Amorocho A K, Jenkins T C, Staples C R
Department of Animal Sciences, University of Florida, Gainesville 32611, USA.
J Dairy Sci. 2009 Oct;92(10):5178-88. doi: 10.3168/jds.2009-2283.
The objective of this study was to evaluate catfish oil (CFO) as a dietary ingredient for lactating Holstein cows. Twelve multiparous Holstein cows (6 fitted with a rumen cannula and 6 noncannulated cows), arranged in a 3 x 3 Latin square design replicated 4 times, were used to evaluate CFO as a dietary ingredient for lactating Holstein cows. Each period lasted 27 d with the last 13 d used for data collection. Dietary treatments were 0, 1.5, and 3% CFO (dry matter basis). Orally dosing with chromium oxide powder was used as an external inert marker for calculation of apparent dry matter and nutrient digestion coefficients. Ruminal fluid was collected hourly for 8 h after feeding to measure pH and volatile fatty acids. Intake of dry matter increased as intake of CFO increased (23.0, 24.4, and 25.4 kg/d). Production of milk was unchanged by the feeding of CFO (29.0, 29.0, and 29.4 kg/d). Concentrations of milk fat (3.57, 3.60, and 3.48%) and protein (3.21, 3.18, and 3.23%) were unchanged by feeding CFO. Concentrations of plasma glucose (57.8, 55.1, and 56.0 mg/100 mL), urea nitrogen (11.6, 11.0, and 12.0 mg/100 mL), and insulin (0.55, 0.53, and 0.57 ng/mL) were not affected by dietary treatments. Average ruminal fluid pH decreased (6.40, 6.20, and 6.15), as did the molar proportions of acetate (64.5, 64.2, and 63.4%), as dietary concentration of CFO increased. The molar proportions of propionate increased (19.4, 20.0, and 20.4%) as did that of butyrate (12.0, 12.4, and 12.5%) as intake of CFO increased. Ruminal protozoa numbers were unchanged by treatments. Apparent digestibility coefficients of dry matter, crude protein, neutral detergent fiber, and acid detergent fiber were increased by addition of CFO. In situ lag, rate, and extent of corn silage dry matter digestion were not affected by the inclusion of CFO. However, in situ digestion rate of neutral detergent fiber was increased (0.023, 0.024, and 0.029 h(-1)) with increasing intake of CFO. In a second study involving 190 Holstein cows, those fed CFO at 1.8% of dietary dry matter produced 1.2 kg more milk/d than those not fed CFO, along with an increase in milk protein concentration. Catfish oil can be a viable lipid source for dairy cows when fed at up to 3% of the dietary dry matter.
本研究的目的是评估鲶鱼油（CFO）作为泌乳荷斯坦奶牛日粮成分的效果。选用12头经产荷斯坦奶牛（6头安装有瘤胃瘘管，6头未安装），采用3×3拉丁方设计，重复4次，以评估CFO作为泌乳荷斯坦奶牛日粮成分的效果。每个试验期持续27天，最后13天用于数据收集。日粮处理为0%、1.5%和3%的CFO（干物质基础）。口服氧化铬粉末作为外部惰性标记物，用于计算表观干物质和养分消化系数。饲喂后每小时采集瘤胃液8小时，以测量pH值和挥发性脂肪酸。随着CFO摄入量的增加，干物质摄入量增加（分别为23.0、24.4和25.4千克/天）。饲喂CFO对牛奶产量没有影响（分别为29.0、29.0和29.4千克/天）。饲喂CFO对乳脂（分别为3.57%、3.60%和3.48%）和蛋白质（分别为3.21%、3.18%和3.23%）浓度没有影响。日粮处理对血浆葡萄糖（分别为57.8、55.1和56.0毫克/100毫升）、尿素氮（分别为11.6、11.0和12.0毫克/100毫升）和胰岛素（分别为0.55、0.53和0.57纳克/毫升）浓度没有影响。随着日粮中CFO浓度的增加，平均瘤胃液pH值下降（分别为6.40、6.20和6.15），乙酸摩尔比例下降（分别为64.5%、64.2%和63.4%）。随着CFO摄入量的增加，丙酸摩尔比例增加（分别为19.4%、20.0%和20.4%），丁酸摩尔比例也增加（分别为12.0%、12.4%和12.5%）。处理对瘤胃原虫数量没有影响。添加CFO可提高干物质、粗蛋白、中性洗涤纤维和酸性洗涤纤维的表观消化系数。日粮中添加CFO对玉米青贮干物质的原位滞后时间、消化速率和消化程度没有影响。然而，随着CFO摄入量的增加，中性洗涤纤维的原位消化速率增加（分别为0.023、0.024和0.029小时-1）。在第二项涉及190头荷斯坦奶牛的研究中，日粮干物质中添加1.8%CFO的奶牛比未添加CFO的奶牛每天多产奶1.2千克，同时乳蛋白浓度增加。当鲶鱼油在日粮干物质中的添加量高达3%时，可作为奶牛可行的脂肪来源。
