The effects of energy source and level of digestible undegradable protein in concentrates on silage intake and performance of lactating dairy cows offered a range of grass silages

1999 ◽  
Vol 68 (4) ◽  
pp. 763-777 ◽  
Author(s):  
T. W. J. Keady ◽  
C. S. Mayne ◽  
D. A. Fitzpatrick ◽  
M. Marsden

AbstractThe effects of energy source and level of digestible undegraded protein (DUP) in concentrates on silage intake and performance of lactating dairy cows, offered one of a range of grass silages differing in digestibility and intake characteristics, were evaluated in a partially balanced change-over design experiment involving 48 cows. Four silages were prepared using differing management practices prior to and during ensiling. All silages were treated with an inoculant additive. For silages A, В, С and D, dry matter (DM) concentrations were 199, 320, 313 and 223 (s.e. 4.6) g/kg, pH values 3.82, 4.03, 4·03 and 5·27 (s.e. 0.056), ammonia nitrogen (N) concentrations 58, 122, 66 and 356 (s.e. 13.2) g/kg total N and in vivo DM apparent digestibilities 077, 0.75 , 0.60 and 0.60 (s.e. 0·013) respectively. When offered as the sole diet to 12 dairy cows in a partially balanced change-over design experiment, silage DM intakes were 14.7, 14.7, 12.7 and 10.5 (s.e. 0·36) kg/day respectively for silages А, В, С and D. Six concentrates containing three starch concentrations, each at two levels of DUP, were formulated to have similar concentrations of crude protein, metabolizable energy (ME) and fermentable ME. For the low and high starch concentrates and low and high levels of DUP, starch concentrations were 22·5 and 273 g/kg DM and DUP levels were 44 and 60 g/kg DM respectively. Silages were offered ad libitum supplemented with 10 kg fresh concentrate per head per day. For silages А, В, С and D, DM intakes were 10.8, 11.2, 10·7 and 9·1 (s.e. 0·26) kg/day and milk yields 29.0, 27.6, 27.1 and 25.7 (s.e. 0.69) kg/day respectively. With the exception of milk protein concentration there were no significant (P> 0.05) silage type by concentrate energy source and/or level of DUP interactions on silage intake, milk output or composition. Concentrate energy source had no effect (P> 0.05) on silage DM intake, the yields of milk, fat, protein or fat plus protein or milk fat concentration. However, increasing starch concentration increased milk protein concentration (P< 0·001), urinary allantoin concentration (P< 0·01) and diet apparent digestibility (P< 0·001). Altering concentrate DUP level had no effect (P> 0·05) on silage DM intake, yields of milk, protein, fat or fat plus protein, milk f at concentrations or diet apparent digestibility. Increasing the level of DUP decreased milk protein (P< 0·05) concentration. It is concluded that with silages of varying digestibility, fermentation and intake characteristics, there were no concentrate energy source and/or level of DUP by silage type interactions on silage intake, milk yield or composition, or diet apparent digestibility with the exception of a silage type by concentrate level of DUP interaction on milk protein concentration. With out-of-parlour feeding of concentrates the results of the present study suggest that there is no evidence to justify the formulation of concentrates differing in energy source or level of DUP to complement individual silage types.

1998 ◽  
Vol 66 (1) ◽  
pp. 21-33 ◽  
Author(s):  
T. W. J. Keady ◽  
C. S. Mayne ◽  
M. Marsden

AbstractA partially balanced change-over design experiment was made to examine the effects of concentrate energy source on the voluntary food intake and animal performance of 50 lactating dairy cows offered a diverse range of grass silages. The silages were also offered as the sole diet to 10 dairy cows in a partially balanced change-over design experiment. A total of five silages were prepared. Silages A, B and D and silages C and E were harvested from primary regrowths and secondary regrowths respectively of predominantly perennial ryegrass swards. Herbage was ensiled either pre-wilted or unwilted and either untreated or treated with a bacterial inoculant or formic acid based additives. For silages A, B, C, D and E, dry matter (DM) concentrations were 473, 334, 170, 170 and 256 (s.e. 4·0) g/kg, pH values 4·42, 4·01, 4·88, 4·46 and 3·91 (s.e. 0·059), ammonia-nitrogen (N) concentrations 86, 88, 289, 182 and 135 (s.e. 10·6) glkg total N and in vitro DM apparent digestibilities 0·76, 0·76, 0·75, 0·73 and 0·75 (s.e. 0·009) respectively. When offered as the sole diet DM intakes were 14·1,14·7,10·5,10·1 and 11·5 (s.e. 0·50) kg/day. Five concentrates were formulated to contain similar concentrations of crude protein, effective rumen degradable protein (ERDP), metabolizable energy (ME) and fermentable ME (FME) but using different carbohydrate sources to achieve a wide range of starch concentrations. For the low and high starch concentrates, starch concentrations were 50 and 384 g/kg DM, and acid-detergent fibre concentrations were 128 and 75 g/kg DM respectively. The silages were offeredad libitumsupplemented with 10 kg concentrate per head per day. For silages A, B, C, D and E silage DM intakes were 10·6, 10·5, 8·5, 8·6 and 9·0 (s.e. 0·37) kg/day and milk yields 23·9, 28·1, 26·2, 26·1 and 25·0 (s.e. 0·76) kg/day respectively. Concentrate energy source did not influence (P > 0·05) silage DM intake, diet apparent digestibility or the yields of milk or fat plus protein. For concentrates containing 50, 131, 209, 310 and 384 g starch per kg DM, milk protein concentrations were 32·0, 32·2, 32·5, 33·0 and 33·6 (s.e. 0·13) glkg, milk fat concentrations were 44·5, 43·9, 43·8, 43·3 and 43·1 (s.e. 0·35) glkg and urinary allantoin concentrations 15·2,15·4, 17·0, 1.7·6 and 18·0 mmolll respectively. Increasing starch intake resulted in positive and negative linear relationships for milk protein (P< 0·01, R2 = 0·96) and fat (P< 0·01, R2 = 0·96) concentrations respectively. There were no significant concentrate energy source × silage type interactions on silage intake or yields of milk or fat plus protein (P > 0·05). However there was a concentrate energy source × silage type interaction on milk fat yield (P > 0·05). It is concluded that, with silages of varying fermentation and intake characteristics but similar apparent digestibility, there were no concentrate energy source × silage type interactions on food intake, milk composition or milk yield. Also concentrate energy source had no effect on silage DM intake or milk yield. However increasing starch intake linearly increased milk protein concentration, probably due to increased microbial protein synthesis and decreased milk fat concentration.


1998 ◽  
Vol 67 (2) ◽  
pp. 225-236 ◽  
Author(s):  
T. W. J. Keady ◽  
C. S. Mayne

AbstractThe effects of concentrate energy source on feeding behaviour and energy utilization, when offered with grass silages of differing intake characteristics, were studied in lactating dairy cows. A total of five silages, which differed in fermentation and intake characteristics, were prepared. Silages A, B and D and silages C and E were harvested from primary regrowths and secondary regrowths respectively of predominantly perennial ryegrass swards. Herbage was ensiled either pre-wilted or unwilted and either untreated or treated with a bacterial inoculant or formic acid based additives. Five concentrates (0s, 25s, 50s, 75s and 100s) were formulated to contain similar concentrations of crude protein, effective rumen degradable protein and metabolizable energy (ME) but using different carbohydrate sources to achieve a wide range of starch concentrations. The silages were offered ad libitum, supplemented with 10 kg concentrates per head per day. In experiment 1, a partially balanced change-over design experiment involving 50 lactating dairy cows was undertaken to examine the effects of concentrate energy source on silage feeding behaviour. Silages A, B, C, D and E were each supplemented with concentrates Os, 25s, 50s, 75s and 100s. Concentrate energy source did not alter (P > 0·05) silage feeding behaviour. The number of meals per day decreased (P < 0·01) as silage dry-matter concentration increased. Experiment 2, a completely randomized experiment involving 18 lactating dairy cows, was undertaken to examine the effects of concentrate energy source on energy utilization with cows offered silages B, C and D. These were supplemented with 10 kg/day of concentrates Os, 50s and 100s. Concentrate energy source had little effect (P > 0·05) on ME intake, energy output or on the efficiency of utilization of ME for lactation (k1). In experiment 3, the effect of concentrate energy source on silage preference was examined in a factorial design experiment involving 12 lactating dairy cows. Silages B, C and D were supplemented with concentrates Os, 50s and 100s. Concentrate energy source did not alter (P > 0·05) silage preference. It is concluded that with silages of differing fermentation and intake characteristics but of similar digestibility, concentrate energy source had no effect on feeding behaviour, silage preference or energy utilization. Furthermore there was no evidence of concentrate energy source by silage type interactions on silage feeding behaviour and preference, or energy utilization.


1995 ◽  
Vol 60 (1) ◽  
pp. 31-40 ◽  
Author(s):  
P. Huhtanen ◽  
S. Jaakkola ◽  
E. Saarisalo

AbstractSixteen Finnish Ayrshire cows were used in a four period cyclic change-over experiment to evaluate eight concentrate supplements in a 2 × 2 × 2 factorial arrangement. Two concentrate energy sources (starchy and fibrous) were used, each given with two levels (0 and 180 g/kg on a dry-matter (DM) basis) ofrapeseed meal (RSM) and two levels (0 and 180g/kg on DM basis) of wet distillers' solubles (WDS). The starchy concentrate (S) comprised rolled barley and oats (1:1). For the cows given the fibrous concentrate (F), 600 g/kg of the grain mixture was replaced with a mixture of fibrous by-products. Grass silage was offered ad libitum and the supplements offered at a rate of 9 kg/day (fresh weight).The cows offered F supplements consumed more silage DM than those offered S supplements (P < 0·01) but the difference in the total DM intake was smaller. The cows given S supplements produced slightly more milk than those given F supplement (26·5 v. 25·9 kg/day) but no differences were observed in the yield of milk constituents between the energy supplements. Replacing starch with fibre in the concentrate had no effect on the apparent digestibility of organic matter but tended to increase that of neutral-detergent fibre.Including RSM in the supplement increased total DM intake (P<0·05) and led to increases in the yield of milk and milk constituents (P < 0·001 and P < 0·01). Diet apparent digestibility was not affected by RSM supplementation.There were no significant interactions between concentrate energy source and RSM supplementation. Including WDS in the diet had no effect on food intake. Production responses to WDS supplementation varied with the concentrate energy source. WDS increased (at least P< 0·05) milk yield (1·0 kg/day) and the yields of fat (76 g/day) and protein (48 g/day) when given with the starchy concentrate. With the fibrous concentrate WDS had no effect on milk and protein yield, and decreased fat yield by 52 g/day (P < 0·05). The positive responses in the yields of milk fat and protein to RSM and WDS supplementation were almost additive with the starchy concentrate. Inclusion of WDS in the diet increased the apparent digestibility of organic matter and gross energy.


1988 ◽  
Vol 46 (3) ◽  
pp. 317-331 ◽  
Author(s):  
B. K. Sloan ◽  
P. Rowlinson ◽  
D. G. Armstrong

ABSTRACTThere is increasing interest in how the raw material make-up of concentrates can influence the milk performance of dairy cows. Thus, over two consecutive winters, 54 dairy cows were used to investigate the effects on dry matter (DM) intake, milk yield and its composition of feeding concentrates of diverse energy source (LNDF — 131 g neutral-detergent fibre per kg DM, 492 g starch plus sugars per kg DM; HNDF — 244 g neutral-detergent fibre per kg DM, 293 g starch plus sugar per kg DM) at two formulated crude protein (CP) levels (157v.187 g/kg DM) and three levels of concentrate allowance (9, 11, 13 kg DM). The concentrates were formulated to be of equivalent metabolizable energy concentration (MJ/kg DM) and were offered with silagead libitumfor a 10-week period (weeks 4 to 13 of lactation).Silage intakes were variable but not significantly influenced by concentrate energy source or formulated CP level, except in the 1st year where animals consuming the high CP concentrate ate more silage. Silage DM intake decreased as concentrate allowance was increased with the substitution rate (kg silage DM per kg concentrate DM) increasing as concentrate allowance was increased.Increasing the concentrate allowance effected the expected increases in milk yield. Concentrate energy source did not influence milk yield but the higher CP levels effected a 2-kg increase in milk yield. Feeding of LNDF concentrates depressed milk fat concentration and its yield, the depression being accentuated with each increase in concentrate allowance. The depression in milk fat concentration was negatively correlated with the forage: concentrate ratio of the diet consumed. Furthermore, dietary NDF proportion was shown to account for greater than half of the variation in milk fat concentration. In contrast to the observations made for milk fat, feeding the LNDF concentrates effected an increase in milk protein concentration but only at the lower CP level of the concentrate.


1995 ◽  
Vol 1995 ◽  
pp. 21-21 ◽  
Author(s):  
C.S. Mayne ◽  
Rosemary Agnew ◽  
D.C. Patterson ◽  
R.W.J. Steen ◽  
F.J. Gordon ◽  
...  

Considerable progress has been made recently in improving the accuracy of prediction of silage intake, when offered as the sole food, to growing cattle (Steen et al, 1995). However, in order to incorporate this information into feed rationing programmes, it is essential to obtain information on how silages of differing characteristics interact when offered with a range of levels and types of supplementary feeds. The aim of this study was to examine the effects of concentrate energy source and crude protein concentration, when offered at a range of feed levels, on the voluntary food of a diverse range of grass silages with both growing beef cattle and dairy cows.


1997 ◽  
Vol 1997 ◽  
pp. 9-9
Author(s):  
T.W.J. Keady ◽  
C.S. Mayne ◽  
M. Marsden

Results from a previous study at this Institute indicated that concentrate energy source did not alter silage intake or animal performance of lactating dairy cows offered a range of grass silages of similar digestibility but differing in intake characteristics. Digestibility is probably the single most important variable affecting animal performance from grass silage. The present study was undertaken to examine the effects of concentrate energy source and effective rumen degradable protein (eRDP):digestible undegradable protein (DUP) ratio in the concentrate on the silage intake of, and animal performance from, lactating dairy cows offered a diverse range of grass silages differing in digestibility and intake characteristics.


1987 ◽  
Vol 45 (2) ◽  
pp. 321-323 ◽  
Author(s):  
B. K. Sloan ◽  
P. Rowlinson ◽  
D. G. Armstrong

The forage: concentrate ratio in the diet is known to influence the fermentation characteristics in the rumen (Sudweeks, Ely, Mertens and Sisk, 1981). Increasing the proportion of concentrates in rations fed to dairy cows has been shown to narrow the acetate plus butyrate: propionate ratio in the rumen (Sutton, 1981) with an associated depression in milk fat concentration (Ørskov, Reid and McDonald, 1981). The magnitude of the effect, on milk yield and composition, of increasing the concentrate proportion in the ration has been shown to be dependent on feeding level (Sutton, 1981), and the number of meals of concentrate per day (Johnson, 1979) and also may be influenced by dietary protein level and source (Ørskov et al., 1981).


1996 ◽  
Vol 63 (1) ◽  
pp. 11-19 ◽  
Author(s):  
C. S. Mayne ◽  
J. G. Doherty

AbstractA study was conducted to examine the effect of fine grinding or sodium hydroxide treatment of wheat, and increasing concentrate food level, on milk production. Two concentrates based either on ground wheat (450 g/kg, GW) or sodium hydroxide treated wheat (500 g/kg, SW) were offered at four concentrate levels of 2·5, 5·0, 7·5 and 10·0 kg dry matter (DM) per day to 24 dairy cows in a three-period, change-over design experiment. On average, across all concentrate food levels, silage DM intake was significantly (P < 0·01) higher with the SW concentrates, reflecting a significantly lower silage substitution rate with SW relative to GW concentrates (P < 0·01). Milk yield was also significantly higher with the SW concentrates (P < 0·05), although marginal responses to increased concentrate food level were similar (P > 0·05). Milk protein concentration increased linearly with increasing concentrate food level (P < 0·001), with a significantly greater response with the GW relative to the SW concentrate (0·59 v. 0·24 g/kg (P < 0·05) increase per kg additional concentrate). However, milk protein concentration was also significantly lower with the GW concentrate at low food levels (P < 0·05). Milk fat concentrations were similar with the two concentrate types with significant reductions in milk fat concentration with increasing concentrate food level (P < 0·05). Blood urea (P < 0·001) and β-hydroxybutyrate (P < 0·05) concentrations were significantly lower in animals offered the SW concentrate. Apparent digestibility coefficients were unaffected by either concentrate type or concentrate food level (P > 0·05), although modified acid-detergent fibre apparent digestibility was significantly reduced with increasing concentrate food level (P < 0·001). Results indicate that, at similar levels of concentrate feeding, silage intake and milk yield were significantly greater with SW compared with GW concentrates (P < 0·05 or greater). Increases in milk protein concentration with increasing concentrate food level were significantly greater with GW than with SW concentrates (P < 0·05).


1996 ◽  
Vol 62 (1) ◽  
pp. 1-3 ◽  
Author(s):  
P. C. Garnsworthy

AbstractTwenty-eight Holstein/Friesian dairy cows were divided into four groups of seven. From weeks 4 to 15 of lactation they were given a basal diet consisting of 8 kg hay, 2 kg sugar-beet feed and 2 kg grass nuts, together with a concentrate allowance of 8 kg/day. Concentrates for group A were based on cereals and soya (control). Concentrate B contained 60 g protected fat supplement per kg; concentrate C contained 100 g lactose per kg; concentrate D contained 60 g fat supplement and 100 g lactose per kg. Milk yields were 24·6, 27·7, 25·6 and 26·5 kg/day and milk protein concentrations were 32·3, 30·7, 32·7 and 31·9 g/kg for groups A, B, C and D respectively. The effect of fat supplementation on milk yield and protein concentration was significant (P < 0·05) but the effect of lactose was not significant. Milk fat concentration was not significantly affected by treatment. It is concluded that lactose can partially alleviate the depression in milk protein concentration often observed when cows are given protected fat.


Author(s):  
D. Tristant ◽  
C. A. Moran

SummaryThe following trial was conducted to evaluate the impact of feeding Yea-Sacc® (YS; Alltech Inc, USA), a zootechnical feed additive based on a live probiotic strain of Saccharomyces cerevisiae, to lactating dairy cows over a 12 week period. Sixty-four primiparous and multiparous Holstein dairy cows, grouped to give similar range of parity, physiological and milk production stages, were selected for the study. Cows were equally allocated to either a control feed group or a diet supplemented with YS (32 cows per treatment). The test diet was formulated to include YS (Yea-Sacc® Farm Pak) incorporated in the total mixed ration (TMR), supplying a target dose of 5 × 107 CFU/kg feed dry matter (DM). This target dose delivered 1 × 109 CFU/cow/day, for a cow consuming 20 kg feed (DM basis) daily. Each cow was considered a replicate unit. Cows were fed a nutritionally adequate total TMR plus hay and a supplementary protein/energy concentrate (calculated according to milk yield) for 12 weeks, supplied once a day after the morning milking. Weigh backs of feed were recorded daily, with refusals being maintained at 3% of the total intake. During the 12 week study period, YS had significant beneficial effects on milk production (+0.8 kg/day; P = 0.003), energy corrected milk production (+1.4 kg/day; P < 0.0001), synthesis of milk protein (+36 g/day; P = 0.001), milk protein content (+0.3 g/kg; P = 0.009), and milk urea content (−0.09 mg/l; P = 0.004). The synthesis of milk fat was similar between treatments but milk fat content was lower for the YS group compared to the control group (−1.1 g/kg; P = 0.0002). Lactose content was always higher (+0.8 g/kg; P < 0.0001) for the YS group, indicating enhanced energy utilisation. In general, the effect of YS was higher during the first study period (one to seven weeks), when cows were in early lactation and the production potential was higher. YS cows produced significantly more milk during the study, and an additional 220 kg milk per cow was sold from this group from the output measured from the beginning of the study to two weeks post-trial. However, the statistical analysis including the post-study period did not show a significant effect. The 305-day simulated milk production was higher for the YS group (+400 kg/cow) but again the difference was not significant. In conclusion, YS at a target dose of 5 × 107 CFU/kg DM improved milk production and milk quality in healthy dairy cows. In addition, when the data were included in a whole-farm model, feeding YS reduced methane emissions by 4%, reduced the number of animals required for the desired milk production by 4% and increased overall farm margins by 1.4%.


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