Rodríguez-Cordero Daniel, Carrillo-Muro Octavio, Hernández-Briano Pedro, Correa-Aguado Paola Isaira, Rivera-Villegas Alejandro, Barreras Alberto, Lazalde-Cruz Rosalba, Zinn Richard A, Plascencia Alejandro
Unidad Académica de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Zacatecas, General Enrique Estrada 98500, Mexico.
Instituto de Investigaciones en Ciencias Veterinarias, Universidad Autónoma de Baja California, Mexicali 21100, Mexico.
Animals (Basel). 2025 Apr 18;15(8):1170. doi: 10.3390/ani15081170.
Fifty high-risk bull calves were used in a completely randomized design (ten calves/treatment) to evaluate the optimal period of calcium propionate (CaPr) supplementation following arrival into the feedlot. The variables evaluated were the growth performance, dietary energetics, body fat reserves, serum metabolites, and economic return at day 56 of arrival. Calves, which were weighed at the moment of reception (156.2 ± 1.57 kg off-truck body weight, BW), were received with a 50:50 forage-to-concentrate ratio diet and clean water. At 12 h from reception, they were housed in individual pens during a 56 d feeding period and assigned to treatments consisting of a daily supplementation of a commercial product (Propical Dresen Química, SAPI de CV., Mexico City, Mexico) that provided 19 g CaPr/calf for 0, 14, 28, 42, or 56 d following arrival into the feedlot. Compared with the other treatments, the calves receiving CaPr during the initial 42 d had a greater average daily weight gain ( ≤ 0.035) without affecting the dry matter intake ( ≥ 0.24). Thus, the gain efficiency ( ≤ 0.050) and dietary energy utilization were improved ( ≤ 0.046). Rib fat thickness ( ≥ 0.090) and muscle area ( ≥ 0.112) were not affected by the CaPr supplementation, whereas calves showed the greatest values ( ≤ 0.038) to the rump back fat thickness at 42 and 56 days of CaPr supplementation. With the exception of the total albumin (being maximal at day 56 ( ≤ 0.024)) and total cholesterol (which, compared to the controls, was maximal at 28 and 42 d; = 0.030), the serum metabolic profiles were not affected by the treatments. Using the profit estimated for the control group as a baseline, supplementing CaPr for 42 d yielded a greater net income (USD 34.84 more/calf). CaPr supplementation for more or less than 42 d showed a very similar profit (~USD 6.80/calf). Because the cost of gain was very similar for these treatments and the controls (USD 1.42 vs. 1.46/kg), the positive difference in profit was mediated mainly by an increase in income selling (+USD 13.02/calf) for the CaPr calves. Based on the performance, serum metabolites, and profit, it is concluded that the optimal duration of supplemental CaPr is 42 d. Offering 19 g CaPr during this period enhanced the growth performance, dietary energy, and economic returns.
50头高危公牛犊采用完全随机设计（每组10头犊牛），以评估进入饲养场后丙酸钙（CaPr）的最佳补充期。评估的变量包括进入饲养场第56天时的生长性能、日粮能量学、体脂储备、血清代谢物和经济回报。犊牛在接收时称重（下车体重为156.2±1.57千克，BW），接收的日粮为牧草与精料比例50:50的日粮及清洁饮水。接收12小时后，在56天的饲养期内将它们单独饲养在围栏中，并分配到不同处理组，即每日补充一种商业产品（Propical Dresen Química，SAPI de CV.，墨西哥城，墨西哥），该产品在进入饲养场后的0、14、28、42或56天为每头犊牛提供19克CaPr。与其他处理组相比，在最初42天接受CaPr的犊牛平均日增重更高（≤0.035），且不影响干物质摄入量（≥0.24）。因此，增重效率（≤0.050）和日粮能量利用率得到提高（≤0.046）。丙酸钙补充对肋部脂肪厚度（≥0.090）和肌肉面积（≥0.112）无影响，而在丙酸钙补充42天和56天时，犊牛的臀部背膘厚度达到最大值（≤0.038）。除总白蛋白（在第56天达到最大值（≤0.024））和总胆固醇（与对照组相比，在第28天和42天达到最大值；=0.030）外，血清代谢谱不受处理的影响。以对照组估计的利润为基线，补充42天CaPr可获得更高的净收入（每头犊牛多34.84美元）。补充CaPr多于或少于42天的利润非常相似（约每头犊牛6.80美元）。由于这些处理组和对照组的增重成本非常相似（1.42美元/千克对1.46美元/千克），利润的正向差异主要是由CaPr犊牛出售收入的增加（每头犊牛增加13.02美元）介导的。基于生长性能、血清代谢物和利润得出结论，CaPr的最佳补充期为42天。在此期间提供19克CaPr可提高生长性能、日粮能量和经济回报。
