Adverse winter weather can trim away pounds and dollars from feedlot profits. For every animal that dies as a direct result of adverse climatic effects, the overall economic loss to a feedyard is about $4,000. This includes the dead animal, plus the loss of performance of those that survive. If one looks at differences in weather patterns between winters in which cattle do not perform well versus winters in which performance is average or above there may not be a lot that stands out. Bad winters are not always those that have below normal temperatures since this is rarely a problem if it is dry with little precipitation or snow accumulation. Weather conditions that contribute to poor performing cattle in the winter are related to the same patterns that contribute to poor performing cattle in the summer. Wet and/or humid conditions can contribute significantly to heat and cold stress.

Late autumn and early winter snowstorms and/or rain often contribute to difficult feeding conditions for cattle managed in open lots due to shorter days and slow drying conditions. If slow drying conditions persist and additional moisture accumulates, poor feeding conditions will be prevalent into the months of April and May. Other conditions impacting cattle performance in the winter are above normal wind speeds and below normal soil temperatures. Both of these conditions challenge the ability of the animal to buffer the environment through the natural insulatory properties associated with hair coat and body condition.

Economic and physical limitations make it unrealistic to completely control the environment; however, cost-effective methods can be employed to help cattle adapt to conditions. In general, extreme conditions are not as stressful on cattle as are abrupt changes in conditions for which the cattle have not had adequate time to adapt. Generally, it takes two to three weeks for cattle to adapt to a 10 degree change in temperature. Clearly, dramatic drops in autumn and winter temperatures accompanied by wet conditions are extremely stressful.

Bedding and Pen Space
More producers use bedding in the Cornbelt than in the Southern and High Plains regions. However, very few cattle feeding regions are immune from early wet snowstorms, which can significantly impact cattle performance and survivability. Around 2-2.5 lb of bedding per head per day can account for major improvements in gain and feed efficiency. A summary of Colorado and South Dakota data found that under general feeding conditions, gains and feed efficiencies can be improved nearly 7% through the use of bedding (Table 1). Interestingly, the more significant responses came during the later versus early portion of the feeding period. This is likely due to problems heavier cattle often experience with wet, muddy condition, which accompany late winter and early spring precipitation events. Lighter cattle, once they are on feed, are generally not impacted as much.
 

Table 1  Effect of Adding Bedding (wheat straw) to Feedlot Pen Surfaces During Winter and Springa
	No bedding	Bedding
ADG, lb
d 0 to 67	3.00	3.11
d 68 to 172b	3.00	3.29
d 0 to 172b	3.00	3.22
Daily DMI, lb
d 0 to 67	14.84	14.62
d 68 to 172	20.62	21.06
d 0 to 172	18.37	18.54
Feed:gainc
d 0 to 67	4.95	4.70
d 68 to 172b	6.90	6.44
d 0 to 172b	6.14	5.77
aPooled analysis studies conducted in Colorado & South Dakota.       Approximate harvest dates for cattle were middle to late May. bTreatment means are statistically different (P < 0.05). a,bTreatment means are statistically different (P < 0.05) c,dTreatment means are statistically different (P < 0.10).

In more recent studies conducted in North Dakota, net return per head averaged $60 to $80 per head for bedded cattle over unbedded cattle. However, other recent studies conducted in Nebraska (Table 2) found that if ample pen space in available the benefits from bedding are not observed and that doubling normal pen space in the winter, minimizes the adverse effects of mud and/or wet conditions. In the bedding study, bedding was applied at 2 to 2.5 lb/head/day for 65 out of the 110 day feeding period. In general, bedding is not required every day. Conditions which merit bedding application are when outside temperatures drop below 15 degrees, precipitation exceeds 0.1 inch/day (i.e. if 0.4 inches of precipitation was received in one day cattle were bedded four days in a row), and/or when pen surfaces begin getting wet during spring thaw.

 

Table 2 Bedding and Pen Space Effects Evaluated Over Two 110-day Winter Feeding Trials*
	Trial 1	Trial 2
Bedding – 2 lb/day	~65 days           none	none              none
Pen space – ft2/hd	500                  500	500                 250
ADG, lb	3.86                 3.85	3.93a              3.65b
Daily DMI, lb	22.19              22.40	22.46              22.12
Feed:gain	5.76                 5.85	5.72c            6.08d
*Trials were conducted simultaneously using similar types of cattle for each trial.

Most feedlots do not have the luxury of doubling pen space, nor is there a big desire on the part of feedlot managers to bed cattle. Nevertheless, at the very least, pens holding sick cattle are candidates for bedding. Feedlot managers must maintain the bedding. When bedding is used, wet residues must be removed from pens periodically. Place bedding in the pen after feeding, not before. Also, during the winter, give cattle as much dry area as possible to allow animals to spread out and lay down. The more animals are concentrated under wet conditions, the less the chance for pen surfaces to dry, which will increase cattle’s maintenance energy requirements. Winter maintenance requirements can be easily more than 50% greater for wet versus dry cattle. In addition to being wet, one of the greatest hindrances to cattle performing in non-summer months is mud. On cattle, mud decreases the ability of the hair coat to provide insulation. Muddy pens can easily double cattle’s maintenance requirements and feed conversions, while cutting gains by half or more. Good lot drainage is critical to minimizing mud. To facilitate drainage, maintain a 3% to 5% slope in the pen (away from feed-bunks) and a center-mounded surface, flanked by valleys for optimum drainage.

Windbreaks and Shelters
On average, cattle fed in the winter with wind protection have better performance than cattle without protection with comparable feed intakes. Volumes of data show cold stress will stimulate intake; however, with less daylight in the winter and cold conditions not being as conducive to cattle aggressively accessing the bunk, feed intake does not always increase. Thus, feed efficiency is often compromised. Under these conditions, windbreaks have been found to be useful, especially for heavyweight cattle. It is important to design windbreaks to keep snow out of the feedlot and to protect the bunk. When bunks aren’t protected from wind, cattle will stay behind the windbreak. When the wind dies down, cattle will usually charge the bunk, setting up a scenario for metabolic problems to occur. Wind protection needs to be far enough back or north of the bunk-line to prevent snow from dumping into the pen. Snow itself is not all bad if frozen or rough, dry, surfaces exist, because it fills in crevices, cracks, and hoof-prints. However, when snow is excessive, it will create muddier conditions upon melting.

New cattle coming into the feedlot and cattle 30 to 45 days from slaughter are most susceptible to cold stress. They need shelter and/or bedding to maintain health and stay on feed. When a snowstorm hits, a higher roughage diet can be fed to minimize overeating provided ration changes aren’t made too aggressively. Maintaining a stable rumen environment facilitates feedlot cattle health. While there is more heat in roughage per unit of digestible energy, there is more heat in grain when measured per unit of weight.

Confined Structures
Recent interest has been shown in solid–floor confinement feedlot units, in which bedding is applied year-round in pens on a weekly basis. These units can cost 50% to 100% more than traditional outside feedlot units and have shown promise for controlling the total amount of waste that has to be managed and for greater control of environmental factors. These units appear to have the greatest benefit in areas of the corn-belt and northern plains where surface drainage is poor, soil and winter drying conditions enhance mud build-up, and added waste water generated from normal precipitation constitutes a disposal problem.

Conclusion In today's cattle feeding environment, it is becoming increasingly important that feedlot managers maintain optimum cattle comfort not only for optimizing efficiency but also for enhancing consumer confidence and acceptance. Keeping cattle dry, clean, and comfortable is critical for accomplishing this goal, whether in open-lots or in more confined structures.