Complete diets for dairy cows: a comparison between complete diets and separate ingredients

Abstract

One hundred and ninety-four lactating British Friesian cows were used over a 2-year period to determine the effects of mixing diet ingredients on dry-matter (D.M.) intake, animal performance, digestibility coefficients, rumen fermentation and efficiency of food utilization. Four treatments were imposed in both years and were complete diet and separate ingredients at ad libitum and restricted levels of feeding.In Expt 1 a complete diet at ad libitum and restricted levels of feeding was compared with separate ingredients. The diet consisted of 60 % concentrates and 40 % forage and contained 20, 20, 10 and 50 % on a D .M. basis of maize silage, lucerne silage, dried sugarbeet pulp and dairy compound, respectively. Method and level of feeding were the same in Expt 2; however, the diet in the 2nd year consisted of 50 % concentrates (40 % dairy compound, 10% dried sugar-beet pulp) and 50% grass silage.In Expt 1 cows fed the complete diet ad libitum consumed 16-5 kg D.M./day which was significantly more than the 14-3 kg/day consumed by those offered the separate ingredients ad libitum. Intakes in Expt 2 were not significantly affected by method of feeding. Much of the difference in Expt 1 was attributed to the fact that many cows rejected lucerne silage when fed in an unmixed form and therefore to keep the concentrate to forage ratio constant other diet ingredients were reduced proportionately.Mixing diet ingredients did not significantly affect milk yields, which were for the complete diet ad libitum and restricted and the separate ingredients ad libitum and restricted 22-2, 22-2; 22-1 and 20-7 kg/day in Expt 1 and 23-6, 20-8; 24-2 and 21-5 kg/ day in Expt 2, respectively. In Expt 1 when the concentrate to forage ratio was 60:40, cows fed the complete diet ad libitum produced milk with a significantly higher milk fat concentration (39-2 g/kg) than those fed the separate ingredients (31-6 g/kg). Similar effects were not recorded in Expt 2 when the concentrate to forage ratio had been reduced to 50:50. Changes in milk protein concentration were more closely related to changes in intake rather than method of feeding. Mixing diet ingredients tended to decrease live-weight loss in early lactation and accelerate live-weight gain in midlactation.In vivo digestibility coefficients determined in lactating dairy cows showed that in Expt 1 the D.M. and organic-matter digestibility coefficients for the complete diets fed ad libitum (0-689 and 0-713) were lower than those recorded (0-712 and 0-732) for the unmixed diet ad libitum. Although the digestibility coefficient of the acid-detergent fibre of the complete diet was markedly higher at 0-519 compared with 0-478 for the separate ingredients, the difference was not significant. In Expt 2 the only difference in digestibility coefficients was that for nitrogen, which for the complete diet was significantly higher than that of the separate ingredients at both levels of feeding.At an ad libitum level of feoding in Expt 1, the molar proportions of acetate and butyrate were 620 and 11...

An examination of the effect of method and level of concentrate feeding on milk production in dairy cows offered a grass silage-based diet

“…This result is in accord with results of previous studies comparing complete diet feeding with separate feeding of forage and concentrates (Phipps et al, 1984;Istasse et al, 1986). This result is in accord with results of previous studies comparing complete diet feeding with separate feeding of forage and concentrates (Phipps et al, 1984;Istasse et al, 1986).…”

“…The results of the present study, suggest that neither complete diet feeding nor increasing the frequency of concentrate feeding from twice to four times daily had any significant effect on milk yield. Previous studies by Greenhalgh et al (1979) and Phipps et al (1984) suggested that method of feeding only affected milk production with high concentrate diets (greater than 0-60 of total DM intake). However, in agreement with observations by Nocek et al (1986), animals offered complete diets in the present study had significantly higher DM intakes and hence energy intakes, than animals offered concentrates either twice or four times daily but did not produce significantly more milk.…”

Comparison of supplementary concentrate levels with grass silage, separate or total mixed ration feeding, and duration of finishing in beef steers

“…Gaynor et al, 1989) intakes due to TMR feeding. Some intake increases can be explained by the rejection of unpalatable feeds in unmixed rations, something that is not possible in a TMR (Phipps et al, 1984). Otherwise, intake increases could be due to the extra processing that occurs during the preparation and mixing of the TMR or to the fact that the whole diet is constantly available.…”

“…Gordon et al, 1995) but in others no effects or negative effects have been observed. For example, Yan et al (1998) found no differences in digestibility or VFA ratios between TMR and separate feeding of the same ingredients while Phipps et al (1984) reported lower dry matter (DM) digestibility for TMR feeding.…”

Prospects of complete feed system in ruminant feeding: A review

“…Complete feeding system is considered better over separate feeding system [60]. Complete ration has beneficial effects in terms of utilization of low-grade roughages; besides, its densification into feed blocks [19,26,61] or extrusion of the complete mash feed into pellets [7,8,12,14,17,27,62] distinctly improves the DM/nutrient intake and nutritive value of mash diet, thereby ensures efficient utilization of the feed [63].…”