Pacheco Rodrigo D L, Souza Johnny M, Marino Carolina T, Bastos João Paulo S T, Martins Cyntia L, Rodrigues Paulo H M, Arrigoni Mario D B, Millen Danilo D
Department of Breeding and Animal Nutrition, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, Brazil.
Department of Animal Production, College of Agricultural and Technological Sciences, São Paulo State University (UNESP), Dracena, Brazil.
Front Vet Sci. 2023 Mar 20;10:1090107. doi: 10.3389/fvets.2023.1090107. eCollection 2023.
This study was designed to evaluate a spray-dried multivalent polyclonal antibody preparation (PAP) against lactate-producing bacteria as an alternative to monensin (MON) to control ruminal acidification. Holstein cows (677 ± 98 kg) fitted with ruminal cannulas were allocated in an incomplete Latin square design with two 20 days period. Cows were randomly assigned to control (CTL), PAP, or MON treatments. For each period, cows were fed a forage diet in the first 5 days (d-5 to d-1), composed of sugarcane, urea and a mineral supplement, followed by a 74% concentrate diet for 15 days (d 0 to d 14). There were no treatment main effects ( > 0.05) on dry matter intake (DMI) and microbial protein synthesis. However, there was a large peak ( < 0.01) of intake on d 0 (18.29 kg), followed by a large decline on d 1 (3.67 kg). From d2, DMI showed an increasing pattern (8.34 kg) and stabilized around d 8 (12.96 kg). Higher mean pH was measured ( < 0.01) in cattle-fed MON (6.06 vs. PA = 5.89 and CTL = 5.91). The ruminal NH-N concentration of CTL-fed cows was lower ( < 0.01) compared to those fed MON or PAP. The molar concentration of acetate and lactate was not affected ( > 0.23) by treatments, but feeding MON increased ( = 0.01) propionate during the first 4 days after the challenge. Feeding MON and PAP reduced ( = 0.01) the molar proportion of butyrate. MON was effective in controlling pH and improved ruminal fermentation of acidosis-induced cows. However, PAP was not effective in controlling acidosis. The acidosis induced by the challenge was caused by the accumulation of SCFAs. Therefore, the real conditions for evaluation of this feed additive were not reached in this experiment, since this PAP was proposed to work against lactate-producing bacteria.
本研究旨在评估一种喷雾干燥的多价多克隆抗体制剂（PAP），其针对产生乳酸的细菌，作为莫能菌素（MON）的替代品以控制瘤胃酸化。给安装有瘤胃瘘管的荷斯坦奶牛（677±98千克）按照不完全拉丁方设计分配，分为两个20天的周期。奶牛被随机分配到对照（CTL）、PAP或MON处理组。在每个周期中，奶牛在最初5天（第-5天至第-1天）饲喂粗饲料日粮，由甘蔗、尿素和矿物质补充剂组成，随后15天（第0天至第14天）饲喂74%的精饲料日粮。在干物质摄入量（DMI）和微生物蛋白质合成方面，处理组没有主要影响（>0.05）。然而，在第0天摄入量出现一个大峰值（<0.01）（18.29千克），随后在第1天大幅下降（3.67千克）。从第2天起，DMI呈上升趋势（8.34千克），并在第8天左右稳定下来（12.96千克）。饲喂MON的奶牛测量到更高的平均pH值（<0.01）（6.06，而PAP组为5.89，CTL组为5.91）。与饲喂MON或PAP的奶牛相比，饲喂CTL日粮的奶牛瘤胃NH-N浓度较低（<0.01）。处理组对乙酸盐和乳酸盐的摩尔浓度没有影响（>0.23），但在挑战后的前4天，饲喂MON会增加丙酸盐（=0.01）。饲喂MON和PAP会降低丁酸盐的摩尔比例（=0.01）。MON在控制pH值方面有效，并改善了酸中毒诱导奶牛的瘤胃发酵。然而，PAP在控制酸中毒方面无效。挑战诱导的酸中毒是由短链脂肪酸的积累引起的。因此，在本实验中未达到评估这种饲料添加剂的实际条件，因为这种PAP被提议用于对抗产生乳酸的细菌。
