The use of sheep as a model to predict the relative intakes of silages by dairy cattle

1994 ◽  
Vol 59 (3) ◽  
pp. 415-420 ◽  
Author(s):  
A. Cushnahan ◽  
F. J. Gordon ◽  
C. P. W. Ferris ◽  
D. M. B. Chestnutt ◽  
C. S. Mayne

AbstractA study was carried out to determine if sheep could be used as a model for predicting the intakes of silages by cattle. Fifty ewes and 45 cows were offered five grass silages unsupplemented in two parallel randomized-block experiments over a 4-week period. Each silage had been made using the same equipment over a range of cutting dates (May, July, August 1991). The silages differed in fermentation characteristics, with lactic acid concentrations varying from 15·3 to 90·7 g/kg dry matter, and ammonia-nitrogen concentrations from 77 to 198 g/kg nitrogen. When expressed on a metabolic live-weight basis, the mean intakes of silages by cows were 2·25 times those of the sheep, with the mean intakes being 35·1 and 79·1 g/kg M0·75 for the sheep and cows respectively. However, there was no significant correlation between recorded intakes during the 4th week of the study by the two species (y (cows) = 0·62× (sheep) + 58·40; r2 = 0·03). It was concluded that sheep were not a useful model system to predict the intakes of a range of grass silages of similar chop length by dairy cows.

1975 ◽  
Vol 26 (4) ◽  
pp. 769 ◽  
Author(s):  
SC Valentine ◽  
JC Radcliffe

Formaldehyde-prepared silages and untreated silage were made from grass-clover herbage and offered to dairy cows. Formaldehyde was applied at 0.6 and 1.2% of the dry matter of the herbage. The 1.2% formaldehyde-prepared silage had significantly lower concentrations of ammonia nitrogen, total organic acids and propionic acid than untreated silage, but a higher concentration of lactic acid. The 0.6% formaldehyde-prepared silage had a similar degree of fermentation to untreated silage, but more lactic acid and less butyric acid were produced. Treatment with formaldehyde significantly reduced the in vitro digestibilities of dry matter and nitrogen. Cows offered the formaldehyde-prepared silages had significantly greater ad libitum dry matter intakes, produced significantly more milk, protein, butterfat and solids not fat (SNF), and utilized digestible energy more efficiently for milk production than cows offered untreated silage. Differences between treatments in the percentages of butterfat, protein and SNF in milk from cows offered the silages were generally not significant. Treatment with formaldehyde was a suitable method of controlling the ensiling fermentation to Increase the ad lib. dry matter intake and the production of milk and milk components by dairy cows.


2003 ◽  
Vol 2003 ◽  
pp. 113-113
Author(s):  
H. C. F. Wicks ◽  
J. D. Leaver

A method to estimate total dry matter intake (DMI) of individual dairy cows on commercial farms was developed to aid nutritional research on commercial farms (Wicks, 2001). Recently a second validation of the model was carried out using cows from the Agricultural Research Institute of Northern Ireland (ARINI) dairy herd. The results from the validation process at Wye and ARINI are shown and the mean square prediction error (MSPE) of the model for live weight prediction and DMI estimation were calculated.


1991 ◽  
Vol 52 (3) ◽  
pp. 407-420 ◽  
Author(s):  
A. J. Rook ◽  
M. Gill ◽  
R. D. Willink ◽  
S. J. Lister

ABSTRACTData for individually recorded silage dry-matter intake (SDMI), concentrate dry-matter intake (CDMI), live weight, milk yield and milk composition of lactating dairy cows offered silage ad libitum and concentrates on a flat-rate basis, together with data for silage composition from experiments conducted at four sites, were used to obtain simple and multiple regressions of SDMI on other variables.Simple regressions showed that the most important variables affecting SDMI were, in order of importance: silage ammonia nitrogen, fat yield, CDMI, silage digestible organic matter concentration (DOMD) and live weight. The best multiple regression for the mean SDMI over weeks 4 to 13 of lactation accounted for proportionately 0·649 of the variation. Examination of week by week data for weeks 3 to 20 of lactation showed that two models for early and mid lactation were required to give a reasonable pattern of residual variances. These models accounted for 0·627 and 0·581 of the variation respectively. It was necessary to fit time effects explicitly in early lactation. Live weight was best represented by fitting post-calving live weight and deviations from post-calving live weight separately. A number of models requiring fewer input variables were also obtained to allow for use in situations where the full range of measurements is not made.The new models were tested using independent data from three sites. They performed better than a number of previously published models but the best model still gave a prediction error of proportionately 0·17 about the mean actual silage intake in early lactation and 015 in late lactation.The results suggest that there is little to be gained from further refinement of the functional form of the models and that the construction of a number of models for specific food and management situations is preferable to the use of global models.


1998 ◽  
Vol 66 (2) ◽  
pp. 357-367 ◽  
Author(s):  
N. W. Offer ◽  
D. S. Percival ◽  
R. J. Dewhurst ◽  
C. Thomas

AbstractNinety-four silages were made over 5 years from predominantly perennial ryegrass swards using a range of cutting dates (19 May to 18 September), wilting periods (0 to 48 h) and additives (none, acids, inoculants, sugar, sugar + acids, sugar + inoculants). A wide range of silage composition was achieved (CV for dry matter (DM), crude protein (CP), digestible organic matter (DOMD), lactic acid, total volatile fatty acids (VFA) and sugar were 0–2. Silage dry-matter intake (SDMI) was measured for 88 silages using lambs (mean live weight (M) 28 kg) given silage as their sole diet in four incomplete block design experiments using four lambs per silage and a standard hay given every third period for covariance correction. Thirty-four of the silages were also evaluated using early lactation cows (M, 561 kg and milk yield 27 kg/day) with 7 kg/day of concentrate in eight incomplete block change-over experiments each using 12 cows.Intakes (SDMI mean, range, s.d. glkg M075) were 56, 25 to 84, 13·7 for lambs and 90, 64 to 119, 13·4 for cows. Scaling lamb SDMI by M1'47 accounted best for the effect of lamb weight on intake (mean, range 5·07, 2·43 to 7·68). Silage predictors were grouped as follows: traditional values (BASAL) - DM, CP, organic matter (OM), DOMD,neutral-detergent fibre (NDF), acid-detergent fibre (ADF), ammonia nitrogen (NH3N), pH, acid hydrolysed ether extract (AHEE); silage fermentation values obtained by high-performance liquid chromatography (HPLC); or by electrometric titration (ET); and near infra-red reflectance spectra (NIRS) obtained on either 100°C dried (NIRSdry) orfreshsamples (NIRSwetl using a vertical transport mechanism and NIRSwet2 using a rotating cup). The most useful predictors within each group were firstly identified by step-wise multiple linear regression and models were then derived by partial least squares.Standard errors of cross validation (SECV) obtained by the ‘leave one out’ method were for lamb SDMI (g/M1·47) 0·81, 0·81, 0·75, 0·52, 0·82 and 0·56 for BASAL, BASAL + HPLC, BASAL + ET, NIRSdry, NIRSwetl and NIRSwet2 respectively. Corresponding values for cows (g/M0·75) were 7·3, 7·3, 5·9, 5·1, 6·2, and 2·5. Inclusion of fermentation measurements made by ET, but not by HPLC, improved SDMI prediction over that obtainedfromthe BASAL set. However, NIRSdry and NIRSwet2 were the most accurate methods giving values for s.d. (reference population)ISECV of 2·27 and 2·13 for lambs and 2·65 and 5·28 for dairy cows. Use of these methods in advisory silage evaluation should substantially reduce the errors of predicting the intake potential ofgrass silages.


1991 ◽  
Vol 52 (1) ◽  
pp. 11-19 ◽  
Author(s):  
D. A. Jackson ◽  
C. L. Johnson ◽  
J. M. Forbes

ABSTRACTAn experiment was carried out to investigate the effects of compound composition and silage characteristics on silage intake, feeding behaviour and productive performance of dairy cows during the first 25 weeks of lactation. Over a period of 3 years, 36 lactating British Friesian cows (12 per year), in their third or later lactations, were divided into two groups. The cows in each group received either compound S, in which the principal energy source was cereal starch, or compound F containing a mixture of high quality digestible fibre. Cows given compound F ate 2·2 kg more silage dry matter per day (P < 0·05). The type of compound had no effect on the frequency of silage feeding and the time spent eating was significantly different only over weeks 10 to 25 of lactation (P < 0·05), with cows on compound F spending on average 20 min longer feeding per day. Cows on compound F produced 1·7 kg more milk per day than cows on compound S. Although there were no significant differences in the concentration of milk constituents, compound F was associated with higher yields of milk constituents. Significant differences were found between the years of experiment in the frequency of feeding (P < 0·05) and also in the concentration of milk protein and milk fat. There were no significant differences in the magnitude of live-weight change between treatments or year of experiment.


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.


2010 ◽  
Vol 55 (No. 11) ◽  
pp. 468-478 ◽  
Author(s):  
K. Poláková ◽  
V. Kudrna ◽  
A. Kodeš ◽  
B. Hučko ◽  
Z. Mudřík

The main aim of this study was to investigate experimentally the effect of different composition of non-structural carbohydrates (NFC) in prepartum feed rations administered to high-yielding dairy cows at a high concentration of NFC in the diet on dry matter intake both before and after parturition and on subsequent milk performance, body condition and physiological traits of rumen fluid and blood. Thirty-six high-yielding dairy cows were allocated into one of the three well-balanced groups (K, O, and C), and each group received a different feeding rations. Feeding rations differed in non-structural carbohydrate (NFC) structure. The "K" (control) group received a feeding ration with NFC in the form of maize starch in particular, while the feeding rations of the other two (experimental) groups contained either (besides maize starch) saccharose from dried sugar beet (the "O" group) or a dominant amount of NFC was in the form of saccharose (the "C" group). After calving, all dairy cows were given the same feeding ration from the first day after parturition. The experiment was conducted for 21 days before and 50 days after calving. FR in the form of total mixed ration was offered ad libitum. Dry matter intake, milk performance, body condition, live weight, and blood and rumen parameters were recorded for the duration of the experiment. Average daily dry matter intake before calving was highest in the "K" group (14.32 kg per head). Differences among groups were statistically significant (P &lt; 0.05). Prepartum dry matter consumption dropped as the rate of saccharose in the diet of cows increased. Dry matter consumption levelled off after calving. Milk yield was also highest in the "K" group (43.71 kg/head/day), but fatness of milk and thus the production of fat corrected milk were lowest in this group. The highest milk fat content (4.10%) and fat corrected milk production (44.03 kg/head/day) were recorded in the "C" group, whereas the highest milk protein concentration was found in the milk of the "O" group. The composition of NFC affected dry matter intake before parturition, but these concentrations did not significantly affect dry matter intake, milk yield, milk composition, live weight, body condition or blood serum and rumen fluid parameters after calving


1979 ◽  
Vol 42 (1) ◽  
pp. 89-96 ◽  
Author(s):  
N. F. Suttle

1. The minced carcases of twenty-seven lambs, ranging from 18 to 69 kg in live weight, and twenty-five calves (30–90 kg) were analysed for copper, iron, manganese and zinc. The lambs were weaned whereas the calves were reared exclusively on milk.2. Mean concentrations of Fe, Mn and Zn for groups of lamb carcases fell within the ranges 52.6–75.1, 0.7–1.2 and 20.8–25.6 mg/kg fresh carcase weight respectively. The concentrations of Fe and Mn decreased while that of Zn increased slightly with age at slaughter. The concentrations of Fe, Mn and Zn in calves were close to thosein lambs.3. For both species, the concentration of Cu in the carcase varied erratically: variation in hepatic Cu storage was implicated. In an additional study of ten full-term foetuses from Cu-depleted or Cu-supplemented ewes, a dietary Cu supplement (10 mg/kg dry matter (DM)) increased foetal Cu status 10-fold, due largely to an increase in foetal liver Cu.4. The mean retentions of trace elements in the lamb carcases (%intake) were approximately: Cu 2.0, Fe 1.3, Mn 0.08, Zn 4.0. The corresponding values for the milk-fed calves were all probably much higher (Cu 23, Fe 43.7, Mn 4.9, Zn 34.0) but Cu intake was not accurately measured.5. After allowing for tissue storage of Fe and Mn, values of 55, 0.85 and 24 mg/kg carcase gain were taken to represent the approximate net growth requirements of lambs for Fe, Mn and Zn respectively: the corresponding value for Cu was probably < 1.0 mg/kg. Values for calves were similar to those for lambs.6. It was concluded that the total net requirements of ruminants for Fe and Zn shouldbe considered in terms of daily intakes of the metans rather than dietary concentrationsbecause of the relatively large and constant contribution of the growth component to thetotal requirement.


1986 ◽  
Vol 55 (1) ◽  
pp. 87-98 ◽  
Author(s):  
Anna L. Rainbird ◽  
A. G. Low

1. Simple gastric cannulas were surgically fitted to four pigs, initially of 30 kg live weight, to examine the effects of guar gum on gastric emptying.2. Four semi-purified high-fat diets based on starch, casein, soya-bean oil and tallow were given to each pig. They contained 0 (control), 20, 40 or 60 g powdered guar gum/kg diet. The meals as fed contained 257 g dry matter (DM)/kg.3. The contents of the stomach were evacuated, with rinsing, before feeding or 0.5, 1, 2 or 4 h after feeding.4. The mean pH of the digesta was unaffected by guar gum until 4 h after feeding when the value increased as the amount of guar gum in the diet rose.5. The only significant effects of guar gum on the emptying of digesta and its components (compared with the control diet) were to reduce the rate of emptying of (a) digesta 1 h after feeding (60 g/kg diet) and 4 h after feeding (40 and 60 g/kg diets), (b) dry matter and glucose 1 h after feeding (60 g/kg diet), (c) nitrogen 1 h after feeding (60 g/kg diet) and 4 h after feeding (40 and 60 g/kg diets).6. When expressed on a half-time (T50) basis, the emptying of digesta and N (but not of DM and glucose) were significantly slower for diets containing 40 and 60 g guar gum/kg than for the control diet.7. The apparent viscosity of the gastric digesta ranged between 0.5 and 23.7% of the values for the diets as consumed.8. It was concluded that the effects of guar gum on gastric emptying of high-solid meals were small, and that this was unlikely to be an important aspect of the mechanism by which guar gum reduces postprandial blood glucose concentrations.


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