| 作者单位 |
1. Xinjiang Academy of Animal Science, Urumqi 830052, China; 2. Xinjiang Agricultural University, Urumqi 830052, China; 3. Southwest University, Chongqing 402460, China; 4. Key Laboratory of Animal Nutrition and Feed, Ili Kazakh Autonomous Prefecture, Yining 839300, China |
| 摘要 |
[Objective] The paper was to investigate the effects of substituting corn pellets with potato residue on the growth performance, rumen fermentation indicators and economic benefits of Xinjiang Brown cattle. [Method] A total of 80 Xinjiang Brown cattle, each 22 months old and with a similar body weight of (250±15) kg, were randomly assigned to four groups, with 20 cattle in each group, utilizing a single-factor experimental design. The total mixed diets for the experimental groups I, II, and III were formulated by substituting corn pellets with 2.00%, 4.00%, and 6.00% potato residue, respectively, while the diet in the control group was not substituted with potato residue. The duration of the test was 100 d, which comprised a pre-test period of 10 d and a formal test period of 90 d. During the test period, the average dry matter intake, average daily weight gain and feed-gain ratio were assessed at 30-day intervals, and body size indicators were measured on days 0 and 90. Rumen fluid samples were collected from the oral cavity on days 0, 30, 60, and 90 to assess rumen fermentation parameters. Additionally, jugular blood samples were obtained during the fasting period, and serum was separated for the analysis of total protein mass concentration, urea nitrogen, and glucose concentration. Furthermore, the economic benefits accrued during the test period were calculated. [Result] The dry matter intake in experimental group I was significantly higher than that in the control group from days 31 to 60 (P<0.05). In contrast, the differences in dry matter intake between experimental groups II and III and the control group were not statistically significant (P>0.05). From days 61 to 90, the dry matter intake in experimental group I remained significantly higher than that in the other groups (P<0.05). Throughout the entire experimental period, the average daily weight gain observed in experimental group I was significantly greater than that recorded in the other groups (P<0.05). Additionally, the total weight gain over the entire period was significantly higher than that of experimental group II (P<0.05) and markedly higher than that of both the control group and experimental group III (P<0.01). The feed-gain ratio in experimental group I was significantly lower than that in experimental group III (P<0.05). There were no statistically significant differences observed in body height, slope length, thoracic circumference, abdominal circumference, rumen pH, acetic acid, propionic acid, butyric acid, valeric acid, total volatile fatty acids, and ammoniacal nitrogen mass concentration among the groups (P>0.05). On the 90th day of the experiment, the serum urea nitrogen concentration in beef cattle from experimental groups I and II was significantly lower than that in the control group and experimental group III (P<0.05). Additionally, the profit margins in experimental groups I, II, and III were higher than those in the control group, and the profit margin in experimental group I was the highest. [Conclusion] The substitution of corn pellets with potato residue has the potential to enhance the average daily weight gain and total weight gain throughout the entire period in beef cattle, while simultaneously reducing the feed-gain ratio. However, this substitution does not appear to have a significant impact on body size indicators, rumen fermentation parameters, or the concentrations of serum total protein and glucose in beef cattle. Furthermore, this approach may yield improved breeding profitability, with a recommended substitution ratio of 2.00% based on the conditions of this experiment. |
