Voluntary intake of food by mature sheep following restricted feeding

1970 ◽  
Vol 74 (3) ◽  
pp. 477-485 ◽  
Author(s):  
D. M. Keenan ◽  
W. R. McManus ◽  
M. Freer
Keyword(s):  
Volatile Fatty Acids ◽  
Energy Content ◽  
Live Weight ◽  
Relative Increase ◽  
Energy Utilization ◽  
Energy Status ◽  
Total Energy Content ◽  
Digestible Organic Matter ◽  
Voluntary Intake ◽  
The Difference

SUMMARYNine Merino wethers were used in a cross-over experiment to compare the voluntary intake of three diets after a 4-week period in which the intake of the same diets was restricted, either to a level which maintained the live weight and energy status of the sheep, or to one which resulted in losses of 18% and 26% in their live weight and total energy content respectively. The diets were prepared from lucerne hay; chaffed (L), ground and pelleted (P) and pelleted after mixing with ground wheat (W).The voluntary intake of food increased only slowly during the 4 weeks after restrictions were removed; the total intake of digestible organic matter from diets W, L and P was in the ratio 100:122:146. Differences between diets L and P, but not W, were associated with their rates of disappearance from the rumen. Sheep which had been severely restricted ate less food during the first fortnight and no more during the second fortnight than those which had previously maintained their energy status. The difference in the first fortnight was less for diet P than for diet L. The process of adaptation by the sheep to unrestricted feeding was associated with an increase in the net rate of disappearance of volatile fatty acids from the rumen.Sheep offered food ad lib. after a period of submaintenance feeding gained more weight than sheep which had previously been fed to maintain weight and this increase was greater with diet P than with diet L. However, the differences in live-weight change consisted largely of water in the gut and did not result from a relative increase in the voluntary intake of food or in the efficiency of energy utilization.

Prediction of the voluntary intake of grass silages by beef cattle. 1. Linear regression analyses

1990 ◽  
Vol 50 (3) ◽  
pp. 425-438 ◽  
Author(s):  
A. J. Rook ◽  
M. Gill
Keyword(s):  
Dry Matter ◽  
Volatile Fatty Acids ◽  
Live Weight ◽  
Ammonia Nitrogen ◽  
Dry Matter Intake ◽  
Digestible Organic Matter ◽  
Voluntary Intake ◽  
Relationship Of ◽  
The Relationship ◽  
Linear Regressions

ABSTRACTData on individually recorded silage dry-matter intake (SDMI), concentrate dry-matter intake (CDMI) and live weight of steers and data on silage composition including toluene dry matter (TDM), pH, total nitrogen (N), ammonia nitrogen (NH3-N), volatile fatty acids (VFAs), digestible organic matter in the dry matter (DOMD) and neutral-detergent fibre (NDF) obtained from experiments conducted at three sites were used to obtain simple and multiple linear regressions of SDMI on other variables.Live weight accounted for a high proportion of the variation in intake but this effect could generally be removed by scaling intake by live weight raised to the power of 0·75 (M0·75). CDMI was the most important factor affecting scaled intake in mixed diets. TDM, NH,-N and VFAs all had important effects on SDMI. The relationship of SDMI with TDM was curvilinear suggesting that there is little to be gained in intake terms from wilting to TDM above 250 g/kg. The effect of NH3-N appeared to be related more to its correlation with VFAs than with any other nitrogenous constituent while the VFAs appeared to have a direct effect on SDMI. The effects of N and pH on SDMI were generally small. DOMD and NDF had relatively little effect on SDMI. Significant differences in intercepts between sites were found for most relationships although common slopes were often found.

A comparison of the effects on voluntary intake by sheep of either dietary or intra-ruminal addition of silage juices

2000 ◽  
Vol 70 (2) ◽  
pp. 325-333
Author(s):  
N.W. Offer
Keyword(s):  
Volatile Fatty Acids ◽  
Solid Phase ◽  
Rumen Fluid ◽  
Latin Square ◽  
Live Weight ◽  
Control Treatment ◽  
Juice Extraction ◽  
Digestible Organic Matter ◽  
Voluntary Intake ◽  
Daily Intakes

AbstractTwo silages were made from a regrowth of perennial ryegr ass following a 24-h wilt using either 2·5 l/t (LF) or 5·5 l/t (HF) of Add Safe (an aqueous solution of ammonium tetraformate, Trouw Nutrition, Cheshire, UK). Composition of silages LF and HF respectively were for dry matter (DM, g/kg) 205, 217; crude protein (g/kg DM) 106, 104; digestible organic matter (g/kg DM) 665, 692, pH 3·8, 3·9; lactic acid (g/kg DM) 103, 84; neutralizing value (meq/kg DM) 1051, 892; acetic acid (g/kg DM) 18·4, 14·0. Experiment A measured the intakes of the two silages using 12 Scottish Blackface wether lambs (mean live weight 25 kg) using a cross-over design with periods of 21 days. Intakes (g DM per day) were significantly greater (P < 0·05) for silage HF (329) than for LF (268). Experiment B measured the voluntary intakes of dried silage residues following juice extraction using the same protocol as for experiment A, except that only six lambs were used. There were no significant differences in composition or intake (P > 0·05) of the dried residues from the two silages. Experiment C used a 5 × 5 Latin-square design to measure the effects on voluntary intake of adding juices from the two silages to unmolassed sugar-beet nuts (SBN) pre-feeding or administered directly into the rumen in two discrete doses per day. Sheep on treatments LED and HFD received juices added to SBN (1·5 l/kg) and water added into the rumen in equal volume to the juice consumed with the previous day’s SBN. Treatments LFR and HFR received water added to the SBN (1·5 l/kg) and juice into the rumen in equal volume to the water consumed with the previous day’s SBN. The control treatment (W) was water added both to the SBN and into the rumen. Total mean daily intakes (g/day) were 1930,1954,1296, 2034 and 1703 (s.e.d. 179) for treatments LED, HFD, LFR, HFR and W respectively. Treatment LFR gave significantly lower mean daily intakes (P < 0·05) than all other treatments. Values for pH, volatile fatty acids and ammonia in the rumen fluid were not significantly affected by treatment (P > 0·05). Differences in voluntary intake for the two silages made from the same crop using different ensilage methods were attributed to differences in the silage liquid and volatile phases and not to the non-volatile solid phase. The effects of juice composition on intake were greater when added directly to the rumen than when added to the diet suggesting that effects on taste or smell were relatively unimportant.

A comparison of supplementary sources of nitrogen and energy for increasing the voluntary intake and utilization of barley straw by sheep

1976 ◽  
Vol 86 (1) ◽  
pp. 163-169 ◽  
Author(s):  
T. N. Barry ◽  
P. D. Johnstone
Keyword(s):  
Weight Loss ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Latin Square ◽  
Live Weight ◽  
Barley Straw ◽  
Additional Energy ◽  
Digestible Organic Matter ◽  
Voluntary Intake ◽  
Ground Wheat

SUMMARYChopped barley straw was fed ad libitum to penned Romney wether sheep. Supplements of urea, ground wheat grain + urea, lucerne hay and autumn saved pasture (ASP) were given for five periods each of 3 weeks using a 5 × 5 Latin square design. The latter three supplements supplied similar amounts of nitrogen and approximately 20% of the energy required for maintenance.The concentration of ammonia in the rumen fluid of sheep fed the basal straw diet was low and was increased by all the supplements. The concentration of total volatile fatty acids (VFA) in rumen fluid was unaffected by supplementation with urea, but was increased by the three supplements of nitrogen and energy. Differences in VFA molar proportions between treatments were small.Sheep offered straw alone had a digestible energy (DE) intake of 69% of maintenance and showed a weight loss of 121 g/day. Supplementation with urea had no effect upon apparent energy digestibility (42%) or voluntary intake, but significantly reduced the rate of live-weight loss. The lucerne hay and ASP supplements also had no effect upon straw consumption, but increased total DE intake to 87% of maintenance due to the additional energy provided by the supplements, and reduced live-weight loss. Supplementation with wheat + urea increased the estimated amount of digestible organic matter derived from straw by 8·5%, increasing DE intake to 94% of maintenance and reducing live-weight loss to 18 g/day.Averaged over all five groups of animals, straw intake increased by 9% in the second period of feeding and then gradually decreased with time, reaching a value in period 5 which was similar to period 1.

Milk production from diets of silage and dried forage. 1. Effects of methods of processing dried grass and of including barley in the supplementation of grass silage given ad libitum

1976 ◽  
Vol 23 (2) ◽  
pp. 197-209 ◽  
Author(s):  
J. C. Tayler ◽  
K. Aston
Keyword(s):  
Energy Content ◽  
Live Weight ◽  
Experimental Period ◽  
Milk Composition ◽  
Weight Changes ◽  
Treatment Groups ◽  
Grass Silage ◽  
Digestible Organic Matter ◽  
Ad Libitum ◽  
Female Cattle

SUMMARY1. Young adult and adult British Friesian female cattle (heifers and cows) which were lactating were individually fed on diets of grass silage ad libitum with supplements of dried grass, dried grass/barley or barley/groundnut in two randomized block experiments.2. In Experiment I, equal quantities of dry matter (DM) as dried grass in the form of a wafer (W), cob (C) or pellet (P) were given with the silage during weeks 8 to 18 of lactation, to three groups of 12 heifers. Silage DM intakes were respectively 14·2, 14·3 and 15·8 ± 0·43 g/kg live weight per day (P<0·05). Milk yields were 14·0, 15·6, 16·7 ± 0·35 kg/day (P< 0·001). Milk composition and live-weight change did not differ significantly.3. In Experiment II, five treatment groups of heifers and cows were offered silage with equal amounts of a supplement of either dried grass pellets (treatment 1) or dried grass/barley in the ratios of 2: 1 (treatment 2), 1: 2 (treatment 3), or a barley/groundnut supplement (treatment 4). In treatment 5 the cattle received the same supplement as in treatment 4, but at a 10% higher level. Silage DM intakes for treatments 1 to 5 during lactation weeks 6 to 22 were 8·64, 8·94, 7·96, 6·96, 7·63 kg/day (1, 2>4, P<0·01; 2>5, P<0·05). The intake of digestible organic matter, milk yields and live-weight changes over the whole experimental period were not influenced significantly by treatments 1 to 4, but in treatment 5 the milk was significantly higher in fat, protein and energy content than in treatments 1 to 4. Blood composition was normal and did not differ markedly between treatments.

The voluntary intake by cattle of four silages differing in dry matter content

1970 ◽  
Vol 12 (4) ◽  
pp. 591-599 ◽  
Author(s):  
N. Jackson ◽  
T. J. Forbes
Keyword(s):  
Dry Matter ◽  
Live Weight ◽  
Matter Content ◽  
Metabolizable Energy ◽  
Dry Matter Content ◽  
Meadow Fescue ◽  
Digestible Organic Matter ◽  
The Mean ◽  
Voluntary Intake ◽  
Daily Intakes

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).

The effect of oestradiol-17 β implantation on the response in voluntary intake, live-weight gain and body composition, to fishmeal supplementation of silage offered to growing calves

1987 ◽  
Vol 108 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Margaret Gill ◽  
D. E. Beever ◽  
P. J. Buttery ◽  
P. England ◽  
M. J. Gibb ◽  
...  
Keyword(s):  
Organic Matter ◽  
Weight Gain ◽  
Dry Matter ◽  
Live Weight ◽  
Energy Utilization ◽  
Live Weight Gain ◽  
Gross Efficiency ◽  
Grass Silage ◽  
Voluntary Intake

SummaryThe effect of oestradiol-17β on the response to fishmeal supplementation of grass silage was studied in young growing cattle. Voluntary intake and live-weight gain were recorded over 63 days with 36 British Friesian male castrates (initial live weight (LW) 119 kg) offered silage alone (C) or with 50 (FM1), 100 (FM2), or 150 (FM3) g fishmeal/kg silage dry matter. Twelve calves were allocated to each of treatments C and FM3 and six to treatments FM1 and FM2. Half of the calves on each treatment were ear-implanted with oestradiol-17β (Compudose 365) at the start of the experiment. The calves on treatments C and FM3 were slaughtered after 75 days and chemical analysis conducted on half of each carcass. The silage had an organic-matter digestibility in vivo of 0·794 and was well-fermented, with a pH of 3·7. Intake averaged 24·2±0·42 g D.M./kg LW over all the treatments and live-weight gain was 0·77 kg/day on the silage alone. There was a significant (P < 0·05) interaction between fishmeal and oestradiol-17β, such that response to the hormone was observed only in the presence of fishmeal at 100 or 150 g/kg silage D.M. A similar interaction was apparent between fishmeal at 150 g/kg silage D.M. and oestradiol-17β in the final weights of empty body and carcass. This level of fishmeal also increased protein gain from 96 to 147 g/day and this was further increased to 179 g/day in the implanted animals receiving fishmeal. However, the overall effect of oestradiol-17β on protein gain was not significant. Gross efficiency of energy utilization was significantly (P < 0·01) increased by fishmeal supplementation suggesting an improved balance of nutrients compared with the silage alone diet.

Experiments on the nutrition of the dairy heifer. XI. Further observations on the effect of energy intake on protein utilization

1978 ◽  
Vol 91 (2) ◽  
pp. 399-413 ◽  
Author(s):  
W. H. Broster ◽  
T. Smith ◽  
J. W. Siviter ◽  
E. Schuller ◽  
Valerie J. Broster
Keyword(s):  
Weight Gain ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Live Weight ◽  
Regression Equations ◽  
N Retention ◽  
Live Weight Gain ◽  
N Utilization ◽  
Digestible Organic Matter ◽  
Dry Food

SUMMARYFive experiments were made to observe the effect on nitrogen (N) utilization by young cattle of supplements of sucrose, glucose monohydrate (dextrose), and maize starch when added to basal diets of concentrates and straw. The supplements provided about 12% of the total intake of air-dry food. Twenty-four yearling Friesian heifers were used in each of two randomized block experiments to measure live-weight gain, and 6, 10 and 10 yearling Friesian steers in three changeover design experiments to measure N retention.Rates of live-weight gain and N retention were increased by all the supplements amongst which no order of superiority in benefit conferred could be established. The improvement in N retention was associated with a marked reduction in urinary N and a small increase in faecal N with supplemented rations.The proportions of volatile fatty acids (VFA) in rumen fluid were not affected by starch supplementation. Both sugars, but glucose more than sucrose, decreased the ratio of acetic to propionic acid, measured 2 h after feeding.Statistically significant multiple linear regression equations were observed between N retained and intakes of N and digestible organic matter (DOM), both as absolute amounts with live weight as a further independent variate, and as intakes/unit metabolic body size. N2and DOM × N as additional variates did not benefit the fit of the equations over the range of intakes studied.

Towards improved silage quality – A review

2001 ◽  
Vol 81 (2) ◽  
pp. 157-168 ◽  
Author(s):  
E. Charmley
Keyword(s):  
Volatile Fatty Acids ◽  
Nutritive Value ◽  
Protein Solubility ◽  
Animal Production ◽  
Energy Utilization ◽  
Negative Effects ◽  
Silage Fermentation ◽  
Feeding Value ◽  
Silage Quality ◽  
Voluntary Intake

Silage quality, as with all forages, is governed by the maturity of the crop at harvest. However, fermentation in the silo further influences nutritive value of silage by reducing voluntary intake and utilization of digestible nutrients. Silage research up to the present time has focussed on closing the gap between feeding value of the original crop and that of the resulting silage. This review focuses on the advances made towards closing that gap, and explores the possibility that in the future ensiling can become a tool for actually increasing the feeding value of forages. Following a section defining silage quality, the relationships between silage fermentation quality and voluntary intake and between silage fermentation and protein and energy utilization will be examined, with emphasis placed on measures to minimize the negative effects of fermentation on animal production. Recent literature is reviewed, which suggests that many factors previously thought to reduce silage intake, such as pH, lactic acid and dry matter (DM), have, in fact, only a casual relationship with intake. Concentrations of fermentation acids do not seem closely related to silage intake; however, they are critical in determining the balance of volatile fatty acids (VFA) produced in the rumen. This in turn, affects the non-glucogenic ratio and can influence milk and body composition in productive livestock. While rumen ammonia is often implicated in reducing silage intake, protein solubility may be more the causal agent than ammonia per se. Protein solubility is also a major factor in reducing the efficiency of silage protein utilization. Methods to reduce protein solubility in silages are discussed. Methods shown to improve silage feeding value include effective wilting and rapid acidification, either by direct acidification or the use of inoculants. Their widespread adoption has undoubtedly contributed to improvements in animal production from silages in recent years. Key words: Silage, feeding value, voluntary food intake, fermentation, ruminant

Body composition and performance of autumn-calving Holstein-Friesian dairy cows during lactation: chemical composition of the body

1992 ◽  
Vol 1992 ◽  
pp. 102-102 ◽  
Author(s):  
M.J. Gibb ◽  
W.E. Ivings ◽  
J.D. Sutton
Keyword(s):  
Body Composition ◽  
Dairy Cows ◽  
Energy Content ◽  
Post Partum ◽  
Live Weight ◽  
The Body ◽  
Energy Status ◽  
Body Tissues ◽  
The Right ◽  
Nutritional Studies

One of the major limitations in nutritional studies of lactation in dairy cows is the unknown contribution of body tissues to the energy status of the animal. Both fat and protein are thought to be mobilised in early lactation (Bauman and Elliot, 1983) when nutrient intake is insufficient to meet the demands for energy and amino acids. The present experiment investigates the effects of diet on changes in weights of chemically determined fat and crude protein (CP) in the carcass and non-carcass fractions over the first 29 weeks of lactation.Body composition was measured by serial slaughter of autumn-calving dairy cows offered grass silage (206 g CP and 18.56 MJ GE per kg DM)ad libitumand 3(L), 6(M) or 9(H) kg DM/day of concentrate (206 g CP/kg DM)(Sutton, Aston, Beever and Fisher, 1992). Cows with post-calving live weights between 500 and 700 kg and previous lactation yields between 5000 and 7000 litres were used, and were blocked for parity and expected calving date before allocation across treatments and slaughter times. Six cows were slaughtered at 2 to 4 dayspost partum(week 0), and two from each treatment (one 2nd, and one 3rd or 4th parity) at 2, 5, 8, 11,14,19, 24 or 29weeks post partum.After slaughter the right half carcass and all other non-carcass components were frozen and minced before chemical analysis for fat, CP, ash and water. All weights were adjusted by covariance for live weightpost partumand parity. Energy content was calculated assuming values of 39.19 and 23.23 MJ/kg for fat and CP respectively.

The effect of roughage to concentrate ratio in the diet on protein and energy utilization by the non-pregnant ewe

1970 ◽  
Vol 74 (3) ◽  
pp. 415-421 ◽  
Author(s):  
J. J. Robinson ◽  
T. J. Forbes
Keyword(s):  
Organic Matter ◽  
Weight Change ◽  
Live Weight ◽  
Dietary Treatment ◽  
Energy Utilization ◽  
Regression Equations ◽  
Digestible Organic Matter ◽  
Protein And Energy Utilization ◽  
Pregnant Ewe ◽  
Dietary Treatments

SUMMARYThirty-six Border Leicester x Scottish Blackface ewes were separated from their lambs after approximately 12 weeks lactation and brought indoors. They were allocated at random to nine dietary treatments comprising three dietary ratios of chopped roughage to concentrate, each offered at three levels of feeding. During the course of the experiment digestibility and nitrogen balance trials were carried out using three ewes from each dietary treatment.The daily nitrogen intakes required for nitrogen equilibrium were calculated from the regressions of nitrogen intake on nitrogen retained for each of the three ratios. The intakes increased from 0·47 g/kg W0·75 on the diet containing the lowest proportion of roughage to 0·59 g/kg W0·75 on the diet containing the highest proportion of roughage. The corresponding digestible organic matter intakes did not differ significantly from the pooled value of 18·8 g/kg W0·75.The daily digestible organic matter intakes required for the maintenance of live weight on the three ratios did not differ significantly from the pooled estimate of 26·9 g/kg W0·75 which is in close agreement with other published results. The nitrogen intakes required for the maintenance of live weight increased from 0·70 on the diet containing the lowest proportion of roughage to 0·84 g/kg W0·75/day on the diet containing the highest proportion of roughage.The coefficients for live-weight change in the regression equations relating digestible organic matter to live weight and live-weight change for each ratio did not differ significantly from the pooled estimate of 2·0 g DOMI/g live-weight change.The significance of the results are discussed in relation, to the nutritional status of the ewe and other research findings.

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