Introduction
Water is an essential nutrient for the growth and well-being of livestock (Beede, 2005; Huuskonen et al., 2011) as poor-quality drinking water has been shown to affect animal health and productive performance (NRC, 2005; Brew et al., 2008). Results of previous studies have demonstrated that poor-quality drinking water affects water intake (Socha et al., 2003; Grout et al., 2006; Sharma et al., 2017), feed intake (Ru et al., 2004; Umar et al., 2014; López et al., 2016), average daily gain [ADG] (Lardner et al., 2005; Waldner and Looper, 2007; Sharma et al., 2017), milk production (Solomon et al., 1995; Shapasand et al., 2010), and ruminal conditions (Coria et al., 2007; Valtorta et al., 2008). In addition, poor-quality drinking water favors diseases (Gould, 1998) and pathogen incidence in the digestive tract of dairy cows (LeJeune et al., 2001; Brew et al., 2008). Nonetheless, the intake of poor-quality drinking water and its impact on growth and health of young animals has been scarcely studied (Beede, 2005).
The “Comarca Lagunera” is the most important dairy region in northern México, with dairy operations that contribute approximately 20% of México’s national milk production (SIAP, 2017). In this region, the water available for forage production and animal nutrition has undesirable physicochemical characteristics (Rosas et al., 1999), such as a high concentration of total dissolved salts (TDS), sulfates, nitrates, and toxic minerals like arsenic (Wong et al., 2005). High-salinity drinking water may also affect growth, production, health, and well- being of dairy cows and their calves.
Desalination is a physico-chemical process consisting of removing salts from water to obtain fresh water suitable for consumption. The scarcity of good quality water for the agricultural industry due to depletion and salinization of aquifers requires the use of water desalination, especially for drinking water for animals (Schütz 2012; Umar et al., 2014). The reverse osmosis desalination technique has shown to be effective and economically viable for water desalination, especially when solar or wind energy are used in the process (Dévora et al., 2012). Therefore, the objective of the present study was to evaluate the effect of dissolved salts content in drinking water on the productive performance of Holstein-Friesian calves during artificial rearing.
Materials and Methods
Ethical considerations
This project was approved by Instituto de Investigación y Posgrado en Ciencia Animal of Universidad Autónoma Chapingo, Mexico (approval no. 145503001, March 2014).
Location
The study was conducted at “18 de Julio” dairy production experimental station of Universidad Autónoma Chapingo, located at Bermejillo, Durango, México. The farm is at 25º 54’ 07” N and 103º 35’ 09” W, with an altitude of 1,137 masl and 239 mm average annual precipitation. The climate of the study area is classified as semi- arid, with summer rain from July to September (García, 2004).
Animals, diets, and management
The experiment took place from August to November 2014. At this time of year, the temperature and relative humidity of the study area are moderate. Twenty-nine 1-d-old Holstein- Friesian calves weighing 39±0.94 kg were used. Calves were fed colostrum from their dams during the first 3 d after birth. Thereafter, they consumed a commercial milk substitute twice a day (at 07:00 and 16:00). The milk substitute was prepared by dissolving 200 g of a commercial product (Master Milk, Alltech®, Flemington, NJ, USA) in 2 L of water at 37 ºC. The experimental period of artificial rearing lasted 8 weeks (56 d). After day 7, all calves ate solid feed for weaning formulated by Nuplen® (Gómez Palacio, Durango, México) offered daily at 09:00. Three samples of water extracted from a deep well were taken, one at the beginning, one in the middle, and one at the end of the experimental period. Samples of non-filtered groundwater and reverse-osmosis (Ultraliner®, WI, USA) filtered groundwater were collected in pre-washed and sterilized, amber-colored, 250-mL bottles and kept refrigerated for 1 h at 4 ºC before being processed in a certified laboratory for analysis of chemical and microbiological composition (Table 1).
Item | HTDS | LTDS |
---|---|---|
pH | 7.0 ± 0 | 6.6 ± 0 |
Total dissolved salts, mg L-1 | 1,469 ± 75 | 107 ± 31 |
Total hardness, mg L-1 | 913 ± 21 | 46 ± 17 |
Chlorides, mg L-1 | 115 ± 3 | 6 ± 3 |
Bicarbonates, mg L-1 | 196 ± 6 | 34 ± 8 |
Sulfates, mg L-1 | 853 ± 13 | 24 ± 10 |
Nitrates, mg L-1 | 117 ± 3 | 20 ± 0.4 |
Nitrites, mg L-1 | 0.06 ± 0 | 0 ± 0 |
Total coliforms, CFU 100 ml-1 | 1,506 ± 1,296 | 29 ± 21 |
Fecal coliforms, CFU 100 ml-1 | 1,301 ± 1,210 | 18 ± 15 |
HTDS, high concentration of total dissolved salts; LTDS, low concentration of total dissolved salts.
A SevenCompact™ S230 (CH-8603; Schwerzenbach, Switzerland) conductivity meter was used to determine Total Dissolved Salts in water (TDS). A Redlemon 0-14 digital potentiometer (Mexico City, Mexico) was used to determine water pH. The volumetric method with EDTA was used to determine total water hardness. Chloride content was obtained by the Mohr volumetric method using argentometry (Espinosa et al., 2006). Carbonate level in water was determined using the methodology described by Mexican standard NMX-K-282-SCFI-2012 (NMX, 2012). A UV-VIS spectrophotometer (PerkinElmer® Lambda 35 model; Madrid, Spain) was used for measuring sulfates in water employing the procedure established in Mexican standard NMX-AA-074-SCFI-2014 (NMX, 2014). A Checker HI781 and a Checker® HC (Hanna Instruments, Mexico) colorimeters were used to determine nitrate and nitrite contents. The membrane filtration procedure described by Espinoza et al. (2006) was used for quantification of total and fecal coliforms.
Calves were randomly assigned to one of two treatment groups and housed in individual pens. Treatment 1 (n=14; 6 females, 8 males) consisted of groundwater extracted from a deep well with high TDS concentration (1,469±75 mg L-1). Treatment 2 (n=15; 7 females, 8 males) consisted of drinking water extracted from the same well but filtered by reverse osmosis and containing low TDS concentration (107±1 mg L-1). At the end of the artificial rearing period (56 d postpartum) all calves were fed a solid concentrate, had free access to forage for 32 d after weaning, and drank nonfiltered groundwater with at least 1,469±75 mg L-1 TDS.
All variables were measured considering each calf as an experimental unit. Water and feed intake were measured daily during the experimental period. Preweaning ADG was determined by weekly weighing of each calf. Postweaning ADG was measured 28 d after the artificial rearing period. Digestibility of dry matter and crude protein in the solid feed was determined using the insoluble acid fiber of the concentrate offered and the content in feces as an internal marker following the technique proposed by Penning and Johnson (1983). To estimate the disappearance of dry matter and crude protein, samples of concentrate and feces were placed in AnkomF57® bags (Macedon, NY, USA) and then incubated for 24 h in the rumen of two fistulated adult sheep using the procedure proposed by Huhtanen et al. (1994).
Data analysis
Water intake, feed intake, and ADG were analyzed using the MIXED procedure of SAS program, version 9.4 (SAS Institute Inc., Cary, NC, USA; 2013). The statistical model included the fixed effects of TDS concentration in drinking water and the sampling week, coefficient of linear regression for the weight at birth, coefficient of linear regression for average weekly environmental temperature, and the random effects of calf and residual values as terms of experimental error. Data of dry matter digestibility and crude protein were analyzed with the GLM procedure of SAS (SAS, 2013) using a completely randomized design. A p<0.05 was considered statistically significant, and a p between 0.05 and 0.10 was considered as a significant trend.
Results
Water quality
The TDS content in drinking water (carbonates, chlorides, sulfates, nitrates, sodium, potassium, calcium, and magnesium) decreased from 1,469 to 107 mg L-1 along with pH decrease from 7.0 to 6.6 after being filtered (Table 1). Sulfates content in the filtered water was 97% lower than in the nonfiltered water (24 versus 853 mg L-1). Nitrates concentration also decreased from 117 to 20 mg L-1 after filtration. Moreover, the filtration process reduced by 98% the microbiological load in the drinking water.
Productive performance of calves
Calves that drank filtered water during artificial rearing increased their live weight approximately 10% (p<0.05) compared with calves that drank water with high TDS concentration (Table 2). Moreover, a postweaning effect of drinking saline water on calf live weight during rearing was observed (p<0.05); calves drinking filtered water weighed 4.8% more at 84 d-old than calves that drank non-filtered water. Similarly, increases of 23 to 26% in dry matter intake and ADG, respectively, were observed in calves that drank filtered water compared with those that drank nonfiltered water (both p<0.05). The increase in feed intake and ADG in calves that drank water low in TDS can be explained by the improvement in the drinking water quality, which permitted the calves to increase their water and total digestible nutrient intake. Postweaning ADG (57-84 d-old) was similar (p>0.05) between the treatment groups. The TDS content in drinking water slightly affected water intake but not significantly (p<0.08; Table 2). Calves that drank water with a high TDS concentration drank 13% less water than those that drank water with a low TDS content.
Characteristics | HTDS | LTDS |
---|---|---|
Initial live weight, kg | 39.6 ± 1.18a | 39.8 ± 1.15a |
Live weight at 56 d, kg | 58.6 ± 1.18b | 64.3 ± 1.14a |
Live weight at 84 d, kg | 120.6 ± 13b | 126.4 ± 13a |
Feed intake, g d-1 | 500 ± 44b | 676 ± 42a |
ADG at 56 d, g d-1 | 335 ± 30b | 434 ± 20a |
ADG at 84 d, g d-1 | 2240 ± 68a | 2250 ± 67a |
Water intake, mL d-1 | 3088 ± 268a | 3554 ± 250a |
Nitrites, mg L-1 | 0.06 ± 0 | 0 ± 0 |
Total coliforms, CFU 100 ml-1 | 1,506 ± 1,296 | 29 ± 21 |
Fecal coliforms, CFU 100 ml-1 | 1,301 ± 1,210 | 18 ± 15 |
ADG, average daily weight gain; means within rows with different superscript (a, b) letters are statistically different (p<0.05).
Feed and protein digestibility
The digestibility of dry matter and crude protein in solid feed offered to calves during the artificial rearing period was not affected by the decrease in TDS of filtered drinking water (p>0.05; Table 3).
Discussion
Water quality
The chemical composition of groundwater-previously filtered by reverse osmosis- was within permissible standards published by the National Research Council (2001 and 2005) for dairy cattle. According to Beede (2005), the pH of drinking water for dairy cattle should be between 6.4 and 7.0 to prevent health disorders, and from 7.0 to 8.0 for proper functioning of ruminal microorganisms. Thus, water pH (filtered or nonfiltered) was within suitable quality range.
Several studies have shown that dairy cows and calves drinking highly chlorinated water for extended periods are susceptible to decreased productive performance and health problems (Bahman et al., 1993; Solomon et al., 1995; Shapasand et al., 2010). Due to the high concentration of anions and their capacity to combine with metal cations, such as calcium and magnesium, non-filtered groundwater was harder in the present study (913 mg L-1), although it can be softened through desalination (46 mg L-1). Nevertheless, previous findings have shown that drinking water high in calcium, magnesium, zinc, iron, and manganese ions does not significantly affect water or feed intake, productive performance, or animal health (Umar et al., 2014). Although no adverse effects of high concentrations of carbonates in ruminant drinking water have been reported, water high in both calcium and magnesium affects the productive performance of animals because these elements increase the TDS content (El- Mahdy et al., 2016).
High sulfate levels in drinking water affect water and feed intake in calves, decreasing ADG and increasing the risk of polio-encephalomalacia (Patterson et al., 2003; Patterson et al., 2005; Drewnoski et al., 2014). Moreover, high sulfate concentrations in calf diets interfere with absorption of copper and selenium, generating thiamine deficiency, the main cause of bovine polio-encephalomalacia (Lutnicki et al., 2014). However, sulfate concentrations lower than 1,000 mg L-1 may not affect calf productive performance or health (Wright, 2007).
The National Research Council (2001) established nitrates permissible range in drinking water for livestock as 45-132 mg L-1. Nitrates ingested by ruminants rapidly convert to nitrites by rumen microorganisms, and although no maximum tolerable levels of nitrites in drinking water have been reported, they are absorbed in the rumen wall and flow into the blood, reducing the efficiency of red blood cells to transport oxygen and can cause asphyxia (Wright, 2007). Moreover, although the presence of coliform bacteria in drinking water has negative consequences for livestock health and productive performance, there are few scientific studies concerning this topic (LeJeune et al., 2001; Willms et al., 2002; Sanderson et al., 2005).
Productive performance of calves
The results of the present study are consistent with those found by Patterson et al. (2003), who observed a significant 6.7% increase in dry matter intake and 26% increase in ADG of calves when TDS concentration in drinking water decreased. In a similar study, calves that drank water with 512 versus 7,478 mg L-1 TDS, dry matter intake and ADG increased by 10 and 22%, respectively, in animals that drank water with lower TDS (López et al., 2016). Recently, Sharma et al. (2017) reported similar effects in Murrah buffalo calves, estimating a 17.2% increase in dry matter intake for those that drank water with low TDS (557 versus 8,789 mg L-1 TDS). Likewise, high levels of dissolved sulfates in drinking water decreased dry matter intake and ADG of Holstein-Fresian calves (Weeth and Capps, 1972; Patterson et al., 2004a). In contrast, Bahman et al. (1993) reported that saline water intake (3,574 mg L-1 TDS) had no effect on dry matter intake of Holstein cows, whereas Solomon et al. (1995) reported similar feed intake (23.0 versus 22.6 kg DM d-1) in dairy cows drinking water high or low in salts. In addition, Willms et al. (2002) found that calves that drank clean water (675 mg L-1 TDS) had 9% higher ADG than calves that drank dirty water from puddles (1,783 mg L-1 TDS) during the rearing period, although postweaning ADG of calves was similar between groups.
Water intake
The present results agreed with those reported by Patterson et al. (2004b) who observed a 37% decrease in the intake of water containing 7,268 mg L-1 TDS relative to calves that drank water with 1,226 mg L-1 TDS. Solomon et al. (1995) also observed 8.5% reduced intake of water with high TDS in dairy cattle, while Johnson et al. (2004) reported a water intake decrease of 13% (p<0.06) in growing steers when sulfate concentration increased from 401 to 4,654 mg L-1. Additionally, Sharma et al. (2018) reported a negative correlation (p<0.01) between water intake and TDS level in Murrah buffalo calves. Grout et al. (2006) also observed that high concentrations of MgSO4 (1,500, 3,000, and 4,500 mg SO4 L-1) in the drinking water linearly decreased (p<0.01) water intake of growing calves, and the decrease in water intake was accompanied by an increase in dry matter of feces, suggesting a decrease in feed digestibility. Other researchers (Yirga et al., 2018) suggest that TDS content in drinking water has a greater impact on young animals than adults.
Feed and protein digestibility
The results of the present study are consistent with those reported in other studies (Attia- Ismail et al., 2008; López et al., 2017; Sharma et al., 2017). Sharma et al. (2017) found no differences (p>0.05) in the apparent digestibility of nutrients (dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber) between buffalo calves that drank water with low and high TDS content. The loss of nitrogen in urine, however, was higher (p<0.05) in calves drinking water with 8,789 mg L-1 TDS compared to water with 6,113 mg L-1 TDS or lower. Likewise, López et al. (2017) did not detect significant effects (p>0.05) of high salinity water on digestibility of organic matter and neutral detergent fiber by calves. Previously, Attia-Ismail et al. (2008) also reported nonsignificant (p>0.05) effects of water salinity on digestibility of nutrients in sheep and goats. In contrast, Tsukahara et al. (2016) found decreased organic matter digestibility for goats drinking brackish water (6,900 mg L-1 with 100% saturation of salts) compared with water with lower TDS (505 mg L-1).
In conclusion, the quality of drinking water for rearing calves is of critical importance. Good quality drinking water improves feed and water intake of calves without affecting dry matter digestibility. These improvements allow an increase in total digestible nutrient intake and ADG. Further studies are needed on the effects of specific components of drinking water on the performance of dairy cattle during early growth, development, and production.