Intake and Production Responses by Holstein-Friesian Cows to the Level and Pattern of Crude Protein Supplied in a Fixed Concentrate Diet given with Grass Silage ad Libitum

Author(s):  
K. Aston ◽  
W.J. Fisher ◽  
A.B. McAllan

Recent trials with cows fed grass silage have shown significant increases in intake and in yields of milk and milk solids when the crude protein (CP) concentration in a supplementary concentrate was raised. Giving additional CP in the concentrate was a more effective strategy for improving yields of milk and milk protein than giving extra energy (Aston et al 1992). The objective of this trial was to examine the influence of changes to the amount and pattern of distribution of CP supplied in a fixed concentrate ration given with grass silage ad libitum.Fifty-five Holstein-Friesian cows in their second and subsequent lactations were given a standard diet for two weeks from calving and then were used in a continuous feeding trial from weeks 4 to 21. The cows received 5 kg of fresh concentrate daily containing 156 (LP), 245 (MP) or 338 (HP) g CP per kg dry matter (DM), MP comprised equal amounts of LP and HP. Concentrate carbohydrate sources were cereals and digestible fibre and CP was increased by a mixture of 3:1 soya:fish meals. Grass silage contained 253 g toluene DM/kg, 162 g CP/kg DM, D value in vivo 0.723, pH 3.7, fermentation acids 135 g/kg DM of which 0.85 was lactic acid and NH3-N 91 g/kg total N.

Author(s):  
J.D Sutton ◽  
D.E Beever ◽  
K. Aston ◽  
S.R. Daley

Recent experiments have shown consistent improvements in grass silage intake and milk yield by cows in response to increasing concentrations of crude protein (CP) in the concentrates. Such results have led to recommendations that a strategy for winter feeding of dairy cows should be based on relatively small amounts of high-protein concentrates with grass silage ad libitum. There is, however, little information about the possible effects of such a strategy on milk nitrogen fractions. The purpose of this experiment was to examine the effects of two approaches to increasing the CP concentration of the concentrates on milk yield and composition, particularly nitrogen fractions.From calving, 44 muciparous Holstein-Friesian cows were given 3 weeks on a standard diet and then were allocated to one of five concentrate treatments with grass silage ad libitum from weeks 4 to 18 of lactation. Concentrates were formulated to contain 200, 300, 400 or 600g CP/kg DM (Table 1). The silage contained 312g DM/kg and, per kg DM, 483g neutral detergent fibre, 286g acid detergent fibre, 168g CP, 16lg lactic acid, 14g acetic acid and l.lg butyric acid. Ammonia-N was 69g/kg total N and pH was 3.9.


Author(s):  
K. Aston ◽  
J.D. Sutton ◽  
R.D. Baker ◽  
W.J. Fisher

The response in yields of milk constituents to increases in the amounts of standard dairy concentrate (SC, 200 g crude protein (CP) per kg DM) given to cows consuming grass silage ad libitum were reported recently (Aston et al 1991; Baker et al 1991). A change of level however adjusts the supply of both energy and CP. Previous work also showed .linear responses in silage intake and milk and milk protein yields when CP was increased in a fixed ration of concentrate of constant energy value. In this trial energy and CP levels were varied Independently. The objective was to separate the effects of energy on the performance of lactating cows from those of CP.


1996 ◽  
Vol 1996 ◽  
pp. 85-85 ◽  
Author(s):  
R.J. Dewhurst ◽  
D.W.R. Davies ◽  
W.J. Fisher ◽  
K. Aston

Previous studies (Moorby et al, 1994) have shown increased yields of protein and lactose in the subsequent lactation as a consequence of feeding additional undegradable dietary protein (UDP) and restricting energy intake during the dry period. This experiment was undertaken to investigate the effect of supplementary UDP in the dry period diet of Holstein-Friesian cows given unrestricted access to grass silage and 1.5 kg of barley per day.Sixty-one cows received diets based on ad libitum access to grass silage with either (a) 1.5 kg barley / day or (b) 1.0 kg barley and 0.5 kg Maize Gluten Meal / day. After calving, cows had ad libitum access to grass silage (Metabolisable Energy (ME)=11.3 MJ/kg DM; crude protein (CP)=181 g/kg DM) and received 5 kg/day of concentrates (ME=13.0 MJ/kg DM; CP=250g/kg DM).


1996 ◽  
Vol 1996 ◽  
pp. 85-85
Author(s):  
R.J. Dewhurst ◽  
D.W.R. Davies ◽  
W.J. Fisher ◽  
K. Aston

Previous studies (Moorby et al, 1994) have shown increased yields of protein and lactose in the subsequent lactation as a consequence of feeding additional undegradable dietary protein (UDP) and restricting energy intake during the dry period. This experiment was undertaken to investigate the effect of supplementary UDP in the dry period diet of Holstein-Friesian cows given unrestricted access to grass silage and 1.5 kg of barley per day.Sixty-one cows received diets based on ad libitum access to grass silage with either (a) 1.5 kg barley / day or (b) 1.0 kg barley and 0.5 kg Maize Gluten Meal / day. After calving, cows had ad libitum access to grass silage (Metabolisable Energy (ME)=11.3 MJ/kg DM; crude protein (CP)=181 g/kg DM) and received 5 kg/day of concentrates (ME=13.0 MJ/kg DM; CP=250g/kg DM).


1999 ◽  
Vol 1999 ◽  
pp. 32-32 ◽  
Author(s):  
J.D. Sutton ◽  
S.B. Cammell ◽  
D.E. Beever ◽  
R.H. Phipps ◽  
D.J. Humphries

Increasing maturity at harvest of maize silage has been shown to affect feed intake and milk production in Holstein-Friesian cows (Phipps et al., 1998). The purpose of the present experiment was to determine whether the milk production response was related to improvements in the efficiency of feed energy utilisation.Four multiparous Holstein-Friesian cows (mean live weight 620 kg) fitted with permanent cannulas in the rumen and proximal duodenum were given diets based on maize silage and grass silage (3:1 DM ratio) offered ad libitum plus 8.7 kg DM/day of a concentrate (254 g crude protein (CP)/kg DM) starting 5-10 weeks post-calving. The maize silage was harvested at four different stages of maturity as defined by DM content and ensiled without additives. The grass silage was a first-cut perennial ryegrass (260 g DM/kg, 519 g neutral detergent fibre (NDF)/kg DM, 146 g CP/kg DM).


1992 ◽  
Vol 54 (2) ◽  
pp. 169-173 ◽  
Author(s):  
A. J. Rook ◽  
W. J. Fisher ◽  
J. D. Sutton

AbstractEighteen multiparous Holstein-Friesian cows were offered grass silage ad libitum and 3,6 or 9 kg dry matter per day of concentrates. Triplicate milk samples were taken at each of two daily milkings over a 28-day period and analysed for fat protein and lactose concentration. Milk yield and fat concentration were more variable than protein and lactose concentrations both between animals and between days. Sampling variation was small for all component concentrations. The main source of variation for all traits was time of milking (morning or afternoon) followed by variation between cows and by day-to-day variation. There was little linear trend with time in the data due to cows being close to peak yield. There was no evidence of cyclical variation over time for any trait. Mean weekly or monthly yields and concentrations were better predicted using samples from four rather than from two consecutive milkings but there was no further advantage from using six samples.


Author(s):  
K.Aston ◽  
C.Thomas ◽  
R.D.Baker ◽  
P.M.Hughes ◽  
S.R.Daley

Carbohydrates in dairy concentrate originate from cereals containing high starch and a variety of by-products with high levels of fibre. Selection is based on unit cost and chemical analysis. Comparisons between starchy and fibrous sources were made at a single level of crude protein (CP) by Thomas et al (1986) and Sutton et al (1987). Voluntary intake of forage increased and yields of fat and protein were similar when fibre replaced starch. The objective of this trial was to extend the range of comparisons by establishing the effects of three types of carbohydrate at four levels of crude protein given with grass silage ad libitum to lactating dairy cows.


1998 ◽  
Vol 1998 ◽  
pp. 206-206
Author(s):  
R.J. Dewhurst ◽  
D. Wadhwa ◽  
L.P. Borgida ◽  
D.W.R. Davies ◽  
W.J. Fisher

Falling prices for cereals and beneficial effects on milk protein concentrations may promote greater inclusions of rapidly fermented ingredients in dairy rations. There is, however, a limit to the inclusion of these feeds into dairy rations beyond which performance declines due to sub-acidosis and related disorders. The feed compounder will need to be able to set limits on levels of feeding concentrates according to these risks. The objective of this experiment was to evaluate the effect of feeds of different acidogenicity (Wadhwa et al., 1998) on lactation performance of dairy cows offered diets based on grass- or maize-silage.Twelve multiparous Holstein-Friesian cows in the third month of lactation were used for this experiment. The experimental design involved adaptation and covariance recording on a standard diet (grass silage and 10 kg concentrates per day), followed by three 21-day experimental periods arranged as four 3x3 Latin Squares. The Latin Squares were constrained to a single forage to avoid difficulties in changeovers between grass silage and maize silage.


1997 ◽  
Vol 1997 ◽  
pp. 90-90
Author(s):  
I.M. Carrick ◽  
D.C. Patterson ◽  
F.J. Gordon

Dairy cow genetic merit continues to increase in the dairy herd. These animals require a higher level of nutritional input than lower genetic merit cows if higher performance levels are to be sustained. The high cost of ingredients for ruminant diets highlights the need for greater precision in ration formulation in order to improve the efficiency of feed utilisation. This experiment was carried out to assess the effect of DUP supplementation on the performance of dairy cows with ad libitum access to grass silage.An experiment was conducted to investigate the response by high genetic merit Holstein Friesian dairy cows (PTA90 fat plus protein = 61 kg) to both source and concentration of protein in the concentrate, given in addition to ad libitum grass silage (metabolisable energy (ME) = 10.9 MJ/kg DM; crude protein (CP) = 166 g/kg DM). Twenty-four cows, including 12 first parity animals (mean days calved 37.5, s.d. 22.3), were blocked according to milk yield, calving date and parity. The experimental design was a balanced changeover with four 4-week periods.


1998 ◽  
Vol 1998 ◽  
pp. 206-206 ◽  
Author(s):  
R.J. Dewhurst ◽  
D. Wadhwa ◽  
L.P. Borgida ◽  
D.W.R. Davies ◽  
W.J. Fisher

Falling prices for cereals and beneficial effects on milk protein concentrations may promote greater inclusions of rapidly fermented ingredients in dairy rations. There is, however, a limit to the inclusion of these feeds into dairy rations beyond which performance declines due to sub-acidosis and related disorders. The feed compounder will need to be able to set limits on levels of feeding concentrates according to these risks. The objective of this experiment was to evaluate the effect of feeds of different acidogenicity (Wadhwaet al., 1998) on lactation performance of dairy cows offered diets based on grass- or maize-silage.Twelve multiparous Holstein-Friesian cows in the third month of lactation were used for this experiment. The experimental design involved adaptation and covariance recording on a standard diet (grass silage and 10 kg concentrates per day), followed by three 21-day experimental periods arranged as four 3x3 Latin Squares. The Latin Squares were constrained to a single forage to avoid difficulties in changeovers between grass silage and maize silage.


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