A study of factors affecting the voluntary intake of food by cattle

1969 ◽  
Vol 11 (2) ◽  
pp. 145-153 ◽  
Author(s):  
T. A. McCullough

SUMMARYSix diets providing ratios of concentrate to hay of 100 : 0, 95 : 5, 90 : 10, 80 : 20, 70 : 30 and 60 : 40 were given ad libitum to 24 British Friesian steers. The hay (in the long form) was offered separately from the concentrates. From 91 to 136 kg live weight, as the proportion of hay in the diet increased, daily dry-matter intake decreased. Over the weight range, 136 to 363 kg live weight, the addition of small amounts of hay to the concentrate diet caused an increase in intake. At 42 weeks of age a digestibility trial was carried out. Daily drymatter intake was maximal when the diet contained 80% concentrates. The apparent digestibility and mean retention time of the diets increased as the proportion of concentrates increased. Differences in estimated gut fill were not significant. The diet consisting of concentrate only resulted in the lowest concentration of acetic acid and the highest concentration of propionic and butyric acids in the rumen liquor. Net-energy intake tended to increase as the proportion of concentrates increased from 60 to 90% but then remained fairly constant.

1970 ◽  
Vol 12 (1) ◽  
pp. 23-36 ◽  
Author(s):  
T. T. Treacher

SUMMARY1. Scottish Half-bred ewes carrying twin foetuses were fed individually to make live-weight gains in the last six weeks of pregnancy of (1) 20%, (2) 10% and (3) 0% of their live weight in week 14 of pregnancy. In lactation the ewes were fed ad libitum. The lambs were removed 12 to 16 hr after parturition and the ewes were machine-milked twice daily for the first six weeks of lactation.2. Total birth weights per ewe of twin lambs from the treatments were (1) 10·10 kg, (2) 9·44 kg and (3) 8·18 kg and differed significantly.3. The level and pattern of voluntary intake in lactation did not differ significantly between the treatments. Total dry-matter intakes in the six weeks of lactation were (1) 121·9 kg (2) 105·9 kg and (3) 109·5 kg.4. The pregnancy treatments affected the level of milk production and the shape of lactation curves. The total yields in the first six weeks of lactation were (1) 58·8 kg, (2) 43·5 kg and (3) 26·9 kg. Higher contents of fat and protein and the lower content of lactose in the milk from treatment-3 ewes on days 1 and 3 of lactation indicated a slower onset of lactation in these ewes. Between days 7 and 35 of lactation the contents of fat and SNF were lowest on treatment 3 but the differences were not significant.5. The live-weight changes in lactation, which were in inverse order to the gains in late pregnancy, were (1) 3·4 kg, (2) 5·5 kg and (3) 9·5 kg.


2017 ◽  
Vol 26 (2) ◽  
Author(s):  
Katariina Manni ◽  
Marketta Rinne ◽  
Erkki Joki-Tokola ◽  
Arto Huuskonen

The objective of this study was to determine the effects of restricted feeding strategies on performance of growing and finishing dairy bulls. The feeding experiment comprised in total 32 Finnish Ayrshire bulls with an initial mean live weight (LW) of 122 kg and age of 114 days. Feeding treatments were silage ad libitum and daily barley allowance of 93 g kg-1 LW0.60 (A); restricted feeding (R) at 0.80 × A; increasing feeding (I) similar to R until LW of 430 kg and thereafter similar to A; and decreasing feeding (D) similar to A until LW of 430 kg and thereafter similar to R. Restricted feeding strategies decreased daily dry matter intake and LW gain and increased the time to reach the target carcass weight (300 kg). Bulls on I exhibited compensatory growth. There were no significant differences in feed efficiency between the treatments. The present experiment indicates that silage intake ad libitum and supplemented with concentrate resulted in most effective beef production.


1990 ◽  
Vol 50 (3) ◽  
pp. 425-438 ◽  
Author(s):  
A. J. Rook ◽  
M. Gill

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.


1995 ◽  
Vol 46 (8) ◽  
pp. 1579 ◽  
Author(s):  
JF Perez ◽  
J Gasa ◽  
C Castrillo ◽  
JA Guada

Rates of passage of liquid and particulate markers (Co-EDTA, Cr mordanted fibres and Yb) were measured in ewes at late pregnancy, lactation and non-breeding status. Animals were given ammonia treated barley straw ad libitum supplemented daily with 250 and 550 (pregnancy), 550 and 850 (lactation) and 250, 550 and 850 (non-breeding) g of concentrate. The effect of the reproductive state was analysed only on ewes fed on 550 g of concentrate. Lactating ewes showed a higher voluntary straw intake (970 g/day) than pregnant or non-breeding ewes (720 and 790 g/day respectively), but there were not significant differences in the OM digestibility (OMD) among reproductive states. Increasing concentrate supplementation promoted significant decreases in the voluntary intake of straw, associated with an enhanced OMD ( P < 0.05). Fractional outflow rates (FOR/h) were higher in pregnant and non-breeding than in lactating ewes, although differences were only significant ( P < 0.01) for Chromium derived values. Ewes given 250 g of concentrate showed lower ( P < 0.05) FOR than those given 550 and 850 g/day. Results support the idea that in ruminants fed on low quality roughages, voluntary dry matter intake is mainly restricted by rumen capacity, although the energy status of the animals might influence the extent of this restriction.


1980 ◽  
Vol 31 (3) ◽  
pp. 243-250 ◽  
Author(s):  
K. Aston ◽  
J. C. Tayler

ABSTRACT1. Experiment 1. Six treatment groups of one British Friesian and four South Devon × British Friesian bulls, initially 432 kg mean live weight and aged 491 days, were offered individually maize or grass silage ad libitum plus 0, 5 or 10g barley dry matter per kg live weight daily for 80 days. The silages had similar digestible dry matter and estimated metabolizable energy contents but the grass silage contained more ammonia and acetic, propionic and butyric acids. Mean values for groups receiving respectively maize and grass silage diets were for dry-matter intake 17·7, 20·3, 20·4 and 13·0, 16·6, 18·7 g/kg live weight and for live-weight gain 1·00, 1·32, 1·46 and 0·65, 0·98, 1·22kg/day. Significantly more maize than grass silage dry matter was eaten when the silages were given alone and dry-matter intakes, live-weight and carcass gains were greater for maize silage diets. Dry-matter intake, live-weight and carcass gains, efficiency of feed use and carcass quality significantly improved when barley was given.2. Experiment 2. Six groups of five British Friesian bulls, initially 418 kg mean live weight and aged 474 days, were offered individually maize silage ad libitum with either urea or one of two quantities of aqueous ammonia mixed in at the time of feeding, plus 0 or 5 g barley dry matter per kg live weight daily for 90 days. The urea and ammonia-treated silages contained 125, 124 and 148 g crude protein per kg dry matter respectively, with pH values of 3·8, 3·9 and 4·3, and when given alone or with barley mean daily intakes (g dry matter per kg live weight) were 17·1, 18·6 for urea-treated silage diets, and 17·8, 18·8 and 16·9, 19·1 respectively for ammoniatreated silage diets. Live-weight gains were 0·69, 0·94, 0·63, 1·09, 0·64 and 1·07 kg/day. Ammonia treatment had no effect on intake or live-weight gain. Live-weight and carcass gains and carcass quality improved when barley was given.3. The maize silage offered in Experiment 1 contained similar metabolizable energy but more starch than that in Experiment 2 and was used more efficiently for live-weight gain.


1973 ◽  
Vol 16 (1) ◽  
pp. 95-98 ◽  
Author(s):  
W. Rutter

SUMMARYTwo experiments involving the sequential slaughter of intensively fattened store lambs were each carried out over a period of 12 weeks. In the first experiment the lambs were offered a concentrate diet ad libitum. In the second experiment they were offered swede turnips ad libitum with a limited amount of concentrates.In each experiment, similar groups of lambs were slaughtered at equal intervals in order to measure progressive changes in live weight, carcass weight and dry-matter intake. Carcass-weight gain as a proportion of live-weight gain was found to be 74% in the first experiment and 86% in the second experiment.


1979 ◽  
Vol 93 (3) ◽  
pp. 553-562 ◽  
Author(s):  
J. Vadiveloo ◽  
W. Holmes

SUMMARYInformation on the total dry-matter intake (TDMI), concentrates supplied (C), live weight (LW), week of lactation (WL), milk yield (MY) and composition, quality of forage fed to, and parities of, 385 cows from five different sources were assembled to develop appetite prediction equations. The equations were based on multiple regression and least squares constants and were calculated using the data from each source and the data pooled from all sources. The major factors affecting total dry-matter intake (TDMI) were C, LW, WL and MY and for the pooled data these factors explained 73–76% (R2) of the total variation in TDMI. The predictive values of some of the equations were tested against independent sets of data and for groups of cows and individual cows, the equations predicted TDMI within ±1·1 and 1·6 kg, respectively. The application of the equations in the field is discussed and some suggestions made for increasing the R2 of future appetite equations.


1992 ◽  
Vol 55 (3) ◽  
pp. 389-396 ◽  
Author(s):  
R. Sanderson ◽  
C. Thomas ◽  
A. B. McAllan

AbstractSeventy-two, 4-month-old, British Friesian steers were used to investigate the effects of feeding a supplement of fish meal on the voluntary intake and live-weight gain by young growing cattle given a well preserved ryegrass silage. The silage was offered either alone or mixed with 50,100 or 150 g fish meal per kg silage dry matter (DM) and the diets were offered either ad libitum or intakes were restricted to 16, 19 or 22 g dietary DM per kg live weight (LW). Intakes were recorded daily, LW weekly and in vivo apparent digestibility over one 7-day period during the 132-day trial.For animals fed ad libitum, the absolute intake of dietary DM increased linearly with an increase in the level of fish-meal supplementation such that intake when the highest level of fish meal was given was significantly higher (P < 0·01) than when silage was given alone. However, DM intake per unit LW (approx. 24 g DM per kg LW) was not affected significantly (P > 0·05).Inclusion of fish meal in the diet did not affect the apparent digestibility of dietary DM, organic matter, acid-detergent or neutral-detergent fibre (NDF) although there was a trend for slightly higher (P > 0·05) gross energy apparent digestibility when fish meal was given. Increasing the level of feeding reduced NDF digestibility. The coefficients measured at the 22 g and ad libitum levels of intake were lower (P < 0·01 and P < 0·05 respectively) than that measured at the 16 g DM per kg LW level.Animals given silage alone to appetite achieved LW gains of 0·6 kg/day. LW gains increased linearly with increasing level of feeding (P < 0·001) and increasing level offish-meal supplementation (P < 0·001).


1978 ◽  
Vol 26 (2) ◽  
pp. 143-150 ◽  
Author(s):  
J. M. Wilkinson ◽  
Ines M. Penning ◽  
D. F. Osbourn

ABSTRACTWhole-crop maize was harvested at 20% (L), 29% (M) and 38% (H) dry-matter (DM) content, chopped to 7·67 mm (F) or 33·3 mm (C) average particle length and ensiled. The six silages were offered ad libitum to 36 entire male calves (initially 96 kg live weight), together with supplements of urea and dried ryegrass, for 42 days. Voluntary intake and the apparent digestibility of the diets were measured. Intake of DM was not affected by the DM content of the silages, but was higher for F than C by 6·6% (P<0·01). Apparent digestibility of DM, organic matter and cell walls decreased with increasing silage DM content (P<0·001) and was higher for F than C (P < 0·01).


1976 ◽  
Vol 86 (2) ◽  
pp. 379-392 ◽  
Author(s):  
T. N. Barry

SummaryIn three separate experiments, lucerne hay was sprayed with solutions of formaldehyde as it was being baled. Moisture content at baling was respectively 20, 28 and 34% in Expts 1, 2 and 3, the latter being considered higher than normal. Dry matter lost during 4 months of storage averaged 6·7% and was unaffected by formaldehyde treatment.Increasing rates of formaldehyde application decreased the amount of plant nitrogen digested in the microbial stage of an in vitro system and increased the amount of nitrogen digested in the subsequent acid-pepsin stage (Expt 1 only). When the hays were fed at constant intake to sheep in metabolism cages, formaldehyde treatment depressed the concentration of ammonia and volatile fatty acids (VFA's) in rumen fluid and lowered the molar proportions of iso- and n-valeric acids, but caused either very little or no depression in apparent energy digestibility. It was concluded that formaldehyde treatment of the hays reduced protein degradation by rumen microorganisms and probably increased the amount of protein digested in the post-ruminal region of the digestive system, and that this was achieved without any serious effect on energy digestion.The hays were also fed for 50 days at restricted and ad libitum intakes to young Komney sheep kept in outdoor pens, followed by a 55-day post-treatment period on spring pasture. Voluntary intake was high in both experiments and was unaffected by formaldehyde treatment in hay baled at normal moisture content. There was a tendency for formaldehyde treatment to cause a small increase in voluntary intake in hay baled at the highest moisture content, but this was counteracted by its effect in depressing digestibility, giving no increase in digestible dry-matter intake. Live-weight gains were low in relation to intake, giving a weight loss in most treatment groups. Formaldehyde treatment significantly reduced weight loss and the effect was still present at the end of the post-treatment period. From regressions of weight change on digestible energy intake, it was considered that formaldehyde treatment had brought about a small improvement in the efficiency with which energy was used below maintenance.Wool growth rates appeared normal for the levels of intake achieved and were increased 14·5% by formaldehyde treatment at ad libitumintake and 5·5% at restricted intake. Residual responses to formaldehyde treatment in the post-treatment period averaged 8%. The total amount of extra clean wool produced from formaldehyde treatment over both periods was 46and94g respectively at the restricted and ad libitum intakes, representing only 1·5 and 3·0% of the annual fleece production. Wool growth on diets treated with formaldehyde in sheep feed at the maintenance level of energy intake is discussed in relation to the concentration of protein-bound sulphur-containing amino acids (SAA's) in the diet dry matter. It was concluded that large responses in wool growth from protein protection of forage diets are unlikely unless the concentration of SAA's in the dry matter can be considerably increased from their present low levels. It is suggested that the possibility of achieving this through plant breeding techniques be investigated.


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