EVALUATION OF WHOLE COTTONSEED AS EFFECTIVE FIBER SOURCE IN EARLY LACTATING HOLSTEIN COWS
Morteza Salehpour, Hamid Amanlou
Twelve Holstein cows in early lactation were used in balanced changeover design to evaluate the effect of replacing alfalfa Neutral Detergent Fiber (NDF) with NDF from whole cottonseed at different levels (0,7,14,20 %) on dry matter basis. The diets were similar as crude protein and neutral detergent fiber on dry basis. Cows were fed with total mixed ration individually. Dry matter intake and milk yields were higher for cows fed with high whole cottonseed (14.20%) diets than for the alfalfa control diet. High whole cottonseed diet had best efficiency. Milk fat percentage and milk fat yield were highest for high whole cottonseed diets, but no significant difference were found among the another milk composition compounds (protein, lactose and SNF). Milk component yields were significantly different (p<0.05). Rumen pH and fecal pH were not significantly affected by experimental diets. Chewing activity increased linearly when whole cottonseed percentage increased. High percentage of whole cottonseed percentage was associated with increased physically effective fiber. Digestibility results were indicated that control diet and 7 % whole cottonseed diets had highest dry matter digestibility (p<0.05), while organic matter, crude protein and NDF digestibility were not significantly affected among diets. Daily weight gain and body condition score change were affected by diets. Thus, the14 and 20 % whole cottonseed diets produced the highest daily weight gain and body condition score (p<0.05). Plasma urea nitrogen was higher for 14 and 20 % whole cottonseed in diets.
Key words: Early lactation, Holstein cows, Whole cottonseed, Alfalfa hay, Effective NDF, Chewing activity