Effects of two different blends of naturally mycotoxin-contaminated maize meal on growth and metabolic profile in replacement heifers
Effects of two different blends of naturally mycotoxin-contaminated maize meal on growth and metabolic profile in replacement heifers
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DOI：
10.1017/s1751731114001475
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发表时间：
2014-10-01
期刊：
影响因子：
3.6
通讯作者：
Pirlo, G.
中科院分区：
文献类型：
--
作者：
Abeni, F.;Migliorati, L.;Pirlo, G.
本试验的目的是评估在自然污染的玉米粒中施用不同真菌毒素组合对小母牛生长、血液测量和青春期开始的影响。将35头黑白花母牛随机分为3个试验组，分别为18-21周龄和42-45周龄。在24周实验期（EP）内，小母牛饲喂相同的饮食，但玉米粉来自三个不同污染批次：极低污染，作为对照（C）;中低黄曲霉毒素污染（A）;和混合黄曲霉毒素-伏马菌素污染（A-F）。在EP结束时，他们回到没有污染玉米的普通饮食，并对他们进行了额外的12周监测（实验后阶段，PEP）。从EP开始到EP结束，每4周测量一次体重、体高、臀高、体长和胸围。同时，评估身体状况评分，并从颈静脉采集血样，分析血液学、血清蛋白和代谢概况。青春期的年龄通过测量40至52周龄的每周血浆孕酮水平来评估。分别对EP和PEP的平均日增重进行方差分析，并对生长曲线参数进行分析。使用混合模型评价血液学、血清蛋白和代谢特征，同时考虑每只动物的重复测量。在EP期间，A组和A-F组母牛的生长都被延迟，这表现在三个组的BW生长曲线的线性系数不同。严重污染的饲料不会影响血液学特征，因此可以得出结论，这些霉菌毒素污染水平不会对生长期小母牛的造血和免疫力产生任何特定影响。真菌毒素慢性毒性的主要血液标志物是。血浆中的谷氨酰转移酶活性水平，即使在去除真菌毒素后也似乎发生了变化。在EP期间，与C组相比，污染饲料组的血糖较低。营养状况的改变和长期的肝损害的共同作用可能是A组，特别是A-F组青春期延迟的原因。本试验的结果证明，奶牛饮食中的慢性黄曲霉毒素-伏马菌素污染可以决定这些动物生殖生涯的重要延迟。
The aim of this trial was to assess the effects of the administration of different combinations of mycotoxins in naturally contaminated maize grains on dairy heifer growth, blood measurements and puberty onset. A total of 35 Friesian female heifers were randomly allotted to three experimental groups from 18-21 to 42-45 weeks of age. During the 24-week experimental period (EP), heifers were fed the same diet, but with maize meal derived from three differently contaminated lots: very low contamination, as control (C); medium-low aflatoxin-contaminated (A); and mixed aflatoxin-fumonisin contaminated (A-F). At the end of the EP, they returned to a common diet without contaminated maize, and they were monitored for an additional period of 12 weeks (post-experimental period, PEP). BW, wither height, hip height, body length and heart girth were measured every 4 weeks from the beginning of EP to the end of PEP. At the same time, body condition score was evaluated and blood samples were taken from the jugular vein to be analysed for haematological, serum protein and metabolic profiles. Age at puberty was assessed by measuring weekly plasma progesterone levels from 40 to 52 weeks of age. Body growth measurements were processed both by ANOVA of average daily gain of EP and PEP separately, and by the analysis of growth curve parameters. Haematological, serum protein and metabolic profile were evaluated using a mixed model, taking into account the repeated measurements in time on each animal. Heifers' growth was delayed both in A and A-F groups during EP, as evidenced by the different linear coefficients of the BW growth curve in the three groups. Differently contaminated diets did not affect the haematological profile, so that it can be concluded that these levels of mycotoxin contamination do not determine any specific effect on haematopoiesis and immunity in growing heifers. The main blood marker of mycotoxin chronic toxicity was the.-glutamyl transferase activity level in plasma, which appeared to be altered even after the removal of mycotoxins. During EP, plasma glucose was lower in the groups fed contaminated diet compared with C. The joint actions of an altered nutritional status and a long-lasting liver damage were probably the causes of the delay in puberty attainment in A and, particularly, in the A-F group. The results from this trial evidenced that a chronic aflatoxin-fumonisin contamination in diets of dairy heifers can determine an important delay in the reproductive career of these animals.