Push performance at night

If the heat generated by digestion could keep cattle from expending energy to increase their resting-heat rate when temperatures drop, the notion is that cattle performance could increase. So far, a two-year study at the University of Manitoba (UM) is lending credence to the possibility. In the study, 500 crossbred cattle were fed at three locations in two provinces across two winters. The cattle

If the heat generated by digestion could keep cattle from expending energy to increase their resting-heat rate when temperatures drop, the notion is that cattle performance could increase.

So far, a two-year study at the University of Manitoba (UM) is lending credence to the possibility.

In the study, 500 crossbred cattle were fed at three locations in two provinces across two winters. The cattle fed after 8 p.m. yielded 9-28% more gain and as much as 6% more feed efficiency compared to peers fed during the day.

According to researchers, it takes weeks for an animal to elevate its resting-heat production, and weeks, whether cold or not, for it to subside at the end of winter. That means that energy that could go for performance is used to acclimate resting heat.

“By feeding at night we wanted to make feed available to the animal during the coldest part of the day,” says Alma Kennedy, UM researcher. Suspecting the usual overnight dip in body temperature might direct the body to acclimate resting-heat production, she explains researchers hoped that nighttime feeding would prevent the dip in body temperature and prevent energy from being used to elevate resting-heat production.

“We achieved a proof of concept that winter night feeding can produce positive responses in cattle,” Kennedy says. “Further study with larger groups of animals will be needed to determine exact benefits and how to produce consistent results, but it's clear the winter night feeding has some real potential.”

Wes Ishmael, BEEF Stocker Trends Newsletter

Alfalfa hay levels may be decreased when wet corn gluten feed (WCGF) is added to steam-flaked corn (SFC) diets as 25% or more of the dietary dry matter in cattle finishing diets. Researchers at the department of animal sciences, Kansas State University, working with the Minnesota Corn Processors, Marshall, used one finishing trial and one digestibility trial to evaluate WCGF and alfalfa hay (AH) combinations in SFC finishing diets.

In Exp. 1, crossbred heifers were fed SFC-based diets containing combinations of WCGF at 25%, 35% or 45% of diet dry matter (DM) and AH (2% or 6% of dietary DM). No interactions existed between WCGF and AH for heifer performance.

Increasing dietary WCGF decreased gain efficiency, dietary NEg concentration and 12th-rib fat thickness. Cattle fed 35% WCGF had the lowest occurrence of abscessed livers.

In Exp. 2, ruminally cannulated Jersey steers were fed SFC-based diets containing combinations of WCGF (25% or 45% of diet DM) and AH (0%, 2%, or 6% of diet DM). Starch intake was lower, but NDF intake was greater as AH and WCGF increased in the diet. Ruminal pH was increased by AH and tended to increase with WCGF.

Feeding 2% AH led to the greatest ruminal NH3 but the lowest total VFA and propionate. Adding AH to diets containing 25% WCGF increased acetate to a greater extent than adding it to diets containing 45% WCGF. Feeding 45% WCGF tended to increase passage rate and decrease total tract digestibility but increase in situ degradation of DM from AH and WCGF.

J. Anim. Sci., Dec 2003. 81:3121-3129

Two trials were conducted to determine the effect of corn processing method on performance and carcass traits in steers fed finishing diets containing WCGF. Research by University of Nebraska scientists working with Cargill Corn Milling, Blair, NE, indicated that WCGF contained approximately 25.3% more energy when fed with SFC than when fed with dry-rolled corn (DRC). In general, more intensively processing corn improved gain:feed in finishing diets containing WCGF.

All treatment groups made up of steer calves receiving WCGF consumed more dry matter feed than steers fed DRC or SFC without WCGF. Steers fed SFC + WCGF gained 8% faster, and steers fed DRC 9.5% slower than steers receiving all other treatments.

Daily gains did not differ among other treatment groups. Steers fed SFC or SFC + WCGF gained 10% more efficiently than all other treatment groups.

J. Anim. Sci., Dec 2003. 81:3121-3129

Iowa Beef Cow Business Records show that the major factor separating high- and low-profit cow-calf producers is the cost of feeding stored feeds over the winter. To reduce these costs, winter grazing systems using corn crop residues and/or stockpiled grass-legume forages have been developed and evaluated for pregnant mature beef cows.

However, heifers have additional requirements for body growth, and they don't intake as much as mature cows. As a result, heifers require a diet with higher concentrations of nutrients, especially in late gestation when nutritional values in stockpile forages may be reduced.

Researchers at Iowa State University evaluated the effects of stocking rate and corn gluten feed (CGF) supplementation on the performance and forage intake of pregnant heifers grazing stockpiled tall fescue-red clover pastures.

Two, 30-acre fields were seeded with “Fawn” endophyte-free, tall fescue and red clover in 2000. In 2001 (year 1) and 2002 (year 2), forage was harvested as hay in two cuttings and stockpiled for winter grazing beginning in early August. Each field was divided in four pastures of 6.25 or 8.75 acres subdivided into eight paddocks. Twenty-four heifers in mid-gestation were allotted to the eight pastures to strip-graze stockpiled forage and eight similar heifers were placed in a dry lot to be fed hay.

CGF was supplemented to heifers in pastures at each stocking rate and in the dry lot to meet the target weight gain levels for pregnancy and growth while heifers in the remaining pastures were supplemented at levels to meet the target weight gains for pregnancy only.

Average daily gains and body condition score increases for heifer grazing stockpiled forages were greater than those in the dry lot, even though the heifers grazing stockpiled forages required 49% and 90% less CGF at the high and low stocking rate in year 1, and required no corn supplementation while heifers in the dry lot required 1.8 lbs./day in year 2.

Researchers found heifers grazing stockpiled forage had greater body weight gains with less CGF supplements than heifers fed hay in dry lots. As a result, costs for heifers grazing stockpiled forages were 23% to 48% less than heifers in the dry lot.

Also, because pasture forage utilization was less than designed and the body weight gains for heifers grazing at the high-stocking rate were only slightly lower than those grazing at the low stocking rate, which reduced grazing costs even more.

Iowa State University Animal Industry Report 2004, A.S. Leaflet R1879

Increasing the backgrounding period decreases the time and total concentrate requirements in the feedlot, but may decrease quality grade, say University of California-Davis researchers.

Researchers studied the effects of different grazing and feeding periods on performance and carcass traits of beef steers. Over three consecutive years, fall-born steer calves were weaned in May and divided into three groups:

  • calf-fed steers that entered the feedlot at weaning;

  • short yearlings that grazed irrigated pasture for another four months and entered the feedlot in September; and

  • long yearlings that grazed with short yearlings during the summer, remained on annual California foothills range through the fall, winter and spring, and entered the feedlot the following May.

All steers were fed until the average group backfat, determined by ultrasound, reached 11-12 mm. On pasture, short- and long-yearling steers gained weight in the summer. Long yearlings slightly lost weight in the fall and winter then gained weight the following spring.

Average days in the feedlot were 188, 158 and 94 for calves, short yearlings and long yearlings, respectively. Feedlot dry matter intake increased with age and weight at feedlot entry, with no difference among groups in gaid:feed ratio.

There was no gain of backfat while the animals were on pasture, even when they were gaining weight. This increased rapidly when animals were placed on a high-energy diet.

Final body weights were heaviest on the long yearlings, followed by short yearlings and then calves. Moreover, total carcass fat contents and percentage of Choice or above were all lower in cattle that were older at feedlot entry. Prolonged grazing may decrease quality grade by impairing the animal's ability to deposit intramuscular (IM) fat or by decreasing the time during which dietary energy supply is adequate for IM fat deposition to occur.

J. Anim. Sci., Feb. 2004. 82:292-297