Effects of Salinity Levels of Drinking Water on Water Intake and Loss, Feed Utilization, Body Weight, Thermoregulatory Traits, and Blood Constituents in Growing and Mature Blackhead Ogaden Sheep and Somali Goats

Abstract

This experiment was conducted to evaluate the effects of drinking water salinity levels on water intake and loss, feed intake and digestion, body weight (BW), thermoregulation, and blood characteristics on growing and mature (18.8 ± 0.39 and 21.8 ± 0.40 kg BW, and 0.6–1 and 1.5–2 years of age, respectively) Blackhead Ogaden sheep and Somali goats. The animals were assigned to a 4 (water salinity) × 2 (sheep and goat species) × 2 (growing and mature animals) factorial arrangement for the 60-day experimental period and 10-day digestibility determination. Water treatments were fresh water (FRW) and low (SW-L), moderate (SW-M), and high (SW-H) levels of salinity (i.e., the addition of NaCl to obtain 10, 13.5, and 17 g of total dissolved salts (TDSs)/L, respectively). The salinity of drinking water did not affect feed intake, BW, thermoregulatory traits (respiration rate, rectal temperature, and heart rate), or blood parameters (p > 0.05); however, drinking water, total water intake, urine excretion, and total water loss increased (p < 0.01) while apparent dry matter digestibility decreased quadratically (p < 0.01) with increasing water salinity. Analysis of the interaction between water treatment and species showed that PCV (p = 0.059) and hemoglobin (p = 0.070) levels tended to be higher in sheep than in goats drinking FRW, and AST activities were greater (p = 0.036) in goats consuming SW-M than in sheep consuming water with the same salinity level. In conclusion, increasing the salinity level of drinking water by adding NaCl to up to 17 g/L of TDSs had no adverse effect on the water intake, feed intake, BW, and health status of growing and mature Blackhead Ogaden sheep and Somali goats.