Comparison of fresh and ensiled white and red clover added to ryegrass on energy and protein utilization of lactating cows

Abstract

Two respiratory chamber experiments were conducted with dairy cows to compare metabolizable energy and protein utilization when feeding white or red clover with ryegrass. In experiment 1, fresh ryegrass was mixed with fresh white (WF) or red clover (RF) (60/40, on dry matter (DM) basis). Experiment 2 involved similar mixed diets in ensiled form (WS and RS, respectively), and two ryegrass silage diets, without (GS) or with supplementary maize gluten (GS þ ). Barley was supplemented according to requirements for milk production. Voluntary forage DM intake remained unaffected in experiment 1 and was higher ( P , 0·01) in experiment 2 for WS than for GS and GS þ (128 v. 98 and 106 g/kg M 0·75 ). Within experiments, no treatment effects occurred for apparent nutrient digestibilities, milk yield, and composition. Protein utilization (milk-N/N-intake) was numerically lower on all clover-based diets (0·24 to 0·25) versus GS (0·29). With added maize gluten (GS þ ), protein utilization decreased to 0·23, indicating that ryegrass silage (plus barley) alone provided sufficient metabolizable protein. Consequently, higher ( P , 0·01) urinary energy losses occurred in GS þ compared with GS, despite similar metabolizable energy intakes, and a trend for the highest plasma urea levels was found for GS þ cows (7·59 mmol/l; P , 0·1). Overall, this study illustrates that the white and red clovers investigated were equivalent in energy and protein supply, also in comparison to the ryegrass. It remains open whether these forage legumes, when supplemented to a moderate-protein ryegrass, would have contributed to metabolizable protein supply or would have merely increased metabolic nitrogen load.

Comparative potential of white and red clover to modify the milk fatty acid profile of cows fed ryegrass‐based diets from zero‐grazing and silage systems

“…12 The milk fat content was also not affected by dietary treatment in either experiment. In both experiments, all diets showed a favourable n-6/n-3 ratio for achieving the goal of an average ratio below 5 for a human diet, as recommended by DACH.…”

“…Both experiments also included the determination of the milk fatty acid profile from the experimental cows at the start of the experimental periods (the baseline milk fatty acid profile). The protein-and energy-related metabolic aspects of these experiments have been reported elsewhere, 12 where a further experimental group had been investigated in experiment 2.…”

Swiss diet types for cattle: how accurately are they reflected by the Intergovernmental Panel on Climate Change default values?

“…Dietary concentrate allowance was below 20%. In Experiment 5, the same ryegrass-clover mixtures were used as in Experiment 4, but now in ensiled form (van Dorland et al 2006). These forages were additionally compared with either ryegrass-only silage or ryegrass silage supplemented with maize gluten.…”

“…The horizontal line denotes the IPCC (2006) default value of 6.5% together with its uncertainty range of +1% (grey area). Data sources: Mu¨nger (1997), Hindrichsen et al (2006aHindrichsen et al ( , 2006b), Klevenhusen et al (2010), van Dorland et al (2006, Estermann et al (2002), Staerfl et al (2012). 2000), this default value was 6% for developed countries like Switzerland, whereas it was 6% or 7% for cattle or buffaloes kept in developing countries depending on livestock category and diet type. The revised default value for Y m (IPCC 2006) will be applied in the Swiss GHG inventory from 2013 onwards, unless country-specific data have been submitted to, and approved by, the IPCC until then.…”

“…The purpose of Experiment 4 was to compare the effects of feeding fresh red and white clover together with ryegrass to dairy cows (van Dorland et al 2006). Dietary concentrate allowance was below 20%.…”