A COMPARISON OF SILAGE AND BARN-DRIED HAY FOR BEEF PRODUCTION

Three trials were carried out to compare the feeding value of silage and barn-dried hay for fattening bullocks of approximately 8 cwt initial body weight. In each case the silage and hay were cut from the same sward at the same time. In the first trial the bullocks fed on hay gained 1·88 lb/day while those self-fed on silage gained 1·55 lb/day during a 70-day feeding period. In the second trial of 70 days, the bullocks fed on hay gained 1·96 lb/day and those fed on silage from a trough gained 2·39 lb/day. In the third trial, individually-fed bullocks housed in stalls and given the same hay and silage as used in Trial 2 gained 123 lb/day on hay and 127 lb/day on silage. The significance of these results is discussed in relation to the findings of other workers.     

A COMPARISON OF TWO HAYS FOR BEEF PRODUCTION

A medium quality barn-dried hay and a poor quality field-cured hay were each supplemented with 3 levels of concentrate in the diet of young beef cattle, averaging 313 kg liveweight. The supplement was given on predetermined hay concentrate metabolizable energy (ME) ratios based on the determined ME of the hays and an assumed ME of 3·0 McalsAg DM for the supplement. The hay concentrate ratios used were 1:1, 1:2 and 1:3, the aim being to provide a reasonable rate of growth (0·7 kg/day) with the poorer hay. It was necessary to include urea in the concentrate mixtures used on the 1:1 and 1:2 ratios with the field-cured hay. The urea appeared to have an adverse effect on the intake and utilization of DM on the 1:1 ratio. The range of mean intakes of supplement DM was 3·02 to 4·41 kg/day for the barn-dried hay and 2·23 to 4·61 for the field-cured hay. Mean daily liveweight gains with the barn-dried hay were 0·76, 0·89 and 0·85 kg for the 1:1, 1:2 and 1:3 ratios, respectively, with no significant difference between ratios. The mean daily gains with the field-cured hay were 0·39, 0·77 and 0·75 for the three ratios, the mean gain on the 1:1 ratio being significantly lower than those of the other ratios. The ME conversion ratios were not significantly affected by either ratios or hay type, except on the 1:1 ratio with field-cured hay. There were significant differences between the barn-dried hay and field-cured hay diets in the digestibilities of DM, organic matter, crude protein and energy; the mean coefficients for DM being 74·5% and 65·6%, respectively.     

A REVIEW OF NUTRIENT LOSSES AND EFFICIENCY OF CONSERVING HERBAGE AS SILAGE, BARN-DRIED HAY AND FIELD-CURED HAY

A review of American literature indicates that barn drying of hay and silage making are both greatly superior to the field curing of hay in preserving nutrients. This is true of total dry matter, crude protein, ether extract and ash; crude-fibre losses are greater in silage making. Energy losses run parallel with dry matter. Bam drying of hay with heat preserves a rather greater proportion of nutrients than does silage making.
Chemical composition and digestibility are mostly a function of stage of maturity of the crop at the time of cutting. Actual carbohydrate (energy) losses are greater than protein losses in all methods. The influence of method of conservation is unimportant if conservation is properly carried out, but considerable deterioration can result from bad application. Field-cured hay usually suffers most in this respect, due to weather damage.
The conservation processes reviewed have no influence per se on feeding value where each is applied under ideal conditions. Differences found in practice are usually linked to the stage of maturity or to weather damage, which explains the usually superior feeding value of silage and barn-dried hay over field-cured hay.
When the efficiency of each method is compared by determining the quantity of milk produced from equal areas of forage, conserved in the three different ways, barn-dried hay is somewhat superior to silage, but both are greatly superior to field-cured hay.     

Grass silage as a basic feed for store lambs. 3. Effect of barley supplementation of silages varying in chop length on silage intake and lamb performance

An experiment was carried out to study the effect of silage chop length and barley supplementation on silage intake and the performance of store lambs. The silages were cut from a perennial ryegrass regrowth at a relatively mature stage of growth in early July. Different types of harvester were used to produce a long silage (L), single-chopped (S), double-chopped (D), medium precision-chopped (MP) or a short precision-chopped (SP) silage. The chop length of the silages averaged 37.4, 12.4, 8.4, 7.0 and 2.9 cm respectively. All silages were treated with formic acid at 2.51 t^?1grass. They were well preserved and of a good quality with a dry-matter (DM) digestibility of 720–760 g kg^?1 DM. The silages were fed ad libitum to Suffolk crossbred store lambs over a period of 10 weeks. Each silage was fed either alone or was supplemented with whole barley at 400 g lamb^?1 d^?1. When offered silage alone, intakes were 738, 679, 773, 980 and 910 (± 30) g DM d^?1 for silages L, S, D, MP and SP respectively. Similar relative differences in intakes between the silages were evident when supplemented with barley. Liveweight gain on silage alone was higher on the precision-chopped silages (85–93 g d^?1) than the long or flail-chopped silages (28–49 g d^?1). Liveweight gain on the precision-chopped silages was also better when supplemented with barley (150 vs. 90–112 (± 90) g d^?1). Silage intake and lamb performance were similar for the MP and SP silages, despite the difference in chop length. Barley supplementation reduced silage intake to a similar extent for all silages (-9%) and increased total DM intake (+ 30%) and metabolizable energy intake (+ 37%). The substitution rates of silage for barley were similar for all silages and averaged 0.24 g silage DM g^?l barley DM. The response in weight gain per 100g of barley fed was similar for all silages and averaged 20.0 g liveweight gain and 13.4 g carcass gain. Feed conversion efficiency of the total diet was similar for the Mail-chopped and precision-chopped silages but was less for the long silage. The results of this study show that the benefit in weight gain due to the higher intake of precision-chopped silage was maintained when the silage was supplemented with a moderate level of barley. Such silage required supplementation with barley (400 g d^?l) to achieve a rate of liveweight gain of 150g d^?1.     

Comparison of the fermentation quality and nutritive value of sulphuric and formic acid-treated silages fed to beef cattle

Five experiments were carried out in the years 1980-1983 and 1986 to study the effect of treating grass at ensiling with sulphuric acid (850 g kg^?1) and formic acid (850 g kg^?1) additives alone, and in mixtures with or without formalin on the preservation of grass, in vivo digestibility in sheep, in-silo loss, intake and performance of finishing cattle. Primary growth grass was ensiled in experiments 1 (3–4 June 1980), 2 (12-15 June 1981) and 3 (31 May-2 June 1982), primary regrowth grass in experiment 4 (1-2 August 1983) and secondary regrowth grass in experiment 5 (7-10 October 1986). During the ensiling period within each experiment, approximately 60 t of unwilted, double-chopped, additive-treated or untreated grass was packed into covered concrete-walled 60-t capacity silos. The dry matter (DM) contents of the ensiled grass in experiments 1, 2 and 5 ranged from 155-180 g kg^?1 and were lower than those recorded in experiments 3 and 4 (214 g kg^?1). With the exception of grass ensiled in experiment 2, where water-soluble carbohydrate (WSC) contents were low, at 104 g kg^?1 DM, grass in all other experiments contained relatively high WSC contents ranging from 140-154 g kg^?1 DM. In experiments 1, 3 and 4 all silages were well-preserved. However, in experiment 2 the 450 g kg^?1 sulphuric acid-treated and formic acid-treated silages displayed significantly lower pH, buffering capacity (Bc) and ammonia nitrogen contents than the untreated silage. In experiment 5, the sulphuric acid-treated and formic acid-treated silages displayed significantly lower pH, Bc, ammonia nitrogen, butyrate and volatile fatty acid (VFA) contents than the untreated silage. Each of the silages was offered daily with various levels of a supplementary concentrate for approximately 70-d periods to twelve animals of mixed breed in experiments 1, 3, 4 and 5 and to fifteen animals in experiment 2. All animals weighed between 380-470 kg at the start of the experiments. In experiments 1, 2 and 3 there were no significant differences between silages for any of the intake or animal performance parameters. In experiment 4, cattle fed the formic acid-treated silage displayed significantly higher silage DM intakes and daily liveweight gains than those fed the sulphuric acid-treated and untreated silages; in experiment 5, cattle fed the formic acid-treated silage displayed significantly higher silage DM intakes than those fed the untreated silage. It was concluded that formic acid was a more effective silage additive than sulphuric acid. Increasing the level of supplementation significantly decreased silage DM intakes in cattle in experiments 3 and 4, and significantly increased daily liveweight gains and daily carcass in cattle in experiments 1, 3 and 4.     

A COMPARISON OF NUTRIENT LOSSES IN BALED HAY MADE FROM FORAGE-HARVESTED, CRIMPED OR TEDDED SWARDS WITH THOSE IN BARN-DRYING

Two experiments were conducted to study the effect on nutrient loss and feeding value of making hay by different means, using a barn-drier, a forage-harvester, a crimper and conventional tedding. Both forage-harvesting and crimping of the herbage significantly increased the rate of drying, compared with tedding alone. In Exp. 2 this effect enabled the crimped and forage-harvested hays to be baled for storage 3 days earlier than the tedded hay. The use of the forage-harvester significantly reduced the yield of herbage compared with conventional mowing. Nutrient losses from cutting until storage were highest for the forage-harvested hays, the loss of dry matter between cutting and storage in the forage-harvested hays being 39·9 and 19·3%, respectively, in Expt 1 and 2 with corresponding losses in the conventionally made hays of 7·1% and 9·3%. Crimping the hay resulted in higher nutrient losses than tedding. In Expt 2 there was a loss of dry matter of 17·5% in the conventionally made hay during an 18-week storage period, compared with 3·6% in barn-dried hay, 10·8% in forage-harvested hay and 8·8% in crimped hay.
In Expt 2, in which digestibility determinations were made, conservation decreased the total digestible nutrients and starch equivalent in all treatments. The use of the barn-drier gave the most efficient conservation of total digestible nutrients, followed by the crimped, forage-harvested and conventional treatments in that order. The starch equivalent values of hays made from the same sward were 43·0 when barn-dried, 39·8 when crimped, 38·6 after forage-harvesting and 31·6 after tedding.     

FACTORS AFFECTING THE VOLUNTARY INTAKE OF SILAGE AND HAY

Experiments with cows and sheep are described in which the voluntary intakes of hay and silage of differing digestibility were determined. The voluntary intake of hay increased consistently with increasing digestibility, but the relationship was not as well defined for silage. The addition of concentrates depressed the intake of hay, and this effect was more marked for hay with a high digestibility than with poorer quality hay. Concentrates appeared to depress the intake of hay by sheep more than by cows, an effect which was again more marked when the hay had a high digestibility value.     

Comparisons of some factors affecting digestibility in sheep and cows

A comparison was made of some factors affecting digestibility in sheep and cattle. In one experiment four castrated male sheep and four non-lactating cows were given diets of hay and of hay and concentrates, and in another experiment similar groups of animals were offered diets consisting mainly of hay or hay and lucerne cobs. In both experiments there was good agreement in digestibility between the sheep and cows. With diets which did not stimulate maximum rumination, sheep tended to ruminate for a longer time per day than cows. At high feed intakes rumination times were similar in sheep and cows. Times spent eating, ruminating or chewing per unit of feed DM were 6 to 19 times longer in the sheep than in the cows. Retention times of stained hay in the gut tended to be slightly shorter in sheep than cows and those of stained barley husk and of processed lucerne were similar in the sheep and cows. The median size of faecal particles was 1.4 to 1.9 times greater in cattle than sheep. The similarities and differences between sheep and cattle in the factors affecting digestibility are discussed.     

COMPARATIVE FEEDING VALUE OF SILAGES MADE FROM WILTED AND UNWILTED GRASS AND GRASS/CLOVER HERBAGE

Silage was made from wilted and unwilted grass in May 1965, 1966 and 1967. The silage was made in sealed silos, but these were not evacuated and additives were not used.
The silages were fed as follows: in 1965 to milking dairy cows and 1-year-old beef steers; in 1966 to steers coming into the experiment at 3, 9 and 15 months of age; in 1967 to weaned steer calves, with or without rolled barley (1 or 2 kg/head per day). In all years the silages were of high in vivo digestibility. The intake of wilted silage was higher than that of unwilted silage. There was no significant difference between the milk yields of cows fed on wilted and unwilted silage only. Liveweight gains were higher with wilted silage in 1965 and 1966, but not in 1967. In 1966 gains increased with age of animal and in 1967 gains were higher at successively higher levels of concentrate feeding.     

A STUDY OF THE UTILIZATION OF SILAGES OF DIFFERENT DRY–MATTER CONTENT BY YOUNG BEEF CATTLE WITH OR WITHOUT SUPPLEMENTARY BARLEY

Three Uages containing 18.7, 35.2 and 51.0% DM were given to young beef cattle without supplementary barley or with a daily allowance of 1.8 or 3.6 kg air-dry fortified barley. Each diet was given to 9 individually fed animals, the mean fasted liveweight of which at the start of the experiment was 304 kg. The dafly voluntary DM intake was recorded for a 10-day period for the 9 animals on each silage without supplementary barley. The mean DM intakes per kg W^0.73 were 58.4, 94.6 and 104.1 g for Silages 1, 2 and 3 and the intakes increased curvilinearly with the DM content of the silage. The mean daily liveweight gains on Silages 1, 2 and 3 were 0.63,0.73 and 0.75 kg, respectively; the relationship was significantly linear (P <0.01). The barley supplement also had a significantly linear CP <0.01) effect on daily gains. The mean daily gains for 0, 18 and 3 6 kg fortified barley per day were 0.54, 0.74 and 0.84 kg, respectively. The DM and digestible organic matter required per kg liveweight gain were not significantly affected by the DM of the silage, but were significantly (P < 0.01) affected by supplementation. The metabolizable energy (ME) values of Silages 1,2 and 3 were 2.46, 2.52 and 2.50 Meal/ kg DM, respectively. The supplementary concentrate increased the ME concentration significantly (P < 0.05), although the overall increase was small. The mean values were 2.49, 2.54 and 2.61 Meal/ kg DM, respectively, for 0, 1.8 and 3.6 kg fortified barley per day. The digestibilities of DM and organic matter were not significantly affected by the type of silage, but there was a significant increase with increasing intake of supplementary barley.     

THE INTAKE OF HAY AND SILAGE BY COWS

Three comparisons were made, with non-lactating fistulated cows, of the voluntary intake of silage and hay prepared from similar herbage. On average 28% more dry matter was eaten as hay than as silage. Silage and hay had similar digestibilities, but silage residues tended to remain in the gut longer than those of hay. The amount of digesta in the reticulo-rumen immediately after a meal ad lib . was greater with hay than with silage. The cows spent longer eating and ruminating per kg dry matter of silage than of hay. The results are discussed in relation to possible factors determining the voluntary intake of silage.     

THE GROWTH OF BEEF CATTLE FED ON MAIZE SILAGE SUPPLEMENTED WITH DRIED LUCERNE, FISHMEAL OR UREA

Two experiments are reported in which 119 steers were fed ad lib. on maize silage, supplemented with different proportions of dried lucerne. In addition, the effect of including white fishmeal with the silage at levels up to 13% of the total diet was studied in one experiment. In another, the effect of adding urea to the silage (at 0.9% of the DM) was investigated. In hoth experiments the response in liveweight gain to increasing amounts of lucerne was curvilinear. The highest mean level of daily gain (1.5 kg/head per day) in the first experiment was achieved when the diet contained 62% lucerne or 13% fishmeal. In the second experiment the highest mean daily gain (1.1 kg/head per day) was achieved when the diet contained 71% lucerne. Daily liveweight gains were simOar for the cattle fed 25% of the diet as lucerne with sQage to which urea had heen added, and for those fed higher proportions of lucerne with untreated silage.     

THE FEEDING VALUE OF SILAGES MADE FROM WHOLE-CROP BARLEY

Whole crops of barley were conserved and fed to sheep and cattle. In the first experiment the barley was cut at the mealy-ripe stage of growth and conserved by ensilage or by drying artificially. Cattle and sheep lost weight when the resulting silages were fed ad lib.; wilting the crop before ensiling did not improve the performance. Sheep fed artificially-dried whole-crop barley increased in liveweight; and the intake of this was significantly higher than that of the silages. In the second experiment, barley was cut and ensiled at the watery-ripe, mealy-ripe and late mealy-ripe stages of growth. Intakes and levels of performance by sheep fed these silages did not differ with the growth stage at which the crop was harvested, but supplementation of the silages with lucerne pellets resulted in large improvements in performance.     

Effect of restriction of silage intake and the provision of an alternative forage on the performance of dairy cows

In three experiments the effects of restricting the silage ration of dairy cows and of offering alternative forages as buffer feeds were investigated.
In the first experiment of changeover design with 3-week periods, restricting the intake of low-quality silage to 0.62 of ad libitum had no significant effect on milk yield in spite of the large energy deficit. Offering high-quality hay as a buffer feed increased total DM intake and milk production of cows receiving either restricted or ad libitum silage.
In the second experiment of similar design, restricting the DM intake of high-quality silage to 0·58 of ad libitum significantly reduced milk yield and was associated with a large negative energy balance. Offering straw or ammonia-treated straw with the restricted silage diet did not restore milk production to the level achieved with ad libitum silage but these supplements slightly reduced the energy deficit of the cows. In the third experiment of continuous design lasting 7 weeks, restricting the silage ration to 0.85 of ad libitum had no significant effect on milk production. Offering a strawmix based on straw, barley, molasses and soya with the restricted silage ration restored total DM intake to the ad libitum silage level.
In all three experiments milk protein content was reduced by restricting the silage ration and partially restored by offering alternative forages. There were no significant effects on milk fat content and milk lactose content was only reduced by the severest restriction in Experiment 2. It is concluded that short-term minor restrictions of silage intake can be partly sustained by body fat mobilization but more severe restrictions will result in loss of milk yield. Good-quality hay and a strawmix were of benefit in restoring DM and metabolizable energy intakes, whereas straw and ammonia-treated straw were of little value.     

Maize silage with a non-protein nitrogen additive as feed for autumn-calving cows

Maize silages made in October were fed to forty-three autumn-calving cows during a 20-week winter feeding trial. The control silage received no additive whereas a non-protein nitrogen (NPN) additive was applied to the other silage at harvest time. The four experimental feeding treatments were: A, maize silage + 6 kg d^?1 barley; B, maize silage with NPN + 6 kg d^?1 barley; C, maize silage + 5 kg d^?1’barley + 1 kg d^?1 extracted decorticated groundnut cake; D, maize silage with NPN. The mean daily milk yields of cows on the treatments were 14.7, 15.1, 15.3 and 15.0 kg respectively. All cows received maize silage ad libitum. There were no significant differences in milk yield but the milk produced by the cows on treatment D had significantly lower concentrations of milk fat, protein and solids-not-fat when compared to the other three treatments. The cows on treatment D had a negative liveweight change which was significantly different (P < 0.05) from those of the cows on treatments B and C.     

THE EFFECT OF LEVEL OF PROTEIN IN SILAGE ON THE INTAKE AND PRODUCTION OF DAIRY COWS

Two silages of contrasting protein content were compared in a 16-week winter-feeding experiment with 12 Ayrshire cows. One silage contained 8.2% DCP in its DM and the other 15.9% DCP. The silages were fed ad lib . with a supplement of either barley or barley plus groundnut cake. The DM digestibilities of the low and high protein silages were 74 and 67%, respectively, and the calculated S.E.s 56 and 47. Silage and total DM intakes were highest in the treatments containing low protein silage and in those containing groundnut. The mean daily milk yields for the treatments with and without groundnut were 35.4 and 32.s5 Ib (16.1 and 14.8 kg), respectively, with the high-protein silage, and 38.1 and 35.0 Ib (17.3 and 15.9 kg) with the low-protein silage. The S.N.F. contents of the milk were low and averaged 8.26 and 8.34% on the high- and low-protein silage treatments, respectively, and were not affected significantly by the supplements. It is concluded that the low-protein silage was superior to the high-protein silage as a feed for cows, and that the digestibility of the silage DM was a truer indication of quality than protein content.     

COMPARATIVE STUDIES OF PERENNIAL RYEGRASS. TIMOTHY AND MEADOW FESCUE.

Hays made, mainly in May, from pure swards of perennial ryegrass, timothy and meadow fescue were fed to 8-month old steers in 1963 and to yearling steers in 1964. High-quality hay was obtained, but no significant differences in growth rate were observed between calves fed on hays from the 3 species. In 1963, barley (1.5 kg DM/ head per day) was fed, in addition to the hays, to half the animals and resulted in a significant increase in live weight gain. The productivity, in terms of liveweight gain/ unit area, of each species when managed for hay and‘zero grazing', or hay and grazing, was calculated. On this calculation perennial ryegrass was the most productive species.     

Effects of applying a bacterial inoculant to silage immediately before feeding on silage intake, digestibility, degradability and rumen volatile fatty acid concentrations in growing beef cattle

In an experiment, involving twelve male cattle (initially 235 kg live weight), the effects of applying lactic acid bacteria [Lactobacillus plantarum; 10⁹ colony-forming units (g fresh silage)^?1] to grass silage, immediately prior to that silage being fed, on dry-matter (DM) intake of the silage, degradability of nitrogen (N) and fibre in the rumen, total tract digestibility and composition of rumen fluid in the animals were examined. A grass silage, which had been made from the primary growth of a predominantly perennial ryegrass sward, was offered as the sole diet. The inoculant was applied to the silage at the rate of 2 g of freeze-dried powder reconstituted in 12 ml of water (kg fresh silage)^?1 immediately prior to that silage being fed and an equivalent amount of water was applied to the silage in the control treatment. The two diets were compared in a change-over design. The silage was well preserved, having a pH and concentrations of ammonia N and butyrate of 3.72, 74 g (kg total N)^?1 and 0.11 g (kg DM)^?1 respectively. Application of the inoculant significantly increased true protein, acid-insoluble N and water-soluble carbohydrate concentrations (P < 0.001) in the diet. Silage DM intake was not significantly increased (P= 0.072) by this of inoculant treatment, which had no significant effect (P > 0.05) on rumen degradability or total tract digestibility of DM, N, neutral detergent fibre or modified acid detergent fibre. Rumen pH, ammonia concentration or the molar proportions of volatile fatty acids were not altered (P>0.05) by inoculant treatment. It is concluded that application of the inoculant to the silage prior to silage being fed did not significantly affect silage DM intake, total tract digestibility, or degradability or fermentation in the rumen of cattle offered grass silage as the sole diet. It is also concluded that the results of this experiment provide no evidence that the mode of action of L plantarum, applied as an additive to grass at ensiling in previous studies, is through ‘direct’ effects in the rumen.     

SWEDES OR GRASS SILAGE FOR BEEF CATTLE IN EAST LOTHIAN?

Four East Lothian farms, two growing silage and two roots (swedes) for winter keep of beef cattle were studied in detail. The yields of all crops grown for winter keep and the output of each crop in terms of pounds starch equivalent per acre were measured. The following are the main conclusions reached:
The output per acre from roots was approximately twice that from silage.
Output per acre from hay was lower than from any other fodder crop.
The output per acre from all fodder crops, taken together, was very similar on all four farms. This was because the farms growing swedes grew a proportionately larger acreage of hay than did the silage farms.
The yield of starch equivalent per acre from sugar beet tops was approximately half that from swedes.     

Effects of replacing timothy silage by alsike clover silage on performance,carcass traits and meat quality of finishing Aberdeen Angus and Nordic Red bulls

The objective of the study was to determine the effects of silage plant species and cattle breed on performance and meat quality of finishing bulls. A feeding experiment was conducted using thirty Aberdeen Angus (AA) and thirty Nordic Red (NR) bulls. Both breeds were randomly allotted to three experimental diets. The composition (g kg^?1 dry matter) of the diets was as follows: (i) timothy silage (TS) (650) and barley (350); (ii) TS (325), alsike clover silage (AS) (325) and barley (350); and (iii) AS (650) and barley (350). The bulls were fed a total mixed ration ad libitum. Replacing TS by AS did not affect dry‐matter intake, growth, carcass conformation or meat quality traits of the bulls, but carcass fat score tended to decrease when replacing TS by AS (P = 0·07). The AA bulls grew faster and had better feed conversion and superior carcass conformation compared with the NR bulls (P < 0·001). The loin of the AA bulls had lower shear force value and was given higher scores in sensory analyses compared with the NR bulls (P < 0·01). The experiment demonstrated that replacing TS by AS in the diet of finishing bulls had minor effects on performance or meat quality.