Velasquez-Munoz Ana, Schuurmans Emily J, Brester Jill L, Starken Kathryn, Abuelo Angel
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, United States.
Front Vet Sci. 2023 Feb 23;10:1102421. doi: 10.3389/fvets.2023.1102421. eCollection 2023.
Excessive maternal lipid mobilization in late gestation may impact the immune function of the newborn. However, the long-term effects remain unknown. The objective was to explore associations between excessive maternal lipid mobilization in the last 2 weeks of gestation with offspring health and performance.
A retrospective study was performed including 1,511 calves (heifer = 692, bull = 819) born between 2015 and 2020 in one MI farm. Plasma non-esterified fatty acids (NEFA) was measured from cows 7 to 14 d before calving. Calves were categorized in 2 groups based NEFA concentration: physiological lipid mobilization (PLM = 1,373; NEFA <0.3 mM) and excessive lipid mobilization (ELM = 138; NEFA ≥0.3 mM). Calf records were obtained from the herd's management software. Outcomes of interest were the hazard of pre-weaned digestive and respiratory disease, pre-weaned ADG, age at first breeding and calving, first lactation 305 d mature equivalent milk yield (305ME), and survival until first calving. Statistical models included dam NEFA category adjusted by year and season of birth, parity of the dam, and sex of the calf. Cox proportional analysis was used to determine the hazard of a pre-weaned health event, first breeding, and first calving. Linear regression was used to evaluate ADG and 305ME. The survival until first calving was analyzed with logistic regression.
No difference was detected in the hazard of diarrhea (HR = 1.06; 95% CI = 0.82-1.38) and respiratory disease (HR = 1.29; 95% CI = 0.79-2.10) by NEFA category in the pre-weaned period. Also, no difference was detected for the LSM (±SE) of pre-weaned ADG (PLM = 0.77±1.55, ELM = 0.72±2.76 kg/d). In heifers, the hazard for first breeding favored the PLM group (HR = 1.59; 95% CI = 1.18-2.12), with a reduced median age at first breeding (PLM = 400 d, 95% CI = 397-402; ELM = 412 d, 95% CI = 404-421). However, NEFA category was not associated with the hazard of first calving (HR = 0.94; 95% CI = 0.69-1.27), first lactation 305ME (PLM = 16,665±165 kg; ELM = 16,256±532), the odds of presenting at least 1 health event in the first lactation (OR = 0.78; 95% CI = 0.41-1.49), or the odds of leaving the herd before first calving (OR = 1.21; 95% CI = 0.56-2.02). Overall, dam ELM affected the hazard of first breeding but no other indicators of health or long-term performance. However, associations between maternal lipid mobilization and calf outcomes cannot be excluded, as the NEFA cut-off used has not been established as a predictor of offspring health and performance.
妊娠晚期母体脂质过度动员可能会影响新生儿的免疫功能。然而，其长期影响尚不清楚。目的是探讨妊娠最后2周母体脂质过度动员与后代健康及性能之间的关联。
进行了一项回顾性研究，纳入了2015年至2020年在一个密歇根州农场出生的1511头犊牛（小母牛 = 692头，公牛 = 819头）。在母牛产犊前7至14天测量血浆非酯化脂肪酸（NEFA）。根据NEFA浓度将犊牛分为两组：生理性脂质动员（PLM = 1373头；NEFA <0.3 mM）和脂质过度动员（ELM = 138头；NEFA≥0.3 mM）。犊牛记录来自牛群管理软件。感兴趣的结果包括断奶前消化和呼吸道疾病的风险、断奶前平均日增重（ADG）、首次配种和产犊年龄、第一个泌乳期305天成熟当量产奶量（305ME）以及首次产犊前的存活情况。统计模型包括根据出生年份和季节、母牛胎次以及犊牛性别调整的母牛NEFA类别。采用Cox比例分析来确定断奶前健康事件、首次配种和首次产犊的风险。使用线性回归来评估ADG和305ME。用逻辑回归分析首次产犊前的存活情况。
在断奶前期，按NEFA类别划分，腹泻风险（HR = 1.06；95% CI = 0.82 - 1.38）和呼吸道疾病风险（HR = 1.29；95% CI = 0.79 - 2.10）未检测到差异。此外，断奶前ADG的最小二乘均值（±标准误）也未检测到差异（PLM = 0.77±1.55，ELM = 0.72±2.76 kg/d）。在小母牛中，首次配种的风险有利于PLM组（HR = 1.59；95% CI = 1.18 - 2.12），首次配种的中位年龄降低（PLM = 400天，95% CI = 397 - 402；ELM = 412天，95% CI = 404 - 421）。然而，NEFA类别与首次产犊风险（HR = 0.94；95% CI = 0.69 - 1.27）、第一个泌乳期305ME（PLM = 16,665±165 kg；ELM = 16,256±532）、第一个泌乳期至少出现1次健康事件的几率（OR = 0.78；95% CI = 0.41 - 1.49）或首次产犊前离开牛群的几率（OR = 1.21；95% CI = 0.56 - 2.02）均无关联。总体而言，母牛ELM影响首次配种的风险，但不影响其他健康或长期性能指标。然而，由于所使用的NEFA临界值尚未被确定为后代健康和性能的预测指标，因此不能排除母体脂质动员与犊牛结果之间的关联。
