| Forages and protein-feeds have always been an extremely important source of nutrients in ruminant rations. Additionally, Forages provide fiber in the ration which enhances proper digestion and milk precursors for milk fat in ruminants. Protein-feeds are the basic nutrients in life. However, it is this diversity which presents both opportunities and challenges when attempting to exploit these feeds in ruminant diets. Within the china, the main forage source is corn straw, the main protein-feeds source are miscellaneous meal. Unfortunately, corn straw and miscellaneous meals are not wide-spread use in ruminant diets as the low nutritional value and the lack of basic and systemic research. In recent years, modern dairy farmers altered forage with alfalfa hay, corn silage, chinese wildrye hay and soya bean meal, they use few corn straw and miscellaneous meals. It is therefore important to do the research of locally available corn straw and miscellaneous meals feed resources so as to ascertain wide-spread use of corn straw and miscellaneous meals.The first part was mainly conducted to study the effects of forages and protein-feeds on feeding behavior in dairy cows. Fourty-eight primiparous Holstein cows were divided into3groups fed ad libitum a TMR containing either17.30%alfalfa hay and18.77%corn silage (MF) or36.07%corn straw (CSA) or miscellaneous meals replacement with soya bean meal of CSA (CSB). The experiment period was15week with2week adaptation. Feeding behavior was monitored continuously using a computerized monitoring system during the experimental period. Rumination, drinking and stand behavior of cows fed the3TMR were monitored24h for3d during84-87d. The results showed that meals per day was higher in MFgroup than CSA group and CSB group (P<0.01). CSB group increased total visiting time per day than MF group and CSA group (P<0.05). Meals duration, consumption rate and rumination duration were lower in MF group than CSA group and CSB group (P<0.05). In conclusion, forages and protein-feeds affect dairy cows’ feeding behavior.The second part was mainly conducted to determine the effects of forages and protein-feeds on milk compositon in dairy cows. Dites and cows were similar with the first part. There is another study was to determine the effect of CSA group and CSB group both replacement with MF diet on milk composition in dairy cows. The results of first study showed that higher DMI was observed in MF group than CSA group and CSB group (P<0.01), CSB group significantly increased DMI than CSA (P<0.01). MF group significantly increased milk yield and milk protein content of MF group compared with CSA group and CSB group (P<0.01), there is no significant effect between CSA group and CSB group (P>0.05). Higher milk lactose content for MF group than CSB group (P<0.05), whereas there was similar between CSA group and CSB group (P>0.05). Forages and protein-feeds didn’t affect milk fat content (P>0.05). The results of second study showed that there were no effect on DMI, milk yield, milk protein content and nilk lactose content (P>0.05), whereas MF group increased milk fat content than CSA group and CSB group (P<0.05). In conclusion, forages affect milk protein synthesis not milk fat synthesis. Protein-feeds didn’t affect milk protein and milk fat synthesis.The third part was mainly conducted to study the effects of forages and protein-feeds on health condition of dairy cows. Dites, cows and experimental design were similar with the second part. The results showed that forages and Protein-feeds didn’t affect milk SCC, udder linear traits and hoof health of dairy cows. Forages may affect rumen health, devolepment of mammary acinus and reproduction of dairy cows.In conclusion, Forages affect feeding behavior, milk protein synthesis and may affect rumen health and devolepment of mammary acinus of dairy cows. Protein-feeds affect feeding behavior of dairy cows. Milk fat synthesis was not alerted by forages and protein-feeds. |
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