Study On The Roughage Feeding Of Different GI And Infusion Of Glucose On The Mammary Gland Metabolic Of Dairy Goats

Roughage was the main nutrient source for ruminant animals, which was important for ruminant, but nutrition indicators vary widely between different varieties of forage. The use of roughage mainly relied on the processing of modulation domestic and abroad, and the existence of the own animal nutrition and combination effects was less consider. Therefore, accurate evaluation method of roughage is of great significance. the ruminant nutrition research growing deeply, the importance of glucose was awareness.when the supply of ruminant animals was inadequate, glucose can cause pregnancy toxemia of sheep so that keeping a stable blood sugar levels was essential to animals.Glucose is the important raw material for synthesis of lactose, and many researchers found that glucose supply can influent the milk production. Milk goat formula was currently silage-based, low-quality roughage was unable maintained a high lactation needs for milk goats.we need study of glucose metabolism in mammary gland and milk composition effects for ruminant animals. Three parts of this experiment are:Trial 1: To study the effect of different GI of roughage on blood biochemical indicators and milk performance of the dairy goat. Forty Guanzhong dairy goats with a similar body weight and milk yield were used, divided into five groups, fed basal diet and four different GI roughage,ⅠGroup Chloris,Ⅱgroup of corn stalks,Ⅲgroup of hay,Ⅳgroup of alfalfa. The results showed that: With the GI index of roughage increased, precursors of mammary gland metabolic--plasma acetic acid, propionic acid concentrations were significantly higher (P<0.01), butyric acid concentration only in groupⅢandⅣgroup increased significantly (P<0.05); the total amino acid content in plasma ofⅠ~Ⅳgroup were respectively increased by 1.5%, 2.4%, 3.6% and 4.4%; the cholesterol, triglycerides and total protein content tended to increase but the change was not significant (P> 0.05). Fat content ofⅠ~Ⅳgroup were respectively increased by 1.5%, 2.7%, 3.3%, 5.1%, of which groupⅣwas significantly higher (P <0.05); the milk protein content ofⅠ~Ⅳgroup were increased by 4.6 %, 5.6%, 6.3%, 9.3%; milk yieldⅠ~Ⅳgroup were increased by 4%, 5.3%, 6.6%, 9.3%, of which groupⅣwas significantly higher (P <0.01); lactose and non - fat solids content did not change significantly (P>0.05). The intake of dry matter gradually increased, theⅡ~Ⅳtreatment group were significantly higher (P <0.01). With the GI of dietary roughage increasing, the level of mammary gland metabolic,the volatile fatty acids,total amino acids in the plasma,the milk fat content and milk protein content of the dairy goat increase, The GI index can effectively and accurately assess the quality of the roughage . Trial 2: To study the effect of different GI of roughage roughage combination on the dairy goat blood biochemical indicators and milk performance. Forty Guanzhong dairy goats with a similar body weight and milk yield were used, divided into four groups, fed four different GI roughage roughage,Ⅰg roup hay +corn stalks ,Ⅱg roup of hay+Chloris,Ⅲgroup of alfalfa+corn stalks,Ⅳgroup of alfalfa+Chloris. The results showed that: After mixing roughage,GI arranged in descending order:Ⅳgroup﹥Ⅲgroup﹥Ⅱg roup﹥Ⅰgroup. NDF from the superior to inferior order ofⅣgroup﹥Ⅰgroup﹥Ⅱgroup﹥Ⅲgroup.Ⅳtreatment group dry matter intake and milk yield, milk protein content were significantly higher than the other groups(P<0.05). Milk protein content of the order ofⅣg roup >Ⅰg roup>Ⅱg roup>Ⅲgroup, its sort in line with the NDF sort. GroupⅣacid were significantly higher than the other treatment groups (P<0.01), acetic acid were significantly higher than the other treatment groups (P<0.05). Total plasma amino acid sequence of the;Ⅳgroup>Ⅲgroup>Ⅱgroup>Ⅰgroup, with a mixture of the same order of GI values. Plasma biochemical indicators of measurements, glucose levelsⅣtreatment group was significantly higher than other groups (P<0.05).Trial 3: The paper described effects of perfusing glucose into external pudic artery on nutrient uptake by mammary gland and milk components of lactating goats. Four Guanzhong dairy goats were catheterized at external pudic artery and vein. 4×4 Latin square design was utilized. Glucose was perfused for total of 0 g, 12 g, 24g and 36g per day respectively. The results showed:The butterfat rate significantly decreased with the increase of the glucose perfused(P<0.01). The butterfat yield of high-dose glucose perfused for 36g/d treatment group was significantly decreased than other treatment groups (P<0.01); The lactose yields of 36g/d treatment group was significantly raised than Control group (P<0.01). The group perfused glucose increased milk yield of dairy goats (P<0.01), the milk yield of 24g / d treatment group was significantly raised than control group (P<0.01); Mammary uptake of glucose of 36g/d treatment group was significantly raised than Control group (P<0.01). The content of non-fat solids and triglycerides were not significantly between the groups. (P>0.05). The group perfused glucose increased milk protein yield, the yield of milk protein of 24g/d treatment group was higher than the control group (P<0.05 ). Perfusing glucose significantly reduced dry matter intake of dairy goats (P<0.01). Uptake of amino acids mammary gland were changed insignificantly (P>0.05).In the group perfused glucose, milk protein synthesis from amino acid increased by 1~ 9%, lactose synthesis raised by 0~5 %percent, and the milk composition was improved.