Id# 09-35 Duration of Regrowth of Ryegrass (lolium Perenne) Swards: Effects on Rumen Fermentation of Lactating Dairy Cows
نویسندگان
چکیده
The relative importance of duration of sward regrowth and rumen fill and fermentation on the control of grazing time and intake rate during the first grazing session of the day were studied. Four lactating dairy cows were allowed to graze ryegrass (Lolium perenne) swards, with five different regrowth periods after mowing (6, 9, 16, 22 and 30 d). The cows were allowed to graze until they stopped voluntarily. Samples of rumen liquid were taken at approximately 0, 30, 60, 120 and 240 min after the grazing session was finished. Concentration of volatile fatty acids (VFA) followed a significant quadratic trend with a maximum concentration observed at approximately 110 min after cessation of grazing. In this study, rumen fill, VFA (either total or major components) and ammonia concentration as individual variables were not correlated with grazing time or dry matter intake.
منابع مشابه
Mean retention time in digestive tract and digestion of fresh perennial ryegrass by lactating dairy cows: influence of grass maturity and comparison with a maize silage diet.
The effects of grass maturity on the mean retention time of liquid and particles, digestibility and duodenal nutrient flows were measured by feeding second cuts of perennial ryegrass to 3 fistulated lactating dairy cows over 2 successive periods (late June and mid-July, 28 and 49 d regrowth, respectively). Fresh forage was given ad libitum with 12% (dry matter (DM) basis) concentrate. The incre...
متن کاملPerformance of lactating dairy cows fed alfalfa silage or perennial ryegrass silage.
The nutrient contents of perennial ryegrass (Lolium perenne L.) and alfalfa (Medicago sativa L.) are reasonably similar. Despite similarities, the lactation performance of dairy cows fed perennial ryegrass has not been compared with the lactation performance of dairy cows fed alfalfa. The present study was implemented to compare the performance of lactating cows fed alfalfa or perennial ryegras...
متن کاملParticle breakdown and rumen digestion of fresh ryegrass (Lolium perenne L.) and lucerne (Medicago sativa L.) fed to cows during a restricted feeding period.
1. Five rumen-fistulated cows were given freshly cut ryegrass (Lolium perenne L.) and lucerne (Medicago sativa L.), on separate occasions, to compare rates of particle breakdown and aspects of rumen fermentation. 2. Cattle were required to consume their daily allowance (offered ad lib.) in two 2 h feeding periods daily. 3. During the first 2 h feeding period, dry matter (DM) intakes of ryegrass...
متن کاملRyegrass or alfalfa silage as the dietary forage for lactating dairy cows.
Renewed interest exists in using grass forages to dilute the higher crude protein (CP) and lower digestible fiber present in legumes fed to lactating dairy cows. A 3 x 3 Latin square feeding study with 4-wk periods was conducted with 24 Holstein cows to compare ryegrass silage, either untreated control or macerated (intensively conditioned) before ensiling, with alfalfa silage as the sole dieta...
متن کاملWhite Clover Content in New Zealand Dairy Pastures Affects Milksolids Production
As a preliminary experiment to measuring milksolids (fat plus protein) production of dairy cattle grazing swards containing different levels of white clover (Trifolium repens L.) nine Jersey and nine Friesian cattle housed indoors during late lactation and fed diets containing either 20, 50 or 80% white clover with the balance perennial ryegrass (Lolium perenne L.). During the first 10 day meas...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2001