Amount Of Roughage Research Articles

Factors affecting behavioural disturbances in race-horses

AbstractThe aim of the present study was to identify relations between stereotyped behaviours (cribbing, weaving and box-walking) and wood-chewing in thoroughbred flat-racing horses (TB) and standardbred trotters and the different management, feeding and training factors to which these horses are exposed. This was obtained by inquiries to all the professional trainers of TB and trottinghorses used for racing in Sweden. The usable response rates were 61% for trotters and 72% for TB representing 4597 trotters from 234 stables and 644 TB from 38 stables. A small field study was carried out to control the validity of the main study which gave results similar to those in the main study. There was a large difference between the two horse categories in the occurrence of behavioural disturbances. The TB had significantly more stereotypies than the trotters (P < 0·001) but there were no differences in the occurrence of wood-chewing. There were several differences in external factors between the horse categories, e.g. trotters had more opportunities for social contacts with other horses, they also had more free time outside the stable and they were trained a shorter time per week than the TB. The TB were given larger amounts of concentrate than the trotters. Wood-chewing within each horse category was explained by the amount of roughage (P < 0·05 in trotters and P < 0·001 in TB) together with other factors. Stereotypies in the TB were explained by: amount of concentrate (positive relation), number of horses per trainer (positive relation) and amount of roughage (negative relation).

Analysis and simulation modelling of the production in Danish organic and conventional dairy herds

Case studies, descriptive statistics and modelling by simulation based on detailed documentation from commercial farms were used to obtain knowledge about organic as opposed to conventional livestock farming systems. Data from intensive observations over a 3-year period in 13 organic and 18 conventional commercial farms with dairy production as their main enterprise were used in the analysis. Herd structure, like age of cows and replacement rate, was independent of the farming system. In the organic system, milk peak yield per lactation was lower, but persistently higher, leading to only marginal differences, in annual herd production. A higher amount of roughage in the feed ration reduced the feed intake in early lactation in the organic herd, but a more even intake through lactation could explain the higher persistency in milk production. Feed intake and production results in the two farming systems where simulated with a herd model. The higher amount of roughage, combined with a longer period on pasture and a lower frequency of mastitis in the organic system, could explain the difference between the two systems. It was concluded that if changes in land use and feed supply were the only results of organic farming, feed intake will be reduced, leading to a lower milk production and live weight gain. If conversion to organic farming is followed by a greater attention to pasture management and preventive mastitis control, then our results also show that the effect on feed intake and production will be reduced.

A review of bloat in feedlot cattle.

Improvements in feedlot management practices and the use of various feed additives have reduced, but not eliminated, the occurrence of bloat in feedlot cattle. Feedlot bloat reduces the profitability of production by compromising animal performance and more directly by causing fatalities. In feedlots, bloat is associated with the ingestion of large amounts of rapidly fermented cereal grain and destabilization of the microbial populations of the rumen. An abundance of rapidly fermented carbohydrate allows acid-tolerant bacteria (e.g., Streptococcus bovis and Lactobacillus spp.) to proliferate and produce excessive quantities of fermentation acids. As a result, ruminal pH becomes exceedingly low, and this impairs rumen motility. Further, the excessive production of mucopolysaccharide or "slime" increases the viscosity of ruminal fluid and stabilizes the foam implicated in frothy feedlot bloat. Although protocols have been developed to treat feedlot bloat, the most profitable approach is to use management strategies to reduce its likelihood. Amount of roughage, grain processing techniques, selection of cereal grain (e.g., corn, barley, and wheat), dietary adaptation periods, and various additives (e.g., ionophores) can influence the occurrence of bloat in feedlot cattle. Successful management of these factors depends on a thorough understanding of the behavioral, dietary, and microbial events that precipitate bloat in feedlot cattle.

The effect of diet and frequency of watering on the performance of growing cattle given food at maintenance

AbstractAn 18-week experiment investigated the effects of type of diet and frequency of watering on the performance of growing cattle given food at maintenance (metabolizable energy (ME) allowance (MJ) = 8·3 + 0·091 M where M = live weight of the animal). Three diets with 20: 80 (low, L), 50:50 (medium, M) and 80: 20 (high, H) roughage to concentrate ratios (10·2, 7·8 and 5·4 MJME per kg dry matter) were used in combination with free access to water for 2·5 h once daily or once every 3rd day. A completely randomized-block design with a 3 (diets) × 2 (watering frequencies) factorial arrangement of treatments was used. Five animals were allocated per treatment (average weight 245 (s.d. 21·6) kg).Dry-matter intake increased as the roughage content of the diet increased (P < 0·05) but was not affected by the watering regime (P > 0·05). Total water intake was found to be positively correlated with dry-matter intake and increased with dietary roughage level. Animals watered daily drank more (P < 0·05) water (12·6 v. 10·0 kg/day) than those watered every 3rd day. The apparent digestibility of the diets decreased as the amount of roughage increased (diet L 734g/kg, M471 g/kg and H 433 g/kg). Similar apparent digestibilities were observed under the two watering frequencies (546 g/kg and 547 g/kg).Type of diet significantly (P < 0·05) affected the final weights of the steers. Animals given diet H were proportionately 0·07 heavier than those offered diet L corresponding to total weight changes of −0·8 and +18·4 kg respectively. Carcass weight, backfat thickness and eye muscle area were not affected by the treatments. The chemical composition of the 9 to 11th rib joint was only affected by diet H which gave less fat (P < 0·05). Water, fat, protein and ash content averaged 607,118,190 and 84 g/kg respectively.

Use of sheep maintained by intragastric infusion as a model for studying the endogenous loss of phosphorus in ruminants

Mature sheep fitted with a rumen cannula and an abomasal catheter were used to evaluate whether sheep maintained by intragastric infusion could be used as a model for studying minimum endogenous phosporus loss in ruminants. In control periods the sheep received 1·29 g phosphorus day −1 by infusion and maintained phosphorus balance. The withdrawal of phosphorus from the infusate led to a reduction in the excretion of phosphorus to 6·4 mg kg liveweight −1 day −1, a level lower than that currently used to estimate maintenance phosphorus requirements. However, salivary phosphorus secretion, based on rumen phosphorus outflow, averaged only about 1·2 g day −1, a level which would be considered insufficient to meet rumen microbial requirements in a normally fed animal. Allowing the sheep access to a small amount of roughage, although contributing little additional phosphorus, greatly increased salivary phosphorus flow and increased their endogenous excretion of phosphorus to levels close to those used to estimate maintenance requirements. These results suggest that this technique may offer an alternative way of measuring minimum endogenous mineral loss to those currently in use.

Growth of lambs offered fixed amounts of roughage and concentrate either simultaneously, progressively or separately

SUMMARYTwo experiments were carried out to study the efficiency of energy utilization by Suffolk × Blackface lambs. In the first experiment, a digestibility trial, the lambs were fed on either a roughage (chopped dried grass), concentrate (whole barley, ground barley and fishmeal), or mixed (roughage and concentrate) diet. The dry matter (DM) and organic matter digestibility coefficients of the mixed diet were slightly, but not significantly, lower than the ‘expected’ values calculated by summation of the separately determined digestibility coefficients of the component feeds. Similarly, the metabolizable energy (ME) value was 1·6% lower than the ‘expected’ value.In the second experiment, lambs were offered 52·5 kg roughage DM (ME 9·96 MJ/kg DM) and 52·5 kg concentrate DM (ME 11·59 MJ/kg DM) as:(i) a mixed diet (M); (ii) a progressive change from roughage to concentrate (R–C); (iii) a progressive change from concentrate to roughage (C–R); or 105 kg roughage or concentrate DM as either (iv) a roughage diet (R), or (v) a concentrate diet (C). Lambs on treatments R–C, C–R and R and C combined took a similar time to consume their allocation of food and achieved a similar final empty body weight (EBW) and empty body composition. In addition, the total energy retention (ER) of lambs on these treatments was similar to that predicted by a feeding standards model for lambs of a similar liveweight offered diets of the same ME content. Lambs on treatment M consumed their allocation of food faster than those on all other treatments and achieved a slightly, but not significantly, higher final EBW, which contained a higher proportion of fat. The ER was higher than predicted. The higher overall efficiency of lambs on treatment M was attributed to higher daily intakes and differences in the ratio of protein: fat deposited and maintained by lambs on each treatment. The adoption of separate efficiency constants for both deposition and maintenance of protein and fat in current feeding standards would result in a more accurate prediction of animal performance.

Effects of alfalfa form and level on subacute acidosis (1994)

Eight ruminally cannulated crossbred steers (1225 lb) were used to investigate the effects of 5 vs 10% alfalfa hay or pellets on rumen characteristics during subacute acidosis. Alfalfa hay was obtained from one source, and alternate bales were either chopped (3- to 4-inch length) or ground and pelleted (3/8-inch pellet). Intake during the recovery period after feed challenges tended (P=.12) to be greater for diets containing 10% alfalfa. Duration of rumen pH below 5.5 was less for diets with chopped vs pelleted (P<.10) or 10 vs 5% (P<.05) alfalfa. Total volatile fatty acid (VFA) concentrations during the challenge ph ase and for the overall experimental period were increased (P<.05) when steers were fed 5 vs 10% alfalfa diets but were similar during the baseline and recovery periods. The higher pH and lower VFA concentration resulting from feeding 10% alfalfa diets suggest that steers fed a moderate amount of roughage can withstand greater fluctuations in intake without developing acidosis.

Growth of lambs offered fixed amounts of roughage and concentrate either simultaneously or sequentially

SUMMARYTwo experiments were carried out in Scotland 1984 to study the efficiency of energy utilization by Suffolk × Blackface lambs. In the first experiment, a digestibility trial, the lambs were fed three diets: roughage (R) consisting of chopped dried grass; concentrate (C) containing 700 g whole barley, 225 g ground barley and 75 g fishmeal/kg dry matter (DM); and a mixed diet (M) containing 500 g of roughage and 500 g of concentrate/kg DM. The DM and organic matter digestibility coefficients of diet M were lower than the ‘expected’ values calculated by summation of the separately determined digestibility coefficients of the component feeds. Similarly, the metabolizable energy (ME) value was 4·0% lower than expected.In the second experiment, 40 lambs ofc. 20 kg live weight (LW) were offered 50 kg roughage DM (ME 9·74 MJ/kg DM) and 50 kg concentrate DM (ME 12·21 MJ/kg DM) either as a mixture (treatment M) or sequentially (treatment S). Lambs on treatment S took 33 days longer to consume their allocation of food than those on treatment M, but achieved a similar final empty body weight and empty body composition. This contrasts with results predicted by a feeding standards model for lambs of a similar LW offered diets of the same ME content. The longer feeding period, and hence greater overall maintenance requirement, of lambs on treatment S was partly offset by associated effects causing a reduction in the total ME available to lambs on treatment M, and partly to improved efficiency of energy utilization for gain and/or a lower daily maintenance requirement of lambs on treatment S. Allowing for associated effects and the adoption of a variable maintenance requirement in current feeding standards would result in a more accurate prediction of animal performance.

Altering Milk Composition by Feeding

Nutrition offers a means of making rapid changes in milk composition, but the relationship between feed constituents and milk composition is complex. The greatest changes can be brought about in the concentration of milk fat. Particularly important dietary factors are the amount of roughage, forage:concentrate ratio, the carbohydrate composition of the con-centrates, lipids, intake, and meal frequency. Far smaller changes are possible in milk protein concentration. The best documented effects are for intake and lipid supplements. Dietary protein has only small effects on either milk fat or protein concentration. Very small changes in lactose concentration occur sometimes in response to diet but they are inconsistent and not of practical value. Exploitation of these possibilities requires repeatable responses and accurate prediction of overall animal performance. Empirical prediction equations have been developed for some factors but the complexity of the interrelationships of the several different responses to a single dietary change suggest that mechanistic models covering complete nutrient utilization by the dairy cow may be necessary. Whatever the technical developments, economic factors will be the final determinant of the uptake of such techniques by the dairy farmer.

Dietary Interaction of Cane Molasses with Source of Roughage: Intake and Lactation Effects

Effects of cane molasses at 0, 4, and 8% of DM in complete mixed diets were evaluated when molasses was fed to lactating dairy cows with cottonseed hulls, alfalfa haylage, or both combined. Thirty-six mature Holstein cows from mid to late lactation were used in a partially balanced incomplete block design with three 28-d periods. Variables measured were DM intake, milk yield, and composition. With cottonseed hull diets (30% of DM), molasses improved milk yield, milk fat percentage, solids-corrected milk, and feed efficiency. Dry matter intake was not affected by molasses. With alfalfa haylage diets (35% of DM), 8% molasses depressed actual milk yield and solids-corrected milk, DM intake, milk fat percentage, milk protein percentage, and feed efficiency. Milk fat percentage was increased with 4% molasses. With 65% alfalfa haylage diets, most variables measured were unaffected by molasses; however, with 8% molasses, DM intake increased and milk protein percentage decreased. In diets with both roughages combined, molasses did not affect any variable measured; however, these diets gave highest solids-corrected milk yields. Results show clearly that molasses effects depend on percentage molasses and type and amount of roughage in the diet.

Polioencephalomalacia

Polioencephalomalacia, a disease of ruminants, is most likely due to a thiamine deficiency and is most frequently associated with intensive feeding conditions or with recent changes in management. The clinical signs of incoordination and blindness followed by recumbency and opisthotonus can resolve relatively rapidly when treated early with thiamine and supportive care. The disease can frequently be prevented by thiamine supplementation and inclusion of a minimum amount of roughage in feedlot rations.

Growth of Lambs Offered a Fixed Amount of Roughage and Concentrate by Two Feeding Strategies

Fixed amounts of roughage and concentrate can be allocated to growing ruminants in a number of different ways e.g. a) a mixed diet containing equal parts of roughage and concentrate b) split feeds, roughage being given alone until exhausted, then concentrate alone c) a mixture changing . progressively from all roughage to all concentrate d) half the animals given roughage and half concentrate. The results of these alternatives can be predicted from computer models based on current feeding standards. Recent evidence (Ørskov et al, 1981a; Williams et al, 1984) suggests that in cattle carcasses of similar weight and composition can be obtained by giving a fixed amount of roughage and concentrate as either a mixed diet, or as separate feeds, (i.e. alternatives (a) and (b), above)even though animals on (b) took significantly longer. (Ørskov et al (1981a) concluded that improved efficiency of energy utilisation in the split group could be accounted for by a decrease in the maintenance requirement of the animals, or an increase in the efficiency of energy utilisation during realimentation following a period of reduced nutrition. The results could also be explained by differences in carcass composition of the animals, since no measurement of the protein and fat content of the carcasses was made. Williams et al (1984) found no significant difference in carcass composition between the two groups, as determined by specific gravity measurements and concluded that associative effects caused a reduction in the energy available from straw when offered with barley in a mixed diet.

Holstein Friesians, Dutch Friesians and Dutch Red and Whites on two complete diets with a different amount of roughage: Performance in first lactation

Groups of 20 Holstein Friesian (HF), 23 Dutch Red and White (DRW) and 20 Dutch Friesian (DF) heifers were fed a complete diet with only roughage (a mixture of grass and corn-silage) or the same mixture of roughage with 50% concentrates on a dry matter basis, from 2 months before the first calving until 10 months after calving. No significant breed-feed composition interactions were found for any of the characteristics. The HF, DRW and DF heifers differed significantly in feed intake and milk production. They consumed 4725, 4432 and 4476 kVEM, respectively, and produced 5331, 4562 and 4660 kg milk, respectively, with 3.96, 4.20 and 4.22% of fat, respectively, and 3.25, 3.49 and 3.40% of protein, respectively. The concentrates and roughage groups differed significantly in feed intake, milk production, average body weight and gain. The respective mean values for the concentrates and the roughage groups were: 5160 and 3928 kVEM, 5534 and 4168 kg milk, 4.00 and 4.26% fat, 3.52 and 3.24% protein, 542 and 506 kg body weight and 97 and 38 kg gain, respectively. HF heifers used 51% of their energy intake for milk production (milk energy), DF heifers 49% and DRW heifers 48%. Both feed composition groups used 49% of their energy intake for milk production, but the roughage group used 8% more of the energy intake for maintenance than the concentrates group, as a result of lower energy intake.

Holstein Friesians, Dutch Friesians and Dutch Red and Whites on two complete diets with a different amount of roughage: Differences in performance between first and second lactation

Groups of 11 Holstein Friesian (HF), 11 Dutch Red and White (DRW) and 12 Dutch Friesian (DF) second calved cows were fed a complete diet with only roughage (a mixture of grass- and corn-silage) or the same mixture of roughage with 50% concentrates on a dry matter basis. The animals had participated in the same experiment during their first lactation. For none of the characteristics was a significant breed-feed composition interaction found. The differences between breeds in feed intake, milk production, body weight and gain were equal with both feed compositions. The breeds differed significantly in the increase in milk, fat and protein yield from the first to the second lactation. This increase was 902, 194 and 103 kg milk, 46, 16 and 5 kg fat and 27, 1 and 3 kg protein for the HF, DRW and DF animals, respectively. The body weight gain of the concentrates group in the second lactation was much less than in the first lactation. For the HF animals, 55% of total energy intake was used for milk yield, 37% for maintenance and 8% for gain; corresponding values for the DRW animals were 48, 41 and 11%, respectively, and for the DF animals 44, 37 and 19%, respectively. For the concentrates group, this partition was 51, 36 and 13%, respectively, and for the roughage group 47, 41 and 13%, respectively.

Differences in feed intake between holstein Friesian, Dutch Red and White and Dutch Friesian cattle

In a comparison of Holstein Friesian (HF) from North America with Dutch Red and Whites (DRW) and Dutch Friesians (DF), the feed intake of 20 animals per breed was measured at different stages of lactation and at different ages. In the experiments with dairy cows, the animals were offered concentrates individually according to their milk yield. In all experiments roughage (silage or hay) was offered ad libitum. In all experiments the DRW animals ate less roughage than the HF and DF animals, although they ate the lowest amount of concentrates in nearly all experiments, due to their lower milk yield. The HF animals were offered more concentrates than the DF animals, but ate the same amount of roughage.

The influence of some nutritional factors on the incidence of the repeat breeder syndrome in high producing dairy herds

Data on feeding and the incidence of reproduction disorders in dairy cattle were collected and compared between 2 groups composed of 6 Kibutz dairy herds each. One group contained herds picked at random from dairies with a good overall conception rate (45% and above according to rectal pregnancy examinations) and the other group was randomly selected from those with a low overall conception rate (32% and below). The two groups differed significantly in the incidences of repeat breeder cows (5.48% and 27.35%, respectively), the percentage of problem cows not pregnant 150 days after parturition (14.62% and 38.8%), days to conception (98.5 and 113.7 days), percentage of cows culled due to infertility (5.6% and 15.33%), and in the feeding practices. During the first half of lactation (the high production period) the differences occurred in the amount of digestible protein (11.9% and 9.9% of total dry matter) and in the amount of roughage (33.5% and 20.3% of total dry matter) fed. During the second half of lactation the significant differences between the 2 groups were in the energy level (16.5 F.U. and 13.6 F.U.) and digestible protein fed (10.25% and 8.73% of total dry matter), as well as in the total dry matter fed (17.7 Kg and 15.1 Kg). In the dry period, the only significant difference was in the total dry matter fed (12.7 Kg and 10.5 Kg). It appears that the incidence of repeat breeder cows is influenced by nutritional factors, particularly by the roughage, protein, and energy levels. Proper amounts of these three constituents in the ration during the entire inter-valving period is essential for providing appropriate fertility levels in high producing dairy herds.

Carbohydrate metabolism in the ruminant. Bacterial carbohydrates formed in the rumen and their contribution to digesta entering the duodenum.

1. Samples of mixed bacteria were separated from rumen digesta taken from calves, kept out of contact with adult animals, and from sheep and cows.2. For calves receiving a diet made up of equal amounts of roughage and cereals with 13–16 g nitrogen/kg dry matter, samples of mixed bacteria taken 4–6 h after feeding contained, on average, 140 g glucose in α-linked polymers (α-dextran), 25 g galactose and a total of 25 g other non-glucose, non-galactose sugars (mainly rhamnose, ribose and mannose) in combined forms per kg dry matter.3. The α-dextran content of similar bacteria samples from sheep or cows receiving diets of similar composition was 70 g/kg dry matter. Samples from animals receiving all-roughage diets contained only 25 g α-dextran/kg dry matter, but those from cows given more than 70% of their ration as concentrates (mainly cereal) contained 150 g α-dextran/kg dry matter.4. Addition of supplementary protein or urea to cereal–roughage diets given to calves greatly depressed the amount of α-dextran in the rumen bacterial samples to an average value of 60 g/kg dry matter.5. Samples taken before a morning feed (i.e. after 16 h fasting) contained less α-dextran than samples taken 4–6 h after feeding for both calves and cows.6. Under different conditions, variations in the amounts of galactose in rumen bacteria sometimes paralleled variations in α-dextran. Amounts of other non-glucose sugars did not vary greatly.7. It was estimated, from a comparison of the compositions of rumen bacteria and duodenal contents, that, in the latter, the rhamnose, ribose and mannose came mainly from the bacteria, the arabinose, xylose and cellulose-glucose mainly from the diet and the galactose and α-dextran-glucose from both sources.

Rearing of dairy cattle. 4. Effect of concentrate supplementation on the live-weight gain and feed intake of calves offered roughages ad libitum

SUMMARYThe effects of three levels of concentrate supplementation on the live-weight gain and intake of roughages of 12-week-old British Friesian female calves were examined. Each supplement was offered for 12 weeks to two replicates of five calves which were group fed. The following six roughages were studied; high quality hay, dried grass wafers, grass silage, barley straw, poor quality hay and maize silage. The digestibility of the roughages was measured with sheep by total collection of faeces.Increasing the level of concentrate supplementation gave linear increases in live-weight gains of calves with all roughages, the greatest response occurring with roughages of low digestibility. The intake of roughage was depressed by increasing the level of concentrate supplementation, the greatest depressions occurring with roughages of high digestibility. Live-weight gains and roughage intakes were higher with dried grass wafers and lower with maize silage than would be expected from their respective digestibility coefficients.Multiple regression equations were calculated to relate live-weight gains or roughage intakes to concentrate intake and roughage digestibility. These equations predict from the digestibility of a roughage, the amount of concentrates required daily to produce a given live-weight gain, and the amount of roughage which is eaten under these circumstances.

Effect of Feeding Buffered Concentrate Rations on the Performance and Metabolism of Lactating Dairy Cattle in a Subtropical Environment

Buffered concentrates were fed to lactating Holsteins receiving 5.46 to 10.9kg of roughage daily in three trials with 12 cows per trial. Sodium bicarbonate fed as 3.84% of the concentrate or as .34kg per cow daily significantly increased (P<.05) 4% fatcorrected milk, daily fat production and acetic:propionic ratio with all levels of roughage fed. Concentrate plus NaHCO3 fed with 5.46 to 9.1kg of roughage per day increased fat and total solids percentages, molar proportion of rumen acetic acid, and decreased molar proportion of rumen propionic acid. Highroughage (10.9 kg/day) plus NaHCO3 significantly increased rumen pH to 6.70 compared with 6.25 for low-roughage control (7.28 kg/day). A combination of 1.92% each of NaHCO3 and MgO added to the concentrate significantly reduced concentrate intake, weight gain, total milk and total protein and increased fat and total solids percentages. These data indicate that amount of roughage in the diet influences response to NaHCO3. Addition of MgO depressed feed intake and milk yield. Experimental design did not permit evaluation as to whether other effects were due to MgO or reduced concentrate intake.

The nutrition of the veal calf. 4. The effect of offering roughage on health and performance.

1. Eighteen bull calves, comprising twelve Ayrshires, three Friesians and three Jerseys were reared from birth to a slaughter weight equivalent to 22 % of mature cow weight of the breed.2. All the calves were given a milk substitute diet ad lib. in two feeds daily. Six of the calves received this diet alone and the remaining twelve calves were offered roughage ad lib. from I week of age, either as meadow hay or as barley straw. The calf-house was maintained at a mean temperature of 23' and a mean relative humidity of 62 %.3. The mean total intake of meadow hay and barley straw over the experimental period of about 12 weeks was 3.0 kg and 0.4 kg respectively. Only three calves were consuming any meadow hay and only two calves any barley straw at 7 weeks of age.4. The roughage consumed had no effect on the incidence of diarrhoea, on dry-matter intake from milk or on live-weight gain. All the calves offered meadow hay had lung lesions at slaughter. Severity of lung lesions in the Jersey and Friesian calves combined, but not in the Ayrshires, tended to be inversely related to the relative humidity to which they were exposed.5. Dressed carcass weight and killing out percentage tended to be lower for the calves offered meadow hay. There was a highly significant inverse relationship between total intake of hay and killing out percentage. Perirenal fat depositionin relation to carcass weight was significantly lower and carotenoid content of the fat significantly higher for the calves offered the meadow hay. Skin weight per unit of slaughter weight 0.78 or carcass weight OJ* was significantly greater for the calves given the milk substitute diet only.6. It is concluded that the calf shows very little desire to eat roughage when given a good- quality milk substitute diet ad lib. and that, even when the amounts of roughage consumed are small, this has a deleterious effect on carcass quality.