Department of Animal Science, Oklahoma State University, Stillwater, OK 74078, USA.
American Institute for Goat Research, Langston University, Langston, OK 73050, USA.
J Anim Sci. 2021 Oct 1;99(10). doi: 10.1093/jas/skab282.
The objective of this study was to investigate the effects of water quality on water intake (WI), forage intake, diet digestibility, and blood constituents in beef cows and growing beef heifers. This was a replicated 5 × 5 Latin square with five drinking water treatments within each square: 1) fresh water (Control); 2) brackish water (100 BRW treatment) with approximately 6,000 mg/kg total dissolved solids (TDS); 3) same TDS level as 100 BRW achieved by addition of NaCl to fresh water (100 SLW); 4) 50% brackish water and 50% fresh water to achieve approximately 3,000 mg/kg TDS (50 BRW); and 5) same TDS level as 50 BRW achieved by addition of NaCl to fresh water (50 SLW). Each of the five 21-d periods consisted of 14 d of adaptation and 5 d of data collection. Animals were housed individually and fed mixed alfalfa (Medicago sativa) grass hay cubes. Feed and WI were recorded daily. Data were analyzed with animal as the experimental unit. Age, treatment, and age × treatment were fixed effects, and animal ID within age was the random variable for intake, digestibility, and blood parameter data. Water and feed intake were greater than expected, regardless of age or water treatment. No treatment × age interactions were identified for WI (P = 0.71), WI expressed as g/kg body weight (BW; P = 0.70), or dry matter intake (DMI; P = 0.21). However, there was an age × treatment tendency for DMI when scaled to BW (P = 0.09) in cows consuming 100 BRW compared with fresh water. No differences were found for the other three treatments. Heifers provided 50 SLW water consumed less (P < 0.05) feed (g/kg BW) compared with heifers provided fresh water and 100 BRW. No differences (P > 0.05) in water, DMI, feed intake, or diet digestibility were found due to water quality treatment. In conclusion, under these conditions, neither absolute WI, absolute DMI, nor diet digestibility was influenced by the natural brackish or saline water used in this experiment. These results suggest that further research is necessary to determine thresholds for TDS or salinity concentration resulting in reduced water and/or feed intake and diet digestibility.
本研究旨在探讨水质对肉牛和育肥牛饮水量（WI）、采食量、日粮消化率和血液成分的影响。这是一个重复的 5×5 拉丁方设计，每个方有 5 个饮水处理：1）淡水（对照）；2）咸水（100 BRW 处理），总溶解固体（TDS）约为 6000mg/kg；3）通过向淡水添加 NaCl 达到与 100 BRW 相同的 TDS 水平（100 SLW）；4）50%咸水和 50%淡水，以达到约 3000mg/kg TDS（50 BRW）；5）通过向淡水添加 NaCl 达到与 50 BRW 相同的 TDS 水平（50 SLW）。每个 21 天周期包括 14 天适应期和 5 天数据收集期。动物单独饲养，喂食混合紫花苜蓿（Medicago sativa）干草方块。每天记录饲料和 WI。数据采用动物作为实验单位进行分析。年龄、处理和年龄×处理为固定效应，年龄内动物 ID 为摄入量、消化率和血液参数数据的随机变量。无论年龄或水疗处理如何，水和饲料摄入量均高于预期。WI（P=0.71）、以 g/kg 体重表示的 WI（P=0.70）或干物质摄入量（DMI；P=0.21）均未发现处理×年龄相互作用。然而，在 100 BRW 组与对照组相比，BW 校正后的 DMI 存在年龄×处理趋势（P=0.09）。对于其他三种处理，未发现差异。提供 50 SLW 水的小母牛的饲料摄入量（g/kg BW）低于提供淡水和 100 BRW 的小母牛（P<0.05）。由于水质处理，未发现水、DMI、饲料摄入量或日粮消化率有差异（P>0.05）。综上所述，在这些条件下，绝对 WI、绝对 DMI 或日粮消化率均不受本实验中使用的天然咸水或盐水的影响。这些结果表明，需要进一步研究以确定导致水和/或饲料摄入量以及日粮消化率降低的 TDS 或盐度浓度阈值。
