东湖杂交绵羊奶不同月份常规营养成分及相关性分析

Analysis of Conventional Nutrient Composition and Correlation of Hybrid Sheep Milk in Different Months

为探究东佛里生羊和湖羊杂交奶绵羊的奶样常规营养成分在不同月份中的变化规律以及各营养成分间的相关性,本试验以健康状况良好的东湖杂交奶绵羊为研究对象,每月定时采集其常乳,除采集月份不同外,其余各试验条件均保持相同。使用乳品分析仪测定样品的非脂固形物、总固形物、乳脂、乳蛋白、乳糖、pH、灰分、电导率、密度和冰点,根据所得数据绘制变化曲线图;利用Duncan多重比较和Pearson相关性分析(双侧)等方法对数据进行分析。结果表明,泌乳月份对羊乳中非脂固形物、总固形物、乳脂、乳蛋白、乳糖、pH、灰分、电导率、冰点的影响差异极显著(P<0.01)。除电导率外,其余各指标间均存在显著相关性。乳脂与非脂固形物、蛋白质、灰分、总固形物、密度、乳糖呈显著正相关(P<0.05),与冰点呈显著负相关(P<0.05);非脂固形物与乳糖、乳蛋白、总固形物、灰分、密度间呈极显著正相关(P<0.01),除灰分外,均与冰点呈显著负相关(P<0.05);pH与乳脂、总固形物、非脂固形物、乳蛋白、灰分、冰点、密度呈显著正相关(P<0.05)。随泌乳月份的变化,总固形物、非脂固形物、乳脂、乳蛋白、灰分总体呈现出先下降后上升的趋势,乳糖、密度的变化则趋于平稳;pH总体呈现出上升、下降、上升的趋势,电导率呈现出下降、上升、下降的趋势,并于10月份达到最大;冰点呈现出先下降后上升的趋势。综上,羊乳泌乳月份显著影响绵羊奶的常规营养成分,且呈现一定的变化规律;各营养成分间也存在显著相关性,该研究为奶绵羊实际生产和绵羊乳制品的开发提供了理论基础。

The objective of this study was to explore the variations in conventional nutrients in milk samples obtained from East Friesen sheep and Hu sheep hybrid across different lactating months,and to analyze the correlation between these nutrients.The healthy Dong-hu hybrid dairy sheep were used as the research object,and their milk was collected regularly every month.The experimental conditions remained consistent across the varying months.An automatic milk sample analyzer was utilized to measure non-fat solids,total solids,milk fat,milk protein,lactose,pH,ash,conductivity,density,and freezing point,with subsequent generation of variation curves based on the collected data.Data analysis involved the use of Duncan multiple comparison and Pearson correlation analysis in SPSS 26.0 software.The findings revealed significant variations(P<0.01)in non-fat solids,total solids,milk fat,milk protein,lactose,pH,ash,conductivity,density and freezing point across different months.Notably,significant correlations were observed among the various indicators other than conductivity.Milk fat exhibited positive correlations with non-fat solids,protein,ash,total solids,density and lactose(P<0.05),and a negative correlation with freezing point(P<0.05).Non-fat solids were significantly positively correlated with lactose,protein,total solids,ash,density(P<0.01),while freezing point was significantly negatively correlated with these indexes(P<0.01)except for ash.Across lactating months,total solids,non-fat solids,milk fat,milk protein,ash and ash displayed a decreasing-then-increasing trend,while lactose and density exhibited stability.The overall pH demonstrated a slight increase,followed by a decrease and subsequent increase.The conductivity displayed a decreasing-then-increasing-then-decreasing trend,reaching its peak in October.The freezing point showed a decreasing-then-increasing trend.In summary,lactating months exerted a significant impact on the conventional nutrients of sheep milk,with noticeable variations and interrelationships between the nutrients.The study offers valuable technical support for the practical production of dairy sheep and the advancement of sheep dairy products.