Effects Of Total Mixed Ration Technique On Production Performance And Some Blood Biochemical Indexes Of Dairy Cows

This study investigated the effect of TMR (Total Mixed Ration) feeding system on the production performance and some blood biochemical indexes of dairy cows by comparing with traditional feeding system in the city of Wuhan. Some metabolic mechanisms have also been studied.The main experiments and results are as follows:1. The effect of TMR feeding system on the production performance of dairy cows.48 healthy Holstein cows from 3 dairy farms which had similar body weight and similar age were sampled and the DHI data of them were analyzed. These 48 cows constituted 3 groups automatically, each in equal number: TMR group (Ba Yi dairy farm 2003), control Ⅰ (Wu Chang dairy farm), and control Ⅱ (Ba Yi dairy farm 2002). Namely, Production performance data of these dairy cows in their standard lactation (10 milking months) were collected and analyzed.For the study of production performance changing tendency of the whole herd, all of the studied cows were divided into 3 sub herds according to their lactation stage, i.e. early stage (0-50 days), middle stage (51-200 days), and later stage (after 200 days).The results showed that: the TMR group (25.33kg/d) produced 13.75% more milk than that of control Ⅰ (22.30kg/d) (p<0.05), but 1.69% less than that of control Ⅱ (25.76kg/d) (p>0.05) in the standard lactation period. When 4% fat corrected milk yield being compared, TMR group (26.85±7.11 kg/d) produced 19.85% more milk than that of control Ⅰ (22.41 ±7.08kg/d) (p<0.01)and 7.28% more than that of control Ⅱ (25.03 ± 9.02kg/d) (p<0.05).Production performance changing tendency of the whole herd: The average milk production in the year was 9.49% higher in TMR group than that of control Ⅰ , 1.72% higher than that of control Ⅱ. It has a higher milk production persistency in TMR system when reached peak milk production after fifty days lactation. This study also found that TMR system could improved the dairy cow milk production in the summer.Cows on TMR had higher milk fat percentage than cows on traditional feeding system. The average milk fat percentage of TMR group was 4.5% and it was 15.38% higher than that of control I (3.9%) (p<0.01), 14.77% higher than that of control II(3.92%) (p<0.01) in the standard lactation. The average milk fat percentage in the year was 9.27% higher than that of control 1,14.08% higher than that of control II.It had the same diversification of milk protein percentage in the standard lactation. But it had no difference in each group (p>0.05). The average milk protein percentage of TMR group, control I and control II were 2.90±0.18, 2.86±0.17, 2.90±0.15. There were also had no difference on the whole herd (p>0.05).The milk SCC of cows on TMR was significant lower than that traditional feeding system (p<0.01) in the whole lactation period and, so did in the whole herd.2. The effect of TMR on dairy cows' rumen fermentation and some blood indexes.70 healthy Holstein dairy cows which had resemble body weight, age, parity from Ba Yi and Wu Chang dairy farm were selected in this trail. They had been divided into TMR group and control group. In each treat the dairy cows were divided into four groups, high milk producing cows, middle milk producing cows, lower milk producing cows, under the milk production at random. Ba "Yi dairy farm was using TMR system, and Wu Chang was using traditional feed system.The results of this study showed that: the rumen pH of high producing cows, middle producing cows and lower producing cows on TMR was significant lower than that of control(p>0.05), while the rumen pH of dry cows on TMR was higher than that of control. The value for each group in different treatment was (5.83±0.23, 6.05±0.21); (5.86±0.17,6.08+0.16); (5.95±0.17, 6.18±0.27); (6.69±0.78,6.29±0.34).There was a significant difference on blood glucose, blood fat and blood Ca2+ among treatments (p<0.01). BUN and blood organic phosphorus of dairy cows did not differ among the treatments. Mean value of BUN, blood glucose, blood fat on TMR treatment were 11.81+3.26 mg/dl, 38.89+10.11 mg/dl, 700.52+193.79 mg/dl, all of them lower than that of control. Blood Ca2+ and blood organic phosphorus were higher in the TMR treatment compare with control. The mean value of them were 2.41+0.31 mmol/L, 3.16 ±0.51 mmol/L.