting may be a useful technique for eliminating the effect of physical structure when studying factors affecting the voluntary intake of pasture plants.

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.


1969 ◽  
Vol 72 (4) ◽  
pp. 531-543
Author(s):  
Angel V. Méndez-Cruz ◽  
Norma Corchado-Juarbe ◽  
Víctor Siberio-Torres

An evaluation of the hay obtained from tropical grasses coastcross I (Cynodon dactylon), stargrass (Cynodon nlemfuensis), callie (Cynodon plectostachyus), slenderstem (Digitaria pentzii), and guinea (Panicum maximum) was made at three harvest intervals (35-, 45-, and 55-day) and four storage periods (γ than 4, 4 to 8, 8 to 12, and < than 12 months). In vivo dry matter digestibility and voluntary intake trials were performed with Holstein steers, weighing from 340 to 390 kg. Mean digestibility was 60.8%, 56.8% and 55.0%, respectively, for 35-, 45- and 55-day harvest intervals. The mean reduction caused by storage was from 60.8 to 50.6%, from 56.8 to 48.8%, and from 55.0 to 47.2% for the 35-, 45-, and 55-day intervals, respectively. The lower digestibility values were measured in callie. Voluntary intake declined 12, 18, and 17% and the digested dry matter voluntary intake declined from 1.47 to 1.1%, from 1.31 to 0.9%, and from 1.15 to 0.82%. Crude protein content decreased by 17.0, 15.4, and 15.6% for the respective intervals. The major detrimental effect in hay quality was observed after a 12-month storage. Plant maturity influenced the mean increase of neutral detergent fiber (NDF) from 69.7 to 72.6 and 76.6%, acid detergent fiber (ADF) from 37.9 to 43.4 and 47.7%; and lignin content, from 5.2 to 9.3% for the three growth intervals. This increase was 9, 16, and 42% for each parameter. However, as storage effect, NDF, ADF, and lignin content were raised by 4.3%, 12.3%, and 5.0%, respectively.


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.


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.


1982 ◽  
Vol 98 (1) ◽  
pp. 123-129 ◽  
Author(s):  
D. C. Patterson ◽  
N. Walker

SUMMARYThree experiments were carried out to investigate factors which might affect the voluntary intake of effluents.Effluent was introduced into the diet of pigs at rates of 25, 50 and 100 g D.M./day, replacing dry meal to maintain a constant amount of dry matter offered. The mean maximum daily intakes of effluent on the three treatments were similar indicating that, within this range, the rate of introduction of effluent had no effect on its potential maximum intake.When solutions with differing concentrations of effluent dry matter were offered it was found that the intakes at the 20 and 10 g/kg concentrations were progressively lower than when tho concentration was 30 g/kg or higher. This suggested a physical limitation to the intake of effluent at low concentrations. A physiological limit may operate at concentrations of 30 g D.M./kg or higher.In the third experiment daily air-dry meal allowances of 80, 90, 100 and 110 g/kg W0.75 were offered in addition to an ad libitum supply of effluent. The voluntary intake of effluent dry matter was not significantly affected by tho amount of meal offered and the total amount of dry matter consumed remained virtually constant.


1970 ◽  
Vol 12 (4) ◽  
pp. 591-599 ◽  
Author(s):  
N. Jackson ◽  
T. J. Forbes

SUMMARYHerbage from the same timothy/meadow fescue/white clover sward was ensiled at four different dry matter contents. The resulting silages had dry matter contents of 19·0, 27·3, 32·3 and 43·2%, the dry matter content increasing with the length of the wilting period. An experiment was carried out to determine the voluntary intake of the silages. Each silage was given to 7 animals individually, the mean live weight of these being 334 kg.Although the silages made from wilted herbage were lower in digestibility than that made from unwilted herbage, wilting increased dry matter intake and metabolizable energy (ME) intake. The mean daily intakes of digestible organic matter were 53·0, 58·1, 59·6 and 59·6 g/kgW0·73, for silages of increasing dry matter content. The corresponding ME intakes, expressed as a multiple of the ME requirement for maintenance, were 1·17, 1·29, 1·30 and 1·28. The percentage of acetic acid in the silage dry matter was significantly (r= −0·56) and linearly related to voluntary intake. The relationship between lactic acid concentration and voluntary intake was significantly curvilinear (r= 0·48).


1957 ◽  
Vol 8 (2) ◽  
pp. 162 ◽  
Author(s):  
D McEAlexander

Estimates were made of dry matter and nitrogen contents of parts of sultana vines sampled a t frequent intervals from October to January in one season and January to July in the following season. From early October until the commencement of leaf drop in February there was a linear increase in the amount of nitrogen in the annual aerial growth. This nitrogen was present mainly in the laminae and fruit. After February the amount of nitrogen in the fruit continued to increase while that in the leaves decreased. The loss from the leaves could be partly accounted for by translocation to fruit or woody tissues and the remainder by leaf fall. The data obtained gave no indication of the best time for applying nitrogen to sultana vines. The amount of nitrogen in stems, and also the percentage of nitrogen in trunks, main roots, and feeder roots, increased to July, which suggested that root absorption from the soil continued throughout autumn. It is suggested that the total nitrogen content of laminae gives the most reliable indication of seasonal nitrogen uptake provided that due allowance is made for time of sampling. '


1973 ◽  
Vol 13 (61) ◽  
pp. 153 ◽  
Author(s):  
DJ Minson

On five occasions during the growing season Chloris gayana, Digitaria decumbens and Pennisetum clandestinum were fertilized with urea at 125 or 500 kg ha-1 and cut after one month's regrowth. The minimum nitrogen level in herbage was 0.96 per cent and hence voluntary intake of these feeds was not limited by a nitrogen deficiency per se. Fertilizing at the high level increased dry matter yield (P < 0.01) and depressed the leaf percentage significantly in C. gayana. Each cut was fed to ten wethers to determine digestibility and voluntary intake. The higher rate of nitrogen fertilizer increased the overall mean dry matter digestibility 2.2 per cent, organic matter digestibility 1.3 per cent and voluntary intake of dry matter 2.3 gWkg0.75 (P > 0.05). Within the harvests significant increases and decreases in digestibility and voluntary intake were found. The direction and magnitude of these changes in feeding value were not correlated with differences in yield, leaf percentage or nitrogen content.


1985 ◽  
Vol 53 (3) ◽  
pp. 649-656 ◽  
Author(s):  
R. A. Hunter ◽  
B. D. Siebert

1. In a number of experiments voluntary food intake of three low-quality roughages, either alone or supplemented with rumen-degradable nitrogen and sulphur and minerals, was measured in Brahman (Bos indicus) and Hereford (Bos taurus) steers. The chaffed hays were Spear grass (Heteropogon conform) (6.2 g N/kg organic matter (OM)), Pangola grass (Digitaria decumbens) (7.9 g N/kg OM), and Pangola grass (12.0 g N/kg OM). Rumen characteristics relating to rate of fluid outflow from the rumen were also determined.2. There was no significant difference between breeds in the dry-matter intakes of the unsupplemented diets which ranged from 11.3 to 17.8 g/kg body-weight (BW) by Herefords and from 11.8 to 16.1 g/kg BW by Brahmans.3. Supplementation of Spear grass with N and S significantly (P < 0.05) increased intake by Herefords (24%) but not by Brahmans. When the lower-N Pangola grass was supplemented there was a significant increase in intake by both breeds with the magnitude of the response in Herefords (42%) (P < 0.001) being greater than that in Brahmans (15%) (P < 0.05). The intakes of both the supplemented Spear grass and the lower-N Pangola diets were significantly (P < 0.05) greater by Herefords than Brahmans. There was no breed difference in intake when the higher-N Pangola grass was supplemented. Both breeds recorded an 8% intake response to supplementation, although the increase was only significant (P < 0.05) in Herefords.4. The mean retention time of fluid in the rumen on the unsupplemented Pangola grass diet of lower N content was 12.7 h in Brahmans compared with 17.5 h in Herefords (P < 0.01). When the higher-N Pangola was fed, both alone and supplemented, the mean retention times were similar on both diets (10.5 and 9.9 h for Herefords; 9.5 and 8.1 h for Brahmans for unsupplemented and supplemented diets respectively).5. Plasma urea concentrations were higher in Brahmans than in Herefords on all diets. Rumen ammonia concentrations were significantly (P < 0.001) higher in Brahmans than Herefords when the lower-N Pangola grass diet was unsupplemented.6. The intakes and the variable intake responses to supplementation between breeds and diets are discussed in relation to a number of animal and dietary factors.


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