Performance of Calves Fed Heat-Damaged Cottonseed R.E. Lichtenwalner Animal Science, James Center North Carolina State Univ.

Sixty calves (average initial weight of 573 lbs.) were randomly allotted to 15 pens and fed a corn silage based ration supplemented with either soybean meal (SBM), cottonseed (CS) or heated cottonseed (HCS). Rations were fed ad libitum during the 105 day feeding period. Average daily intakes (as is basis) for the trial were: 25.7,17.2 and 13.8 lbs/head for the SBM, CS and HCS fed calves, respectively. Average daily gains for the trial were 2.68, 2.05 and 1.42 lbs for the SBM, CS, and HCS supplemented calves, respectively. The results of this trial indicate that cottonseed that has undergone a heat during storage does not support sufficient growth in calves to be considered as a feedstuff for growing cattle.

Introduction:

With the expansion of the cotton acreage in Eastern North Carolina, ready access to whole cottonseed has presented local cattlemen with an economical alternative to oil derived supplements. After ginning, the whole cottonseeds are stored in warehouses but time and equipment for closely monitoring the temperature of stacked cottonseed is limited resulting in overheating and, in some cases, warehouse fires. Since the feed value of such heat-damaged cottonseed is unknown, it often winds up in landfills. The purpose of this trial is to ascertain the feeding value of heat damaged cottonseed for growing cattle.

Procedure:

Sixty crossbred calves ( average initial weight of 573 pounds) from the breeding herd at the Tidewater Research Station were randomly allotted to fifteen pens. Pens were assigned to one of three corn silage based rations supplemented with either 44% soybean meal (SBM), good cottonseed (GCS) or heated cottonseed (HCS). The heated cottonseed was derived from a stack that was smoking but had not yet caught fire. It was removed, spread until cool and then re-stacked. The good cottonseed was derived from the same gin but from a different warehouse. Soybean meal was added at the rate of two pounds per head per day and cottonseeds were added at the rate of four pounds per head per day. Calves were daily fed ad libitum their respective rations. Feed refusals were recorded daily. Calves were weighed approximately every 28 days.

Results:

The performance of calves fed heated cottonseed is presented in tables 1 and 2. Gains of calves was affected by type of supplement; gains were 2.68, 2.05 and 1.43 lbs per day for the SBM, GCS and HCS groups, respectively. Initially, gains were quite high but declined throughout the trial. Differences in gains among supplemented calves were evident from the start of the trial(table 1).

Table 1. Weights & Gain of calves fed Heated Cottonseed

Differences in intake of calves fed the three supplements (table 2) mirror the pattern seen in gains. Average daily intake for the trial was 25.7, 17.2 and 13.8 for the SBM, GCS and HCS supplemented calves, respectively. Calves consumed less of the cottonseed supplements form the very beginning of the trail and never caught up with the SBM supplemented calves during the trial. Calves fed the SBM supplemented ration consumed about 3.6 % of their body weight (1.9% on dm basis) whereas the cottonseed supplemented calves consumed only about 1.25% (dm basis) of their body weight. Feed efficiencies were similar among all cattle but it took more feed per pound of gain at each stage of the trial.

Table 2. Intake & Efficiency of calves fed Heated Cottonseed

Expressing performance of the cottonseed supplemented calves as a percentage of the SBM supplemented calves (table 3) shows that GCS supplemented calves consumed 32.9% less feed and gained 22.3% slower than the SBM supplemented calves. Calves fed the HCS treatment consumed 46.3 and 19.8 % less and gained 46.6 and 30.3 % slower than the SBM and GCS supplemented calves, respectively.

Table 3. Reduction in Performance, %

TRT:	SBM	GCS	%SBM		HCS	%GCS	%SBM
Average daily intake and % Reduction
Start	19.4	14.0	27.8		11.2	20.0	42.3
Mid	27.0	16.4	39.3		12.9	21.3	52.2
End	30.8	21.1	31.5		17.2	18.5	44.2
Trial	25.7	17.2	32.9		13.8	19.8	46.3
Average daily gain and % Reduction
Start	5.08	3.81	25.0		2.96	22.2	41.7
Mid	3.05	2.23	26.8		1.72	22.9	43.6
End	2.18	1.85	15.1		1.08	41.4	52.9
Trial	2.68	2.05	22.3		1.43	30.3	46.6

Discussion:

Data from this trial indicate that heat damaged cottonseed is unacceptable as a feed supplement for growing calves. It is well known that heat treatment of oil seeds binds proteins and renders much of the protein content unavailable to cattle. These data also show an intake effect due to heating. Calves fed the HCS supplemented never "dove-in" to their rations and were very irregular in their eating pattern. Although the HCS had a burnt odor, the GCS had no detectable burnt odor but still was not readily consumed by the calves. There was a "musty" odor to the GCS and it is unknown whether it had undergone minor heating during storage. Usually, the odor associated with corn silage is strong enough to mask odors from other feedstuffs, but this particular silage was rather dry (43%dm) and the typical odor was not as strong as in wetter silage. These data indicate that even slight, humanly undetectable spoilage in stored cottonseed has a deleterious effect on performance of growing calves. Typically, cottonseed sells for about one-half the price of SBM since it contains about one-half the protein of SBM. Given the uncertainty of the quality of stored cottonseed, it should be fed to mature cattle or discounted another 20 to 25%.

Last revised March 18, 1999

Published by North Carolina Cooperative Extension Service

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