A new look at energy discounts: using published studies to calculate discounted net energy values for dairy cows fed ad libitum

2007 ◽  
Vol 87 (1) ◽  
pp. 57-70 ◽  
Author(s):  
P. H. Robinson
Keyword(s):  
Dairy Cows ◽  
Energy Intake ◽  
Energy Output ◽  
Net Energy ◽  
Energy Prediction ◽  
Stage Of Lactation ◽  
Feeding Experiments ◽  
Ad Libitum ◽  
Prediction Systems ◽  
The University

Correct assessment of the energetic density of a diet fed to dairy cows is fundamental to accurate prediction of performance. Feeding experiments using lactating Holstein cows fed ad libitum, as reported by North American research facilities in peer-reviewed publications since 1990 in which the actual NEl density of the diet could be calculated from performance, and three dietary energy prediction systems [i.e., NRC (1989), NRC (2001) and an approach developed at the University of California at Davis (UCD)] were used to determine if the NEl discount (i.e., depression) in diets above maintenance (M) energy intake (i.e., 1 ×M) is linear or curvilinear. The principle used was that the expected NEl of the diets could be estimated using the three systems (at 3 ×M ), as well as the NEl calculated from observed performance of the cows, and the deviation (or difference) between the actual and estimated dietary NEl density could be regressed against the actual NEl output (×M) to determine the form of the expected decline in the NEl density of the diet as the energy output (relative to maintenance energy intake) of the cows increased. Results show that output of NEl (×M) is not a predictor of the deviation of the actually calculated NEl level of the diet vs. that estimated by any system. This was unexpected, as all three NEl estimation systems presume a linear decline in the deviation as level of NEl output (×M) increases. In contrast to NEl output (×M), intake of DM (g kg-1 body weight) was a weak predictor (r2 = 0.36 to 0.39 depending on system) of the diet NEl density deviation. The best predictors of diet NEl deviation in all three systems were DM intake (g kg-1BW) and NEl output (×M) combined, where r2 values were much higher (0.76 to 0.79), and there was little evidence of prediction bias in any system. Results suggest that the NEl density of a diet is a function of the inherent characteristics of the diet (i.e., its intrinsic digestibility), its level of consumption, and the genetic merit (and/or stage of lactation ) of the cows that eat it. The lack of a relationship between the deviation of the actually calculated vs. predicted NEl concentration shows that the three NEl prediction equations examined are fundamentally incorrect in their assumption that the NEl concentration of diets declines as the NEl output (×M) of the cows consuming them increases. However, the inaccurate estimates of the actual NEl densities by the systems can be corrected by application of appropriate equations that consider the anticipated level of DM intake and NEl output. Key words: Discount, net energy for lactation

The effect of genetic merit and concentrate proportion in the diet on nutrient utilization by lactating dairy cows

1999 ◽  
Vol 132 (4) ◽  
pp. 483-490 ◽  
Author(s):  
C. P. FERRIS ◽  
F. J. GORDON ◽  
D. C. PATTERSON ◽  
M. G. PORTER ◽  
T. YAN
Keyword(s):  
Dairy Cows ◽  
Energy Intake ◽  
Milk Production ◽  
Milk Fat ◽  
Nutrient Utilization ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Energy Output ◽  
Genetic Merit ◽  
Gross Energy

Sixty Holstein/Friesian dairy cows, 28 of high genetic merit and 32 of medium genetic merit, were used in a continuous design, 2 (cow genotypes)×4 (concentrate proportion in diet) factorial experiment. High and medium merit animals had Predicted Transmitting Abilities for milk fat plus protein yield, calculated using 1995 as the base year (PTA95 fat plus protein), of 43·3 kg and 1·0 kg respectively. Concentrate proportions in the diet were 0·37, 0·48, 0·59 and 0·70 of total dry matter (DM), with the remainder of the diet being grass silage. During this milk production trial, 24 of these animals, 12 from each genetic merit, representing three animals from each concentrate treatment, were subject to ration digestibility, and nitrogen and energy utilization studies. In addition, the efficiency of energy utilization during the milk production trial was calculated.There were no genotype×concentrate level interactions for any of the variables measured (P>0·05). Neither genetic merit nor concentrate proportion in the diet influenced the digestibility of either the DM or energy components of the ration (P>0·05). When expressed as a proportion of nitrogen intake, medium merit cows exhibited a higher urinary nitrogen output and a lower milk nitrogen output than the high merit cows. Methane energy output, when expressed as a proportion of gross energy intake, was higher for the medium than high merit cows (P<0·05), while urinary energy output tended to decrease with increasing proportion of concentrate in the diet (P<0·05). In the calorimetric studies, neither heat energy production, milk energy output and energy retained, when expressed as a proportion of metabolizable energy intake, nor the efficiency of lactation (kl), were affected by either cow genotype or concentrate proportion in the diet (P>0·05). However when kl was calculated using the production data from the milk production trial the high merit cows were found to have significantly higher kl values than the medium merit cows (0·64 v. 0·59, P<0·05) while k l tended to fall with increasing proportion of concentrate in the ration (P<0·05). However in view of the many assumptions which were used in these latter calculations, a cautious interpretation is required.

scholarly journals Comparative Study of Intake, Apparent Digestibility and Energy and Nitrogen Uses in Sahelian and Majorera Dairy Goats Fed Hay of Vigna unguiculata

Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 861
Author(s):  
Fafa Sow ◽  
Khady Niang ◽  
Younouss Camara ◽  
El Hadji Traoré ◽  
Nassim Moula ◽  
...  
Keyword(s):  
Energy Intake ◽  
Dry Matter ◽  
Nutrient Digestibility ◽  
Energy Output ◽  
Chemical Components ◽  
Average Weight ◽  
Net Energy ◽  
Adaptation Period ◽  
Fresh Matter ◽  
Use Efficiency

This study aimed to compare digestive and metabolic characteristics in Sahelian (S) and Majorera (M) goat breeds. Six lactating females from each breed, with an average weight 27.0 ± 1.93 and 23.7 ± 1.27 kg, respectively, were used. Cowpea hay, variety 58/74, was offered as sole feed ingredient, at a rate of 2 kg of fresh matter per animal per day. The animals were placed in metabolic cages and a digestibility test was conducted according to an adaptation period of 15 days and a collection period of 7 days. The daily chemical components offered and refused and recovered faeces, urine and milk were measured in order to assess energy and nitrogen utilization. The M and S goats had similar levels of dry matter (DM) intake as well as nutrient digestibility. On a metabolic weight basis, dry matter intake, gross energy intake, metabolizable and energy intake, digestible energy and energy lost as methane production were significantly higher (p < 0.01) in M than in S goats. Urinary energy excretion was similar (p = 0.9) between breeds, while faecal energy output was higher in M than in S goats. The milk energy output from the M goats was higher than that the S goats (p < 0.05). However, metabolizable to net energy conversion efficiency (klm) was not affected by breed (p = 0.37), while N intake, milk N yield and faecal N losses, relative to metabolic weight, were significantly higher (p < 0.05) in M than in S goats. Similarly, the percentage of dietary N intake excreted in urine (UNIN) was higher in S than in M breeds. The breed factor had no effect on N retained, N digestibility, urinary N and N use efficiency. In conclusion, the M and S goats were similar in terms of energy and nitrogen use efficiency, despite higher daily milk production and DM consumption in the M goat. This suggests that the M breed is possibly more dependent on a dense nutrition diet than the S breed but requires less maintenance nitrogen.

Hay supplements to overcome underfeeding of dairy cows. 2. Late lactation

1981 ◽  
Vol 21 (109) ◽  
pp. 157 ◽  
Author(s):  
KR King ◽  
CR Stockdale
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Body Condition ◽  
Dry Matter ◽  
Nutritive Value ◽  
Dry Matter Intake ◽  
High Quality ◽  
Stage Of Lactation ◽  
Ad Libitum ◽  
Ration Composition

The effect of hay supplementation on the performance of dairy cows on a restricted intake of paspalum-dominant perennial pasture was studied in two 21 -day periods in the eighth and ninth months of lactation. In each period, there were three groups fed pasture only at mean intakes of 15.2, 11.5 and 7.3 kg/cow day-1, two groups fed at similar pasture restriction levels and supplemented with hay ad libitum, and one further group fed an average of 7.3 kg of pasture supplemented with only 4.3 kg of hay. The data were analyzed by regression, using total dry matter intake as the dependent variable, and pseudovariables were used to examine the effects of hay feeding. The relations between total dry matter intake and milk, butterfat, protein and solids-not-fat production, and change in body condition of dairy cows were not altered by ration composition. Milk production declined linearly by 0.66 kg and 0.31 kg/cow day-1 in the eight and ninth months of lactation, respectively, for each kg reduction in total dry matter intake. Similar responses were obtained for butterfat, protein and solids-not-fat production. Gain in body condition of the cows also decreased as total intake fell, but the relation was curvilinear and not affected by stage of lactation. It was concluded that high quality hay can be used to overcome shortages of paspalum-dominant perennial pasture in autumn, and that it has similar. nutritive value to pasture in terms of milk production and body condition.

Lactational responses of dairy cows to changes in dietary protein fed at different stages of lactation

1990 ◽  
Vol 1990 ◽  
pp. 17-17
Author(s):  
Bethan L Wood ◽  
D J Roberts ◽  
E A Hunter
Keyword(s):  
Body Weight ◽  
Dairy Cows ◽  
Dietary Protein ◽  
Milk Protein ◽  
Design Experiment ◽  
Standard Diet ◽  
Protein Sources ◽  
Stage Of Lactation ◽  
Milk Protein Content ◽  
Ad Libitum

There is evidence from a range of experiments of increases in milk production, including improvements in milk protein content, to additional dietary inclusions of low degradability ‘animal’ protein sources. This experiment was designed to examine the effect of stage of lactation on the response of dairy cows to increased dietary protein.The continuous design experiment was conducted with 20 individually fed autumn calved dairy cows and four heifers over the first 26 weeks of lactation. The animals were fed initially a ‘standard diet’ of silage ad libitum and 8 kg (freshweight) of concentrate per day up to the 14th day of lactation. The cows were then allocated to four balanced groups of five cows (and one heifer) on the basis of lactation number, body weight and current milk yield. The data recorded during the first 14 days were used for subsequent covariance analysis.

The effect of days in milk and physiological state (number of mammary glands milked) on the partitioning of increments of metabolisable energy in dairy cows

1999 ◽  
Vol 1999 ◽  
pp. 198-198
Author(s):  
R.M. Kirkland ◽  
F.J. Gordon
Keyword(s):  
Dairy Cows ◽  
Energy Intake ◽  
Milk Production ◽  
Physiological State ◽  
Cost Effective ◽  
Mammary Glands ◽  
Body Tissue ◽  
Energy Output ◽  
Diminishing Returns ◽  
Metabolisable Energy

The response in milk energy output to increasing metabolisable energy intake (MEI) is curvilinear and obeys the law of diminishing returns (Blaxter, 1966). This curvilinearity can be explained by the increased partitioning of MEI to body tissue as intake increases. Rationing dairy cows for cost-effective milk production requires prediction of the extent and nature of this partitioning phenomenon. However, the current rationing system in the U.K., the ME system, does not address this issue. The objective of this study was to examine two of the possible animal factors which might influence the partitioning of increments of MEI given above requirements i.e. days in milk (DIM) and physiological state (number of mammary glands milked) of the animal.

Efficiency of energy utilization in cattle given food ad libitum: predictions according to the ARC system and practical consequences

1994 ◽  
Vol 59 (1) ◽  
pp. 43-47 ◽  
Author(s):  
B. J. Tolkamp ◽  
J. J. M. H. Ketelaars
Keyword(s):  
Energy Intake ◽  
Agricultural Research ◽  
Energy Content ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Net Energy ◽  
Ad Libitum ◽  
Overall Efficiency ◽  
Diet Type

AbstractOverall efficiency of energy utilization (i.e. total net energy intake as a fraction of metabolizable energy intake) in cattle given food ad libitum was calculated from information included in the United Kingdom energy evaluation system as published by the Agricultural Research Council. For growing cattle (live weight 250 kg), overall efficiency was estimated for five levels of diet metabolizability (ranging from q = 0·45 to q = 0·65) for each of two diet types: coarse/long roughage and fine/pelleted diets. The overall efficiencies varied from 0·58 to 0·62 and were not systematically affected by diet type or diet metabolizability. For lactating cattle (live weight 600 kg), overall efficiency was also calculated for five diets with metabolizability ranging from 0·45 to 0·65. Calculations were made for cows at equilibrium intake (i.e. zero energy balance) and at milk production levels proportionately 0·30 higher or lower than those attained at equilibrium intake. Overall efficiencies varied from 0·60 to 0·63 and were not systematically affected by diet metabolizability.It is concluded that, in practical cattle production systems with ad libitum feeding, the net energy content of food may be estimated at 0·6 of the metabolizable energy content (or 0·5 of the digestible energy content), irrespective of diet type, diet metabolizability or productive function.

scholarly journals Effects of lipid and starch supplementation as water intake mitigation techniques on performance and efficiency of Nursing Holstein Calves

2021 ◽  
Author(s):  
A Macias-Franco ◽  
A E M da Silva ◽  
F H de Moura ◽  
A B Norris ◽  
K Van Den Broek ◽  
...  
Keyword(s):  
Energy Intake ◽  
Water Intake ◽  
Corn Starch ◽  
Metabolizable Energy ◽  
Milk Replacer ◽  
Net Energy ◽  
Total Water ◽  
Holstein Calves ◽  
Ad Libitum ◽  
Net Energy Intake

Abstract Exploring alternative supplementation sources capable of maximizing feed and water efficiency in nursing Holstein calves is often ignored. The goals herein involve investigating the effects of two isoenergetic supplements on a non-medicated milk replacer diet on total water intake, milk water intake, fresh water intake, feed intake parameters, and performance of Holstein nursing bull calves. Twenty-three animals (body weight [BW] = 94.67 ± 12.07 kg, age = 67 days old) were randomly assigned to one of three treatments for 68 days: control (CON; ad libitum milk replacer, n = 7), carbohydrate supplement (CHO; corn starch on top of ad libitum milk replacer-based diet, n = 8), or lipid supplement (FAT; menhaden fish oil on top of ad libitum milk replacer-based diet, n = 8). The isoenergetic supplementation consisted of 3% menhaden fish oil addition on DM basis for FAT. This was matched energetically with corn starch for the CHO group resulting in a 7% composition in DM basis. All animals were provided free access to mineral mix and 120 g daily dried microbrewer’s spent grains (BG). Data were analyzed with the GLMMIX procedure of SAS in a completely randomized design with the diets as a fixed effect. Dry matter intake (DMI) adjusted by average daily gain (ADG; DMI/ADG) resulted in significantly lower values for supplemented groups with CON = 2.48, CHO = 2.38, and FAT = 2.27 kg/kg(ADG) (P = 0.033). Energy intake values were lower for CON when analyzing metabolizable energy intake (P &lt; 0.0001), net energy intake for maintenance (P &lt; 0.0001), and net energy intake for gain (P &lt; 0.0001), followed by CHO, and then FAT. Total water intake (P &lt; 0.0001), milk water intake (P &lt; 0.0001), and fresh water intake (P &lt; 0.0001) all resulted in CHO consuming 0.5 L or less water than the other two treatments. Energy requirements as digestible energy (P &lt; 0.0001), metabolizable energy (P &lt; 0.0001), net energy for maintenance (P &lt; 0.0001), and net energy for gain (P &lt; 0.0001) were lower for CHO, followed by CON, and then FAT having the highest requirements. Similar results were observed for residual feed (RFI; P = 0.006) and residual water intakes (RTWI; P = 0.902). Ultimately, no performance differences were detected with regards to BW, (CON = 146.71, CHO = 146.25, and FAT = 150.48 kg; P &gt; 0.1). These results indicate that lipid-based and starch-based supplementation can potentially increase feed efficiency and decrease voluntary water intake without adversely affecting performance.

scholarly journals Evaluation of the independent and combined effects of xylitol and polydextrose consumed as a snack on hunger and energy intake over 10 d

2005 ◽  
Vol 93 (6) ◽  
pp. 911-915 ◽  
Author(s):  
Neil A. King ◽  
Stuart A. S. Craig ◽  
Tammy Pepper ◽  
John E. Blundell
Keyword(s):  
Energy Intake ◽  
Repeated Measures ◽  
Functional Foods ◽  
Energy Content ◽  
Significant Suppression ◽  
Appetite Control ◽  
Medium Term ◽  
Repeated Measures Design ◽  
Ad Libitum ◽  
The University

The study assessed the independent and combined effect of two speciality carbohydrates (polydextrose and xylitol) on appetite. Eight female and seven male lean volunteers were recruited from the University of Leeds campus. Using a repeated measures design, volunteers completed four conditions in a counterbalanced order. Each condition varied according to the yoghurt formulation administered: a control yoghurt (C, yoghurt+25 g sucrose) and three experimental yoghurts (X, yoghurt+25 g xylitol; P, yoghurt+25 g polydextrose; and XP, yoghurt+12·5 g xylitol and 12·5 g polydextrose). Each condition lasted for 10 d during which volunteers consumed 200 g yoghurt on each day. On days 1 and 10, the short- and medium-term effects of yoghurt consumption were assessed by measuringad libitumlunch intake and subjective motivation to eat. The three experimental yoghurts (X, P and XP) induced a slight suppression of energy intake compared with the control (C) yoghurt, but the differences were not statistically significant. However, when the energy content of the yoghurt pre-loads were accounted for, there was a significant suppression of energy intake for P compared with C (P=0·002). The XP yoghurt induced a significantly stronger satiating effect (increase in subjective fullness) compared with C, both with (P=0·003) and without (P<0·001) the differential in energy content of the yoghurt pre-loads accounted for. The study demonstrated that pre-loads of xylitol and polydextrose caused a mild increase in satiety and suppression of energy intake, and that the effects persist after repeated daily administration. The effects exerted by the formulations containing xylitol and polydextrose did not arise from the differences in energy content of the yoghurtper se. Therefore, the usefulness of xylitol and polydextrose as ingredients in functional foods for appetite control are as a result of their lower energy content and suppression of appetite.

The fasting metabolism by non-pregnant dry dairy cows offered forage diets ad libitum prior to starvation

1997 ◽  
Vol 1997 ◽  
pp. 117-117
Author(s):  
T. Yan ◽  
F. J. Gordon ◽  
C. P. Ferris ◽  
R. E. Agnew ◽  
M. G. Porter ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Energy Output ◽  
Lactating Dairy Cows ◽  
Classical Studies ◽  
Regression Techniques ◽  
Metabolisable Energy ◽  
Ad Libitum ◽  
High Forage ◽  
Lactating Dairy Cattle ◽  
Forage Diets

In classical studies estimates of maintenance energy requirements for cattle have been derived from measurements of fasting heat production (FHP) and urinary energy output following a period of restricted nutrition. Using 8 such sets of data, ARC (1980) developed equations to calculate the metabolisable energy (ME) requirement for maintenance (MEm) for lactating dairy cattle. This approach was further supported by AFRC (1990). However, recent studies using regression techniques at this Institute would suggest that the MEm for lactating dairy cows with access ad libitum to high forage diets is considerably higher than that calculated from AFRC (1990). The objective of the present study was therefore to measure the FHP of dairy cows offered forage diets ad libitum prior to fasting and to establish if this would support the higher MEm for dairy cows obtained using regression techniques .

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