Effect of the level of concentrate supplementation, herbage allowance and milk yield at turn-out on the performance of dairy cows in mid lactation at grazing

Abstract

In 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.

Effect of increasing pasture allowance and concentrate supplementation on animal performance and microbial protein synthesis in dairy cows

“…Previous studies have reported yield increases in response to concentrate feeding (Horan et al 2005). Milk yield with 3 and 6 kg of concentrate was higher (19.2 and 21.7 kg, respectively) than the milk yield of non-supplemented cows (15.1 kg), in agreement with the reports of Delaby et al (2001), Kennedy et al (2003), Sairanen et al (2006) and McEvoy et al (2008). The marginal yield to the use of concentrate was higher when supplementing with 3 kg of concentrate (1.3 kg milk kg -1 concentrate) when compared to supplementation with 6 kg (1.1 kg milk kg -1 of concentrate).…”

“…When evaluating the fat production (kg cow -1 day -1 ) Kennedy et al (2007) and Kennedy et al (2008) did not find differences, just as in this study. The increase in pasture allowance caused higher concentrations of milk protein, similar to the reports of Delaby et al (2001) and McEvoy et al (2008), as a consequence of the higher DM and energy intake of the cows. The milk urea (MUN) concentrations were similar among pasture allowances (table 2).…”

“…The lower marginal response of the last 3 kg of concentrate at the highest level of supplementation could be due to the fact that the cows would have increased the energy spent in other physiological functions (Kuoppala et al 2004); in this case to reduce the milk urea and to improve the persistence of lactation (Bargo et al 2002, Pulido andLeaver 2003). The supplementation with concentrate caused a linear increase of the fat and milk protein yield of 0.1 kg per kg -1 of supplement due to the higher milk yield, as reported by Delaby et al (2001), Bargo et al (2002), Sairanen et al (2006) and Kennedy et al (2007). The concentrations of milk fat and protein did not change when the level of supplementation increased, maybe as a consequence of the adequate fiber intake and moderate intake of concentrate.…”

Effect of different feeding strategies on lactation performance of Holstein and Normande dairy cows

“…This milk response is slightly higher than classically observed (Delaby et al, 2001a;Kennedy et al, 2003a;Horan et al, 2005), also resulting from the more severe pasture management applied to the Low group. Indeed, the response to supplementation is enhanced when the herbage allowance or herbage intake level is restricted (Bargo et al, 2002).…”

The effect of concentrate allocation on traffic and milk production of pasture-based cows milked by an automatic milking system

“…An increase in milk production between 0.96 and 1.36 kg/kg concentrate at grazing was observed by Bargo et al (2002), between 0.86 and 1 kg/kg concentrate by Reis and Combs (2000), 1.12 kg/kg concentrate by Jago et al (2007) and 1.04 kg/kg concentrate by Delaby et al (2001). Should periods of high pasture availability not been considered (e.g.…”