K-State Research and Extension

Objective: The objective of this study was to evaluate the impact of limit feeding in conjunction with shade allotment on animal performance, animal comfort, and water usage during periods of heat stress.

Study Description: During the summers of 2021 and 2022, 852 heifers were assigned to one of four treatments: limit-fed high-energy ration or high-roughage ration fed for ad libitum intake with or without access to shade. Growth performance and water usage were measured during a 90-day growing period. Calves were fed a gut equilibration diet for 7 days to account for gut fill.

Effects of diet type and shade on growth performance, feed efficiency, and water usage
	Treatment
	No shade		Shade			P-value
Item,	451	601	451	601	SEM2	Diet	Shade	D × S
Number of pens	20	20	20	20
Number of animals	214	213	215	210
Body weight, lb
Day 0	551	551	548	549	3.0	0.90	0.22	0.76
Day 90	784	772	801	787	6.2	<0.01	<0.01	0.80
Day 97	785	799	802	811	6.3	<0.01	<0.01	0.58
Average daily gain, lb/day	2.25	2.39	2.44	2.53	0.056	<0.01	<0.01	0.47
Dry matter intake, lb/day	20.14	14.84	21.45	14.92	0.27	<0.01	<0.01	<0.01
Feed-to-gain, lb/lb	9.04	6.37	8.82	6.09	0.157	<0.01	0.03	0.76
Water usage,3 gal/day	11.9	10.8	10.6	9.8	0.28	<0.01	<0.01	0.13
145 = High-roughage diet fed for ad libitum intake; 60 = High-energy limit-fed diet. 2Standard error of the mean. 3Analysis of year 1 data only.

  The Bottom Line: Limit feeding a high-energy ration at 2.2% of body weight daily on a dry matter basis in combination with shade can improve animal efficiency, reduce water consumption, and improve animal comfort during periods of heat stress.

The full research report is available. DeBord, Z. L.; Duncan, Z. M.; Pflughoeft, M. G.; Suhr, K. J.; Ellis, W. C.; Hollenbeck, W. R.; Montgomery, S. P.; Spore, T. J.; Titgemeyer, E. C.; Blasi, D. A.; and Tarpoff, A. J. (2023) “Effects of Limit Feeding and Shade Allocation on Growing Calf Performance, Water Usage, and Animal Comfort,” Kansas Agricultural Experiment Station Research Reports: Vol. 9: Iss. 1. https://doi.org/10.4148/2378-5977.8413