scholarly journals Estimation of Nitrogen Use Efficiency for Ryegrass-Fed Dairy Cows: Model Development Using Diet- and Animal-Based Proxy Measures

Dairy ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 435-451
Author(s):  
Wumaierjiang Aizimu ◽  
Omar Al-Marashdeh ◽  
Simon Hodge ◽  
Richard J. Dewhurst ◽  
Ao Chen ◽  
...  

This study aimed to identify suitable predictors of nitrogen (N) use efficiency (NUE; milk N/N intake) for cows that differed in breeds and were fed with ryegrass pasture, using existing data from the scientific literature. Data from 16 studies were used to develop models based on the relationships between NUE and dietary and animal-based factors. Data from a further 10 studies were used for model validation. Milk urea N (MUN) and dietary water-soluble carbohydrate-to-crudeprotein ratio (WSC/CP) were the best and most practical animal- and diet-based proxies to predict NUE. The results indicate that it might be necessary to adopt separate models for different breeds when using WSC/CP to predict NUE but not when using MUN.

2001 ◽  
Vol 2001 ◽  
pp. 29-29
Author(s):  
M.R.F. Lee ◽  
D.K. Leemans ◽  
D.R. Davies ◽  
R.J. Merry ◽  
J. M. Moorby ◽  
...  

Novel lines of high sugar ryegrass have been shown to increase the efficiency of N use and milk production in zero-grazed cattle (Miller et al., 1999). An experiment was carried out to determine whether this was in part due to an increase in the efficiency of microbial protein synthesis in response to the amount and availability of water soluble carbohydrate (WSC) increasing the balance between energy and nitrogen supply to the rumen microbial population.


2004 ◽  
Vol 32 ◽  
pp. 247-248
Author(s):  
J. C. Ince ◽  
A. C. Longland ◽  
A. J. Cairns ◽  
M. Moore–Colyer

The carbohydrate (CHO) fraction of pasture grasses is a major source of energy for many domestic herbivores. However, the amounts, and types, of the water–soluble carbohydrate (WSC) fraction (i.e. glucose, fructose, sucrose, and polymers of sucrose and fructose, the fructans) present in such grasses, varies with species and environmental conditions. As the WSC constitute a highly digestible, energy yielding fraction of grasses, it is important to be able to measure their levels in a sward so that the diets of pastured animals may be designed to elicit optimal health and productivity. The aim of this study was to characterise the WSC profile of six UK pasture grasses, and to develop a technique for extracting the fructan portion of the WSC.Six species of UK pasture grasses [Cocksfoot (C), Timothy (T), Meadow Fescue (M), Italian Ryegrass (IR), Perennial Ryegrass (PR) and Hybrid Ryegrass (HR)] were grown in experimental field plots at IGER.


1971 ◽  
Vol 26 (2) ◽  
pp. 123-134 ◽  
Author(s):  
D. E. Beever ◽  
D. J. Thomson ◽  
E. Pfeffer ◽  
D. G. Armstrong

1. The effect of drying and ensiling ryegrass on the site of digestion of the energy andcarbohydrate fractions was studied in sheep fitted with rumen cannulas and re-entrant can-nulas in the proximal duodenum and terminal ileum.2. The sheep were given fresh (frozen) grass, dried grass, wilted and unwilted silage pre-pared from herbage harvested from the same sward. The grass diets were offered twice dailyto each animal and paper impregnated with chromium sesquioxide was administered twicedaily into the rumen. Twenty-four hour collections of duodenal and ileal digesta, adjusted togive 100 yo recovery of Cr2O3, were analysed to determine the extent of digestion in the fore-stomachs, the small intestine and the caecum and colon.3. Total digestibility of the gross energy was similar for the fresh grass, dried grass andwilted silage diets (67·4,68·1 and67·5 %)but higher for the unwilted silage (72·0 %, P < 0·01).There was an increased flow of energy into the small intestine when the sheep were given driedgrass and unwilted silage. The proportion of the apparently digested energy lost within thesmall intestine was greater when the dried grass was given (302 yo) than when the fresh grasswas given (23·6 yo).4. Drying or ensiling of wilted material affected digestion neither in the entire alimentarytract nor in the different sections of the tract, of some carbohydrate fractions. About 97 yo ofthe digested water-soluble carbohydrate, over 90 yo of the digested cellulose and over 70 yo ofthe digested hemicellulose were digested before reaching the small intestine. The increasedamount of energy entering the duodenum of the sheep given the dried grass was notaccounted for by changes in the fate of these carbohydrate fractions in the digestive tract. Withunwilted silage, digestibilities of the cellulose and hemicellulose fractions were higher, andlower proportions of the digested carbohydrates were lost before the small intestine.


2020 ◽  
Author(s):  
Jie Wu ◽  
Zi-Sheng Zhang ◽  
Jing-Qiu Xia ◽  
Alamin Alfatih ◽  
Ying Song ◽  
...  

AbstractNitrogen (N) is one of the key essential macronutrients that affects rice growth and yield. Inorganic N fertilizers are excessively used to boost yield and generate serious collateral environmental pollution. Therefore, improving crop N use efficiency (NUE) is highly desirable and has been a major endeavor in crop improvement. However, only a few regulators have been identified that can be used to improve NUE in rice to date. Here we show that the NIN-like protein OsNLP4 significantly improves the rice NUE and yield. Field trials consistently showed that loss-of-OsNLP4 dramatically reduced yield and NUE compared with wild type under different N regimes. In contrast, the OsNLP4 overexpression lines remarkably increased yield by 30% and NUE by 47% under moderate N level compared with wild type. Transcriptomic analyses revealed that OsNLP4 orchestrates the expression of a majority of known N uptake, assimilation and signaling genes by directly binding to the nitrate-responsive cis-element in their promoters to regulate their expression. Moreover, overexpression of OsNLP4 can recover the phenotype of Arabidopsis nlp7 mutant and enhance its biomass. Our results demonstrate that OsNLP4 is a master regulator of NUE in rice and sheds light on crop NUE improvement.


2018 ◽  
Vol 58 (6) ◽  
pp. 1043 ◽  
Author(s):  
A. Jonker ◽  
G. Molano ◽  
E. Sandoval ◽  
P. S. Taylor ◽  
C. Antwi ◽  
...  

Elevated water-soluble carbohydrate (WSC) concentration in the diet may affect rumen fermentation and consequently reduce methane (CH4) emissions. The objective of the present study was to determine CH4 emissions from male sheep (8 per treatment) in respiration chambers for 48 h and fed either a conventional diploid (CRG), a high-sugar diploid (HSG) or a tetraploid (TRG) perennial ryegrass cultivar, each offered at 0.7 or 1.0 kg dry matter (DM)/day during periods in early spring 2013 (P1), early autumn 2014 (P2) and late spring 2014 (P3). There was a significant (P < 0.001) interaction between cultivar and period for CH4 yield (g/kg DM intake). In P1 yield was 9% lower (P = 0.007) for sheep fed HSG than for sheep fed CRG or TRG, in P2 yield was 16% lower (P < 0.001) for sheep fed TRG than that for sheep fed CRG or HSG, and in P3 yield was 15% lower (P < 0.001) for sheep fed TRG than that for sheep fed CRG, with HSG-fed sheep being intermediate and not significantly different from either CRG or TRG. Despite there being a cultivar × period interaction, overall, CH4 yield was lower for sheep fed HSG or TRG than for sheep fed CRG (P < 0.001). There were no cultivar × level of feed offer interactions and, overall, yield of CH4 was 9% higher (P = 0.003) for sheep offered 0.7 than for sheep offered 1.0 kg DM/day. In each period, one or other of the high-WSC diploid (HSG) or tetraploid cultivars (TRG) gave lower CH4 yields than did the control diploid (CRG), suggesting that CH4 yield is reduced by characteristics of these cultivars. However, the effect was not consistently associated with either cultivar and could not be attributed to higher forage water-soluble carbohydrate concentrations.


1998 ◽  
Vol 1998 ◽  
pp. 49-49
Author(s):  
R.J. Orr ◽  
S.M. Rutter ◽  
P.D. Penning ◽  
N.H. Yarrow ◽  
L.D. Atkinson ◽  
...  

Grazed herbage is the cheapest feed available for dairy cows but total intake of nutrients from grazed pasture alone is generally insufficient to allow high yielding dairy cows to reach their production potential. Cows have their main daily meal following afternoon milking in the period up to sunset (e.g. Rook et al., 1994 ). In addition, both the DM content and water soluble carbohydrate (WSC) concentration of grass increase over the day (e.g. Orr et al., 1997) due to the loss of moisture and the accumulation of the products of photosynthesis. Based on this evidence, this study tested the hypothesis that dairy cows receiving strip-grazing allocations following the afternoon rather than the morning milking would show higher intake rates and consequently higher milk yields.Twenty Holstein-Friesian cows (median calving date 10 February 1997) were each supplemented with 4 kg concentrates day-1 and strip-grazed a perennial ryegrass pasture in four groups of 5 cows.


2019 ◽  
Vol 17 (4) ◽  
pp. 539-544
Author(s):  
Md Juiceball Hassan ◽  
Md Masudul Karim ◽  
Md Amirul Islam ◽  
Md Habibur Rahman Pramanik ◽  
Md Alamgir Hossain

Submergence stress at early vegetative stage is one of the most important constraints in the productivity of rice in Bangladesh. Submergence causes yield loss of rice at Aman season in Bangladesh and therefore, it is necessary to develop submergence tolerant rice cultivars. A pot experiment was conducted at the net house of Department of Crop Botany, Bangladesh Agricultural University, during Aman season from July to December, 2017 to evaluate the changes in root porosity and water soluble carbohydrates (WSCs) associated with submergence tolerance in rice. The experiment consisted of two factors—(i) Rice cultivars (Binadhan-11, Binadhan-12, BRRI dhan51 and BRRI dhan52 as tolerant and BRRI dhan49 as susceptible) and(ii) Submergence stress: Submergence for 14 days at vegetative stage and control. Submergence stress was imposed by dipping of pots into a water tank with about 90 cm depth of water while the control plants are maintained in the pot house of the field laboratory. The plants were sampled at seven days interval during submergence to determine the changes in root porosity and to examine the contribution of shoot reserves for their survival. The root porosity was measured by pycnometer method and water soluble carbohydrate was measured by the anthrone method. Tolerant cultivars showed greater root porosity development in both control and stress condition but the susceptible cultivar showed significantly lower root development in stress condition. Higher root porosity might help tolerant cultivars to survive in submergence stress more efficiently. Tolerant rice cultivars had high initial soluble carbohydrate than the susceptible one. Under submergedcondition, the tolerant cultivars showed slow depletion of water soluble carbohydrate compared to susceptible cultivar. Higher carbohydrate contents in tolerant cultivars might act as buffer stock during submergence for their better survival and growth. J Bangladesh Agril Univ 17(4): 539–544, 2019


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