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North Carolina State
University Return to main menu Cottonseed
Hull Based Diets for Calves and Heifers B. A. Hopkins and L. W. Whitlow Introduction Proper feeding and management of dairy calves and
heifers will ensure that heifers are large enough to breed at an age that
allows them to enter the milking string when needed. At NC State University,
we have developed several complete feeds, including a calf starter; a
self-fed total mixed ration (TMR) for 2 to 6 month old heifers; and a
self-fed TMR for yearling heifers. The key ingredient in these rations is
cottonseed hulls (CSH) that serve as the primary source of fiber. These
rations have supported excellent growth and health while reducing labor
expenses. Because cottonseed hulls are high in fiber, and low in energy, the
cottonseed hull based TMR's can be self-fed, with ad libitum intake providing
appropriate energy requirements. Nutrient Composition of Cottonseed
Hulls The 2001 NRC lists the nutrient value of cottonseed
hulls as 6.2% crude protein, 34.3% TDN and 64.9% ADF. Cottonseed hulls are an
excellent source of "effective" fiber and can have the
associative effect of increasing dry matter intake. As a byproduct of the
cotton industry, hulls are normally available in the market, especially in
the Southeast, and are easily transported and handled in bulk, but are not
easily handled by auger systems. Evaluation of a Calf Starter with 15%
Cottonseed Hulls: The development of a functional rumen is related to
the intake of solid feed. A goal of conventional calf feeding programs is for
the calf to increase intake of calf starter with age. The calf should be
consuming enough starter at weaning to easily transition off of liquid feed.
The starter should also stimulate rumen development. As part of a recent
research study (S.R. Hill, NCSU Masters Degree Thesis), a calf starter was
formulated that contained 15% cottonseed hulls. Calves received experimental
treatments from birth through 63 days of age. The effects of feeding this
starter on starter intake, growth, health measures and rumen development were
compared to a standard calf starter with no cottonseed hulls. The ingredient
composition of the two starters is shown in Table 1 and
the nutrient composition is shown in Table 2. It is important to formulate calf starter diets with
enough protein. Notice that the cottonseed hull based starter fed in this
study contained 18% crude protein. Starters should also contain vitamins,
including B vitamins, appropriate mineral levels, and a coccidiostat. Results from the Calf Starter Study Results from this study are presented in Table 3. Holstein calves fed the cottonseed hull based
calf starter had significantly greater daily intakes of starter dry matter
and fiber than calves fed the starter without cottonseed hulls. Calves fed
the cottonseed hull based starter also had greater average daily body weight
gains and lower fecal scores. Average daily gains were 1.32 and 1.19 pounds
per day for calves fed the cottonseed hull based starter and those fed the
starter without cottonseed hulls, respectively. Feed efficiency was lower for
calves fed the cottonseed hull based starter because they had greater
intakes. Calves fed the cottonseed hull based starter weighed
significantly more during weeks 7, 8 and 9 of the trial and had a final
average body weight about 10 pounds greater than calves fed starter without
cottonseed hulls. Self-Fed Cottonseed Hull Based TMR for
2 to 6 Month Old Heifers We have also developed a self-fed TMR for
post-weaned 2 to 6 month old heifers that contains 30% cottonseed hulls. This
TMR was based on the original work done in this area by Dr. A.H. Rakes at NC
State University. The formula for this TMR is presented in Table
4. This TMR can be fed through gravity-flow self-feeders so heifers have
the feed available at all times. The level of 30% cottonseed hulls provides
an amount of fiber which limits intake due to rumen fill and is low enough in
energy content to avoid overfeeding of energy. Therefore with 30% cottonseed
hulls and ad libitum intake, the heifer's energy needs for appropriate growth
are met. Before the weaned calves are removed from their
individual hutch or pen, they are gradually changed over a period of about a
week from the calf starter to the heifer TMR. Calves are then moved into a
small group lot where they have access to a gravity flow self-feeder for ad
libitum access to the ration until about 6 months of age. Bloat or other
digestive problems have not been noted. Nutrient intake is consistent and
similar for all heifers in a group. The heifers are fed this TMR through a
self-feeder and grow very well, while labor costs have decreased. As calves
reach 6 months of age, they should be offered hay in addition to the TMR, or
the amount of cottonseed hulls in the TMR must be increased to avoid too much
weight gain. Intake and Growth of Heifers fed a
Cottonseed Hull Based TMR compared with Hay and Grain Fed Separately We conducted a study to compare the performance of 2
to 6 month old heifers fed a TMR containing 30% cottonseed hulls with heifers
fed hay and grain separately. Both diets were formulated to contain 16% crude
protein and 21.5% acid detergent fiber (ADF). The amount of grain offered in
the hay and grain treatment diet was limited to a maximum based on the amount
of grain consumed by calves fed the cottonseed hull based TMR treatment.
Calves fed hay and grain separately tended to consume less grain even though
it was available. The chopped grass hay in the hay and grain diet was offered
free-choice. Feed intake on an as-fed basis; average daily gain; and feed
efficiency are presented in Table 5. Feed efficiency
was greater for calves fed the hay and grain separately. However, heifers fed
the cottonseed hull based TMR had greater intakes and average daily gains
than heifers fed the hay and grain diet. Advantages of Feeding a Self-fed
Cottonseed Hull Based TMR to Heifers At the Piedmont Research Station, we have observed several advantages to using a TMR that contains 30% cottonseed hulls for post-weaned 2 to 6 month old heifers including: Consistent nutrition: This blended TMR is formulated for the correct
nutrient balance and is always available to the heifers. Competition among heifers is minimized: Since the feed is always available, the problem
with boss heifers is minimized and each heifer can consume what she needs. Uniform heifer growth: Nutrient intake is consistent. Feeding this TMR
post-weaning helps to reduce the "growth slump" that often occurs
when heifers are placed in a group feeding situation following weaning. Average Daily Body Weight Gains: Heifers fed this TMR normally gain about 2 pounds
per day. The level of cottonseed hulls in the diet can be adjusted to maintain
the desired rate of gain. Labor savings:
This TMR is mixed about once per week and placed in the covered gravity-flow
self-feeder. This eliminates having to mix and deliver feed to the heifers
every day which saves a large amount of labor. Development of a Cottonseed Hull Based
TMR for Yearling Heifers We have also developed a cottonseed hull based TMR
for yearling dairy heifers. Examples
of two TMR formulas that can provide excellent results are shown in Table 6. Formula 1 contains dried brewers grains while
Formula 2 contains soybean meal. Notice that cottonseed hulls comprise 75% of these
diets. Heifers fed these TMR’s should average about two pounds of daily body
weight gain. In addition, because of the increased dry matter intake
associated with feeding cottonseed hulls, ration crude protein levels in
these TMR’s for yearling heifers have been reduced to about 9% without
affecting desired growth rates. Since these rations in Table 6
contain 75% cottonseed hulls, they are very bulky and will not flow readily
though conventional gravity-flow feeders. However, they can still be self-fed
to heifers through a covered feeder where the heifers have free-choice access
to the TMR. Supplemental pasture and/or hay for these yearling heifers is
recommended. Cottonseed Hull Based TMR for 6 to 12
Month Old Heifers High cottonseed hull based diets have not yet been
developed for this age group. This is a period where the amount of cottonseed
hulls needs to be transitional from 30% up to 75% of the ration so that ad
libitum intake of the TMR provides proper amounts of energy. Summary The key ingredient in these diets is cottonseed
hulls that are high in fiber, and low in energy. The cottonseed hull based
TMR's can be self-fed, with ad libitum intake providing appropriate energy
requirements. In our studies, a calf starter with 15% cottonseed hulls
increased intake and average daily gains in preweaned calves. We also found
that a self-fed TMR that contains 30% cottonseed hulls provides consistent
nutrition and growth for 2 to 6 month old heifers while reducing labor
expenses. In addition, excellent growth rates in yearling heifers have been
obtained by feeding rations containing 75% cottonseed hulls. Consider
including cottonseed hull based TMR's in your calf and heifer feeding
management program. Table 1. Ingredient Composition of Calf Starter Diets (% of
diet DM)
Table 2. Nutrient Composition of Calf Starter Diets
Table 3. Calf Starter Intake, ADG, Feed Efficiency and Fecal
Scores
Table 4. Self-Fed TMR for Post-Weaned Heifers 2 to 6 Months
of Age
Table 5. Average
Daily Intake, Average Daily Gain and Feed Efficiency
Table 6. Two
Self-fed Cottonseed Hull Based TMR for Yearling Heifers
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