Increased concentration of water‐soluble carbohydrate in perennial ryegrass (<i>Lolium perenne</i> L.). Evaluation in dairy cows in early lactation

Moorby, J. M.; Evans, R.T.; Scollan, Nigel D.; MacRae, J.C.; Theodorou, Michael K.

doi:10.1111/j.1365-2494.2006.00507.x

Cited by 125 publications

(141 citation statements)

References 24 publications

Supporting

Mentioning

120

Contrasting

Unclassified

Order By: Relevance

“…The relatively small and non-significant dietary effect on NUE contrasted with results from cows fed a diet of around 3.2% N with elevated WSC in the diet, which showed improvement in NUE (Miller et al, 2001). In this study, the proportion of NI excreted in urine (UN/NI) was high (on average >48%; Table 3) compared with results from lactating dairy cows studies (Miller et al, 2001;Moorby et al, 2006). Our results are in contrast to the suggestion from the review of Edwards et al (2007) that increased NUE and decreased UN/NI of dairy cows should be observed when WSC : N increased from 4.4 to 8.1 g/g.…”

Section: N Metabolismcontrasting

confidence: 66%

The effect of dietary water soluble carbohydrate to nitrogen ratio on nitrogen partitioning and isotopic fractionation of lactating goats offered a high-nitrogen diet

Cheng

Edwards

Dewhurst

et al. 2016

Animal

View full text Add to dashboard Cite

The objective of this study was to investigate the relationship between nitrogen (N) partitioning and isotopic fractionation in lactating goats consuming diets with a constant high concentration of N and increasing levels of water soluble carbohydrate (WSC). Eight lactating goats were offered four different ratios of WSC : N in the diet. A two-period incomplete cross-over design was used, with two goats assigned to each treatment in each period. N balance measurements were conducted, with measurement of feed N intake and total output of N in milk, faeces and urine. Treatment, period and infusion effects were tested using general ANOVA; the relationships between variables were analysed by linear regression. Dietary treatment and period had significant effects on dry matter (DM) intake (g/day). DM digestibility (g/kg DM) and N digestibility (g/kg N) increased as the ratio of WSC : N increased in the diet. No treatment effect was observed on milk urea N concentration (g/l) or urinary excretion of purine derivatives (mM/day). Although dietary treatment and period had significant effects on N intake, the change of N intake was small; no effect was observed for N partitioning among faeces, milk and urine. Milk, plasma and faeces were enriched in 15 N compared with feed, whilst urine was depleted in 15 N relative to feed. No significant relationship was established between N partitioning and isotopic fractionation. This study failed to confirm the potential to use N isotopic fractionation as an indicator of N partitioning in dairy goats when diets provided N in excess to requirements, most likely because the range of milk N output/N intake and urinary N output/N intake were narrow.Keywords: nitrogen utilisation, urea nitrogen, stable isotopic discrimination, dairy goats Implications Current approaches to determine the sole contribution of water soluble carbohydrate (WSC) to animal performance is limited by the fact that chemical components (e.g. nitrogen (N) and WSC) in feed are not independent, at least in pasture. Therefore, this study was designed to test the effect of increasing dietary WSC concentration, at a consistently high N concentration, on N utilisation and isotopic fractionation. Results showed inclusion of WSC neither improved microbial protein synthesis nor N utilisation. Further, the study failed to confirm the use of N isotopic fractionation as a simple indicator of N partitioning.

show abstract

Section: N Metabolismcontrasting

confidence: 66%

The effect of dietary water soluble carbohydrate to nitrogen ratio on nitrogen partitioning and isotopic fractionation of lactating goats offered a high-nitrogen diet

Cheng

Edwards

Dewhurst

et al. 2016

Animal

View full text Add to dashboard Cite

show abstract

“…In Wales, the potential of using perennial ryegrass with enhanced levels of water-soluble carbohydrates (WSC) was investigated in dairy cows using experimental perennial ryegrass varieties bred to contain a high concentration of WSC (Miller et al, 2001;Moorby et al, 2006). The concept is that provision of readily available energy can have a significantly positive influence on N utilisation efficiency and animal performance.…”

Section: Variation Of Nutrient Supply At Grazing Relative To Animal Rmentioning

confidence: 99%

Managing variations in dairy cow nutrient supply under grazing

Peyraud

Delagarde

2013

Animal

View full text Add to dashboard Cite

Grazed pasture, which is the cheapest source of nutrients for dairy cows, should form the basis of profitable and low-input animal production systems. Management of high-producing dairy cows at pasture is thus a major challenge in most countries. The objective of the present paper is to review the factors that can affect nutrient supply for grazing dairy cows in order to point out areas with scope for improvement on managing variations in nutrient supply to achieve high animal performance while maintaining efficient pasture utilisation per hectare (ha). Reviewing the range in animal requirements, intake capacity and pasture nutritive values shows that high-producing cows cannot satisfy their energy requirements from grazing alone and favourable to unfavourable situations for grazing dairy cows may be classified according to pasture quality and availability. Predictive models also enable calculation of supplementation levels required to meet energy requirements in all situations. Solutions to maintain acceptable level of production per cow and high output per ha are discussed. Strategies of concentrate supplementation and increasing use of legumes in mixed swards are the most promising. It is concluded that although high-producing cow cannot express their potential milk production at grazing, there is scope to improve animal performance at grazing given recent developments in our understanding of factors influencing forage intake and digestion of grazed forages.

show abstract

“…They observed a higher digestible DMI (+ 1.5 kg d ) and NUE (+ 7%), and a lower proportion of urinary N (10%) in cows fed the HS cultivar. Two years later in a similar study with early lactation cows, Moorby et al (2006) ) and total DMI (18.8 vs. 16.6) and a non significant tendency to a higher milk yield (+ 2.3 kg d -1…”

Section: Supplementation Criteria Authorsmentioning

confidence: 99%

Nutritional Strategies to Improve Nitrogen use Efficiency by Grazing Dairy Cows

Keim

Anrique

2011

Chilean J. Agric. Res.

View full text Add to dashboard Cite

Grazing dairy cows are characterized by converting a low proportion of dietary N into milk N. This low N use efficiency (NUE) is mainly due to an excessive supply of crude protein (CP) of pasture with regard to animal requirements. Excess N in the diet has negative effects for the animal; it alters the organoleptic characteristics of milk and pollutes the environment through N excretions. The aim of this review was to analyze the available information on nutritional strategies to improve NUE by grazing dairy cows, such as diluting the dietary N through supplementation, synchronizing ruminal carbohydrate (CHO), and N fermentation rates, and using pastures with a high water soluble carbohydrates (WSC) content. There is a beneficial effect of carbohydrate supplementation on NUE, with an increase in milk yield (MY) of 0.83 ± 0.34 kg milk kg -1 supplement and a reduction of ammonia N (NH 3 -N) in the rumen. A better synchrony between CHO and rumen N does not improve MY and NUE. However, a positive effect on NUE was identified as a result of increasing the WSC/CP ratio. The use of cultivars with high WSC content increases the dry matter intake (DMI), MY, and milk N production, with no consistent effect on NUE.

show abstract

Increased concentration of water‐soluble carbohydrate in perennial ryegrass (Lolium perenne L.). Evaluation in dairy cows in early lactation

Cited by 125 publications

References 24 publications

The effect of dietary water soluble carbohydrate to nitrogen ratio on nitrogen partitioning and isotopic fractionation of lactating goats offered a high-nitrogen diet

The effect of dietary water soluble carbohydrate to nitrogen ratio on nitrogen partitioning and isotopic fractionation of lactating goats offered a high-nitrogen diet

Managing variations in dairy cow nutrient supply under grazing

Nutritional Strategies to Improve Nitrogen use Efficiency by Grazing Dairy Cows

Contact Info

Product

Resources

About