Silage and milk production: comparisons between grass silage of three different chop lengths

Abstract

Three grass silages of different chop lengths made from a uniform sward of S23 perennial ryegrass were compared in four experiments including a feeding experiment with twelve lactating cows, an eating behaviour study, a rate of passage investigation and a selection trial. The silages had median chop lengths of 9-4. 17-4 and 720 mm, termed short, medium and long, with pH values of 3-93, 3-94 and 417 and D-values of 659, 65-2 and 64 4 respectively.The daily intakes of silage DM and the daily milk yields increased as silage chop length decreased. The milk yield response to shorter chopping was significant with a supplement of groundnut but not significant with a supplement of sugar-beet pulp. Chop length had small and generally non-significant effects on milk composition.Eating and ruminating times expressed as min per kg DM decreased as silage chop length decreased but the retention time ofthe silage residues in the entire digestive tract was not significantly affected by chop length. When offered simultaneously, the intakes of the individual silages were 52 2, 319 and 15 9% ofthe total DM intake for the short, medium and long treatments respectively.Although silage with a chop length of 9 mm had nutritional advantages over longer silages, it is concluded that the mechanical and economic aspects of silage making must be considered fully when defining optimum chop length.

Effects of the amount of barley and time of access to grass silage on the voluntary intake, eating behaviour and production of dairy cows

“…In Experiment 3 the time the cows spent eating silage was 180 min daily and was much shorter than that observed by Campling (1966), Castle et al, (1979) and Castle et al, (1981) with dry cows offered silage ad libitum. There was an appreciable variation in rate of eating silage with coefficients of variation of 24% and 38% with the low and high amounts of barley, respectively.…”

The Influence of Physical Form of Ration on Chewing Activity and Rumen Motility in Lactating Cows

“…The highest number of ruminating periods reported in the literature ranged from 14 to 18. These numbers have been found with ad libitum feeding of grass silage, hay or straw in a long physical form to cows Campling, 19666;Castle et al, 1979Castle et al, , 1981.…”

The effect of system of silage harvesting and feeding on milk production

“…These have shown that while wilting prior to ensiling will improve dry matter (DM) intake it does not generally improve milk output and in some instances will reduce output (Gordon, 1980;Gordon, 1981;Castle and Watson, 1982), when compared to well preserved, unwilted material. In addition, alterations to the degree of chopping or laceration of silage have not been found to influence milk output at this Institute (Gordon, 1982;Gordon and Unsworth, 1985), although small increases in yield have been reported following fine chopping in some trials elsewhere (Dulphy and Demarquilly, 1975;Castle et al, 1979), and especially when compared with silages of very long particle length (Murphy, 1983).…”