Facultad de Medicina Veterinaria y Zootecnia, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Km 15.5 Carretera Mérida-Xmatkuil, Mérida, Yucatán, Mexico.
Facultad de Medicina Veterinaria y Zootecnia, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Km 15.5 Carretera Mérida-Xmatkuil, Mérida, Yucatán, Mexico.
Vet Parasitol. 2021 Dec;300:109620. doi: 10.1016/j.vetpar.2021.109620. Epub 2021 Nov 19.
In sheep, infection with Haemonchus contortus may increase the need for energy, and this demand may vary according to the infection level. In this study, the energy intake, digestibility, and energy retention of lambs artificially infected with different levels of H. contortus were estimated. A total of 24 hair sheep lambs reared parasite-free were experimentally infected with H. contortus at one of three infection levels: non-infected (n = 6); infected with 300 infective larvae (L) of H. contortus/kg body weight (BW) (n = 9); and infected with 500 H. contortus L/kg BW (n = 9). The lambs were fed for an individual weight gain of 100 g/day, and intake of organic matter (OMI) and gross energy (GEI), digestible (DEI) and metabolizable energy (MEI) were measured weekly. The digestibility of organic matter (OMD) and GE (GED) and the metabolizable energy (ME) balance adjusted to zero nitrogen balance (ME) were measured for each lamb during the prepatent and patent periods of infection. From day 21 post-infection (PI), the individual eggs per gram (EPG) of feces and the total number of eggs in feces (TEF) were estimated weekly. After humane slaughter on day 42 PI, the worm burden (WB) was determined. Correlation and regression analyses were performed to estimate the relationships between the parasitological variables (L, EPG, TEF and WB) and the response variables (OMI, GEI, DEI, MEI, OMD, GED, ME). During the prepatent period, there were no significant relationships of L with the response variables (OMI, GEI, DEI, MEI, OMD, GED, ME, ME). Similarly, during the patent period, no relationship was evident between infection (EPG, TEF or WB) and OMI, GEI, DEI, GED, OMD, ME or ME. Thus, the gradient of H. contortus infection examined in the present study did not influence energy balance in hair sheep lambs, and infection did not impose any detectable energy cost. Further studies are needed to fully assess the impact of H. contortus infection on energy metabolism in hair sheep.
在绵羊中，感染捻转血矛线虫可能会增加对能量的需求，而这种需求可能因感染水平而异。在这项研究中，我们估计了人工感染不同水平捻转血矛线虫的羔羊的能量摄入、消化率和能量保留。总共 24 只无寄生虫的毛发绵羊羔羊被实验性感染捻转血矛线虫，感染水平为：未感染（n = 6）；感染 300 条捻转血矛线虫感染性幼虫/kg 体重（BW）（n = 9）；感染 500 条捻转血矛线虫 L/kg BW（n = 9）。羔羊被喂食以实现每天 100 克的个体体重增加，每周测量有机物摄入量（OMI）和总能（GEI）、可消化有机物摄入量（DEI）和可代谢能摄入量（MEI）。在感染的前潜伏和潜伏期间，为每只羔羊测量有机物消化率（OMD）和 GE（GED）和零氮平衡调整的可代谢能（ME）平衡（ME）。从感染后第 21 天（PI）开始，每周估计粪便中的每克卵数（EPG）和粪便中的总卵数（TEF）。在感染后第 42 天（PI）人道屠宰后，确定蠕虫负荷（WB）。进行相关和回归分析，以估计寄生虫变量（L、EPG、TEF 和 WB）与反应变量（OMI、GEI、DEI、MEI、OMD、GED、ME）之间的关系。在前潜伏期间，L 与反应变量（OMI、GEI、DEI、MEI、OMD、GED、ME）之间没有显著关系。同样，在专利期内，感染（EPG、TEF 或 WB）与 OMI、GEI、DEI、GED、OMD、ME 或 ME 之间没有明显关系。因此，本研究中检查的捻转血矛线虫感染梯度没有影响毛发绵羊羔羊的能量平衡，感染没有造成任何可检测的能量成本。需要进一步研究才能充分评估捻转血矛线虫感染对毛发绵羊能量代谢的影响。
