Performance of holstein cows fed wet corn gluten feed or soyhull-Performance of holstein cows fed wet corn gluten feed or soyhull-steep liquor pellets during early lactation steep liquor pellets during early lactation

Wet corn gluten feed and soyhull-steep liquor pellets tended to increase dry matter intake and milk yield. Combining condensed corn steep liquor with raw soybean hulls provides a convenient source of digestible fiber and rumen degradable protein.


Introduction
Complete lact ation milk yield is p ositively related to peak milk yield, which gene rally occurs by 50 to 60 days in milk.Nutrition limits peak milk yield because of inadequate dry matter intake.Body tissue mobilization and ruminal adjustments are made in an attempt to meet nutrient deficits.Therefore, it is imperative during ear ly lactation to provide dietary ingredients that are highly digestible in order t o enhance nutrient availabilit y.A critical issue in diet formulation is balancing fiber content to prevent ruminal acidosis.Short-term studies (28-day period) conducted at Kansas State University with wet corn gluten feed (WCGF) and a pelleted feedstuff made by combining soy hulls and condensed corn steep liquor (SHSL) indicated that these feedstu ffs improve dry matter intake and maintain ruminal pH.The purpose of this study was to evaluate the response of dairy cows to WCGF and SHSL during the first 90 days in milk.

Procedures
Forty-six multiparous Holstein cows were used in a randomized incomplete block design.Cows were blocked on calving date and assigned r ando mly to e ither of three diets: 1) control, 2) wet corn gluten feed at 20% of dry matter; or 3) soy hull-steep liquor pellet at 20% of dry matter.Treatment diets were balanced for previous lactation milk yield, body weight, and bo dy condition score as much as possible.Wet corn gluten feed (WCGF) replaced 10, 5, and 5% of the alfalfa hay, cor n silage, and corn grain in the control diet (DM basis), respectively and soy hull-steep liquor (SHSL) replaced 10, 5, 2 , and 3% o f the alfalfa hay, corn silage, corn grain, and solvent soybean meal in the contro l diet (DM basis) , resp ect ively.Treatment diets were initiated beginning at the first feeding after calving and fed ad libitum twice daily as a total mixed ration.Feed ingredients were collected weekly and composited mont hly for analyses.Individual feed intakes and milk yield were measured daily.Milk samples (am and pm composite) were analyzed weekly for milk composition.Protein, fat, lactose, solids-not-fat, milk urea nitrogen (MUN), and somatic cells were measured by the Heart of America DHI Labor ator y, Manhattan.Cows were weighed within 24 hr after calving and on two consecutive days weekly thereaft er.Bod y conditio n was scor ed w eek ly.

Results and Discussion
The experimental diets and their composition are shown in T able 1. Diet s cont aining WCGF or SHSL provided more neutraldetergent fiber (NDF) than the control diet and SHSL increased the dietary acid-detergent fiber (ADF) relative to the other diets.Cows fed diets containing WCGF or SHSL tended to consume ap proximately 3 to 4 lb more dry matter, respectively, than cows fed the control diet.The increase in dry matter intake tended to increase daily milk yield by approximately 8 to 9 lb for cows fed WCGF or SHSL, respectively, than those fed the control diet.Peak milk yield and days to peak milk yield prior to rbST administration (9 th week of lactation) was 112, 44; 116, 46; 119, 39 for cows fed the contr ol, WCGF, and SHS L die ts, resp ect ively.
Milk from cows fed the control diet contained more (P<0.05)than fat (4%) than cows fed the other diets (3.7%), but fat yield (lb/ day) was similar for all diets due to t he difference in milk vo lume.Milk prot ein percentage was similar but pro tein yield tended to increase with milk volume.Energy corrected milk divided by dry matter intake (ECM/DMI) provides a gross measure of efficiency.During the first 90 days in milk, cows usually have a relatively high ECM/DMI value (>1 .5)beca use the y mobilize fat to support milk pr oduct ion.All cows in our st udy s eeme d to be ver y efficient but efficiencies were not different among diets.Loss in body weight was unaffect ed by diets but cows fed the control diet t ended t o have less condition at the end of the first 9 0 da ys in milk.
In summary, WCGF and SHSL pellets tended to increase dry matter int ake and milk yield.Combining condensed corn steep liquor with raw so ybean hulls p rovides a convenient source of digestible fiber and rumen deg radable prot ein.ECM/DMI 2 2.0 1.9 1.9 0.1 a,b Means within a row not bearing common superscripts differ (P<0.05).

Table 3 . Effects of Diet on Body Weight and Condition 1
Means within a row not bearing common superscripts differ (P=0.08).