| Effects of Percentage of Boiled Corn on Lactational Performance, NutrientDigestibility, and Contents of Plasma Glucose and Urea Nitrogen ofLactating Cows Four midlactation Holstein cows were used in a 4×4 Latin square design to determine theeffects of the percentage of boiled corn(BC) on lactational performance, nutrient digestibility,and contents of plasma glucose and urea nitrogen in roughage of wheat straw and corn silage.Four treatments were 0/3 boiled corn, 1/3 boiled corn, 2/3 boiled corn and 3/3 boiled cornrespectively. All corn in diets was cracked with mean particle size of1.4mm. Processing cornpercentage was the proportion of processing corn to all corn in diet. DMI, percent of milk fat,protein, lactose, and SNF, and milk density were not affected by treatments. Compared to0/3BC, 1/3BC increased 3.9% of milk yield and 4.0% of FCM yield (P<0.05), and 2/3BC and3/3BC did not affect yield of milk and FCM, 1/3BC, 2/3BC and 3/3BC increased total tractdigestibility of DM, OM, energy and starch, and decreased total tract digestibility of NDF andADF. Compared to 0/3BC, 1/3BC, 2/3BC and 3/3BC did not affect total tract digestibility ofCP (P>0.05), but relative to 1/3BC, 2/3BC decreased 9.4% of total tract digestibility of CP(P<0.05). Compared to 0/3BC, 2/3BC and 3/3BC, 1/3BC decreased the moisture of feces(P<0.05). Relative to 0/3BC, 1/3BC, 2/3BC and 3/3BC decreased 12.1% (P>0.05), 19.2% and21.1% (P<0.05) of plasma glucose concentration, and increased 2.4%(P>.05), 19.3% and17.5% (P<0.05) of urea nitrogen concentration, respectively.Effects of Percentage of Scalded Corn on Lactational Performance ofLactating CowsTwo experiments were conducted to investigate the effects of the percentage of scaldedcorn (SC) on lactational performance of lactating cows. All corn in diets was cracked withmean particle size of 1.4mm. Processing corn percentage was the proportion of processingcorn to all corn in diet. Trial 1: Four midlactation Holstein cows were used in a 4×4 Latinsquare design to determine the effects of the percentage of SC on lactational performance inroughage of wheat straw and corn silage. Four treatments were 0/3 SC, 1/3 SC, 2/3 SC and3/3 SC. The results show that: DMI, percent of milk fat, protein and SNF, and milk densitywere not affected by treatments; compared to 0/3BC 2/3BC increased 6.4% of milk yield(P<0.05)and 7.0% of FCM yield (P>.05), and there are no significant difference of milkyield and FCM yield among 0/3BC, 1/3SC and 3/3SC (P>0.05).　Ｉn trail 2: six midlactationHolstein cows were used in two replicate 3×3 Latin square design to determine the effects ofthe percentage of SC on lactational performance in roughage of green alfalfa and corn silage.Three treatments were 0/4 SC, 1/4 SC and 2/4 SC. The results show that: DMI, percent ofmilk fat, protein and SNF, and milk density were not affected by treatments; compared to0/3BC, 1/4SC did not affect milk and FCM yield (P>0.05), but 2/4SC decreased significantlymilk yield (P<0.01)and did not affect FCM yield (P>.05). In conclusion, the optimalpercentage is 2/3, and 2/3SC increased lactational performance the in roughage of wheatstraw and corn silage, but SC tended to decrease lactational performance in forage of greenalfalfa and corn silage.Effects of Percentage of Socked Corn on Lactational Performance ofLactating Cows Eight midlactation Holstein cows were allotted to 2 groups, and were used in two 4×4Latin square design to determine the effects of boiled corn(BC) and socked corn (SKC) onlactational performance of lactating cows in forage of wheat straw and corn silage and inforage of alfalfa hay and corn silage, respectively. Four treatments were control, 1/3 BC, 1/3SKC and 2/3 SKC. All corn in diets was cracked with mean particle size of 1.4mm.Processing corn percentage was the proportion of processing corn to all corn in diet. In forageof wheat straw and corn silage, compared to the control, 1/3SKC and 2/3SKC did not affectDMI, per...
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