99stocker

Preliminary Results:
Fertilizer Source Effects on Performance
of Stockers Grazing Bermudagrass

S. M. DeRouen and J. M. Turpin
Hill Farm Research Station

Findings from 1999 Trial

* Similar growth performance was observed for calves grazing pastures fertilized with either commercial fertilizer or broiler litter.

* Fertilizer costs were reduced by 38% with the use of broiler litter compared to use of commercial fertilizer.

* A net loss resulted by retaining calves and stocking over the summer. A rather high negative price margin and relatively low rates of gain due to dry conditions during the latter half of the trial appeared to be the major contributors to this net loss.

Experimental Approach

* A total of 84 Angus-sired, fall-born, weaned crossbred calves.

* Calves were given a growth implant (except for eight replacement heifers).

* Calves were maintained on pasture (3.5 calves per acre) for the duration of the 120-day trial (April 13 to August 12, 1999).

* Fertilizer source treatments were:

1) 2 tons/acre of broiler litter applied on April 8 and June 23 (BL-2+2);
2) 4 tons/acre of broiler litter applied on April 8 and 150 lb/acre of ammonium nitrate applied on July 12 (BL-4);
3) 250 lb/acre of 17-17-17 (N-P-K) applied on April 13, May 13, and June 11, and 150 lb/acre of ammonium nitrate applied on July 12 (CF-30);
4) 250 lb/acre of 17-17-17 (N-P-K) applied on April 13, May 28, and July 12 (CF-45).

* Approximately equal amounts of N-P-K were applied by BL-2+2 and CF-45 over the growing season. Likewise, approximately equal amounts of N-P-K were applied by BL-4 and CF-30 over the growing season.

* Environmental precautions need to be considered with the use of broiler litter as a fertilizer source. Continued use of broiler litter at high rates over a period of several years increases the potential for build-up and run-off of litter compounds (i.e., nitrates, phosphorus) that can to be harmful to soil and water resources.

Table 1. Monthly Precipitation at Hill Farm Research Station During the 1999 Grazing Season and the Average During 50-year Period (1950-1999).

Month	Year 1999	50-Year average
	----------------inches-------------------
March	5.10	4.57
April	6.65	5.11
May	5.64	5.19
June	8.47	4.25
July	2.27	4.39
August	0.65	2.96

Total	28.78	26.47

Table 2. Weight Gain Performance of Stockers by Fertilizer Source.

Fertilizer source^a	No. of stockers	Initial weight, lb.	121-day average daily gain^b, lb.	Total gain, lb.	Ending weight, lb.
BL-2+2	21	518	1.13	137	655
BL-4	21	518	1.15	139	657
CF-30	21	519	1.25	151	671
CF-45	21	519	1.12	136	655

P level	--	.90	.92	.92	.90

^aFertilizer sources: BL-2+2 - 2 tons/acre of broiler litter applied on April 8 and June 23; BL-4 - 4 tons/acre of broiler litter applied on April 8 and 150 lb/acre of ammonium nitrate applied on July 12; CF-30 - 250 lb/acre of 17-17-17 (N-P-K) applied on April 13, May 13, and June 11, and 150 lb/acre of ammonium nitrate applied on July 12; CF-45 - 250 lb/acre of 17-17-17 (N-P-K) applied on April 13, May 28, and July 12.
^bStarting trial date - April 13, 1999; ending trial date - August 12, 1999.

Table 3. Weight Gain Performance of Stockers by Implant Type.

Sex & Implant type	No. of stockers	Initial weight, lb.	121-day avg. daily gain^a, lb.	Total gain, lb.	Ending weight, lb.
Heifer-no implant	8	505	1.07	130	634
Heifer-Revalor^®	14	506	1.12	135	641
Heifer-Synovex-H^®	14	505	1.11	135	640
Steer-Revalor^®	24	540	1.27	154	694
Steer-Synovex-S^®	24	538	1.23	148	687

P level-heifers	--	.99	.91	.91	.97
P level-steers	--	.92	.49	.48	.72

^aStarting trial date - April 13, 1999; ending trial date - August 12, 1999.

Table 4. Economic Comparisons of Stockers by Fertilizer Source.

	Fertilizer Source^a
Item	BL-2+2	BL-4	CF-30	CF-45
	--------Costs and returns per stocker--------
A. Purchase price (@ $.8900/lb), $	461.00	461.00	462.00	462.00
B. Interest on purchase (@ 10% for 5 months), $	19.20	19.20	19.25	19.25
C. Hay costs, $	6.50	6.50	6.50	6.50
D. Fixed costs (corral, fencing, clipping, etc.), $	6.50	6.50	6.50	6.50
E. Labor, vet., minerals, health, etc., $	12.00	12.00	12.00	12.00
F. Pasture & fertilizer costs^b (@ 3.5 head/acre), $	13.69	17.97	27.57	23.29
Total costs (items A-F), $	518.89	523.17	533.82	529.54
Sales value, (@ $.7560/lb), $	495.18	496.69	505.28	495.18
Net returns, $	-23.71	-26.48	-28.54	-34.36

^aSee Table 2 for description of fertilizer sources.
^bFertilizer costs based on the following actual costs: broiler litter - $11.98/ton; ammonium nitrate - $199.75/ton; 17-17-17 (N-P-K) - $231.24/ton.

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