Apparent ruminal degradation and rumen escape of soluble nitrogen fractions in grass and grass silage administered intraruminally to lactating dairy cows

2002 ◽  
Vol 80 (10) ◽  
pp. 2704 ◽  
Author(s):  
H. Volden ◽  
L. T. Mydland ◽  
V. Olaisen

1998 ◽  
Vol 22 ◽  
pp. 326-328
Author(s):  
A. T. Adesogan ◽  
A. L. Abdalla ◽  
M. S. Dhanoa ◽  
D. I. Givens ◽  
E. Owen ◽  
...  

At maintenance at least, the whole tract digestibility of several foods in sheep and cattle is similar, consequently much of the information on the nutritive value of dairy cow foods in food composition tables is derived from studies conducted in sheep. However, Adesogan (1996) reported that in whole-crop wheat (WCW), starch digestibility is higher in sheep than in dairy cows. This study examined the validity of using sheep to model the ruminal degradation of WCW in cows by comparing the degradability of dry matter (DM) and nitrogen (N) of urea-treated WCW in both species.Winter wheat (cv.Hussar) was harvested at 540 g DM per kg and conserved following urea application at target rates of 20 or 40g/kg DM (WCW2 and WCW4 respectively). The degradability of the forages was examined in dairy cows given 6 kg dairy concentrate and grass silagead libitumand in wethers given 2.4 kg/day of grass silage supplemented with 0.36kg/day of rolled, mineralized barley.



1997 ◽  
Vol 1997 ◽  
pp. 4-4
Author(s):  
T. Yan ◽  
F. J. Gordon ◽  
R. E. Agnew ◽  
M. G. Porter ◽  
D. C. Patterson

The metabolisable energy (ME) requirement for maintenance (MEm) can be determined by measuring the fasting metabolism of the non-lactating cow, but this approach cannot encompass any differences in maintenance metabolic rate between lactating and non-lactating animals. The MEm and efficiency of ME use for lactation (k1) can also be estimated by regression of energy outputs against ME intake (MEI). During 1992 to 1995, a total of 221 Holstein/Friesian lactating dairy cows, which were offered grass silage-based diets, were subjected to gaseous exchange measurements in indirect open-circuit respiration calorimeters. The objective of the present study was to use these data to predict the MEm and k1 by a range of regression techniques for lactating dairy cows offered grass silage-based diets.



2007 ◽  
Vol 2007 ◽  
pp. 166-166 ◽  
Author(s):  
Hamid Mohammadzadeh ◽  
Ali Nikkhah ◽  
Kamran Reza-Yazdi ◽  
Hassan Mehrabani-Yeganeh

Dairy producers use soyhulls, a byproduct of soybean processing, to replace either grain or forage in diets of lactating dairy cows. In view of the nutritional and economical value of soyhulls it is anticipated that this practice will continue to increase in popularity among nutritionists and producers of ruminant animals. According to the NRC (2001), SH contain 60.3% NDF and 44.6% ADF on a DM basis. Also The CP content of SH averaged 11.8%, which is within the range of 13.9± 4.6%. The objectives of this paper are to evaluate the in vitro DM and OM digestibility and in situ degradability of DM, CP and NDF contents of soybean hulls.



Author(s):  
J.R. Newbold ◽  
B.R. Cottrill ◽  
R.M. Mansbridge ◽  
J.S. Blake

Few data are available to evaluate the Metabolisable Protein (MP) System (AFRC, 1992) as an aid to ration formulation for dairy cows. Responses of lactating dairy cows to MP were evaluated in two experiments.In Experiment One, groups of 10 Holstein cows were offered grass silage ad libitum and 7kg DM/d of one of six (treatments 1-6) compound foods from 39d after calving, for eight weeks. All rations were isoenergetic, assuming silage intake of 11kg DM/d (typical for the herd). Ratios between MP supply (calculated from in situ protein degradability measurements) and requirement (calculated for a standard cow: 565kg live weight, 281 milk/d, 40g/kg butterfat, 33g/kg milk protein, liveweight change =0kg/d) were 1.00, 1.02, 1.06, 1.06, 1.1 and 1.17 for treatments 1-6, respectively.



2002 ◽  
Vol 2002 ◽  
pp. 113-113
Author(s):  
T. Yan ◽  
C. P. Ferris ◽  
R. E. Agnew ◽  
F. J. Gordon

AFRC (1993) recommends a reduction of proportionately 0.018 in dietary metabolisble energy (ME) concentration with each unit increase in feeding level above maintenance in dairy cows (feeding level is calculated as total ME intake divided by ME requirement for maintenance). A similar value (0.016) was reported recently by Yan et al. (2001) using a number of linear and multiple regression techniques with lactating dairy cows offered grass silage-based diets. The objectives of the present study were to validate these two values and also to evaluate the effects of feeding level on nutrient digestibility and ME concentration in the mixed diets.



Author(s):  
J.C. Robert ◽  
B.K. Sloan ◽  
C. Denis

Methionine has been shown to be the first-limiting amino acid for milk protein synthesis in lactating dairy cows fed maize silage-based diets complemented with soyabean meal (Sloanet al., 1992) (Pisulewskiet al., 1993). Thus, the aim of this trial was to investigate the hypothesis that methionine was first-limiting or if not at least colimiting with lysine for milk protein synthesis in dairy cows fed grass silage complemented with soyabean meal.8 muciparous and 4 primiparous dairy cows six weeks into lactation were randomly allocated to three 4x4 Latin squares (cows and heifers separately), each period containing 2 weeks. The four treatments consisted of Tl = Control ; T2 = 3.7 g methionine ; T3 = 7.4 g methionine ; T4 = 7.4 g methionine and 22.2 lysine . All figures relate to estimated intestinally available amino acids, g/day (Smartamine™technology Rhône-Poulenc Animal Nutrition). The basal ration was a second cut grass silage offeredad libitumplus 0.57 kg of hay plus an average 10.9 kg concentrate.



2002 ◽  
Vol 2002 ◽  
pp. 107-107
Author(s):  
C.K. Reynolds ◽  
D. J. Humphries ◽  
J. D. Sutton ◽  
B. Lupoli ◽  
D.E. Beever

Crushed rapeseed and other oil seeds offer an economical source of fat and protein in diets for lactating dairy cows, but the potential inhibitory effects of their unsaturated fatty acids on fibre digestion in the rumen are a concern. Feeding crushed rapeseed in a grass silage-based ration increased milk yield without affecting intake (Reynoldset al., 1998), and had no measurable effects on rumen or total tract digestion (Reynoldset al., 2000). In a companion study, feeding increasing amounts of ground rapeseed in a maize silage-based ration decreased DM intake at higher levels of inclusion (Reynoldset al., 2002). This effect may reflect metabolic effects of rapeseed fatty acid absorption, or negative effects of rapeseed oil on rumen fermentation and fibre digestion. The present study was conducted simultaneously to the production study to determine the incremental effects of ground rapeseed on rumen, post-rumen and total tract digestion in lactating dairy cows fed maize silage-based rations.



Sign in / Sign up

Export Citation Format

Share Document