Dairy calves often perform abnormal repetitive behaviors (ARBs) including tongue rolling and non-nutritive oral manipulation (NNOM) when opportunities to perform feeding behaviors are restricted. Many US dairy farms limit access to milk, a well-studied risk factor for ARBs. However, farms also commonly do not feed forage to young calves, and the motor patterns of oral ARBs resemble those necessary for acquiring and chewing solid feed. Our objective was to assess how access to hay from birth influenced time engaged in normal and abnormal oral behaviors across 24 h. Holstein heifer calves were housed individually on sand bedding and fed ad libitum water and grain (Control, n = 11) or given additional access to hay (Hay, n = 11) from birth. Calves were fed 5.7-8.4 L/d (step-up) milk replacer via a teat. At the start of step-down weaning (50 ± 1 d), all calves were given access to a total mixed ration (TMR). Feed and water intake were measured daily. Oral behaviors (eating, ruminating, sucking milk, drinking water, panting, grooming, tongue flicking, tongue rolling, and NNOM) were recorded by direct observation at weeks 2, 4, 6, and 8 using 1-0 sampling at 1-min intervals for 24 h. Grain, hay, and water intake increased over time in the preweaning period. One polydipsic calf regularly consumed >10 L water/d. During weaning, Hay calves tended to consume increasingly more TMR, significantly more water, and less grain than Control calves. Access to hay led to more observations spent eating solid feed (7% vs. 5%, mean percentage of intervals) and ruminating (24% vs. 16%) during the preweaning period compared to calves fed only grain, though Control calves appear to ruminate in absence of forage to re-chew. Rumination occurred, to a large extent, overnight. Hay calves also spent less time self-grooming (12% vs. 14%), tongue flicking (14% vs. 18%), and performing NNOM (17% vs. 21%) than Control calves. While NNOM peaked around milk feedings, all 3 behaviors were performed throughout the day. Tongue rolling was rare across treatments, as was panting, which occurred most frequently around 14:00. There were no behavioral differences during weaning (wk 8). Overall, we found that hay provision affects most oral behaviors that calves perform: it promotes natural feeding behaviors and reduces abnormal ones, suggesting hay should be provided. We also found that calves perform other behaviors, including polydipsia, repetitive grooming, and apparent sham rumination, that may suggest a degree of abnormality in these behaviors that has not been previously identified. These results highlight the importance of utilizing all oral behaviors to better understand calf welfare.

See methods in associated publication.

The following is also included in the README file associated with this Dryad entry.

Supplemental material:

The supplemental materials in this section are referenced in the corresponding paper, and provide additional information and context for the experiment’s design and results.

Tables and captions:

• Supplemental Table 1. Modified Wisconsin Calf Health Scorecard. Rectal temperatures were recorded if a calf scored ³3 for these categories combined, excluding ocular discharge. Observers were trained to >80% reliability (Kendall’s W) using 40-photo tests for nasal discharge, ocular discharge, ear position, and feces. Cough, respiratory, and attitude were not prevalent enough for a test, and were rarely observed during the trial.
• Supplemental Table 2. Behavior model outputs. These three tables reflect the model-predicted (preweaning) or raw (weaning) means, SE, and 95% CI for all oral behaviors scored, along with the model results.
• Supplemental Table 3. Feed and ADG model outputs. These tables reflect the model results for feed (grain, hay, TMR) intake, water intake, and ADG.

Figures and captions:

• Supplemental Figure 1. Rubber mats.pdf; Perforated rubber mats placed on top of sand bedding from d 0-5 for all calves to reduce accidental sand inhalation.
• Supplemental Figure 2. Grain and hay.pdf; Grain and mountain grass hay (mix of orchard and fescue) fed during this experiment.
• Supplemental Figure 3. Pen setup.pdf; Bucket set up for Control (left) and Hay (right) treatments. Control calves had grain, water, and empty buckets (left to right) while Hay calves had grain, water, and mountain grass hay buckets (left to right). Both treatments had access to these buckets beginning on d 0. At the start of step-down weaning (50-60 ± 1 d), TMR was provided for Control calves in the empty bucket (right) and for Hay calves in place of hay.
• Supplemental Figure 4. Tongue roll average by individual.pdf; Overall proportion of 24-h observations engaged in tongue rolling in wk 2, 4, 6, and 8. Each colored line represents an individual calf. The dashed line represents the start of weaning (50-60 ± 1 d). All wk 8 observations were conducted on d 6 of step-down weaning when the 2^nd of 3 milk meals had been removed.
• Supplemental Figure 5. Tongue roll time series by individual.pdf; Proportion of time engaged in tongue rolling in wk 2, 4, 6, and 8 averaged by individual calf in 15-min bins over a 24-h d. Each colored line represents a different calf. Dashed lines represent milk feedings, which occurred at 06:45, 12:45, and 18:45 h in wk 2-6 and at 18:45 h in wk 8, during step-down weaning.

Videos:

A collection of short videos are available to demonstrate what each behavior, as defined in the corresponding paper, looked like. In addition to the defined behaviors, there are videos showing what drinking water looks like as a young calf (3 days) and an older calf (7 weeks), and what appears to be sham rumination; in “Video8_Sham rumination 1” the calf is producing orange froth while chewing, while in “Video9_Sham rumination 2” the calf does not appear to regurgitate a true bolus, and quickly stops chewing.

Raw data and code:

This section includes the data and code used for this paper.

All data in this section were collected from 22 calves fed a standard diet of grain, milk, and water (Control treatment, n=11) and additional access to hay (Hay treatment, n=11) from birth until weaning at 60±1 d. The column “Age_days” reflects the calf’s age when the intake was recorded, while “Date” reflects the exact date of intake. “Week” corresponds to the calf’s age in days (i.e. 1-6 days = week 0, 7-13 days = week 1, etc.).

• OBiC_1-0 behavioral data.csv; 1-0 sampling of oral behaviors (ruminating, eating grain, eating hay, sucking milk, drinking water, grooming, non-nutritive oral manipulation, tongue flicks, tongue rolling, panting) at 1-min intervals for a continuous 24-h day at weeks 2, 4, 6, and 8 of life. Note that in these files, tongue flicks were originally scored with the name “tongue play.” The raw data thus says “tongue.play;” this is the same as tongue flicks. Similarly, sucking milk was originally scored with the name “sucking.liquid.” The column labeled “Eating” is “eating.grain" + “eating.hay” combined, so calves received a 1 if they performed either of those behaviors during that minute.
• JDS.2021-21439_Grain intake data.csv; Daily intake of starter grain in grams (g) from birth through the end of weaning at 60±1 d. The column “Grain_consumed_dried_g” indicates that these values have been converted to a dry matter basis (see paper methods for more information about this weekly feed sampling). NAs reflect instances where 24h intake could not be reliably captured, e.g. because of fecal contamination in the bucket, spillage, negative intake values, or lack of DM conversion.
• JDS.2021-21439_Hay intake data.csv; Daily intake of hay in grams (g) from birth through the start of weaning at 50±1 d. The column “Hay_consumed_dried_g” indicates that these values have been converted to a dry matter basis (see paper methods for more information about this weekly feed sampling). NAs reflect instances where 24h intake could not be reliably captured, e.g. because of fecal contamination in the bucket, spillage, negative intake values, or lack of DM conversion.
• JDS.2021-21439_TMR intake data.csv; Daily intake of TMR in grams (g) through the weaning period (50-60±1 d). The column “TMR_consumed_dried_g” indicates that these values have been converted to a dry matter basis (see paper methods for more information about this weekly feed sampling). NAs reflect instances where 24h intake could not be reliably captured, e.g. because of fecal contamination in the bucket, spillage, negative intake values, or lack of DM conversion. Calves 2936 and 2943 have no TMR values due to stepping in and kicking their TMR buckets around between every feeding.
• JDS.2021-21439_Water intake data.csv; Daily intake of water in liters (L) from birth through the end of weaning at 60±1 d. NAs reflect instances where 24h intake could not be reliably captured, e.g. because of fecal contamination in the bucket or spillage.
• JDS.2021-21439_Weekly calf weights and ADG.xlsx; “Weekly calf weights” sheet presents weights for calves obtained via a scale (d 0 weight) or approximated through heart girth tape measurements (converted to kg using Heinrichs et al. 1992; tape measurements were conducted weekly) that were used to determine preweaning average daily gain (ADG), ADG across the full trial, and final weight differences. The second tab of this sheet shows only ADG by calf (produced by the corresponding .Rmd script, but also included here). In this sheet, “ADG_kg/d” reflects kg/d difference from the last recorded weight for each calf.

RMarkdown code:

All codes in this section use the data files listed above to build and validate models to describe effects of treatment (Hay or Control) and time (Week or Day) on behavior, feed intake, and ADG, and produce the figures used in the corresponding paper. Rmd files can be downloaded and run in R, or downloaded and viewed via the pdf output, which includes the code and output previews. Both versions are annotated.

• JDS.2021-21439_Average daily gain analysis and model (pdf and .Rmd)
• JDS.2021-21439_Feed intake data analysis, models, and figures (pdf and .Rmd)
• JDS.2021-21439_Behavior data analysis, models, boxplots (pdf and .Rmd)
• JDS.2021-21439_Behavior time series plots (pdf and .Rmd)