de Melo Luciano Prímola, Rennó Luciana Navajas, Detmann Edenio, Paulino Mário Fonseca, Júnior Ronaldo Gomes da Silva, Ortega Román Maza, Moreno Deilen Sotelo
Animal Science Department, Federal University of Viçosa, Viçosa 36570-900, MG, Brazil.
Animal Science Department, Faculty of Agricultural Sciences, University of Pamplona, Pamplona 543050, NDS, Colombia.
Vet Sci. 2024 Oct 15;11(10):506. doi: 10.3390/vetsci11100506.
Our objective was to evaluate the effects of protein supplementation frequency and supplementation plans during gestation on productive performance and metabolic responses of grazing super-precocious Nellore heifers. Thirty-five pregnant Nellore heifers were used in a completely randomized design in a 2 × 2 factorial arrangement with an additional control group. The factors were the following: 1. Frequency of supplementation: (a) Daily (seven times per week), (b) Infrequent (three times per week); 2. Supplementation plans: (a) Constant, (b) Increasing. A control group with no supplementation was included. Two digestibility trials were carried out on the 40th and 130th experimental days. Productive performance and body composition were evaluated in the prepartum and postpartum periods. Blood samples were collected at -114, -113, -15, -14, +15, +30, and +45 days relative to calving for measuring metabolic status. Supplementation (daily and infrequent) increased the intake of total dry matter (DM) ( ≤ 0.004), average daily gain ( < 0.001), and body weight at calving ( = 0.008) at prepartum. However, frequency or supplementation plan did not alter ( > 0.17) the intake of total DM and forage DM. There was an effect ( ≤ 0.02) of the supplementation plan on subcutaneous thickness fat in the prepartum period and albumin and non-esterified fatty acid concentrations ( < 0.004) in the postpartum period. Nonetheless, frequency and supplementation plans did not affect ( ≥ 0.10) heifers' productive performance during the postpartum period. In conclusion, protein supplementation frequency and supplementation plan during beef heifers' gestation do not negatively impact their productive performance or metabolic responses.
我们的目标是评估妊娠期蛋白质补充频率和补充方案对放牧的超早熟内洛尔小母牛生产性能和代谢反应的影响。35头怀孕的内洛尔小母牛采用完全随机设计，按2×2析因排列，并设一个额外的对照组。因素如下：1. 补充频率：(a) 每日（每周7次），(b) 不频繁（每周3次）；2. 补充方案：(a) 恒定，(b) 递增。纳入一个不补充的对照组。在试验第40天和第130天进行了两次消化率试验。在产前和产后阶段评估生产性能和身体组成。在相对于产犊的 -114、-113、-15、-14、+15、+30和 +45天采集血样，以测定代谢状态。产前补充（每日和不频繁）增加了总干物质（DM）摄入量（≤0.004）、平均日增重（<0.001）和产犊时体重（=0.008）。然而，补充频率或补充方案并未改变（>0.17）总DM和饲草DM摄入量。补充方案对产前皮下脂肪厚度（≤0.02）以及产后白蛋白和非酯化脂肪酸浓度（<0.004）有影响。尽管如此，补充频率和补充方案在产后阶段并未影响（≥0.10）小母牛的生产性能。总之，肉牛小母牛妊娠期的蛋白质补充频率和补充方案不会对其生产性能或代谢反应产生负面影响。
