• TABLE OF CONTENTS
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 Experimental
 Results and discussion
 Summary
 Table 1 - Nutrient content of coastal...
 Table 2 - Average daily feed intake...
 Table 3 - Digestion coefficients...
 Table 4 - Digestible nutrient content...














Group Title: Department of Animal Science research report - Florida Agricultural Experiment Station ; AL-1981-1
Title: Influence of level of feeding on the digestibility of hay and hay-grain diets by horses
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
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Permanent Link: http://ufdc.ufl.edu/UF00073122/00001
 Material Information
Title: Influence of level of feeding on the digestibility of hay and hay-grain diets by horses
Series Title: Department of Animal Science research report
Physical Description: 2 p. : ; 28 cm.
Language: English
Creator: Ott, E. A ( Edgar A )
University of Florida -- Dept. of Animal Science
University of Florida -- Agricultural Experiment Station
Publisher: Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1981
 Subjects
Subject: Horses -- Feeding and feeds -- Florida   ( lcsh )
Hay as feed   ( lcsh )
Grain as feed   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: E.A. Ott.
General Note: Caption title.
General Note: "January, 1981."
Funding: Animal science research report (University of Florida. Dept. of Animal Science) ;
 Record Information
Bibliographic ID: UF00073122
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 80774294

Table of Contents
    Experimental
        Page 1
    Results and discussion
        Page 1
    Summary
        Page 2
    Table 1 - Nutrient content of coastal Bermudagrass hay and corn
        Page 3
    Table 2 - Average daily feed intake in kg/100 kg body weight
        Page 4
    Table 3 - Digestion coefficients and apparent absorption of nutrients
        Page 5
    Table 4 - Digestible nutrient content of diets
        Page 6
Full Text





Department of Animal Science 1 Florida Agricultural
Research Report AL-1981-1 Experiment Station
January 1981 Gainesville, Florida


INFLUENCE OF LEVEL OF FEEDING ON THE DIGESTIBILITY
OF HAY AND HAY-GRAIN DIETS BY HORSES1

E. A. Ott2


High levels of feed intake have been shown to reduce the efficiency of
digestion in other species, but no information is available on the effect
of intake level on digestion in the horse. Most digestion studies with the
horse are conducted using restricted levels of intake to ensure uniform daily
consumption over the course of the investigation. This procedure may influence
digestion efficiency by the animal resulting in erronous values when applied
to situations where the feed intake is considerably higher. This study was
designed to compare digestion efficiency of two types of diets fed at two
levels of intake.

Experimental

Four Thoroughbred and Quarter Horse type geldings averaging 495 kg were
used in a 4 x 4 latin square experiment testing four diets. The diets formed
a 22 factorial comparing availability of grain (yes or no) and intake level
(low or high). The diets tested were as follows:

Diet I Coastal bermudagrass hay 1.5% BW3/day
Diet 2 Coastal bermudagrass hay 2.5% BW3/day
Diet 3 Coastal bermudagrass hay 0.75% BW3/day
Cracked corn 0.75% BW3/day
Diet 4 Coastal bermudagrass hay 1.25% BW3/day
Cracked corn 1.25% BW3/day
Free choice salt was available at all times.
The experiment was conducted in 4, 28-day periods each of which included
a 21-day preliminary period and a 7-day collection period. Only the last 5
days of the collection period were used for analyses. During the preliminary
period the horses were housed in individual, open drylot paddocks providing
726 ft2 of space per animal including 186 ft2 of covered area. During the
collection period the horses were confined to individual metabolism stalls.
The horses were removed from the stalls and walked via a mechanical walker
for. two, 30-minute periods each day.

Results and Discussion

Analyses of the Coastal bermudagrass hay and cracked corn are shown in
table 1. The hay was of medium quality and was lower in protein than the
8-10% that is typical of most hay of similar maturity harvested in the area.
The corn was also slightly lower in protein than typical corn samples. All
other values were similar to those previously analyzed.

Average feed intake in kg/100 kg body weight (BW) for the four diets is
shown in table 2. The low intake diets (1 and 3) were consumed in total by
all of the horses except a small quantity of the corn portion of diet 3 was

1Data taken from experiment HN-802
2Animal Science Dept.
3As-fed









Department of Animal Science 1 Florida Agricultural
Research Report AL-1981-1 Experiment Station
January 1981 Gainesville, Florida


INFLUENCE OF LEVEL OF FEEDING ON THE DIGESTIBILITY
OF HAY AND HAY-GRAIN DIETS BY HORSES1

E. A. Ott2


High levels of feed intake have been shown to reduce the efficiency of
digestion in other species, but no information is available on the effect
of intake level on digestion in the horse. Most digestion studies with the
horse are conducted using restricted levels of intake to ensure uniform daily
consumption over the course of the investigation. This procedure may influence
digestion efficiency by the animal resulting in erronous values when applied
to situations where the feed intake is considerably higher. This study was
designed to compare digestion efficiency of two types of diets fed at two
levels of intake.

Experimental

Four Thoroughbred and Quarter Horse type geldings averaging 495 kg were
used in a 4 x 4 latin square experiment testing four diets. The diets formed
a 22 factorial comparing availability of grain (yes or no) and intake level
(low or high). The diets tested were as follows:

Diet I Coastal bermudagrass hay 1.5% BW3/day
Diet 2 Coastal bermudagrass hay 2.5% BW3/day
Diet 3 Coastal bermudagrass hay 0.75% BW3/day
Cracked corn 0.75% BW3/day
Diet 4 Coastal bermudagrass hay 1.25% BW3/day
Cracked corn 1.25% BW3/day
Free choice salt was available at all times.
The experiment was conducted in 4, 28-day periods each of which included
a 21-day preliminary period and a 7-day collection period. Only the last 5
days of the collection period were used for analyses. During the preliminary
period the horses were housed in individual, open drylot paddocks providing
726 ft2 of space per animal including 186 ft2 of covered area. During the
collection period the horses were confined to individual metabolism stalls.
The horses were removed from the stalls and walked via a mechanical walker
for. two, 30-minute periods each day.

Results and Discussion

Analyses of the Coastal bermudagrass hay and cracked corn are shown in
table 1. The hay was of medium quality and was lower in protein than the
8-10% that is typical of most hay of similar maturity harvested in the area.
The corn was also slightly lower in protein than typical corn samples. All
other values were similar to those previously analyzed.

Average feed intake in kg/100 kg body weight (BW) for the four diets is
shown in table 2. The low intake diets (1 and 3) were consumed in total by
all of the horses except a small quantity of the corn portion of diet 3 was

1Data taken from experiment HN-802
2Animal Science Dept.
3As-fed







- 2-


was not consumed by two horses. At the higher level of intake only one horse
achieved the 2.5 kg/100 kg BW intake level. All animals consumed over 2.0 kg/
100 kg BW of diet 2, but only two animals reached that level of intake on diet
4.

The horses lost-an average of 15.7 kg/head over the duration of the ex-
periment. Weight changes by period and by diet were not consistent.

Digestion coefficients for dry matter, crude protein, fat, acid detergent
fiber (ADF), neutral detergent fiber (NDF) and. energy and apparent absorptions
of ash, calcium and phosphorous are shown in table 3. Increasing the hay in-
take (diet 2 vs. diet 1) increased digestion efficiency (P<.01) for CP, fat,
energy and phosphorous and decreased absorption efficiency (P<.0l) for calcium.
Increasing the hay-grain diet (diet 4 vs. diet 3) decreased digestion efficiency
(P<.01) for dry matter, CP, fat, energy, calcium and phosphorous. Adding grain
to the diet increased digestion efficiency (P<.OI) for DM, CP, NDF, energy,
calcium and phosphorous. Increasing feed intake increased fat digestibility
(P<.01) but decreased (P<.Ql) calcium and phosphorous absorption. The inter-
action between level of intake and grain availability was significant for
protein (P<.05), fat (P<.01), energy (P<.05), calcium (P<.05) and phosphorous
(P<.05).

Digestible nutrient levels (nutrient x digestion %) for the four.diets are
shown in table 4. The digestible energy content of the hay averaged 1.7 Mcal/
kg. This is 14% below the 1.98 Mcal/kg reported by the NRC and 19% below the
2.10 Mcal/kg we have gotten on better quality hay. Digestible nutrient content
of the diet increased as corn was added. It was calculated by difference that
the corn had a digestible energy content of 3.48 Mcal/kg when fed at the low
level and 3.14 Mcal at the higher rate. These values are 10 and 19% below the
3.87 Mcal/kg used for the NRC (1978).


Summary

Level of feeding influences digestion efficiency in the horse. In this
study, increasing hay intake increased digestion efficiency of CP, fat, energy
and phosphorous and decreased absorption efficiency of calcium. Increasing
the hay-grain diet decreased digestion efficiency for DM, CP, fat, energy,
calcium and phosphorous. The digestibility of both the hay and the grain were
below the average figures used by NRC (1978).






















TABLE 1. NUTRIENT CONTENT OF COASTAL BERMUDAGRASS HAY AND CORN

Dry Crudea Grossa
matter protein Fata ADFab NDFac Asha energy Calciuma Phosphorousa
Ingredient % % % % % Mcal/kg % %

Coastal bermudagrass hay 88.3 6.3 1.5 28.9 60.9 5.0 3.93 .37 .17

Corn grain 86.2 7.66 1.7 3.0 24.8 1.3 3.78 .05 .36


Dry matter basis.
Acid detergent fiber.
Neutral detergent fiber.



























TABLE 2. AVERAGE DAILY FEED INTAKE IN KG/100 KG BODY WEIGHTa

Intake and SE
Diet Hay Grain Total

1 1.50 0 -- 1.50 0
2 2.27 .09 -- 2.27 .09
3 .75 0 .73 + .01 1.48 .01
4 1.04 .12 .78 .10 1.82 .20

aAs-fed.




















TABLE 3. DIGESTION COEFFICIENTS AND APPARENT ABSORPTION OF NUTRIENTS

Dry Crude
Diet matter protein Fat ADF NDF Ash Energy Calcium Phosphorous


1 hay-low level 49.7 39.100 -7.7e ..3..8 43.5 38.4 42.5h 64.8kl 28.8n
2 hay-high level 50.8 46.2b O1.eg 37.1 43.9 46.9 44.1' 59.8k 32.6
3 hay + grain low level 70.0a 59.8cd 1.lf 45.8 60.1 24.9 66.6hi 77.51m 56.2no
4 hay + grain high level 64.9a 52.8d -1.59 36.9 51.4 23.6 59.8'J 63.6m 41.90

1 & 2 No grain 50.2a 42.7b 1.2 38.5 43.7c 42.6 43.3d 62.3e 30.7f
3 & 4 Grain 67.4a 56.3b -.2 41.4 55.7c 24.2 63.2d 70.5e 49.1

1 & 3 low level 59.8 49.4 -3.3a 42.8 51.8 31.6 54.6 71.1b 42.5c
2 & 4 high level 57.8 49.5 4.3a 37.0 47.6 35.3 51.9 61.7b 37.3C

a,b,.''Comparable numbers with like superscripts are different (P<.OI).
























TABLE 4. DIGESTIBLE NUTRIENT CONTENT OF DIETSa

Crude
protein Fat ADF NDF Ash Energy
Diet % % % % % Mcal/kg

I hay-low level 2.5 -- 11.5 26.5 1.9 1.67
2 hay-high level 2.9 .2 10.7 26.7 2.3 1.73
3 hay + grain low level 4.2 0 7.5 25.8 .8 2.57
4 hay + rain high level 3.6 -- 6.6 23.5 .8 2.31

aDry matter basis.




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