Effects of Dried Distiller’s Grains with Solubles as a Replacement for Soybean Meal and Corn in Diets Fed to Boer-Cross Feeder Kids
Report to: Distillers Grains Technology Council, Louisville, KY
Participants: • Mr. Terry K. Hutchens, Extension Specialist, Goat Management, University of Kentucky Animal & Food Sciences Dept • Mr. Charles Smith, Research Cooperator, Smith’s Boer Goats, Glasgow Kentucky • Dr. Kenneth Andries, Animal Science Specialist, Kentucky State University • Dr. John T. Johns, Extension Animal Nutritionist, University of Kentucky Animal & Food Sciences Dept • Dr. Gregg Rentfrow, Meat Scientist, Animal and Food Sciences, University of Kentucky • Dr. Glen E. Aiken, Research Animal Scientist, USDA-ARS-FAPRU, University of Kentucky
Purpose: The objective of this experiment was to determine the effects of replacing soybean meal (SBM) and whole corn (WC) with dried distiller’s grains with solubles (DDGS) on total weight gain, average daily gain and carcass characteristics on purchased feeder kids. This research evaluated the effects of 0, 10, 15 and 25 percent inclusion rates of DDGS on total gain, average daily gain and costs of gain for feeder kids. This work has determined the appropriate replacement rates of WC and SBM with DDGS in goat rations. Additionally, this research has compared the effects of DDGS on carcass yield, area of the longissimus dorsi muscle and fat cover.
Methods: Purchased Boer-cross and mixed breed feeder kids (n=160) were fed four test diets. The control diet contained 0 percent DDGS and consisted of WC, SBM, soybean hulls (SBH) and Kentucky 31 tall fescue hay (KY-31) and three test diets consisting of DDGS fed at 10, 15 and 25 percent of the total diet. These diets also contained SBM, SBH, and declining quantities of WC. Dietary percentages details are shown in table 1.
The forage component, KY-31 was fed ad-lib and an estimate of forage wastage was made. These four diets were balanced for similar nitrogenous levels expressed as crude protein (CP) and energy levels expressed as total digestible nutrients (TDN) and net energy for maintenance and gain (NEM and NEG) as shown in table 2. All diets in the study exceeded the nutritional needs of growing kids. The nutrient requirements were determined by referencing the Nutrient Requirements of Small Ruminants, National Research Council, 2007. Furthermore, small quantities of cotton seed hulls (CSH) and corn syrup were added to the concentrates to reduce separation and dust. Limestone and a mineral-vitamin premix containing monensin (20 g/T) was added to each of the foud concentrates. All diets were formulated at a local mill specializing in co-product commodity feeds, CPC Commodities, LLC, 98 Celsor Road, Fountain Run, KY. 42133. Nutrient content of the foud concentrates and KY-31 was determined by Dairy One Forage Lab, 730 Warren Road, Ithaca, NY 14850.
Table 1: Percent Inclusion Rates of Diets Formulated with DDGS and Other Feed Components
|Diet||DDGS 0||DDGS 10||DDGS 15||DDGS 25|
|SBM - 48%||9||8||8||0|
DDGS = Dried distillers grains with solubles; SBH = soybean hulls; SBM = soybean meal; WC = whole corn; Min Premix = mineral premix and additional limestone needed in diet.
All goats were fed concentrates at 3 percent of live body weight daily. Goats were fed in elevated feeders maintaining a minimum of 12-inches of feeder space per feeder goat. All treatments had equal access to KY-31 and were provided fed ad-lib from identical hay feeders. Hay was weighted into the hay feeders. Hay waste was determined by collection and weighing refusal for three consecutive days. Hay intake was estimated to be 1.5 percent to 2.0 percent of live body weight. Average live weights were determined as a shrunk weight at day zero or the first weight day and the last weight day of the study. Intermittent weights were taken at 14-day intervals.
Table 2: Analysis of Diets Formulated with Increasing Levels of DDGS
|Diet||% TDN||NeM Mcal/lb||NeG Mcal/lb||% CP||% ADF||% NDF||Ca - g||P - g|
All 160 feeder goats used in the study were purchased from area livestock auctions. All goats received appropriate nutrition and preventative medication for a period of two weeks prior to beginning the dietary treatment allocation of animals. Following the receiving period, the 160 goats were weighted and randomly allocated by weight, sex and grade into four treatment groups. Each treatment was replicated one time and each of the eight groups contained 20 goats per group. Each group was then fed one of four dietary treatments for a warm-up period of two weeks prior to the beginning of the test. A goat found not to be responsive to the warm-up period was eliminated from the study and replaced with a more responsive feeder goat. Goats in each treatment group were weighed again at day zero of the test and remained on feed for a period of 56 day.
All animals in the study were weighted at 14-day intervals for a total of five weightings. The first day, zero, and the last weight day, 56, were shrunk weights. Shrunk weight data will be used to adjust all weights. Feed amounts were increased accordingly following each weighing in order to maintain the 3 percent of body weight feeding rate.
Table 3: Weights by Period, Gain and Cost of Gain for Slaughter Kids Fed DDGS
|Diet||Wt 1||Wt 2||Wt 3||Wt 4||Wt 5||Total Gain||ADG||Cost/gain|
n = 160 head, with 20 per pen and 8 pens. Weights are in pounds and taken every 2 weeks starting July 3.
Upon completion of the feeding period, 24 goats -- three per pen or 15 percent of the test group -- were selected from a weight stratified, random sample from each pen. These animals were transported to the University of Kentucky Meats Laboratory, Garrigus Building, Lexington KY for slaughter and carcass evaluation. Following slaughter and evaluation, all carcasses were cut, weighed and frozen.
Preliminary Results: The preliminary results of this feeding trial suggest an advantage to feeding DDGS based diets over the control. The 10-percent DDGS treatment shows a 2.76 pound per head advantage in weight gain over the control. Likewise, the 15-percent and the 25-percent DDGS treatments gained 3.19 and 4.08 pounds more on the average than the control group shown table 3. Average daily gains for the DDGS treatments were 0.35, 0.36 and 0.37 pounds per day, compared to 0.30 lbs per day for the control. Preliminary statistical analysis indicates that an overall difference for treatment on gain is not significant. However, there is a numerical trend that with increase inclusion of DDGS results in a numeral increase in total gain and average daily gain. If more pens and more replication were possible, there would have been a significant difference between the control and the 25-percent inclusion rate (P=0.12).
Table 4: Carcass Yield and Cut Out for Slaughter Kids Fed Increasing Levels of DDGS
|Diet||Live Wt||HCW||CCW||% Yield||Fore||Leg||Loin||Neck||Shank||LEA sq in||Fat mm|
n = 24, 3 head per pen and 8 pens HCW = Hot Carcass Weight, CCW = Cold Carcass Weight, LEA = Loin Area at the 13th rib, Fat depth at the 12th
Statistically non-significant increases in total gain and average daily gain plus a reduction in cost of gain indicates a positive relationship between higher inclusion rates of DDGS and improved productivity.
Table 4 shows the results of a stratified random sample of three taken from each pen for slaughter and carcass evaluation. The samples were stratified by weight resulting in a heavy, medium and light weight male animal representing each pen. The DDGS 10 percent is the lowest yielding treatment having the lowest hot carcass weight (26.83 pounds) and is similar to the DDGS 0-percent treatment (27.35 pounds). The DDGS 15-percent and 25-percent treatments had heavier live (72.17 pounds and 73.92 pounds) and hot carcass weights (32.42 pounds and 32.33 pounds). The best carcass yield was observed on the DDGS 15-percent treatment (44.74 percent) and the lowest was observed in the DDGS 10 percent treatment (41.31%). The DDGS 25% treatment produced the largest loin area at the 13th rib (1.82 in2). The higher DDGS treatments yielded greater cut-out values and higher loin areas and expectable fat deposition.
Overall, this data indicated that DDGS could be incorporated into the diets of feeder kids and may improve growth rates, although the data was not statistically different. The costs of the DDGS to a producer will determine the economics of feeding DDGS as a replacement for soybean meal and corn.