Effect of forage digestibility and type of concentrate on nutrient utilization by lactating dairy cattle

1995 ◽  
Vol 62 (1) ◽  
pp. 15-27 ◽  
Author(s):  
Frederick J. Gordon ◽  
Michael G. Porter ◽  
C. Sinclair Mayne ◽  
Edmund F. Unsworth ◽  
David J. Kilpatrick
Keyword(s):  
Dairy Cows ◽  
Heat Production ◽  
Nutrient Utilization ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Grass Silage ◽  
Forage Digestibility ◽  
Lactating Dairy Cows ◽  
High Fibre ◽  
High Starch

SummarySix lactating dairy cows were used in a three period, part balanced changeover design experiment to investigate the effects of forage digestibility and concentrate composition on the efficiency of nutrient utilization in lactating dairy cows. Six treatments comprising three forage regimens and two concentrate types (starch υ. fibre) were examined in a 3 × 2 factorial design. The three forage regimens were high digestibility grass silage offered ad lib. (HA) or restricted to 6·5 kg dry matter/d (HR) and a low digestibility grass silage offered ad lib. (LA). Within each forage regimen animals were offered 10 kg·d of supplements containing either high-starch or high-fibre concentrations. Experimental periods lasted 28 d with a 10 d recording period, during which animal performance, ration digestibility and nitrogen and energy utilization were measured. Respiratory exchange measurements were made over a 72 h period using indirect open-circuit calorimetry. Throughout the experiment, there were no significant forage × concentrate interactions in any of the intake, production or nutrient utilization results. Milk yield was significantly influenced by forage regimen (24·1, 21·7 and 21·9 kg/d for HA, HR and LA respectively) and concentrate type (21·6 and 23·5 kg/d for high-starch and high-fibre respectively). Concentrate type also significantly influenced milk protein concentration (32·8 and 30·9 g/kg for high-starch and high-fibre respectively). Forage regimen significantly influenced the efficiency of utilization of metabolizable energy (ME) for milk production (κ1) with values of 0·62, 0·64 and 0·59 for HA, HR and LA respectively. Concentrate type had no significant effect on ME intake, heat production or κ1, although animals receiving the high-fibre concentrates synthesized proportionately 0·11 more milk energy per unit of available energy (ME intake – heat production) than those receiving the high-starch concentrates. Interpolation of the values obtained with the two high digestibility forage regimens indicated that at similar ME intakes there was a trend towards a higher κ1 with the diet based on high digestibility silage, and this was in line with the higher metabolizability of the overall diet with this silage.

Effects of ensilage of grass on performance and nutrient utilization by dairy cattle 2. Nutrient metabolism and rumen fermentation

1995 ◽  
Vol 60 (3) ◽  
pp. 347-359 ◽  
Author(s):  
A. Cushnahan ◽  
C. S. Mayne ◽  
E. F. Unsworth
Keyword(s):  
Dairy Cows ◽  
Nutrient Utilization ◽  
Rumen Fermentation ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Nutrient Metabolism ◽  
Rumen Degradation ◽  
Lactating Dairy Cows ◽  
Silage Fermentation ◽  
Urinary Nitrogen

AbstractA study was carried out to examine the effects of ensiling and pattern of silage fermentation on nitrogen and energy utilization, rumen fermentation and rumen degradation characteristics of forage by lactating dairy cows. Six nonfistulated dairy cows and three rumen fistulated dairy cows were offered fresh grass (G) or grass silage produced from the same sward which had undergone either an extensive (E) or restricted (R) fermentation. Animals offered extensively fermented silage had liigher urinary nitrogen (N) outputs (expressed as a proportion of N intake) than those offered fresh grass (P < 0·05). Corresponding values for animals offered restricted fermented silage were intermediate between those offered grass and extensively fermented silage. Animals offered fresh grass and restricted fermented silage also had higher methane energy losses (P < 0·05), than those offered extensively fermented silage. The ensiling of grass had little effect on metabolizable energy (ME) intake or on the efficiency of utilization of ME for lactation (k1). Animals offered extensively fermented silage had higher proportions of propionate and lower proportions of acetate than those offered fresh grass or restricted fermented silage (P < 0·001). Ensiling resulted in an increase in the soluble (a) fraction and a reduction in the potentially degradable (b) fraction of N.

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.

The effects of wilting of grass prior to ensiling on the response to bacterial inoculation. 1. Silage fermentation and nutrient utilization over three harvests

1996 ◽  
Vol 62 (3) ◽  
pp. 405-417 ◽  
Author(s):  
T. Yan ◽  
D. C. Patterson ◽  
F. J. Gordon ◽  
M. G. Porter
Keyword(s):  
Heat Production ◽  
Nutrient Utilization ◽  
Period Change ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Energy Output ◽  
Apparent Digestibility ◽  
Total N ◽  
Silage Fermentation ◽  
The Mean

AbstractFour silages were prepared from perennial ryegrass swards at each of first (primary growth), second (first regrowth) and third (second regrowth) harvests during the 1993 growing season. At each harvest the four silages included two unwilted (without and with inoculant at 2·4 l/t) and two wilted (without and with inoculant at 24 l/t). The four silages within a single harvest, were offered as the total diet at maintenance levels to 12 wether sheep for 3 weeks to determine nutrient apparent digestibilities. They were also given to 12 lactating dairy coivs together with a concentrate supplement, in a three-period change-over study with experimental periods of 8-weeks duration, to examine dry matter (DM) apparent digestibility and utilization of nitrogen (N) and energy in the diets.Inoculation tended to improve silage fermentation with on average lower pH and ammonia-N/total-N across the three harvests, while wilting of grass prior to ensiling significantly increased silage pH fP < 0·001) and ammonia-N/total-N (P < 0·001). Neither inoculation nor wilting had any significant effect on mean nutrient apparent digestibilities, assessed through sheep, across the three harvests. However, at the second harvest inoculation significantly reduced apparent digestibilities of DM (P < 0·001) and N (P < 0·001). At this harvest, wilting also significantly decreased apparent digestibilities of DM (P<0·05) and N (P <0·01), but significantly increased apparent digestibilities of DM (P < 0·05), energy (P < 0·001) and N (F < 0·05) at the third harvest. When the silages were offered as mixed diets to dairy cattle, neither inoculation nor wilting had significant effects on digestibilities of DM, N and energy at any of the three harvests, except for wilting which significantly decreased DM apparent digestibilities (P < 0·05) at the second harvest. However, the mean apparent digestibilities of DM (P < 0·01), N (P < 0·05) and energy (P < 0·01) across the three harvests were significantly lower following wilting, and N apparent digestibility (P < 0·05) was significantly higher following inoculation. The calorimetric data indicated that inoculaton had no significant effects on either methane energy output or heat production. Wilting also had no significant effect on methane energy output, but significantly increased daily heat production (P<0·05) at the first harvest. The efficiencies of metabolizable energy utilization for lactation (k1) were similar between the four silages at each of the first and second harvests, with the average being 0·50. The results of the present study indicated that inoculation tended to improve silage fermentation and significantly increased mean N apparent digestibility of mixed diets across the three harvests, while wilting significantly reduced mean DM, N and energy apparent digestibilities of mixed diets. Neither inoculation nor wilting had significant effects on Rvalue.

Effect of oat particle size on energy and nutrient utilization in growing pigs

2021 ◽  
Author(s):  
Bonjin Koo ◽  
Charles Martin Nyachoti
Keyword(s):  
Particle Size ◽  
Heat Production ◽  
Energy Content ◽  
Geometric Mean ◽  
Nutrient Utilization ◽  
Growing Pigs ◽  
Metabolizable Energy ◽  
Neutral Detergent Fiber ◽  
Energy Utilization ◽  
Experimental Unit

Abstract An experiment was conducted to determine the energy content of oats and to investigate the effects of oat particle size on nutrient and energy balance in growing pigs. Eighteen barrows (23.56 ± 0.94 kg initial body weight) were randomly assigned to one of three dietary treatments with six replicates per treatment. Whole oats were ground with a hammermill fitted with 4.8-mm and 3.2-mm screens to make coarse and medium particle size oats, respectively. Medium oats were further ground with rotary steel cutting grinder fitted with a 2.0-mm screen, and the further ground oats were mixed with medium oats in a 1:3 ratio to make fine oats. Three experimental diets consisted of 96.3% of the coarse, medium or fine oats as a sole source of energy were used. Pigs were fed diets for 16 d, including 10 d for adaptation and 6 d for total fecal and urine collection. Pigs were then moved into indirect calorimetry chambers to determine 24-h heat production and 12-h fasting heat production. All data were analyzed using the MIXED procedure of SAS with the individual pig as the experimental unit. The geometric mean particle sizes for coarse, medium, and fine oats were 765 μm, 619 μm, and 569 μm, respectively. Pigs fed the medium oats diet tended to have (P &lt; 0.10) greater apparent total tract digestibility (ATTD) of starch, neutral detergent fiber, and gross energy than those fed coarse oats diet. The medium oats diet contained greater (P &lt; 0.05) digestible energy (DE), metabolizable energy (ME), and net energy (NE) than the coarse oats diet. Pigs fed the fine oats diet had lower (P &lt; 0.05) ATTD of Ca and P than those fed the coarse oats diet. The DE, ME, and NE contents of fine oats were comparable with those of coarse oats. The determined NE contents for coarse, medium, and fine oats were 2,335, 2,615, and 2,521 kcal/kg on a dry matter basis, respectively. The NE content in medium oats was greater (P &lt; 0.05) than the NE values predicted using published equations. In conclusion, it was suggested to grind whole oats for 619 μm concerning energy utilization. Further grinding to 569 μm reduces Ca and P digestibility.

Energy and nitrogen balance of lactating dairy cows given mixtures of urea-treated whole-crop wheat and grass silage

1998 ◽  
Vol 67 (2) ◽  
pp. 203-212 ◽  
Author(s):  
J. D. Sutton ◽  
S. B. Cammell ◽  
D. E. Beever ◽  
D. J. Humphries ◽  
R. H. Phipps
Keyword(s):  
Dairy Cows ◽  
Milk Fat ◽  
Latin Square ◽  
Metabolizable Energy ◽  
Partial Substitution ◽  
N Losses ◽  
Grass Silage ◽  
Lactating Dairy Cows ◽  
Acid Detergent Fibre ◽  
Gross Energy

AbstractEnergy and nitrogen balances were carried out with four multi-porous Holstein/Friesian cows offered four diets in a Latin-square experiment to evaluate urea-treated whole-crop wheat as a partial grass silage replacement for lactating dairy cows. Grass silage (GS) was produced from the primary growth of a perennial ryegrass sward. Spring wheat (cv. Axona) was harvested at 603 g dry matter (DM) per kg and preserved with 20 (WCW-20) or 40 (WCW-40)kg urea per t DM. The diets were 6 kg DM of a dairy concentrate daily with one of four forage treatments offered ad libitum. The forage treatments were GS alone, a 2:1 DM ratio of GS with WCW-40 (2:1 40), or a 1:2 DM ratio of GS with WCW-20 (1:2 20) or WCW-40 (1:2 40). Each period lasted 4 weeks with energy and nitrogen balances being carried out in respiration chambers over 6 days in the last week. Replacement of GS by diets containing WCW resulted in significant increases in DM intake (P < 0·01). Changes in milk yield and composition were small and non-significant but yields of milk fat and protein were higher on WCW diets than on GS diets (P< 0·05). With increasing proportions of WCW in the diet there were significant linear falls in apparent digestibility of DM (P < 0·001), organic matter (F < 0·001), neutral-detergent fibre (F < 0·01), acid-detergent fibre (F < 0·01), starch (F < 0·001) and nitrogen (P < 0·01). Gross energy intakes (P < 0·01) and faecal (P < 0·001), methane (P < 0·05) and milk (P < 0·05) energy outputs were higher with the WCW diets than with GS but urine energy and heat losses were unaffected. In consequence there were no significant differences among the diets in digestible or metabolizable energy (ME) intakes. However dietary ME concentrations (MJ ME per kg corrected DM) fell with increasing WCW inclusion from 11·54 on GS to a mean of 9·96 on the 1:2 diets (P < 0·001). It was calculated that the ME concentration of the WCW was only 8·1 MJ/kg corrected DM at maintenance intake, considerably lower than values used conventionally. There were no significant diet effects on the partition of ME or on the partial efficiency of ME utilization for milk production (k1). The increasing inclusion of WCW increased N losses in urine (P < 0·05) and faeces (F < 0·01) with no net effect on N digested or retained though there was a small increase in milk N output (P < 0·01). It is concluded that low digestibility is the major cause of the small milk response to the partial substitution of urea-treated WCW for grass silage with no evidence of a reduction in the efficiency of utilization of ME.

The use of regression techniques on calorimetric data to estimate the metabolisable energy requirements of lactating dairy cows

1997 ◽  
Vol 1997 ◽  
pp. 4-4
Author(s):  
T. Yan ◽  
F. J. Gordon ◽  
R. E. Agnew ◽  
M. G. Porter ◽  
D. C. Patterson
Keyword(s):  
Dairy Cows ◽  
Open Circuit ◽  
Energy Requirements ◽  
Gaseous Exchange ◽  
Calorimetric Data ◽  
Grass Silage ◽  
Lactating Dairy Cows ◽  
Holstein Friesian ◽  
Regression Techniques ◽  
Metabolisable Energy

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.

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