Calf Vigor Research Articles

Association of a green tea extract with serum immunoglobulin G status and neonatal vitality in newborn dairy calves.

Poor vigor at birth has been associated with reduced IgG absorption from colostrum and a reduced vitality in neonatal dairy calves. Some natural compounds, such as green tea extract, may improve vitality in compromised calves. The objective of this randomized controlled trial was to evaluate the potential of supplementing a green tea extract (15 mL) to calves to improve vigor and activity behavior for the first 72 h postnatal. Also, this study aimed to investigate the influence of green tea extract supplementation on calf serum IgG concentration and the apparent efficiency of absorption (AEA) of colostral IgG. Holstein calves (n = 24) weighing 42.49 ± 1.07 kg postnatal received a complete random assignment at 3 h of one 15-mL dose of green tea extract (Calf Perk, TechMix) or distilled water orally before tube feeding colostrum replacer (Premolac Plus IgG, Zinpro) at 4 h postnatal. Two observers assessed for calving time and dystocia by live video stream to retrieve all calves within 2 h postnatal. One veterinarian performed a baseline vigor assessment based on heart rate and response to stimuli on all calves at 2.5 h, before colostrum feeding at 3.75 h, as well as at 24, 48, and 72 h postnatal. Calf blood samples were taken to assess total IgG by radial immunodiffusion assay at 2.5, 6, 12, 24, 48, and 72 h. Calf vitality was also observed continuously by video for all calves to determine whether treatment was associated with attempts to stand, lying time, and exploration of their pen environment for the first 24 h. We used an ordinal logistic model to evaluate the odds of green tea extract improving a calf's vigor category from 2.5 h postnatal to 72 h of age. Vigor score was categorized as abnormal (≤4), average (5), or alert (≥6), with hour as a fixed effect. We also ran mixed linear models to evaluate the effect of extract on total IgG and AEA, with time and dystocia as fixed effects. Five dystocia calves were enrolled (2 control, 3 extract), but assistance was minor (e.g., manual assistance and all were assisted within 1 h). Baseline vigor scores and baseline total IgG were not different between groups. Vigor score category was not associated with green tea extract supplementation (odds ratio 1.17; 95% CI: 0.43-3.15) but increased with time compared with controls. We observed no association of treatment with total IgG or AEA in the calves, suggesting green tea extract does not compromise IgG absorption. Calf vitality, lying behavior, and exploratory behavior were not associated with green tea extract treatment. Our findings suggest that green tea extract supplementation does not affect AEA and serum IgG concentration in calves. Future research should evaluate whether green tea extract improves vitality in calves experiencing severe dystocia.

Effects of spring- versus fall-calving on perinatal nutrient availability and neonatal vigor in beef cattle.

To determine the effect of calving season on perinatal nutrient availability and neonatal beef calf vigor, data were collected from 4 spring- (average calving date: February 14; n = 203 total) and 4 fall- (average calving date: September 20; n = 179 total) calving experiments. Time to stand was determined as minutes from birth to standing for 5 s. After birth, calf weight and size (length, heart and abdominal girth, and cannon circumference) were recorded. Jugular blood samples and rectal temperatures were obtained at 0, 6, 12, and 24 h postnatally in 6 experiments and at 48 h postnatally in Exp. 2 to 8. Data were analyzed with fixed effects of season (single point) or season, hour, and their interaction (over time, using repeated measures). Experiment was a random effect; calf sex was included when P ≤ 0.25. Within calving season, correlations were determined between calf size, vigor, and 48-h serum total protein. Fall-born calves tended to have lighter (P = 0.09) birth weight and faster (P = 0.05) time to stand than spring-born calves. Season did not affect (P ≥ 0.18) gestation length, other calf size measures, or 48-h serum total protein. Fall-born calves had greater (P ≤ 0.003) rectal temperature at 0, 24, and 48 h postnatal. Spring-born calves had greater (P ≤ 0.009) circulating glucose at 0 h, serum non-esterified fatty acids at 0 and 6 h, and plasma triglycerides at 0, 6, 12, and 48 h. Fall-born calves had greater (P ≤ 0.03) sodium from 6 to 48 h and magnesium from 0 to 24 h of age. Phosphorus was greater (P ≤ 0.02) at 6 and 12 h of age in spring-born calves. Spring-born calves had greater (P ≤ 0.04) aspartate aminotransferase at 12 and 24 h and creatine kinase at 0 and 12 h of age. Fall-born calves had greater (P ≤ 0.03) albumin, calcium, and chloride, had lower (P ≤ 0.03) bicarbonate and direct bilirubin, and tended to have greater (P = 0.10) anion gap (all main effects of calving season). Calf birth weight had a weak positive relationship (P ≤ 0.03) with 48-h serum total protein and time to stand in fall-born, but not spring-born, calves. Overall, fetal growth was restricted and neonatal dehydration was increased by warm conditions for fall-born calves, but vigor and metabolism were negatively affected by cold conditions in spring-born calves. These data suggest that calving season influences perinatal nutrient availability, which may impact the transition of beef calves to postnatal life.

56 Vitamin and Mineral Supplementation Throughout Gestation Affects Liver Trace Mineral Status of Dam and Neonatal Calves but not Calf Morphometric Characteristics

Abstract Objectives were to evaluate the effects of feeding a vitamin and mineral supplementation (VMSUP) to heifers throughout gestation on trace mineral status of the dam and calf, calving parameters, and calf characteristics. We hypothesized that VMSUP throughout gestation would enhance mineral status in the dam and offspring at birth and positively impact calf morphometric characteristics. Thirty-one Angus-based heifers (body weight [BW]=273.7 ± 1.10 kg) were estrous synchronized, bred with female sexed semen, then were randomly assigned to either a basal diet targeting gain of 0.45 kg/d (CON; n=14) or the basal diet plus a vitamin and mineral supplement (VTM; n=17; 113 g•heifer-1•d-1). Liver biopsies were obtained from dams at breeding, d 84 and 180 of gestation, and at calving from dams and calves. Trace mineral concentrations were determined via inductively coupled plasma mass spectrometry. Calving ease, calf vigor and body weight were recorded at birth, and body measurements were recorded at 24 h after birth. Data were analyzed using the GLM Procedure of SAS using repeated measures analysis when appropriate. In maternal liver, concentrations of selenium and copper were affected by a treatment × day interaction (P < 0.0001), being greater (P < 0.001) for VTM than CON at all post-breeding timepoints and decreasing (P ≤ 0.05) from d 84 to calving; while zinc, molybdenum, manganese, and cobalt were not (P ≥ 0.20) affected by treatment. In calves, concentrations of liver selenium, copper, zinc, and cobalt were greater for VTM than CON (P < 0.05). Gestation length, calving distribution, ease and vigor scores, calf BW and body measurements were not affected by treatment (P = 0.278). Therefore, VTM supplementation throughout gestation affected liver trace mineral reserves of dam and calf; but did not affect calf size or any of the calving parameters evaluated. These results suggest that as gestation progresses, maternal liver mineral stores decrease to provide for the gestating calf.

92 Maternal Nutrient Restriction of Primiparous Beef Heifers During Late Gestation Decreases Colostrum Yield and Reduces Calf Vigor

Abstract We hypothesized that late gestational nutrient restriction (NR) would reduce colostrum yield and impair offspring transition to postnatal life. Primiparous, fall-calving crossbred beef heifers (BW: 451 ± 28 [SD] kg; BCS: 5.4 ± 0.7) were individually-fed either 100% (control; CON; n = 12) or 70% (n = 13) of NASEM net energy and metabolizable protein requirements for maintenance, pregnancy, and growth from d 160 of gestation to parturition. Delivery duration was determined as minutes from first fetal feet expulsion to birth. Calves were reared naturally by their dams and monitored for times from birth to first sternal recumbency, attempt to stand, and stand; vigor scores (1 = very weak, 5 = extremely vigorous) were assigned at 2, 5, 10, and 20 min of age. Total colostrum from one rear quarter was collected pre-suckling. Calf rectal temperatures were recorded at 0, 6, 12, 24, and 48 h postnatally. Data were analyzed with the fixed effects of treatment (single point) or treatment, hour, and their interaction (over time, using repeated measures). Date of calving was a fixed effect; calf sex was included when P < 0.25. Heifers fed CON had greater (P = 0.04) colostrum weight and volume than NR. Although gestational nutrition did not affect (P = 0.72) calf birth weight, calves born to CON heifers had faster (P = 0.02) times to stand and tended to have faster (P = 0.09) times to attempt to stand. Calves from CON heifers had greater (P = 0.05) 20 min vigor scores. Rectal temperatures at 0 h were greater (P = 0.02) in CON calves, but at 24 h were greater (P = 0.04) in NR calves. These data indicate that heifers nutrient restricted during late gestation have reduced colostrum yield and less vigorous calves, which may influence postnatal calf survival.

Longitudinal study of calf morbidity and mortality on smallholder farms in southern Ethiopia.

Calf morbidity and mortality are serious constraints in the success of dairy calf production. Thus, the current study was carried out with the objective to estimate the incidence of calf morbidity and mortality and associated risk factors in milk-shed districts of Gamo Zone, Southern Ethiopia. A prospective cohort and cross-sectional survey were employed from November 2019 to April 2020. A total of 196 calves were recruited by simple random sampling. Recruitment of calves was deployed by both the concurrent and prospective cohorts in calves aged below three months in study herds. The crude incidence of calf morbidity and mortality was 30.9% and 8.64%, respectively. The most frequently encountered disorder was calf diarrhea (10.17%), followed by pneumonia (6.5%). The other disorders were septicemia, omphalitis, arthritis, eye problem and miscellaneous cases. Multivariable Cox regression was revealed significant association for the calf vigor status, colostrum ingestion time, colostrum feeding status, dam parity, age at first calving, and related disorders were found risk factors of calf morbidity; likewise, calf vigor status at birth, time of colostrum ingestion and weaning were risk factors determining calf mortality. Calf morbidity and mortality rates recorded in this study were marginally higher than economically tolerable level, therefore, could affect the productivity of smallholder dairying by decreasing the obtainability of replacement heifers. Among significant explanatory factors investigated, colostrum ingestion time, method and amount were found important determinant factors of calf mortality and morbidity under the small-holder farming in the milk-shed districts of the Gamo zone. Therefore, rigorous calf husbandry practice is a need to manipulate the aforementioned calf determinants with subsequent application of tailor-made interventions.

24 Effects of Spring versus Fall Calving on Fetal Growth, Vigor at Birth, and Neonatal Circulating Metabolites in Beef Calves

Abstract To determine the effect of season on perinatal nutrient availability, assessed through fetal growth, calf vigor, and neonatal circulating metabolites, multiparous and primiparous dams (age: 4.7 ± 2.4 yr; BCS: 5.3 ± 0.6) from 4 spring (2014–2017; n = 202) and 4 fall (2015, 2017–2019; n = 177) calving experiments were observed during parturition. Time to stand (spring: 67; fall: 104) was determined as minutes from birth to standing for 5 sec. After birth, calf BW and size (spring: 99; fall: 169; length, heart girth, abdominal girth, and cannon circumference) were recorded. Jugular blood samples were obtained from 63 spring and 89 fall calves at 0 (pre-suckling), 6, 12, 24, and 48 h postnatally. Data were analyzed either with the fixed effect of season (single point) or the fixed effects of season, hour, and their interaction with hour as a repeated effect (over time); calf sex was included when P < 0.25. Experiment was a random effect. Fall-born calves tended to have lighter (P = 0.09) BW and faster (P = 0.05) time to stand than spring-born calves. Season did not affect (P ≥ 0.18) other calf size measures. The season x hour interaction (P ≤ 0.07) affected circulating glucose, non-esterified fatty acids (NEFA), triglycerides, urea nitrogen, globulin, and total protein. Spring-born calves had greater (P ≤ 0.009) 0 h glucose, 0 and 6 h NEFA, and 0, 6, 12, and 48 h triglycerides than fall-born calves. Fall-born calves had greater (P = 0.03) total protein at 24 h and tended to have greater (P ≤ 0.10) total protein and urea nitrogen at 48 h and globulin at 24 h. Season affected albumin, which was greater (P = 0.003) in fall-born calves. These data suggest that calving season influences perinatal nutrient availability, which may impact the transition to postnatal life.

Influence of calf vigour and suckling assistance from birth to weaning in Guzerá beef cattle

Context Maternal ability, cow nutrition, and calf sex are factors that affect beef cattle production in extensive systems. The Guzerá cattle is an important breed in Brazil, where satisfactory growth rates are reported; however, studies on post-parturition calf and cow behaviour are scarce. Aims This study aimed to identify the influence of vigour at birth (ability to stand and suckle without assistance) and human assistance in colostrum intake (HA) on the haematological profile, cortisol concentration, and growth until weaning of Guzerá beef calf. Methods The following traits were observed in 73 male and 83 female calves: cow age at calving, sex, birthweight, vigour, HA, haematological profile, cortisol concentration, bodyweight at 120 days (W120), weaning weight, average daily gain and mortality. Variance analysis was performed using the general linear model procedure of the SAS software. Key results Haematocrit (P = 0.04) and red blood cells (P = 0.004) were higher in calves requiring HA. Cortisol was also higher (P = 0.03) in calves that required HA (81.34 ng/mL × 59.40 ng/mL). The weaning weight and average daily gain were higher (P < 0.05) in calves that did not require HA and showed good vigour (200.38 kg and 0.83 kg/day respectively) than in calves that required HA and showed good vigour (163.7 kg and 0.68 kg/day respectively). The mortality rate was higher in calves that showed poor vigour at birth (25%). Conclusions Both vigour and the need for HA are important traits that should be evaluated during the development of newborn calves. These assessments in the herd can contribute to minimise the mortality rate and maximise the health and weight gain until weaning of beef calves. Implications Few studies have reported the role of vigour and colostrum intake in the development of calves. Despite the difficulty of human interference in extensive cattle farming, the calf vigour combined with human assistance at birth can minimise the losses and increase the performance of beef cattle.

86 Factors affecting beef calf vigor at birth: Dam peripartum body condition score, calving season, and calf size

Abstract To determine effects of cow BCS and calving season on calf vigor and size and the relationship of calf size with vigor, 310 multiparous and primiparous beef cows (age: 4.6 ± 2.2 yr; BW: 663 ± 86 kg; BCS: 5.3 ± 0.6) from 3 spring (2015, 2016, 2017) and 4 fall (2015, 2017, 2018, 2019) calving seasons were observed during parturition. Time to stand (n = 191) was determined as minutes from birth to standing successfully for 5 sec. Within 24 h, calf BW (n = 187) and size [shoulder to tailhead length (STL), heart girth (HG), and abdominal girth (AG; n = 154)] were recorded. Data were analyzed using a mixed model containing effects of calving season (spring and fall), BCS category (< 5, =5, ≥6), and their interaction. Correlations were determined between time to stand and calf measurements separately for spring (n = 79) versus fall (n = 111). Cows with BCS < 5 gave birth to lighter (P = 0.02) calves that tended to have a faster (P ≤ 0.13) time to stand than =5 and ≥6. Calves from cows with BCS ≥6 tended to have greater (P ≤ 0.09) STL than =5 and < 5. Calves from cows with BCS < 5 had smaller (P = 0.13) HG than =5. Fall-born calves tended to have smaller (P ≤ 0.06) BW, HG, and AG than spring-born calves. Within fall calves, there tended to be a positive relationship (r = 0.16; P = 0.09) between time to stand and calf BW. Despite this, spring calves had a negative relationship (r = -0.26; P = 0.02) between time to stand and calf BW. In conclusion, cow BCS and calving season affect calf size and may affect calf vigor. These data suggest that calving season may dictate the relationship between calf vigor and size.

38 Effect of Breed on Dairy Calf Vigor from Birth to Preweaning

Abstract There is a stigma in the dairy industry that Brown Swiss calves are not as quick to stand and nurse following birth compared to other dairy breeds. The objective of this study is to determine if Brown Swiss calves are less vigorous at birth and if this affects their health status and early calf growth compared with the dairy industry’s most prominent breed, the Holstein. All calves (n = 25) were scored shortly after birth using a modified Apgar scoring system used for infants. Thirteen parameters divided into 5 categories were evaluated to determine overall vigor of each calf. These included visual scores for meconium staining and swelling of the head; initial mobility scores for time to lift head, time to stand, and ear position; general responsiveness scores included strength of the suckling reflex, head shake in response to straw in nasal cavity, tongue withdrawal when pinched, and eye reflex; oxygenation score for mucus membrane color; rates scores included heart rate, respiration rate, and temperature. In addition to the vigor scoring, a weight was taken at birth and 2 weeks post calving. Jugular blood samples were collected at birth, 24 hours later, and at 2 weeks of age, and serum was stored for later analysis of haptoglobin and IgG concentration. Vigor scores and weight data were analyzed by breed using the mixed procedure in SAS. The vigor score for suckling reflex was lower (P = 0.04) for Brown Swiss calves (1.69, n = 12) than Holstein calves (2.39, n = 13). A weakened suckling reflex can lead to more challenges when consuming colostrum. Early colostrum intake is vital to obtaining passive immunity and maintaining health status in young calves. All other vigor scores collected for the Brown Swiss and Holstein calves did not differ (P > 0.05).

39 Effect of Breed on Dairy Calf Vigor from Birth to Preweaning

Abstract There is a stigma in the dairy industry that Brown Swiss calves are not as quick to stand and nurse following birth compared to other dairy breeds. The objective of this study is to determine if Brown Swiss calves are less vigorous at birth, and does this impact their health status and early calf growth compared with the dairy industry’s most prominent breed, the Holstein. All calves (n = 25) were scored shortly after birth using a modified Apgar scoring system used for infants. Thirteen parameters divided into 5 categories were evaluated to determine overall vigor of each calf, these included visual scores for meconium staining and swelling of the head; initial mobility scores for time to lift head, time to stand, and ear position; general responsiveness scores included strength of the suckling reflex, head shake in response to straw in nasal cavity, tongue withdrawal when pinched, and eye reflex; oxygenation score for mucus membrane color; rates scores included heart rate, respiration rate, and temperature. In addition to the vigor scoring a weight was taken at birth and 2 weeks post calving. Jugular blood samples were collected at birth, 24 hours later, and at 2 weeks of age and serum was stored for later analysis of haptoglobin and IgG concentration. Vigor scores and weight data were analyzed by breed using the mixed procedure in SAS. The vigor score for suckling reflex was lower (P = 0.04) for Brown Swiss calves (1.69, n = 12) than Holstein calves (2.39, n = 13). A weakened suckling reflex can lead to more challenges when consuming colostrum. Early colostrum intake is vital to obtaining passive immunity and maintaining health status in young calves. All other vigor scores collected for the Brown Swiss and Holstein calves did not differ (P > 0.05).

Maternal-offspring behavior of Guzerat beef cattle

Abstract: The objective of this work was to evaluate the characteristics of the maternal-offspring behavior of Guzerat bovines (Bos indicus) and the influence of this behavior on herd losses. A total of 73 gestating cows (multiparous and primiparous) and their respective calves were evaluated for the following behavioral traits: contact period between cow and calf (CPCC), cow age at calving, teat conditions, calf vigor at birth, need for human assistance (HA), and calf mortality until weaning. The mean weight of calves at birth was 29.12 kg. Vigor at birth was observed in 61.64% of calves; however, 27.4% of the calves required human assistance. Calf vigor was influenced by the CPCC, and calves without vigor needed more time with their mothers. Calves with low weight at birth required HA, whereas calves from cows with intermediate-sized teats did not. The absence of vigor at birth increased the mortality rate. The traits age of cows and vigor of calves at birth influence both the need for human assistance to calves in their first hours of life and herd losses.

PSI-14 Relationships of neonatal beef calf vigor with metabolic status

Abstract The objective of this study was to evaluate the relationships of neonatal beef calf behavior with calf serum metabolites. Angus, Hereford and crossbred beef females (n = 36; age = 4.0 ± 1.74; BCS = 6.5 ± 1.04; primiparous =5, multiparous = 31; calving date = April 4, 2018) and their calves were monitored continuously from 0 to 4 h post-parturition using a digital video recording system from March to May 2018. Jugular blood samples were obtained from calves at 24 (24.4 ± 1.73) and 48 to 72 (54.7 ± 9.08) h postnatal to determine serum blood urea nitrogen (BUN), glucose, non-esterified fatty acids (NEFA), and total protein (TP). Video was analyzed for behavior latencies calculated from time of birth to time when calf shakes head, kneels, attempts to stand, stands, and suckles. Time to stand had a weak positive correlation (P = 0.03) with time to suckle. Time to shake head had a moderate positive correlation (P ≤ 0.04) with both time to attempt to stand and time to stand, but did not correlate (P = 0.99) with time to suckle. Dam parity (multiparous or primiparous) did not affect (P ≥ 0.20) calf vigor measures. Time to suckle had a moderate negative correlation (P ≤ 0.05) with both serum glucose and total protein at 24 and 72 h, however did not correlate (P ≥ 0.31) with BUN or NEFA serum concentrations. In conclusion, the initial calf vigor measures were poor predictors of time to suckle; however, time to stand may be a viable vigor measure used to predict calf suckling. Further analysis of immunoglobulin G concentrations in calf serum will be used to determine if these vigor measures have a relationship with passive immune transfer in beef calves.

Quantifying subclinical trauma associated with calving difficulty, vigour, and passive immunity in newborn beef calves

This cross-sectional study quantifies subclinical trauma associated with calving difficulty, calf vigour, and passive immunity (PI) in newborn beef calves. The degree of calving difficulty was categorised as: unassisted, easy...

Quantifying the forces applied during assisted calvings and the impacts on newborn beef calves

Dystocia is recognized as the leading cause of mortality in the beef industry, with almost 26% of neonatal calf losses being attributed to birth-related issues. The term dystocia is defined as a prolonged or difficult birth that may or may not require human intervention, while calving ease is a subjective measure of the effort required for an assisted delivery. A Canadian study reported that 8.9% of calvings in beef herds required assistance, with severe dystocia occurring in 3.7% of births. Similarly, in the United States, 7.7% and 3.4% of heifers and 3.2% and 1% of cows, respectively, required easy and hard pulls to deliver their calf. Despite the incidence and impacts of assisted calvings, there is little available data that quantifies the forces applied during an assisted delivery and the associated compromise in the newborn calf. The objectives of this study were to: 1) quantify the force applied during manual and mechanical delivery of beef calves, and 2) examine the association of force with calf birthweight, vigour, acidemia, and tissue trauma.

Effect of implementing a novel calf vitality scoring system and early intervention program on pain management in newborn dairy calves

Pain management in newborn calves after dystocia and assisted calving is still not addressed by most producers or veterinarians. The calf VIGOR scoring system, developed at the University of Guelph, was designed to be applied within minutes after birth to assesses Visual appearance, Initiation of movement, General responsiveness, Oxygenation, and heart and respiration Rates in calves. The VIGOR scoring system was designed to identify high risk/low vigor calves for the purpose of applying interventions to improve vigor and survivability. In different studies conducted at the University of Guelph it was reported that providing pain management with a non-steroidal anti-inflammatory (meloxicam), shortly after birth, may improve calf vitality, health and performance outcomes, particularly in calves experiencing dystocia. The objective of this study was to conduct a randomized controlled trial to evaluate the effect of implementing a novel program that includes assessment of newborns using the VIGOR scoring system followed by provision of meloxicam to calves with low vigor scores, on outcomes reflecting calf well-being and health.

Development of a newborn calf vigor scoring system

Dystocia is a significant issue in Holstein cattle. Injury, pain, inflammation, acidosis, and low overall vitality are common effects seen in calves that survive. In humans, a standard vigor scoring system has been used for over 60 years. This score is based on Appearance, Pulse, Grimace, Activity, and Respiration (Apgar Score). A validated method of assessment of newborn calf vitality has not been developed. Also, pain management in newborn calves after dystocia is not often addressed by veterinarians or producers. It was the overall objective of this research to identify the various effects of calving difficulty on newborn dairy calves, and to relate these effects to easily measurable signs of reduced vigor. These signs were quantified into a VIGOR Scoring System. Also, methods to reduce pain, inflammation, and acidosis resulting from dystocia were investigated.

Quantifying the relationship between calving ease and physiological indicators of trauma in beef calves

Calf survival is crucial to successful cow-calf operations. One major factor that impacts calf health and survival is the amount of difficulty experienced during the birthing process. Assisted calves are often born weak, which can interfere with normal neonatal behaviors such as ingesting colostrum, leading to failed transfer of passive immunity and increased morbidity and mortality before weaning. Few studies have quantified physiological indicators of trauma in calves assisted at birth, nor have the effects of trauma on passive immunity been thoroughly assessed. The objective of this study is to quantify the associations of calving ease, calf vigour, and birth L-lactate, with trauma biomarkers and passive immunity in newborn beef calves.

Predictors and impacts of colostrum consumption by 4 h after birth in newborn beef calves

Newborn beef calf vigor is a vital survival characteristic that promotes timely colostrum consumption. Modified APGAR scores intended to identify compromised calves are not widely adopted due to impracticality, inconsistent associations with blood gas disturbances, and unclear recommendations for intervention. The objectives were to: (1) determine differences in at-birth blood parameters between calves that were successful in colostrum consumption by 4h (CC4) compared to those that failed; (2) develop a Beef Calf Vigor Assessment by determining calving characteristics and clinical examination parameters associated with CC4; and (3) evaluate impacts of failed CC4 on transfer of passive immunity and treatment risk.As a predictor for CC4, suckle reflex had the highest specificity (98%), whereas calving ease had the highest sensitivity (89%). Calves with a weak suckle reflex had 41.6 (95% CI: 7.4–787.5) times greater odds of failed CC4 compared to calves with a strong suckle reflex (P<0.0001). Calves with failed CC4 had lower serum IgG (P=0.01), had lower odds of acquiring optimal passive immunity (>24g/L serum IgG; OR=6.4, 95% CI: 1.2–34.4; P=0.02), and higher odds of being treated (OR=2.8, 95% CI: 1.1–7.4; P=0.03) than those that succeeded. Measuring suckle reflex in combination with calving ease was a quick and easy method to assess newborn beef calf vigor. The value of this Beef Calf Vigor Assessment was further emphasized by the negative impacts of failed CC4 on transfer of passive immunity and pre-weaning health.

Effect of calving assistance and supplementation of colostrum with sodium bicarbonate on newborn calf vigor, success of passive transfer, health, and growth of dairy calves

The objective of this research was to examine the efficacy of supplementing colostrum with sodium bicarbonate for improving passive transfer, health, and growth. An additional objective was to evaluate the effects of calving difficulty on calf vigor. A total of 543 heifer and bull calves from 9 commercial dairy herds were enrolled in this randomized double-blind field trial. At birth, calves were assessed for vigor by the dairy producer, using a prototype calf vigor assessment tool which rated Visual appearance, Initiation of movement, General responsiveness, Oxygenation, and Rates of heartbeat and respiration (VIGOR). Subsequently, calves were fed colostrum supplemented with either 20 g of sodium bicarbonate (SB) or placebo powder. Blood was collected from each calf between 1 and 8 days of age for serum total protein (STP). Each calf was assessed with a standardized clinical score for general health, and measured for growth using a heart girth weight tape at 1, 2, 3, and 6 weeks of age. The findings suggest that calves born with assistance, or that were malpositioned at calving, had lower vigor than those born unassisted. Yet, calf vigor improved with time following birth. Measures from the VIGOR score, including slower responsiveness and a higher heart rate, were associated with reduced health. There was a significant interaction between sex of the calf and SB supplementation of colostrum with STP. Sodium bicarbonate supplementation of colostrum was not significantly associated with improved passive transfer, and had no significant effect on weight gain. Assessment of calf vigor in calves born with assistance may be an important management tool for dairy producers as an indicator that further intervention may be needed to improve health.

1052 Relationships of calf vigor at birth with calf size and circulating metabolites in fall-born beef calves

1052 Relationships of calf vigor at birth with calf size and circulating metabolites in fall-born beef calves