Silage and milk production: a comparison between barley and dried sugar-beet pulp as silage supplements

Two grass silages made from perennial ryegrass, and with D-values of 0·216 and 0·255, were offered ad libitum to 18 Ayrshire cows in two feeding experiments. On the control treatment the silages were supplemented with soybean meal only, and on the other two treatments with equal weights of DM from either barley or dried molassed sugar-beet pulp plus the same weight of soya as on the control treatment. The daily intakes of silage DM were not significantly different on the barley and beet-pulp treatments, and, on average, the intake of silage DM was reduced by 0·24 and 0·20 kg by feeding 1 kg barley and beet pulp DM respectively.
The daily milk yields were not significantly different on the barley and beet-pulp treatments with mean values of 19·2 and 19·2 kg per cow respectively compared with 17·2 kg on the control treatment. On the barley and beet-pulp treatments the fat, SNF, CP and lactose concentrations in the milk and the live weights of the cows were not significantly different. It is concluded that the barley and beet pulp had similar feeding values and replacement rates when used as supplements with grass silage, and that the two feeds were interchangeable on an equal DM basis.     

Silage and milk production: studies with diets containing white clover silage

In three separate feeding experiments using a total of twenty-six individually-housed Ayrshire cows, three wilted silages made from Blanca white clover were offered ad libitum with either different supplements or different proportions of grass silage. The clover silages contained 680 g white clover kg⁻¹ on a DM basis, and had a mean DM concentration of 263 g kg⁻¹ with 231 g CP kg⁻¹ DM and 91 g ammonia-N kg⁻¹ N. The pH values averaged 4·16 and the DOMD concentrations 611 g kg⁻¹. In experiment 1 the daily intake of clover silage given alone was 15.2 kg DM per cow, i.e. 30·1 g kg⁻¹ live weight, and decreased by 0·76 kg DM kg⁻¹ barley DM and by 0·66 kg DM kg⁻¹barley plus soybean meal DM when these feeds were offered as supplements. Milk yield and fat concentration were higher on the supplement treatments than on the clover silage-only treatment. In experiments 2 and 3 the intakes of silage and total DM increased as the weight of clover in the diet increased from 0 to 700 g kg⁻¹ with parallel increases in milk yield. The effects on milk composition were small and generally non-significant. Although white clover silages with excellent fermentations were made, it is concluded that the main role of white clover in a silage system will be in mixed swards with grass to reduce the input of fertilizer N and to increase the voluntary intake of silage.     

Silage and milk production: a comparison between soya, groundnut and single-cell protein as silage supplements

Grass silage made in May from S24 perennial ryegrass was offered ad libitum to twelve Ayrshire cows in a 12-week feeding experiment. The silage had a DM concentration of 217 g kg ^-1, contained 147 g crude protein per kg DM and had a D-value of 64·6. In addition each cow consumed 1 kg hay per d plus concentrate supplements of dried sugar-beet pulp with (A) soya bean meal, (B)‘Pruteen’, a single-cell protein (C) groundnut cake. The three concentrate supplements each contained 250 g crude protein per kg DM and were offered at the rate of 2·9 kg per 10 kg milk. The daily intakes of silage DM were 8·38, 7·94 and 7·49 kg on treatments A, B and C, respectively, with the extreme values being significantly different. The mean daily yields of milk on treatments A and B were both 16·2 kg per cow, and were significantly higher than the yield of 15·2 kg per cow on treatment C. The fat and lactose contents of the milk on the three treatments were not significantly different, but the CP content on treatment C was significantly lower than that on the other treatments. It is concluded that soya bean meal and‘Pruteen’were superior to groundnut cake as a protein supplement in a silage-based ration.     

Silage and milk production: comparisons between hays of different digestibilities as silage supplements

In three separate feeding experiments using a total of thirty individually-housed Ayrshire cows three silages made from perennial ryegrass were given ad libitum together with supplements of four different hays in the long form. The in vitro D-values of the silages ranged from 0·298 to 0·283, and the hays from 0·280 to 0·200. The daily intake of hay DM varied from 0·2 to 4·2 kg per cow and was given either without or with a daily maximum of 2·2 kg concentrate DM containing 379–527 g CP per kg DM. On average, 1 kg hay DM decreased silage intake by 0·24 kg DM with a range of 0·21–1·20 kg. The hay supplements had only small and non-significant effects on total DM intake, milk yield and milk composition, but increased the daily intake of drinking water. In three behavioural studies, the eating and ruminating times expressed as min per kg DM did not differ significantly between the various supplement treatments. It is concluded that hay has only a marginal value as a supplement for grass silage, although the hay could serve as a useful 'buffer' feed if the amount of silage was limited.     

Silage and milk production. A comparision between barley and groundnut cake as supplements to silage of high digestibility

Grass silage of hjgh digestibility made in late May from S23 perennial ryegrass was offered to twelve Ayrshire cows in a 16-week winter-feeding experiment. The silage had a DM content of 27.2% and contained 147% crude protein and 70.3% digestible organic matter in the DM. The silage was fed ad libitum and was the sole feed in the control treatment. In the other three treatments the silage was supplemented with barley, groundnut cake or a mixture of barley and groundnut supplying 4.7, 1.5 and 4.7 kg DM per cow per day respectively. The daily intakes of silage DM were 10.8 kg per cow in the control treatment and 8.6, 11.1 and 9.3 kg per cow in the barley, groundnut and barley plus groundnut treatments, respectively. The daily yields of milk were 14.6 kg per cow in the control, and 16.1, 17.6 and 17.9 kg per cow in the three supplement treatments, respectively. The fat content of the milk was highest in the barley treatment, whereas the SNF and CP contents were highest in the barley plus groundnut treatment. It is concluded that with a high digestibility silage, a supplement of groundnut cake was superior to barley for milk production.     

Silage and milk production: a comparison between additives for silage of high digestibility

Three grass silages made in early June from S23 perennial ryegrass were compared in a 16-week feeding experiment with twelve Ayrshire cows. The silages were made from uniform herbage which received either formic acid (‘Add-F’) at the rate of 201 t^?1, or a formalin-sulphuric acid mixture (‘Syiade’) at rates of 2.0 and 4.4 1 t^?1. The silages were offered ad libitum either alone or supplemented with a cube containing 38% CP in the DM at the rate of 1.4 kg per 10 kg milk. The daily intakes of silage DM were not significantly different on the three silage treatments, and averaged 10.7, 11.0 and 11.0 kg per cow on the formic acid and the 2.0 and 44 1 t^?1 formalin-acid treatments respectively. The mean daily yields of milk were 15.1, 13.3 and 13.7 kg per cow in the unsupplemented treatments, and 18.2, 18.1 and 18.0 kg per cow in the supplemented treatments on the formic acid and the 2.0 and 44 1 t^?1 formalin-acid treatments respectively. On the basis of total animal production expressed in terms of metabolizable energy requirements, it was concluded that the differences between the three silages were small.     

Silage and milk production: a comparison between long, chopped and ground hays as supplements to silage of high digestibility

Grass silage made in May from S24 perennial ryegrass had a DM concentration of 262 g kg^-1 and an in vitro D-value of 0·698, and was given ad libitum to twelve Ayrshire cows in a 16-week feeding experiment. In addition supplements of hay with a mean in vitro D-value of 0·603 were offered in one of three forms—long, chopped (12·1 mm) or ground (0·80 modulus of fineness) and cubed—and of concentrates given at either 2 or 4 kg per 10 kg milk. Hay averaged 18·2% of total forage DM intake with mean daily intakes of 1·28, 1·22 and 2·26 kg DM per cow in the long, short and ground forms respectively. The highest daily intakes of forage, i.e. silage plus hay, occurred on the ground hay treatments, with values of 10·24 and 9·25 kg DM per cow on the 2 and 4 kg concentrate treatments respectively. The mean daily milk yields were 18·2,18·2 and 19·2 kg per cow on the long, short and ground hay treatments respectively but the increase in yield with the ground hay was only significant at the low level of concentrate intake. The hay treatments had small and non-significant effects on milk composition. It is concluded that ground hay was superior to either long or chopped hay as a supplement for silage, but the small advantages depended on the level of concentrate intake.     

Silage and milk production: a comparison between concentrates containing different amounts of protected protein as supplements for silage of high digestibility

Grass silage made in late May from S24 perennial ryegrass was offered ad libitum to eight Ayshire cows in a 16-week feeding experiment. The silage had a DM concentration of 244 g kg⁻¹, contained 163 g crude protein (kg DM)⁻¹ with a ruminal degradability of 0.77 and had an in vitro DOMD concentration of 678 g kg⁻¹. In addition, four concentrates each containing 167 g soya-bean meal kg⁻¹ were consumed at a mean daily rate of 6.43 kg DM per cow. The soya-bean meal was either untreated, or 'protected' by formalin and mixed in the following proportions, 100:0; 66:34; 34:66; and 0:100 respectively, in the four concentrates. The daily intakes of silage DM were not significantly different on the four treatments and averaged 90 kg DM per cow, giving a mean total daily DM intake of 32.4 g kg⁻¹ live weight. The milk yields were not significantly different on the four treatments and averaged 23.9 kg ⁻¹ The treatments had small and non-significant effects on milk composition and live weight. It is concluded that with a high-digestibility, well-preserved grass silage of satisfactory protein content the inclusion of 'protected' protein in the supplementary concentrate had no beneficial effects on milk production.     

Silage and milk production: a comparison between four rates of groundnut cake supplementation of silage of high digestibility

Grass silage made in late May from S24 perennial ryegrass was offered to twelve Ayrshire cows in a 16-week feeding experiment. The silage had a DM content of 25.3%, a pH of 3.91, and contained 16.8% CP and 68.4% digestible organic matter in the DM. The silage was fed ad libitum and was the sole feed in the control treatment. In the other three treatments the silage was supplemented with a cube offered at rates of 0.8, 1.4 and 2.0 kg per 10 kg milk. The cube contained 82.2% groundnut, plus molasses and minerals, and had 37.9% CP in the DM. The daily intake of silage DM was 11.4 kg per cow on average over the four treatments which did not differ significantly. The mean daily milk yields were 14.8 kg per cow in the control treatment, and 16.5, 18.2 and 18.4 kg in the 0.8, 1.4 and 2.0 kg supplement treatments respectively. The SNF, CP and lactose contents of the milk were Wghest on the 1.4 kg supplement treatment. It is concluded that with a high digestibility silage, there is little evidence to support the feeding of more than 1.4 kg of high-protein cubes per 10 kg milk in the declining phase of lactation.     

Silage intake and milk production in cows given barley supplements of reduced ruminal degradability

Three change-over experiments were conducted to determine the effect on ad libitum silage intake and milk production in dairy cows of treatment of barley supplements with an acid-formaldehyde reagent designed to reduce the rate of starch and protein digestion in the rumen. In Experiment 1 there were six dietary treatments consisting of silage with supplements of 4·0,6·5 and 9·0 kg d^-1 of barley given untreated or treated with formaldehyde reagent (8·1 t^-1). In Experiment 2 there were four dietary treatments consisting of silage with supplements of barley (7·0 kg d^-1) or barley and fishmeal (6·0 kg d^-1 plus 1·0 kg d^-1), with the barley untreated or treated with formaldehyde reagent (15·1t^-1). In Experiment 3 there were four dietary treatments consisting of silage given alone or with supplements of barley (9·0 kg d^-1). Treated barley (15·1 t^-1, 9·0 kg d^-1) and barley plus sodium bicarbonate (9·0 kg d^-1 plus 25·0 g d^-1). Treatment of the barley supplement with formaldehyde reagent had no effect on silage intake or milk production in Experiment 1 where the rate of application of the reagent was low and the basal silage-barley diet was limiting in rumendegradable nitrogen. However, in Experiments 2 and 3 treated barley supplements were associated with improvements in silage intake and milk production. As compared with corresponding control diets containing untreated barley, increases in silage intake ranged from 0 to 0·16 of the control value, whilst associated increases in the yields of milk, milk fat, milk protein and lactose were 0·077–0·089, 0·016–0·026, 0·092–0·118 and 0·080–0·092 of the control value. These responses are discussed in relation to the increases in silage intake and milk production observed with fishmeal supplementation of the diet in Experiment 2 and inclusion of sodium bicarbonate in Experiment 3.     

A comparison between supplements to silage of high digestibility offered to dairy cows

Grass silage containing 180 g crude protein and 660g digestible organic matter per kg DM was offered to forty-two dairy cows for 20 weeks in a self-feeding system. In addition, supplements of either mineralized barley (130 g crude protein per kg DM) or barley plus groundnut (180 g crude protein per kg DM) were offered. The mean daily milk yields were 18·5 and 19·4 kg per cow respectively.     

Silage and milk production: comparisons between grass silage of three different chop lengths

Three grass silages of different chop lengths made from a uniform sward of S23 perennial ryegrass were compared in four experiments including a feeding experiment with twelve lactating cows, an eating behaviour study, a rate of passage investigation and a selection trial. The silages had median chop lengths of 9·4, 17·4 and 72·0 mm, termed short, medium and long, with pH values of 3·93, 3·94 and 4·17 and D-values of 65·9, 65·2 and 64·4 respectively. The daily intakes of silage DM and the daily milk yields increased as silage chop length decreased. The milk yield response to shorter chopping was significant with a supplement of groundnut but not significant with a supplement of sugar-beet pulp. Chop length had small and generally non-significant effects on milk composition. Eating and ruminating times expressed as min per kg DM decreased as silage chop length decreased but the retention time of the silage residues in the entire digestive tract was not significantly affected by chop length. When offered simultaneously, the intakes of the individual silages were 52·2, 31·9 and 15·9% of the total DM intake for the short, medium and long treatments respectively. Although silage with a chop length of 9 mm had nutritional advantages over longer silages, it is concluded that the mechanical and economic aspects of silage making must be considered fully when defining optimum chop length.     

Silage and milk production: a comparison between unwilted and wilted grass silages

Three grass silages made in sunny weather in early July from second-harvest perennial ryegrass were compared in a 16-week feeding experiment with twelve Ayrshire cows. The silages were either unwilted or wilted with and without conditioning, and had mean dry matter (DM) concentrations of 201, 261 and 272 g kg⁻¹, and in vitro DOMD concentrations of 650, 669 and 672 g kg⁻¹ DM respectively. All the silages had formic acid ('Add-F') applied at a rate of 2.6 litres t⁻¹ and were offered ad libitum plus 6 kg concentrates per cow per d. The daily intakes of silage DM were 905 kg per cow on the unwilted treatment and 9.86 and 9.65 kg on the wilted treatments with and without conditioning respectively. Daily milk yields were 171, 17.6 and 17.4 kg per cow on the unwilted, and wilted with and without conditioning treatments respectively and were not significantly different. Fat concentrations in the milk were not affected significantly by treatment, whereas the crude protein and solids-not-fat concentrations were significantly higher on the wilted than on the unwilted treatment. The efficiency of utilization of metabolizable energy for lactation was 6–7% lower with the wilted than with the unwilted silages and it is concluded that the unwilted silage was superior to the wilted silages as a feed for dairy cows.     

Silage and milk production: a comparison between three grass silages of different digestibilities

Three first-harvest grass silages made from S23 perennial ryegrass cut on 25 May, 13 June and 25 June, and termed early, medium and late silages respectively, were compared in a 16-week feeding experiment with fourteen Ayrshire cows. The early, medium and late silages had D-values of 71·2, 65·0 and 62·5 respectively. The early silage was offered alone, whereas the medium and late silages were supplemented with a concentrate containing 208 g crude protein per kg DM at rates of 2, 3 and 4 kg per 10 kg milk. Silage DM intake was 12·8 kg per cow per d on the early silage treatment, and decreased progressively as concentrate intake increased on the other silage treatments. The mean daily milk yields were 16·0 kg per cow in the early silage treatment, 17·0, 18·4 and 20·4 kg per cow in the medium silage treatments, and 16·8, 18·1 and 20·2 kg per cow in the late silage treatments on the 2-, 3- and 4-kg concentrate treatments respectively. Fat concentration in the milk was not affected significantly by treatment, whereas the CP and SNF concentrations increased progressively and significantly as supplementary feeding increased. From the relationship between milk yield and concentrate intake it was calculated that the medium and late silages required a daily concentrate supplement of 2·1 kg DM per cow to give the same daily milk yields as the early silage.     

Silage and milk production: a comparison between grass silages of different chop lengths and digestibilities

Four grass silages of two chop lengths and two D-values were made from S23 perennial ryegrass, and compared in a feeding experiment with lactating cows and in an eating-behaviour study with non-lactating cows. The median chop lengths were 11·6 and 11·5 mm in the short silages and 18·2 and 19·5 mm in the medium silages. Chop length had negligible effects on D-value and on pH with values of 3·81 and 3·94 on the short and medium silages respectively.
Silage DM intakes were higher on the short than on the medium-chop silages in both experiments except where the high D-value silage was supplemented with concentrates. Milk yields were not affected significantly by chop length with daily values of 19·3 and 19·7 kg per cow on the short and medium treatments respectively with the high D-value silage, and 18·2 and 18·3 kg per cow with the low D-value silage. Chop length had only small and non-significant effects on milk composition.
Eating times expressed as min per kg DM were significantly lower on the short than on the medium-chop silages.
It is concluded that the small differences between the short- and the medium-chop silages were of no economic importance.     

Silage and milk production: studies with molasses and formic acid as additives for grass silage

In two separate feeding experiments using a total of twenty-four individually housed Ayrshire cows six silages made from perennial ryegrass were offered ad libitum with supplements of concentrates. In Experiment I herbage with a dry matter (DM) concentration of 225 g kg⁻¹ received either formic acid ('Add-F') at the rate of 2·0 litres t⁻¹ or undiluted cane molasses at rates of 10, 20 and 30 litres t^−l; the mean daily silage intakes were 9·54, 908, 9·27 and 9·49 kg DM per cow and the daily milk yields, corrected to 40 g fat kg⁻¹, were 23·2, 22·3, 22·8 and 22·9 kg per cow respectively but none of the differences between the four treatments was significant. In Experiment 2 herbage with a DM concentration of 269 g kg⁻¹ received formic acid at a uniform rate of 2·6 litres t⁻¹ either with or without an additional application of molasses at 20 litres t⁻¹; the mean daily silage DM intakes were 8·70 and 9·28 kg per cow and the daily fat-corrected milk yields were 22·2 and 21·9 kg per cow respectively and were not significantly different. In both experiments the effects of the treatments on milk composition were small and not significant. It is concluded that there were no advantages in applying molasses to herbage treated with formic acid, and that the rate of application of molasses to untreated herbage which equated with the formic acid application was 20·30 litres t^−l when assessed on the basis of silage composition, intake and milk production.     

Silage and milk production: a comparison between three rates of high-protein concentrate supplementation of grass silages of two digestibilities

Grass silages made from first-harvest perennial ryegrass in mid-May and early-June and termed high-D and low-D respectively had mean DOMD values of 694 and 633 g kg⁻¹ and were offered ad libitum to twelve Ayrshire cows in a 16-week feeding experiment using a cyclic changeover design. The silages were supplemented with a concentrate containing 363g CP per kg DM at daily rates of 1.5, 3.0 and 4.5 kg per cow. The average daily intakes of silage DM were 12.6 and 11.1 kg per cow on the high- and low-D silage treatments respectively, and were not significantly different on the three concentrate treatments. The mean daily milk yields were 171, 18.6 and 21.0 kg per cow on the low-D silage treatments, and 19.6, 21.2 and 22.8 kg per cow on the high-D silage treatments at the 1.5, 3.0 and 4.5 kg rates of concentrate feeding respectively. Fat and lactose concentrations in the milk were not affected significantly by treatment, whereas the CP and SNF concentrations increased progressively and significantly as the rate of supplementary feeding increased. It is concluded that a high-protein concentrate supplement allows silage to make the maximum contribution in the diet, and gives a high response in terms of milk yield and composition.     

Mixing whole-crop pea–oat silage and grass–clover silage: positive effects on intake and milk production of dairy cows

Forty‐eight high‐yielding dairy cows of the Swedish Red breed were used to examine the effects of providing pea–oat silage (P), grass–clover silage (G) and a 0·50:0·50 mixture of the silages (M) ad libitum in diets with two concentrate levels (7 or 10 kg d^?1). A 9‐week experiment, including a 2‐week pre‐experimental period in which the cows were all fed the same diet, and an in vivo apparent digestibility study were conducted comparing the six dietary treatments (M7, M10, P7, P10, G7, G10). Intake and digestibility of the diets and milk production and live weight of the cows were measured. The G silage [11·3 MJ ME kg^?1 dry matter (DM)] was first‐cut grass herbage wilted for 24 h prior to addition of an additive, containing formic acid, propionic acid and ammonia, at 4 L t^?1 fresh matter (FM). The P forage was cut when the peas were at pod fill and ensiled directly with 6 L t^?1 FM of the same additive. The main hypothesis tested, that cows fed the M silage would produce more milk than the cows fed either the P or the G silages, was confirmed. The cows fed the M7 dietary treatment had similar milk yield and milk composition to cows offered the M10, G10 and P10 dietary treatments, and cows offered the G7 and P7 dietary treatments had lower milk and milk protein yields. This suggested that a mixed ration of pea–oat bi‐crop and grass–clover silage has a concentrate‐sparing effect, and that the use of pea–oat bi‐crop and grass–clover silage as a mixed ration for high‐yielding dairy cows can be recommended.     

A comparison of grass/white clover and grass silages offered to dairy cows as the sole feed

Two diets were compared: perennial ryegrass ( Lolium perenne L.) silage and perennial ryegrass/white clover ( Trifolium repens L.) silage, in each case fed ad libitum , without supplementation, to lactating dairy cows. The comparison was made with silages cut on each of four dates. The crops were wilted to a dry matter content of at least 256g kg^-1 and no additives were used.
The grass/clover silages were well preserved at all four cuts. The grass was well preserved at three cuts, but, at a May cut, the grass silage was less well preserved and less digestible than the grass/clover silage. When the May silages were fed, milk yield was higher with grass/clover than with grass. Taking the experiment as a whole, however, milk yield and composition were similar on the two diets. The grass/clover silages had a lower proportion of cell wall and their intake by dairy cows was consistently higher than that of the grass silages.
It is concluded that perennial ryegrass/white clover crops can be ensiled successfully and fed successfully, with high intake, to lactating dairy cows, but it should not be assumed that cows will give more milk than when fed equivalent all-grass silage.     

Silage and milk production: comparisons between unwilted and wilted grass silages made with different additives

Four grass silages, all made in mid-July from second-harvest perennial ryegrass swards, were compared in a 16-week feeding experiment with twelve Ayrshire cows. Two silages were unwilted and two wilted. All the silages received formic acid ('Add-F') at the rate of 3 litres t^-1 either with formalin at the rate of 1 litre t^-1 or without formalin. The unwilted and wilted silages had mean dry matter (DM) concentrations of 200 and 243 g kg^-1, and in vitro D-values of 0·293 and 0·272 respectively. The silages were offered ad libitum plus 6 kg concentrates per cow per day. The daily intakes of unwilted and wilted silage DM were 10·2 and 9·2 kg per cow respectively on the formic acid treatment, and 10·2 and 9·2 kg on the formic acid + formalin treatment. The mean daily milk yield on the unwilted silage treatments was 19·2 kg per cow which was significantly higher than the yield of 17·2 kg per cow on the wilted silage treatments. The formalin had no significant effect on milk yield. The four silage treatments had small and non-significant effects on milk composition. It is concluded that the unwilted silages, which had excellent fermentation characteristics, were superior to the wilted silages as a feed for dairy cows.