Effects of Type and Amount of Rapeseed Feed on Milk Production

Abstract

Sixteen dairy cows were used in a 2× 4 factorial experiment, where two rapeseed feeds (RSF) were compared at levels of 0, 1, 2 and 3 kg (fresh weight) day − 1 replacing basal concentrate. The total amount of concentrate fed was 10 kg day − 1 and restrictively fermented grass silage was fed ad libitum. The experiment was arranged as a cyclic change-over design with four periods of 3 weeks each. The experimental feeds were rapeseed meal (RSM) and heat-moisture-treated rapeseed cake (RSC). Silage and total dry matter intake, milk production and milk constituent outputs were linearly increased as the proportion of RSF in the diet increased (at least P B0.01). There were no differences between RSM and RSC. Increased RSF intake led to a linear increase (PB 0.001) in the concentrations of essential and branchedchain amino acids in the blood plasma of the cows. Feeding RSC resulted in higher concentrations of the essential amino acids histidine, isoleucine, leucine and valine (at least P B0.05), but the concentration of methionine tended to be lower (P B 0.10) than on RSM diets. Utilization of amino acids absorbed from the small intestine (AAT) was not affected by dietary treatments, when feed table values, i.e. similar values for both RSFs, were used, but it was progressively increased for RSM diets when AAT values based on ruminal and duodenal nylon bag incubations were used. This suggests that the nylon bag method underestimated the protein value of RSM.

Dairy cow responses to graded levels of rapeseed and soya bean expeller supplementation on a red clover/grass silage-based diet

“…Positive linear responses attained at high levels of protein supplementation (Rinne et al, 1999;Shingfield et al, 2003) Protein supplementation for silage-fed cows have indicated large potential to stimulate mammary protein synthesis either by higher total AA supply or by improved AA profile. Relatively high inclusion (652 g CP on low and 1222 g CP/day on high level of supplementation) from the protein supplements were used to find out if the response is curvilinear.…”

“…Protein supplements are, however, expensive and their use decreases the nitrogen use efficiency (NUE), which increases the environmental load of dairy production. Although NUE linearly decreases with increasing amounts of CP intake (Huhtanen et al, 2008b), high-quality plant protein supplements have often produced linear increases in milk production responses up to relatively high levels of inclusion (Rinne et al, 1999;Shingfield et al, 2003), although curvilinear responses to protein supplementation have also been observed (Olmos Colmenero and Broderick, 2006). Soya bean (Glycine max)-based feeds are widely used as protein supplements for dairy cows, but rapeseed (Brassica napus subsp.…”

Effects of restriction of silage fermentation with formic acid on milk production

“…The results were calculated with a correction equation to convert pepsin-cellulase solubility values into in vivo digestibility by an equation based on a data set comprising of Finnish in vivo digestibility trials. Blood glucose, NEFA, urea and ß-OHB were analysed as reported by Rinne et al (1999). Rumen volatile fatty acid and ammonia N concentrations were determined as explained by Shingfield et al (2001).…”

Use of rapeseed and pea grain protein supplements for organic milk production

“…Rinne et al (1999) reported similar silage intakes between RSM and heat-moisture treated RSC. These experiments show no benefits in silage intake when rapeseed cake is heat-moisture treated to reduce protein degradability in the rumen.…”