Brief Summary of Minutes of Annual Meeting

Objectives:

1. Estimate genetic variation associated with animal health and structural soundness using classical animal breeding and genomic techniques to facilitate sustainable beef cattle production systems.

2. Systems approach to analyzing novel ERTs associated with female production including longevity, fertility, and meat quality database creation.

3. Documentation of genetic components and development of thermotolerance measurements pertaining to heat tolerance adaptive traits in sustainable beef cattle production systems.

1. Procedures: 

Objective 1.1 Eye and facial pigmentation 

We will use photographs and digital quantification software to determine proportion of eyelid with pigmentation. Each animal will have one photo to identify the animal (primarily have used tag or brand), one of full face straight on to clarify markings, one of eye straight across on left side, one of eye aiming up (to characterize the eyelid under the upper eyelashes) on the left side, one of eye straight across on right side, and one of eye aiming up on the right side. Quantifications of pigmentation will be conducted using procedures developed by Davis et al. (2015).  Multiple locations will contribute to this objective. Evaluated breed types will include 1) Hereford, 2) Hereford-Bos taurus crosses, and 3) Hereford-Bos indicus crosses (including Braford in this category even though it is recognized as a distinct breed). The target number of animals in each breed type category is 2,000. 

Objective 1.2 Udder conformation 

Cattle will be evaluated for udder conformation traits and scored according to BIF guidelines (2010) for Udder Suspension and Teat size. Scores for each trait range from 1 to 9 with 9 indicating tight suspension and small teat size and will be evaluated at weaning. In addition, any udder abnormalities such as evidence of mastitis, dead quarters, tumors, injuries or other diseases will be recorded. Cow traits related to weaning performance and calf traits to include birth weight and date, weaning weight and date and post weaning performance will be evaluated. 

Objective 1.3 Foot Structure 

Cattle will be evaluated for hoof conformation traits and scored according to American Angus Association (2015) for Claw Set and Toe Angle. Scores for each trait range from 1 to 9 with 1 indicating straight pasterns and short toes, and 9 indicating curled toes and crossed claws. Hooves will be evaluated at weaning. Additionally, trim records will be recorded. Cow traits related to reproductive performance and calf traits to include birth weight and date, weaning weight and date and post weaning performance will be evaluated. 

Objective 2 Cow Performance

Cow performance and fertility data were collected from fall and spring calving herds and will be combined from each station at the end of the project for analysis.

Objective 3.2 Hair Shedding

Documentation of genetic components pertaining to heat tolerance adaptive traits in sustainable beef cattle production systems. Cattle will be evaluated for hair shedding scores from March through July (28-day intervals, 5 scores). Shedding scores will on a 1 through 5 scale:  where 1 = slick short summer coat (100% shed); 2 = hair coat is mostly shed (75% shed); 3 = hair coat is halfway shed (50% shed); 4 = hair coat exhibits initial shedding (25% shed); and 5 = full winter coat (0% shed).  In addition, cow traits related to reproductive performance, growth performance, and culling will be recorded. Calf traits to be recorded include birth weight and date, weaning weight and date. 

1. Progress of Work:

Objective 1.1

Arkansas: An Angus-based fall calving cowherd (n ≈ 194) was observed, and photos of eye pigmentation were collected from white-faced cows and calves at weaning in white-faced cows housed at the University of Arkansas beef research unit near Fayetteville.  Whole blood samples were also collected and frozen from calves. Cow traits related to weaning performance and calf traits to include birth weight and date, weaning weight and date were recorded for possible future evaluation.  Photos and whole blood will be transferred to Dr. Riley at TAMU in order to collaborate with other locations that are involved with collecting similar data.                

Mississippi- Photographs of each eye were taken on purebred Hereford and Hereford-cross calves to assess eye pigmentation. Pictures will be sent for quantification and contribution to this objective.  Pictures were taken of both eyes for 29 head of purebred Hereford females and 1 Hereford X Angus female. 

Texas- DNA collected on approximately 200 animals in this year (over 4,500 animals with records and DNA).  More photographs (approximately 200 animals) were added to the database. A graduate student at North Dakota State University is currently assessing images. Cow herd at the Martin Ranch (Menard, TX) sold because of drought conditions. 

Objective 1.2

Arkansas: The objective of this study was to determine if any relationships existed between udder conformation and production traits in cows housed at the University of Arkansas beef research unit near Fayetteville. 

An Angus-based fall calving cowherd (n ≈ 194) was observed, and udder scores were recorded at calving in the Fall of 2022 and at weaning in April 2023.  Cows were evaluated on a scale from 1 to 9 for udder suspension and teat size according to BIF guidelines. A score of 1 indicated a very pendulous suspension and large, balloon shaped teats and a score of 9 represented a tight suspension and refined teat size. Phenotypic data for cow age, Pre-Breeding BW, Pre-Breeding BCS, BCS of cow at weaning, BW of cow at weaning, AI pregnancy and overall pregnancy, along with calf weaning weight, and adjusted 205-day weaning weight (adjusted for dam age and calf gender) were collected. Means will be generated for suspension and teat scores by dam age. Cows receiving a suspension or teat score of 1-3 were considered undesirable, scores ranging from 4-6 were ideal and those scores 7-9 will be considered marginal. Cow performance data will be analyzed using the acceptability parameters described with CORR, GLIMMIX, MIXED, and FREQ procedures of SAS.  Significance was declared at P ≤ 0.05 and tendencies were observed at 0.05 < P ≤ 0.10. 

Very little variation in frequency of cows in the ideal and marginal category but far outnumbered the frequency of cows considered unacceptable.  Overall cow frequencies at both calving and weaning for ideal, marginal, and unacceptable for udder suspension were 144, 211 and 13 respectively and teat size frequency were 195, 147 and 4 respectively.  Cows that scored the tightest udders and most refine teats were also the youngest in age and those that scored the most pendulous suspension and biggest teats were the oldest cows.  Correlation for cow age with suspension at calving was statistically different (r= -0.615, p<.0001).  The same was true about cowage with teat size at calving (r= -0.561, p<0.561). At calving, udder suspension and teat size were moderately correlated with cow age (r=-0.394, r=-0.321 respectively).  The effect of udder suspension and teat score on weaned calf performance was not significantly different (P > 0.13, 0.79 respectively). Cows with unacceptable suspension and teat size had higher pre-breeding body weights but were not statistically different from ideal and marginal cows.  Udder Suspension and Teat size did not affect weaning body weight (P = 0.812), weaning body condition scores (P = 0.588), overall AI conception rates (P = 0.753), or overall pregnancy rates (P = 0.601). 

Mississippi- Data were collected on fall calving purebred Angus, Hereford cows and spring calving commercial cows. Udder and teat scores were recorded within 24 hours after calving, during mid-lactation and at weaning. Data will be combined with other stations at the end of the project for analysis.  Udder and teat scores were taken on 38 Angus and 18 purebred Hereford cows at birth, mid-lactation, and weaning. 

Texas- The same cows as resource herds previously described with two scores recorded: teat size scores and udder support scores 1 to 9 per BIF (2010) guidelines at birth when calves are weighed and tagged, mid-lactation 3-4 mo calf age, & one-week post-weaning.  Observations at birth will be on different days according to calving.  The other observations were conducted as much as possible in a single day, and as much as possible by the same person.  Noting abnormalities of the udder may permit us to create analyzable traits.  Assignment of accumulated data to graduate students to facilitate additional analyses.     

Objective 1.3     

Arkansas:  The objective of this study was to determine if any relationships existed between foot soundness and production traits in cows housed at the University of Arkansas beef research unit near Fayetteville. An Angus-based fall calving cowherd (n ≈ 194) was observed, and foot scores were recorded at weaning in April 2023.  Cows were evaluated on a scale from 1 to 9 for foot angle and claw set according to the American Angus Association with 1 indicating straight pasterns and short toes, and 9 indicating curled toes and crossed claws. Phenotypic data for cow age, Pre-Breeding BW, Pre-Breeding BCS, BCS of cow at weaning, BW of cow at weaning, AI pregnancy and overall pregnancy, along with calf weaning weight, and adjusted 205-day weaning weight (adjusted for dam age and calf gender) were collected. Means will be generated for suspension and teat scores by dam age. We assigned cows with a claw and angle score between 4 and 6 to have an overall “ideal” foot score. Those that scored 3 or 7 were considered “marginal” and any scores outside these were assigned “undesirable”. Cow performance data will be analyzed using the acceptability parameters described with CORR, GLIMMIX, MIXED, and FREQ procedures of SAS.  Significance was declared at P ≤ 0.05 and tendencies were observed at 0.05 < P ≤ 0.10. 

Mean Cow Age of ideal Claw set was 4.5, 5.6 for marginal, and unacceptable was 6.3.  Mean cow age of ideal foot angle was 4.5, 5.4 for marginal, and unacceptable was 7.1   The frequency of ideal, marginal and unacceptable scores for both claw set, and foot angle were 212, 135 and 15 respectively.   For claw set and foot angle, statistical differences existed for pre-breeding body weight between ideal and marginal cows (1204,1278, p=0.026, 1200,1269, p=0.021). Pre-Breeding BCS, Weaning BW, Weaning BCS, and calf weaning weight was not affected by claw set or foot angle.         

Objective 2

Mississippi- Cow performance and fertility data were collected on 47 Angus and 18 Hereford purebreds and 67 commercial (Simbrah X Angus, Hereford X Angus) females. 

Texas- Cow performance and fertility data were collected on approximately 1200 cows, most with some Brahman background.  F₂ Nellore-Angus cow fertility did not appear to differ by how the cross was made, i.e., F₁ Nellore-sired bulls bred to F₁ Nellore-sired cows; F₁ Nellore-sired bulls bred to F₁ Angus-sired cows, etc.  

Objective 3

Arkansas: The objective of this study was to measure variation in hair coat shedding and determine if cowherd production performance traits were affected by timing of winter haircoat shedding in cows housed at the University of Arkansas beef research unit near Fayetteville. An Angus-based commercial beef cattle herd (n ≈ 194) was observed in 2022. Once monthly from March until July, at approximately 28-day intervals, mature cows and replacement heifers were evaluated for shedding on a scale from 1 to 5. A score of 5 indicates a full winter coat and a score of 1 represents a slick, short summer coat. Month of first shedding was defined as the month in which a cow received a hair coat score of 3 (approximately 50% shed) or less was reached. Hair coat scores were taken from April through July. Those that had not received a hair coat score of 3 by July were labeled “no shed”. Phenotypic data for cow age, pregnancy success, pre-breeding cow weight and body condition score, calf birth weight, weaning weight and adjusted weaning weight, and cow weaning weight and body condition score were collected and analyzed using the PROC FREQ and PROC GLIMMIX procedures of SAS. Significance was declared at P ≤ 0.05 and tendencies were observed at 0.05 < P ≤ 0.10. 

Frequency of MFS occurred with the following order: June> July>May>No Shed>April. Cow age was different (P < 0.01) with MFS group means for April = 3.7, May = 3.9, June = 5.4, July = 5.1, and No Shed = 2.9. Artificial and Natural Service breeding success was unaffected by hair coat shedding (P > 0.11). Cow pre-breeding body weight and body weight at weaning were both significantly different amongst haircoat shedding groups (P > 0.001) with cows exhibiting MFS in April, May, June and July exhibiting similar body weights at prebreeding and weaning and cows exhibiting MFS as “No Shed” exhibiting lower body weights at prebreeding and weaning.  Calf weaning weight and adjusted weaning weight was not significantly different; however, calf birth weight differed (P < 0.01) with mean birth weight averaging 73, 71, 71, 65 and 48 pounds for calves born to cows that shed in April, May, June, July and No Shed.  All calf birth weights were similar amongst cows that shed in April, May, June, and July but birth weight was least for calves weaned to cows that were in the No Shed group (P < 0.05). Cow weaning body condition score and prebreeding body condition score did not differ by MFS (P > 0.05). 

Mississippi- Hair shedding scores were collected on 47 Angus and 18 Hereford purebreds and 67 commercial (Simbrah X Angus, Hereford X Angus) females. 

MS Experiment 1. Evaluation of the relationship between hair coat shedding ability and apparent digestibility in Angus cattle. The objective of this study was to evaluate winter hair coat shedding ability in conjunction with apparent forage digestibility. Data was collected on fall calving purebred Angus females with calves from March until July in 2019 (n=10) and 2020 (n=31). Dams were observed once monthly by two trained technicians for winter hair coat shedding and were given a visual score of 1 to 5. 1 indicated 100% shed, 2 = 75% shed, 3 = 50% shed, 4 = 25% shed, and 5 = 0% shed. Month of first shed (MFS) was determined when a female reached an average hair shedding score of  3.5 for any given month. Fecal samples were collected during the grazing months of March, May, and July and were then analyzed via proximate analysis to calculate apparent digestibility of crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), ash, and dry matter percentage (DM) of forage. Data were analyzed using repeated measures of the MIXED procedure of SAS with a significance declared at P  0.05. The model included MFS, month, and MFS by month interaction with year and ambient temperature as a covariate with cow ID nested within MFS Interactions of MFS by month were observed for CP, ADF, NDF, ash, and DM. Females with a MFS in May or June showed decreased CP apparent digestibility during the month of May when compared with cows reaching a MFS in April or July. For DM in July, females with an MFS in June and July were similar but decreased when compared to females with an MFS in April and May. 

MS Experiment 2. Evaluation of nutrient digestibility by calves born from early and late shedding Angus dams. Researchers have investigated several factors that could alter fetal growth, including nutrient restriction (Valiente et al., 2021), hair shedding (Gray et al., 2011), and extreme hot and cold temperatures (Davidson et al., 2022). Hot temperatures and increased humidity percentages in the southeast United States caused researchers to investigate the hair coats of Angus cattle in the commercial production setting. An improvement in fiber digestibility and calf birth and weaning weights has been observed in Angus dams that shed 50% of the winter hair coat by May (Gray et al., 2011; Burnett et al., 2021). Our objective of this experiment was to investigate the nutrient digestibility of Angus calves born to cows that on average, shed early compared to calves from cows that later. Newly weaned, purebred Angus bull calves (early; n = 6, late; n = 6) were housed in metabolism crates for 10 d. Prior to the trial, calves had a 14 d adaption period to a 14% CP textured feed (CPC 14% Developer, CPC Commodities, Fountain Run, KY) and offered ad libitum Cynodon dactlyon hay and water. After 3 d crate acclimation period, urine, feces, orts, and hay samples were collected for 7 d. Concentrate was offered at 0.25% of average BW. Approximately 5% samples were taken of feces, and urine samples had 1-1.5% of 25% metaphosphoric acid added to prevent ammonia volatilization, and both collections were composited by animal. Orts were collected at 0600 h daily, dried, and composited by animal. Laboratory analysis included dry matter (DM), organic matter (OM), Ash, neutral detergent fiber (NDF), acid detergent fiber (ADF), Kjeldahl N (CP), and fat. Data were analyzed using the GLM procedure of SAS 9.4 in a completely randomized design with calf as the experimental unit. Significant (P ≤ 0.05) means were separated using Fischer’s protected LSD. The model for intake included average daily DM and OM (kg) and adjusted by body weight (BW%). For digestibility analysis, the model included: DM, OM, ash, NDF, ADF, hemi-cellulose (HC), CP, and fat. The N retention model included: N retained (g/d), N retained/consumed (%), and N retained/DM intake (%). There were no differences between early or late calves for DM intake (5.502 ± 0.2774 kg/d; 2.251 ± 0.1247 %BW), or OM intake (5.199 ± 0.2591 kg/d; 2.128 ± 0.1166 %BW). There were no differences in digestibility for either group for DM, OM, Ash, NDF, ADF, HC, CP, or fat (Table 1.). There were also no differences in N retention in either group of calves (3.686 ± 2.0242 g/d; 4.366 ± 2.3964 %; 0.064 ± 0.0355 %). Replication and further research are needed in this area to adequately understand factors influencing nutrient digestibility in calves born from early and late shedding dams. 

Texas- Recorded monthly winter shedding scores on approximately 70 Angus cows.  Recorded approximately quarterly coat length scores on approximately 400 Bos indicus-influenced cows. 

Florida- Collection of phenotypic data describing thermal tolerance in Bos Indicus influenced populations and characterization of the genetic component underlying these traits. Vaginal temperature was measured at 5-min intervals for 5 days in 286 cows over two years (2015 and 2017) from the multibreed herd (ranging from 100% Angus to 100% Brahman) of the University of Florida. Ambient environmental conditions were monitored using HOBO data loggers, which continuously record temperature, humidity, solar radiation, black globe temperatures, and wind speed which were used to calculate a temperature humidity index (THI). Skin samples were taken during summer (July 17, 2017 and August 7, 2018) between 0700 and 1100 h. A skin biopsy sample was collected using a 0.6 cm diameter punch biopsy instrument (Biopsy Punch, Miltex Inc., PA) and fixed in 10% formalin for approximately 24 h. Samples were dehydrated in 70% ethanol and infiltrated in liquid paraffin and stored until sectioned and stained at the UF Molecular Pathology Core. Images were obtained with the microscope in 40 X, and analyzed with ImageJ software. Sweat gland area (mm2) and sweat gland depth as the distance from the top of the sweat glands to the skin surface (mm) were determined from a constant 4.6 mm2 cropped image area. A certified technician recorded ultrasound images from yearling calves using an Aloka 500 ultrasound system: yearling ultrasound backfat (UFAT, cm) and yearling ultrasound percent intramuscular fat (UPIMF, %) phenotypes. Average information restricted maximum likelihood (AIREML) variance components, heritabilities, additive genetic correlations, and phenotypic correlations were estimated using single-trait and pairwise two-trait animal linear mixed models. The statistical model for both analyses included the direct additive genetic and residual as random effects, breed group (based on genomic breed composition) and group of data collection as class effect, except for short hair length and skin biopsy records, where group was not significant, and age at measurement as a covariate. The pedigree file consisted of 2,327 individuals, 715 sires and 1,286 dams. All analyses were performed using the airemlf90 package from BLUPF90 software (Misztal et al., 2002). 

Heritability estimates for skin histology characteristics, hair characteristics, body temperature under high THI conditions, and ultrasound carcass traits are provided in Table 1. A high heritability of 0.69 was estimated for the sweat gland area while the sweat gland depth had a low heritability estimate of 0.09. Heritability was estimated to be 0.33 for short hair length (undercoat) and 0.16 for long hair length (top coat). Heritability for coat score has been estimated to be 0.6, (Turner and Schleger, 1960) and McEwan Jenkinson et al. (1975) estimated the heritability of hair follicle measurements to range from 0.15 to 0.76. The heritability for body temperature under high THI conditions was estimated to be 0.13 which is similar the heritability estimated reported for rectal temperature in a Brahman x Angus crossbred population (0.19; Riley et al., 2012) and dairy cattle (0.17; Dikmen at al., 2012). Both studies utilized cattle located in Florida. High heritability estimates were obtained for backfat (0.76) and intramuscular fat (0.37) ultrasound measures. 

Two-trait AIREML estimates of direct additive genetic and phenotypic correlations between skin histology characteristics, hair characteristics, body temperature under high THI conditions, and ultrasound carcass traits are presented in Table 2. Sweat gland area had a negative genetic correlation with sweat gland depth (-0.49), short and long hair length (-0.45 and -0.28, respectively), and body temperature under high THI conditions (-0.65). These negative correlations suggest a similarity in the genetic control underlying these traits which would allow for selection of animals with large sweat glands, short hair (both topcoat and under coat), and able to maintain a lower body temperature under high THI conditions. More importantly, although weak, the genetic correlations between sweat gland area and the two production traits (backfat and intramuscular fat) were favorable (0.22 and 0.20, respectively). Similarly, there was a medium negative genetic correlation between the body temperature under high THI and the two ultrasound carcass traits, suggesting animals able to maintain a lower body temperature would be more productive. 

¹UFAT, ultrasound backfat (cm); UPIMF, ultrasound intramuscular fat (%).

Table 2. Two-trait AIREML estimates of phenotypic and direct additive genetic correlations between skin histology properties, hair characteristics, and carcass traits. 

¹SWGA, sweat gland area (mm2); SWGD, sweat gland depth (mm); SHL, short hair length (mm); LHL, long hair length (mm); THighTHI, temperature at high THI (°C); UFAT, ultrasound backfat (cm); UPIMF, ultrasound intramuscular fat (%). 

South Dakota- Genetic selection tools such as expected progeny differences and DNA testing are widely available in the US beef industry. However, genetic selection tools for economically relevant traits and lowly heritable traits are less widely available and frequently are less accurate. For example, genetic selection tools are not available for water intake in beef cattle. 

Climate change models predict that water will become scarcer in some geographical regions of the US. Therefore, genetic selection for cattle that require less water may be beneficial to some beef producers. Our overarching hypothesis is that water requirements vary among animals based on their body weight, age, climatic factors, and genetics. Specifically, we aim to (1) correlate water requirements of beef calves and yearlings at different ages, body weights, feed intakes, and climatic factors, and (2) identify genes associated with thirst in beef calves.

 We expect to estimate updated water requirements in beef calves that can be used by beef producers to predict water needs of their herd. We also expect to determine if genetics affects water intake variation and identify genes important for the thirst response in cattle. Identification of these genes will be an important first step towards understanding genetic variation of water requirements of our beef herd. This project will impact the beef industry by helping producers understand genetic and environmental effects that affect water intake of cattle. 

SD Experiment 1.  Daily water and feed intake were collected on 27 steers from December 11 until June 8. Data were collected prior to the start of this reporting period but analyzed during the reporting period.  Intake data were measured with Insentec feeders and waterers at the SDSU Cow-Calf Education and Research Facility (CCERF). Steers were weighed approximately every 28 days and daily body weights were predicted. Daily body weight was predicted by calculating average daily gain (ADG) between weigh dates and interpolating weight from ADG. Daily weather data were collected from a Mesonet weather station located 2.4 miles from the CCERF. Preliminary analyses show that: 1) liquid water intake increased as body weight and age increased (0.074 kg water intake per 1 kg body weight, P<0.05), and 2) liquid water intake increased as wind chill increased (0.364 kg water intake per 1 kg body weight; P<0.05). The increased fluid water intake with increased body weight was expected from previous reports in the literature, but little to no data has been published describing the relationship between water intake and wind chill values. Beef producers can expect decreased fluid water intake as wind chill decreases. Data on the relationships between water intake, body weight, and age can be used to update predicted water requirements of beef cattle. 

The efficacy of our winter-spring model of beef calf water intake was compared with previously published water intake models using an independent sample of bull calves raised at the CCERF. The model we developed for this project had the lowest absolute value average residual (3.20) and highest squared correlation (R² = 0.81) for liquid water intake, indicating this model explained the largest fraction of water intake variation.

SD Experiment 2.  The effects of temperature, humidity, wind speed, and body weight on liquid water and feed intake were monitored in steers (n=25) from August to November. Data were collected prior to the start of this reporting period but analyzed during the reporting period.  These steers were housed at the Cow-Calf Education and Research Facility (CCERF) and were weighed every 28 days. Data collected included daily feed and liquid water intake, body weight, and weather (temperature, solar radiation, humidity, and wind speed). Average daily gain and predicted body weight were calculated. A linear mixed effects model with random intercept and slope calculated for each animal was tested to estimate effects of these variables on water intake. Increased total water intake (P < 0.05) was correlated with dry matter intake (1.07 kg water intake/kg DMI), body weight (0.08 kg water intake/kg BW), solar radiation (1.3 kg water intake/W/m²), and ambient temperature (0.6 kg water intake/°C). Similar values were estimated for liquid water intake (P < 0.05).  Increased liquid water intake was correlated with dry matter intake (0.675 kg water intake/kg DMI), body weight (0.087 kg water intake/kg BW), solar radiation (1.3 kg water intake/W/m²), and ambient temperature (0.6 kg water intake/°C).

 SD Experiment 3.  Water was withheld from calves (n=3) for 12 h prior to slaughter. After 12 h, calves (n=6; 3 controls) were slaughtered. Insentec water data confirmed that the three control calves consumed water before slaughter. Within 30 minutes of death, the hypothalamus and anterior pituitary gland were removed. The hypothalamus and anterior pituitary tissues were snap frozen in liquid nitrogen. The RNA was isolated from tissue samples, sequencing libraries prepared, and RNA-seq was initiated. Sequencing was completed on hypothalamus tissue for two treatments and two controls and anterior pituitary on one treatment and two controls. Sequencing for the remaining samples is in progress.

 The sequence traces have been mapped to the bovine genome. Preliminary analysis of data identified 40 transcripts differentially expressed between water restricted and control calves (Adjusted P < 0.05). Of these 40 transcripts, 39 were up-regulated in the water restricted calves, including Arginine Vasopressin.  Arginine vasopressin regulates water balance. 

1. Summary: 

Objective 1.1                 

Numbers of images and corresponding DNA samples are reaching appropriate levels for genome-wide association analyses.  Some interim work with image management will be required. 

Objective 1.2

 Locations have accumulated scores across lactations and across years for approximately 400 cows. 

 Objective 1.3

 Data were analyzed to determine if cow herd performance is affected by hoof score. Acceptable foot structure had a significant impact on pre-breeding cow BW, pre-Breeding cow BCS, cow BW at weaning, and cow BCS at weaning.  Calf weaning weight was not affected by foot structure; however, acceptable foot structure tended to impact overall AI pregnancy rates in these data.

 Objective 2 

The accumulation of records is substantial. Combination for analyses is the next step.

 Objective 3 

Arkansas: Data were analyzed to determine if cow herd performance is affected by month of first shedding. In these data, MFS score varied by cow age and influenced calf birth weight and cow prebreeding and weaning BCS. 

Mississippi: There is no clear trend of an association between hair shedding ability and apparent digestibility when measured on cows or their calves. Replication and further research are needed to adequately understand factors influencing nutrient digestibility in calves born from early and late shedding dams.

Work plan for next year: 

        Continue to collect an additional year’s data and begin writing our new project.

Midkiff, K. A., Kegley, E. B., Krumpelman, B., Kutz, B. R., Powell, J. G. 2022. Evaluation of winter hair coat shedding on cow and calf performance in crossbred Angus cattle in Arkansas Journal of Animal Science (Suppl. S3 ed., vol. 100, pp. 208). DOI:10.1093/jas/skac247.378

Baker, E.C., A.D. Herring, T.S. Amen, J.E. Sawyer, J.O. Sanders, C.A. Gill, P.K. Riggs, and D.G. Riley.  2022.  Evaluation of post-weaning efficiency in Nellore-Angus crossbred steers through model predicted residual consumption.  Sust. Agric. Res.  11:46–57.

Mickey, D.M., D.G. Riley, J.O. Sanders, and A.D. Herring.  2022.  Investigation of reciprocal cross effects in F2 Nellore-Angus calves.  Ruminants 2:341–350.  doi:10.3390/ruminants2030023

Baker, E.C., A.E. San, K.Z. Cilkiz, B.P. Littlejohn, R.C. Cardoso, N. Ghaffari, C.R. Long, P.K. Riggs, R.D. Randel, T.H. Welsh Jr. and D.G. Riley.  2023.  Inter-individual variation in DNA methylation patterns across two tissues and leukocytes in mature Brahman cattle.  Biology 12, 252. doi:10.3390/biology12020252

Ruiz-De-La-Cruz, G., A.M. Sifuentes-Rincón, E. Casas, F.A. Paredes-Sánchez, G.M. Parra-Bracamonte, D.G. Riley, G.A. Perry, T.H. Welsh, Jr., and R.D. Randel. 2023.  Genetic variants and their putative effects on microRNA-seed sites: Characterization of the 3′ untranslated region of genes associated with temperament. Genes 14:1004. doi:10.3390/genes14051004

Rodriguez E.E, H. Hamblen, S. Flowers, J.D. Leal-Gutiérrez, C. Carr, T. Scheffler, and R.G. Mateescu. 2023. Carcass and Meat quality in Brangus Steers. Translational Animal Science. 7, 1-6, doi.org: 10.1093/tas/txad021

Martins, T, Rocha, C.C., Driver, J.D., Rae, O., Elzo, M.A., Mateescu, R.G, et al. 2022. What a 31-year multibreed herd taught us about the influence of B. indicus genetics on reproductive performance of cows. J Anim Sci, skac366. doi: 10.1093/jas/skac366.

Davidson, B.D., Sarlo Davila, K.M., Mateescu, R.G., Dahl, G.E., and Laporta, J. 2022. Effect of in utero exposure to hyperthermia on postnatal hair length, skin morphology, and thermoregulatory responses. J Dairy Sci 105, 8898–8910. doi: 10.3168/jds.2022-22202.

Block, J.J., M.J. Webb, K.R. Underwood, M.G. Gonda, A.A. Harty, R.R. Salverson, R.N. Funston, K.C. Olson, and A.D. Blair.  2022.  Influence of maternal protein restriction in primiparous beef heifers during mid- and/or late-gestation on progeny feedlot performance and carcass characteristics.  Animals.  12(5): 588.  doi: 10.3390/ani12050588.

Linde, D.A., E. van Marle-Köster, M.M.  Scholtz, M.G. Gonda, J.L. Gonzalez-Hernandez, & M.D. MacNeil.  2023.  Differential gene expression in the Longissimus dorsi of Nguni and Bonsmara bulls finished on low and high energy diets.  South African Journal of Animal Science. 53(1).  http://dx.doi.org/10.4314/sajas.v53i1.11

Loftin, M. P., R.H. Burnett, B.J. Rude, and T. Smith. 2022. Evaluation of the relationship between hair coat shedding ability and apparent digestibility in Angus cattle. J. Anim. Sci. 100(Suppl. 1):1.

In Press:

Keele, J.A., M. Masaitis, B. Karisch, T. Smith, and B.J. Rude. 2023. Evaluation of nutrient digestibility by calves born from early and late shedding Angus dams. J. Anim. Sci. (Suppl.).