An investigation of the effect of initial milk yield level on the response to sward height and concentrate supplementation in grazing dairy cows

1995 ◽  
Vol 1995 ◽  
pp. 156-156
Author(s):  
R. Pulido ◽  
J.D. Leaver

The increase of milk yield potential of dairy cows raises a number of questions relating to their management at pasture where the intake potential might be limiting. The interaction of initial milk yield (IMY), sward availability (SH) and level of concentrate supplementation (CI) is largely unknown.Two experiments of 42 and 24 days in spring and midsummer were carried out with 45 and 27 Holstein Friesian cows respectively. In spring, five IMY groups (range 16.9 to 35.5 kg/day) and in midsummer three IMY groups (range 22.2 to 31.8 kg/day) were used. In both periods, three compressed sward height(3 to 5, 5 to 7 and 7 to 9 cm) and three CI (0, 3 and 6 kg/day, with 160 g CP/kg DM, 12.8 MJ ME/kg DM) were used. The grazing area consisted of 7.9 ha of perennial ryegrass which was set stocked. The herbage intake (HDMI) was estimated indirectly from individual cow performance. Grazing time (GT) was recorded for each cow on 24 hour observations. Multiple regression analyses were carried out relating the dependent variables herbage intake, grazing behaviour and milk production to the independent variables (IMY, SH, CI).

2003 ◽  
Vol 2003 ◽  
pp. 57-57 ◽  
Author(s):  
P. Dillon ◽  
J. Kennedy ◽  
P. Faverdin ◽  
L. Delaby ◽  
F. Buckley ◽  
...  

Pre-1990 published responses to supplementation at pasture ranged from 0.4 to 0.6kg milk/kg concentrate fed. However since 1990 higher responses to concentrate supplementation at pasture have been published (Delaby 2001). The objective of this study was to determine if milk production responses of Holstein-Friesian dairy cows to concentrate supplementation at pasture are influenced by genetic merit (milk yield potential) in a spring calving grass based system of milk production.


2010 ◽  
Vol 62 (5) ◽  
pp. 1158-1166 ◽  
Author(s):  
O. Hernandez-Mendo ◽  
J.D. Leaver

The preference of lactating dairy cows for grazed herbage or maize silage (MS), simultaneously offered ad libitum in the field, was examined at two sward heights (SH 4-6 and 8-10cm) and two concentrate levels (CL 0 and 6kg day-1) in a 2x2 factorial arrangement within a completely randomised experimental design. The experiment lasted 35 days and was carried out in spring using 24 multiparous Holstein Friesian cows. On average, the cows proportionately spent more time grazing than eating MS (0.85:0.15) and even though the higher rate of intake (RI) of dry matter (DM) of MS compared with grazed herbage (76 versus 26g DM min-1), the proportion of total DM intake as herbage was higher compared to that of MS (0.56:0.44). The higher crude protein and low fibre content of grazed herbage appeared to have a higher priority of choice than RI, as the cows chose to graze for longer (grazing time 385 min, MS feeding time 67min) despite the lower RI of herbage. The low proportion MS intake indicated that RI was a secondary factor of choice. Concentrate supplementation had a greater depressing effect on herbage intake than on MS intake. These results suggest that the animals reduce the intake of feed with lower RI when the labor associated to eat is decreased. The factors influencing the choice for herbage over maize silage remain unclear.


1996 ◽  
Vol 1996 ◽  
pp. 79-79
Author(s):  
R. Pulido ◽  
J.D. Leaver

A major objective in managing high yielding cows at grass is to maximise total DM intake. However, behavioural factors associated with grazing limit herbage intake, and concentrate supplementation is required to sustain yields. In a previous study (Pulido and Leaver, 1985), a level of 6 kg concentrates/day, at a high sward height (7 to 9 cm) failed to prevent high rates of milk yield decline (> 0.19 kg/day). An ad libitum level of concentrates was included in this study to examine the extreme end of the response curve.


2003 ◽  
Vol 77 (2) ◽  
pp. 343-354 ◽  
Author(s):  
S.T. Butler ◽  
G.K. Stakelum ◽  
J.J. Murphy ◽  
L. Delaby ◽  
M. Rath ◽  
...  

AbstractThe objective of this trial was to examine the daily herbage requirement and grass dry matter intake (DMI) of dairy cows of different levels of milk production with rotational grazing and optimum grazing conditions. The daily herbage allowance (DHA) that was required was defined as the allowance that permitted the herds to graze to a post-grazing sward height (SHA) of 70 mm. Four herds of 15 primiparous Holstein-Friesian cows were assembled with similar characteristics but different milk production potentials. The herds grazed separately and were offered a DHA such that the SHA was 70 mm for all herds. The daily yield per cow, for the 4 weeks prior to the start of the experiment (PMY), was 17·4, 19·8, 21·8 and 24·3 kg milk (s.e.0·20, P < 0·001), 0·72, 0·78, 0·87 and 0·93 kg fat (s.e. 0·021, P < 0·001), 0·59, 0·66, 0·71 and 0·77 kg protein (s.e. 0·009, P < 0·001) for herds 1 to 4, respectively. The experiment began on 30 June and finished on 16 August. The swards offered were 18-day re-growths following a previous defoliation by grazing. Herbage mass pre- and post-grazing was 2143 (s.e.33·3) and 622 (s.e.18·2) kg dry matter (DM) per ha above 40 mm, respectively and were similar for the four herds. The DHA was 21·2, 21·9, 22·9 and 23·9 (s.e. 0·13, P < 0·001) kg DM per cow above 40 mm. Individual cow grass DMI was determined once during the experimental period using the alkane technique. Experimental milk yield (EMY) was 15·1, 17·4, 18·6 and 20·8 (s.e. 0·33, P < 0·001) kg per cow per day. DMI was 14·5, 15·4, 15·5 and 16·1 (s.e. 0·47, P > 0·05). Variations in DMI were best described by the relationship: DMI = 0·85 (s.e. 3·038) + 0·32 (s.e. 0·082) ✕ EMY + 0·012 (s.e. 0·0054) ✕ experimental live weight + 2·10 (s.e. 0·738) ✕ weight gain + 0·020 (s.e. 0·0085) ✕ days in milk (residual s.d. = 1·477 and r = 0·75). EMY was linked to DMI and PMY according to the expression: EMY = –0·64 (s.e. 1·532) + 0·256 (s.e. 0·0865) ✕ DMI + 0·705 (s.e. 0·0620) ✕ PMY (residual s.d. = 1·204 and r = 0·872). It is concluded that higher yielding herds require higher DHA and this is associated with higher DMI of those herds.


1996 ◽  
Vol 1996 ◽  
pp. 79-79
Author(s):  
R. Pulido ◽  
J.D. Leaver

A major objective in managing high yielding cows at grass is to maximise total DM intake. However, behavioural factors associated with grazing limit herbage intake, and concentrate supplementation is required to sustain yields. In a previous study (Pulido and Leaver, 1985), a level of 6 kg concentrates/day, at a high sward height (7 to 9 cm) failed to prevent high rates of milk yield decline (> 0.19 kg/day). An ad libitum level of concentrates was included in this study to examine the extreme end of the response curve.


Author(s):  
C. A. Huckle ◽  
A. J. Rook ◽  
R. J. Wilkins

Clements, Huckle and Wilkins (1991) reported that milk yield did not differ significantly between cows grazing grass-clover swards with compressed sward heights maintained at either 4.5 or 6 cm in early season. However, cows grazing the shorter sward produced milk with a lower protein concentration. The feeding of 4 kg concentrates/day resulted in an increase in milk yield at both sward heights but there was no effect on milk constituent concentrations. The present experiment was designed to investigate the effect of a wider range of sward heights and their interaction with concentrate supplementation.Forty eight, multiparous, Holstein Friesian cows with a mean calving date of 21 March were continuously stocked on mixed grass-clover swards. The cows were blocked by calving date, parity and milk yield and randomly allocated to one of six treatments, 0 (U) or 4 kg concentrate supplementation (S) with swards maintained at 4, 6 or 8 cm compressed sward height. Sward heights were maintained by adjusting the grazed area. The swards were permanent pastures which had received no fertilizer nitrogen.


1994 ◽  
Vol 58 (2) ◽  
pp. 167-172 ◽  
Author(s):  
A. J. Rook ◽  
C. A. Huckle ◽  
R. J. Wilkins

AbstractForty-eight spring-calving, Holstein-Friesian cows were continuously stocked on perennial ryegrass-white clover swards maintained at compressed sward heights of 4, 6 or 8 cm and offered 0 (U) or 4 (S) kg concentrates. Milk yields and composition, live weights and intakes (estimated by the n-alkane technique) were recorded for periods 24 May to 27 June (P1) and 28 June to 8 August 1992 (P2) with 4 cm swards not used in P2. Milk and component yields were significantly lower at 4 cm than at 6 or 8 cm in P1 and significantly higher when supplements were offered in both periods with no significant interaction. Herbage intakes were reduced more by supplementation at lower sward heights. Live weight was significantly lower on the 4 cm sward. Fat concentrations were unaffected by height and supplementation in P1 but significantly increased by supplementation in P2. These results suggest that maintaining a sward height of 6 cm offers advantages in terms of individual animal output and output per ha compared with grazing at greater or lower sward heights.


2001 ◽  
Vol 73 (1) ◽  
pp. 171-181 ◽  
Author(s):  
L. Delaby ◽  
J. L. Peyraud ◽  
R. Delagarde

AbstractIn order to establish the response of dairy cow performance to concentrate supplementation in contrasting grazing conditions and for cows differing in milk yield at turn-out, three experiments were conducted. Each year, two levels of herbage allowance were studied in interaction with four (experiment 1) or three (experiments 2 and 3) levels of concentrate on two groups of 30 to 40 mid-lactation Holstein cows producing between 20 and 46 kg milk at turnout. Amount of concentrate and herbage allowance ranged from 0 to 6 kg fresh weight and from 12 to 22 kg dry matter (DM) per cow per day respectively. The supplementation led to average responses, per kg DM concentrate, of 104 kg milk, +66 g/day body-weight gain, +0·19 g/kg milk protein and -0·57 g/kg milk fat. These responses remained linear up to 4 or 6 kg according to the years and treatments. The response to the concentrate did not vary with the milk yield or composition at turn-out. The increase in the herbage allowance from 12 to 16 kg DM per cow per day (experiment 1) improved milk yield (+1·2 kg/day) and milk protein (+0·7 g/kg) while the increase from 16 to 22 kg DM (experiments 2 and 3) had less effect (+0·5 kg/day milk yield and +0·4 g/kg milk protein). There was no clear interaction between concentrate supplementation and herbage allowance. Under the usual conditions of spring pasture, with cows in mid lactation, the use of a constant level of concentrate at grazing proves to be a technique of some interest.


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