The objective of this study was to determine the effect of enhanced whole-milk (WM) feeding systems in calves from birth to 8wk of age on subsequent first-lactation performance. The experiment was conducted as a completely randomized design consisting of 2 treatment groups. At birth, 152 Holstein heifer calves were randomly assigned to 1 of 2 treatments: (i) 4L of WM/d or (ii) 8L of WM/d. The calves were bucket fed 2 or 4L of WM twice daily at 0700 and 1600h. Each calf was housed individually in temperature-controlled nurseries and had ad libitum access to water and textured calf starter daily. Calves consumed greater volumes of textured calf starter when fed 4 versus 8L of WM/d. Water intakes mirrored starter intakes, leading to greater water consumption at weaning. Calves reared on 8L of WM/d were heavier at d 56 than calves reared on 4L of WM/d. The average daily gain of the calves offered 8L of WM/d from d 0 to 56 was greater than that of calves offered 4L of WM/d. Structural measurements were significantly greater for calves that consumed 8L of WM/d. The differences observed in withers height and live BW due to WM feeding level were not apparent by 3 and 12mo of age, respectively. Rumen pH was higher in calves that consumed 8L of WM/d than in calves that consumed 4L of WM/d. Whole-milk feeding level did not affect age at first calving or milk-production parameters. These results suggest that enhanced WM feeding improved growth performance until 3mo of age. However, first-lactation results indicated no lactation-performance benefits of increased nutrition and growth performance during the milk-fed period in dairy calves.

The objective of this study was to determine the effects of supplementing glycerol and soybean oil in drinking water on feed and water intake, calculated energy balance, and production performance of periparturient dairy cows. Ninety multiparous Holstein dairy cows were randomly assigned to 1 of 3 treatments: 1) no nutrients supplemented in the drinking water (control); 2) 20 g/L of glycerin supplemented in the drinking water (glycerol); and 3) 10 g/L of soybean oil supplemented in the drinking water (SBO). The trial lasted from 7 d prepartum to 7 d postpartum. Cows were offered a close-up and milking cow TMR for ad libitum intake, pre- and postpartum, respectively. The dry matter intake of cows supplemented with glycerol and SBO was lower than for the control cows throughout the experimental period but not different from each other. Water intake for the control cows was greater than the average for the glycerol and SBO cows prepartum, and greater than for SBO cows but similar to that of glycerol cows postpartum. Glycerol cows consumed more water than SBO cows. There were no differences in energy intake and energy balance of the cows pre- and postpartum. Serum triacylglycerol concentration for glycerol cows was lower than for the control and SBO cows prepartum and was lower than for the SBO cows postpartum. There were no differences in the serum nonesterified fatty acids and glucose concentrations throughout the experiment. There were no differences in the serum beta-hydroxybutyrate (BHBA) concentrations at parturition, but serum BHBA concentration of the glycerol cows was greater than for control and SBO cows during the prepartum period. However, during the postpartum period, serum BHBA concentrations of the control cows were greater than for glycerol and SBO cows. There were no differences in calf birth weights or milk yield and composition. Although the glucogenic property of glycerol supplemented in the drinking water at 20 g/L may not have been sufficient to elicit a milk yield response, it did reduce the concentration of BHBA postpartum.

Experiments were conducted to investigate the use of added flavor in drinking water of Holstein calves and lactating dairy cattle to determine effects on dry feed intake. Nine calves were used in a replicated 3 x 3 Latin square design, and water offered was unflavored or flavored with orange or vanilla. All calves were offered commercial starter. Feed intake of the dry starter was increased in calves offered the orange flavor treatment compared with the control or the vanilla treatment. The increased dry feed intake agreed with the significant increase in weight gain measured in calves on the orange treatment. Further experiments were performed with 4 second-lactation cows using the addition of another orange flavor to the water compared with unflavored water under conditions of free access or time-restricted water access. No significant changes were found for dry matter intake, water consumption, or milk yield. These findings demonstrate an important finding that flavoring agents need not be added only to the starter feed for calves, but flavor can stimulate dry feed intake and BW gain when used in drinking water.

A variety of measures are currently used to evaluate feed efficiency in livestock, with some of the most popular being the linear regression of nutrient intake on the various energy sinks of the cohort being evaluated. The adoption of novel on-farm technologies has greatly increased the breadth and depth of data being collected on a daily basis, which creates the opportunity for the implementation of more advanced feed efficiency models. The objectives of the current study were to leverage data collected using high-throughput biometric technologies to evaluate changes of early-lactation feed efficiency on a daily basis and to develop a novel measure of feed efficiency based on the NRC net energy model. Daily records of nutrient intake, fat- and protein-corrected milk yield, body weight, and body condition score were used to model 7 different indices of feed efficiency (gross feed efficiency, return over feed costs, residual feed intake, residual net energy intake, and net energy efficiencies of lactation, maintenance, and body reserve flux) in primiparous Holstein heifers (n = 40) from 0 to 150 d in milk. We observed that feed efficiency was dynamic and fluctuated over the course of the experimental period regardless of the efficiency measure used, but most measures followed similar trends in changes of efficiency on a day-to-day basis. Of the measures evaluated, return over feed costs would be most suited for management purposes due to practicality and simplicity, whereas other measures, such as the efficiency of net energy flux to and from body reserves, present potential targets for inclusion in breeding goals. Net energy efficiency of lactation was estimated to have higher repeatability compared with residual feed or energy intake, which may reduce the time required to estimate whole-lactation efficiency. Because decreased net energy balance was strongly correlated with increased efficiency for all indices evaluated, future work investigating the associations of feed efficiency with the magnitude and duration of negative energy balance is warranted.

Water use on 17 Ontario dairy farms was studied over 20 mo using continuous-flow water meters to measure cow consumption and milk-house and parlor usage with the goal of quantifying and assessing the amount of water used on dairy farms. The farmers were also interviewed regarding their perspectives on water use on their operations as well as throughout the industry. The goal was to gauge producers’ opinions and motivations behind water use as well as future environmental and industrial sustainability. Average water use for a free-stall automated milking operation was greater (P < 0.01) than the average usage for a free-stall parlor and a tie-stall operation. Overall, water use was found to be greater (P < 0.05) during the summer (June–August) than the winter months (December–February). Producers of free-stall operations were found to implement sustainable water-use strategies on their farms even without government incentive

The objective of this experiment was to examine the effects of supplementing the drinking water of transition dairy cattle with glucose on the energy and nitrogen status of the cow. Twenty-four multiparous Holstein dairy cows were randomly assigned to one of three treatments for an experimental period that extended from -7 to 21 d of lactation. The treatments included a 0% (control), 1% (10 g L^-1) and 2% (20 g L^-1) glucose solution metered into the drinking water of dairy cows. Water and dry matter intake (DMI) were not affected by treatment. Glucose supplementation in the drinking water significantly reduced the rumen fluid ammonia and serum urea concentrations. No differences were seen in serum concentrations of glucose, β-hydroxybutyrate (BHBA), non-esterified fatty acids (NEFA), and the energy corrected milk (ECM) yield. The calculated NE balance was not affected by glucose supplementation. The results of this trial demonstrate that glucose supplemented into the drinking water of transition cows improves the nitrogen status of the cow, but does not alter the NE_L balance during the periparturient period. Key words: Water supplementation, glucose, transition cow, serum urea