Evaluation of water and feed intake of purebred cattle in confinement and on arid rangelands, and its implications on selection principles

Results Phase 1

Trial 1 of Confinement Phase: Performance and water intake of yearling bulls in confinement

In Trial one of Phase 1 of the project, 70 representing seven breeds were evaluated for daily water intake, watering behavior, dry matter intake (DMI), and growth performance. The Braunvieh breed had numerically higher daily water intakes compared to all other breeds, with the Red Angus bulls having the lowest water intake per head per day (Table 1.).   Overall, however, breed had no significant influence of all variables measured. 

Table 1. Water intake (L) and behavior of yearling purebred bulls fed in confinement at NMSU Rex Kirksey Agricultural Science Center, Tucumcari, NM, 2020.

Water intake estimate formulas have utilized DMI and BW in predicting water consumption (Ward et al., 2017).  Dry matter intake (DMI) has also been shown to be directly correlated to water intake, where increased water intake resulted in greater DMI and performance in feedlot cattle (Alhberg et al., 2019).  Therefore, correlations between water intake and DMI and the other performance variables were made.

When these variables were compared in trial one, the correlation between DMI and water intake were low (r=-.18).  Interestingly there was a moderate correlation between water consumption and RFI (r=0.29); a measure of intake and efficiency. Performance, however, was more closely tied to DMI (r=.75).  Average daily gain (ADG) and feed efficiency (FE) did not appear to be influenced by water consumption (Table 2).

Table 2. Performance parameters of yearling purebred bull trial at NMSU Rex Kirksey Agricultural Science Center, Tucumcari, NM, 2020.

^a Average Daily Gain (ADG) = calculated BW change over 60 days
^b Feed Efficiency (FE) ratio = kg of feed required to achieve 1 kg of gain
^c Residual Feed Intake is a regression coefficient representing efficiency across pen. Negative values represent more metabolically efficient animals.

There was a wide range in breed numbers within the 70 bulls tested. Variation between bulls was greatest in the breeds with fewer individual animals represented in the trials.  

Trial 2 of Confinement Phase: Performance and water intake of yearling bulls in confinement

In trial two, the 57 bulls evaluated performed very similar as in trial one. Intitial BW and final BW were 327 and 408kg, respectively. As in trial one, breed had no significant influence on water consumption (Table 3) or performance (Table 4). When data were correlated with water consumption, there were much lower correlations as in the previous year.  Water intake was negatively correlated with DMI, ADG, and RFI (-0.43, -0.38, and -0.18, respectively).

Table 3. Water intake and behavior of yearling purebred bulls fed in confinement at NMSU Rex Kirksey Agricultural Science Center, Tucumcari, NM, 2021.

^a RAxSIM represents bulls that were a cross between Red Angus and Simmental breeds

Table 4. Performance parameters of yearling purebred bulls at NMSU Rex Kirksey Agricultural Science Center, Tucumcari, NM, 2021.

^a Average Daily Gain (ADG) = calculated BW change over 60 days
^b Feed Efficiency (FE) ratio = kg of feed required to achieve 1 kg of gain
^c Residual Feed Intake (RFI) is a regression coefficient representing metabolic efficiency, where
  all bulls are compared within the 70 bulls tested. Negative values represent more metabolically
  efficient animals.

If comparisons were made between trials one and two, animal type, ranch source, and genetics were similar.  The primary reasons for observed differences in performance, body weights, and variable correlations may be influenced by calf age and their acclimation to the diet and confinement environment.  Calves in trial one were well acclimated to the feed and confinement environment, as they resided at the facility for 60 days prior to trial initiation. These calves had already experienced their maximum rate of gain, therefore, trial one bulls were heavier, but less efficient.

Trial two included a new set of bulls to the NMSU Rex Kirksey Agricultural Science Center.  These bulls were more recently weaned than trial one bulls. They were more naïve and not fully acclimated to provided feed or confinement.  Therefore, they were lighter in initial and end weights.  These facts may partially explain slightly higher observed rate of gain and efficiency, as younger animals tend to grow faster and more efficiently.  Water consumption between trials did not differ.  Given high observed variation in individual performance and the unbalanced data set according to breed, further study is needed to improve comparison of genetics, animal age, body weight, and time of year influences on water consumption for yearling purebred bulls.

An objective of Phase 1 of the project was to determine genetic influence on water consumption in purebred yearling bulls.  As only one trial has been conducted to date, results are preliminary. It is difficult to establish water use efficiency based on breed or genetics within breed at this time.  More trials are needed to reliably develop a more comprehensive data set.  Now that the water system is in place at the Tucumcari Bull Test Station, this research will continue far beyond the life of the project.  Information from the system developed through the grant will help seedstock producers gain knowledge improve the genetic efficiency of their cattle, that will also be passed on to commercial producers.

Trial 3 of Confinement Phase: Performance and water intake of dairy X beef progeny out of known beef sires.

There were differences between groups related to water consumption and behavior (Table 5.)
The AS group had the greatest water consumption and number of visits to the tanks per day. Conversely, the BH group had the lowest water intake and visits.  Variation within group, with SD for water intake being 2.21, 1.88, 2.02, 1.46.for AS, AH, BS, and BH respectively. This variation is up to 50% of the average.

Table 5. Water intake and behavior of dairy- beef crossed calves fed in confinement at NMSU Rex Kirksey Agricultural Science Center, Tucumcari, NM, 2022.

 ^a,b,c,d indicates significant differences between groups P<0.05

Average performance parameters for 77 beef-dairy cross calves of known sire parentage are shown in Table 6. The AS group had the best performance when compared among all groups.  Conversely, the AH group had the lowest ADG and greatest compared to the AS, BS, or BH groups. Steers and heifers from Sire B had more consistent performance in intake, gain, and .

Table 6. Dry matter intake, average daily gain, feed efficiency, and residual feed intake of dairy calves sired from two known beef sires test at NMSU Rex Kirksey Agricultural Science Center, Tucumcari, NM, 2022.

^a,b indicates significant differences between groups P<0.05

In trial 3, DMI, ADG, and RFI were highly correlated with water consumption (r=0.68, 0.80, and 0.97, respectively).  Where animals with higher water consumption had greater ADG, and DMI, animals with lower water consumption had lower RFI values.  The DMI and ADG data are in agreement with published literature tying water intake to growth.  However, as RFI calculations are driven by intake, the expectation.  A negative RIF value is desirable, as it indicates an animal needs less calories to achieve a specified gain. Based on the outcome of trial’s one and three it may also be true for water use efficiency.  

The calves out of the performance proven bull had much more consistent outcomes compared to the calves out of the commercially available AI sire. Consistent performance is desirable for the feedlot industry.  Feeding dairy x beef crossed calves still lags behind in feedlot performance compared feeding most straight beef breeds.  Utilizing proven beef sires in feed efficiency and growth, will improve the increasingly important dairy beef industry. 

Conclusion of Phase 1 (Confinement Phase)

Determining genetic influence on progeny takes significant numbers and generations to establish specific trends.  The collective work of this project, however, shows promise. The fact there were more correlations found between water intake and RFI, but not with DMI needs further study. The water intake system will remain at the Rex Kirksey Experiment Station in support of future planned studies, allowing for additional aggregating data to support livestock producers efforts to improve water conservation through adjustments to herd composition.  Furthermore, efforts continue in development of the water system’s technology. 

Results Phase 2 (Remote Phase)

During the testing phase of the remote DWIS, only onsite NMSU research ranch personnel were able to monitor the system daily.  Although they lacked technical proficiency to address all system bugs, their committed efforts allowed for successful data collection during the two-week testing stage.  Fifteen purebred Brahman cow calf pairs used the system. Water intake and behavior between cows and calves are summarized in Table 7.  Figure 4. shows water intake by individual at a single tank location. Behavioral data was analyzed using proc GLM of SAS and the body weight data was evaluated utilizing a regression formula; Yi=β0+β1Xi+ϵi. 

Table 7. Average water intake (l) and visits per day of Brahman cow calf pairs grazing arid rangelands at the CDRCC in the fall of 2019.  

Full body weight calculations were divided between calves and cows. Each group had their own formula based on the regression outcome.  This allowed for a more accurate prediction of their respective body weights.  Full body weights collected at weaning were used to test the regression. Figure 5 shows frontal body weights and corresponding calculated full body weights of cow 282, the graph also includes her actual BW, collected (11/6/19), 40 days after the trial period.

For growing animals, body weight change was monitored.  In figure 5., frontal body weights were tracked from September 18, 21, 24,27 and October 1, 2019. Gradual gain can be seen over time.

Conclusion of Phase 2 (Remote Phase)

While cattle drank from the DWIS almost immediately, data indicates an acclimation peroid is needed before data collection should begin. Water consumption was much lower than expected. The literature suggests mature cows weighing 489.9 kg should consume closer to 59 liters per day (NAESM, 2016). Our study indicated cows only consumed 5.78 l/d + 9.4 l/d.

Behavior was considered normal, as cow calf pairs would typically come to drink once, and occasionally twice, per day. Early morning was the most common time when cattle came to water to drink.

The frontal body weight sensor was a valuable innovation in system development. Being able to gather weights will help gauge average cow size of the herd monitored and monitor progress of calves.

Proximity of the DWIS to research station headquarters inhibited visitation by wildlife in the area.  No data was collected for wildlife and there was no indication wildlife visited the DWIS. 

More research is needed to validate data collection protocols and to increase data acquisition for improved understanding of ranging beef cattle water intake and behavior. Pandemic related protocols prevented continuation of research at CDRCC and deployment of systems to remote pastures on participating ranches throughout the state.  Despite these challenges, it remains a high priority to achieve original Phase 2 objectives on remote pastures with participating ranches throughout the state.