Effect of aluminized reflective hutch covers on calf health and performance

The effect of polyethylene hutches wrapped in aluminized reflective covers (ARC) on health and performance of pre-weaned Holstein heifers during summer was evaluated. Ambient and hutch temperature and temperature-humidity index (THI) were also assessed. The study was conducted from June to October 2016 where temperature, humidity, and THI ranged from ?1.3 to 38.4°C, 9.8 to 99.7%, and 33.6 to 81.1 units, respectively. Heifers enrolled at 1 d of life and housed in individual polyethylene hutches with (covered) or without (control) ARC were monitored until 60 d of life in 2 study groups (SG1, n = 94, monitored from June to September; and SG2, n = 101, monitored from August to October 2016). Calves were assessed twice per week for health status, behavior, rectal temperature, and respiratory rate. Similarly, hutch inner wall and sand bedding temperatures were determined for comparison between covered and control hutches housing calves. Four empty hutches per treatment group were continuously monitored for temperature and THI. The odds (95% confidence interval) of presenting diarrhea were 1.30 (1.01–1.60) times greater for calves housed in covered hutches than for those in the control group. Similarly, the odds of an abnormal ear score were 1.40 (1.03–2.00) times greater for calves in covered hutches compared with calves in control hutches. The odds of nasal discharge, eye discharge, and clinical dehydration did not differ between treatment groups. Rectal temperatures and respiratory rates were also similar in both groups. No differences were found in average daily gain between calves housed in covered and control hutches. Calf location determined at a fixed time during the day (starting at 1200 h) was associated with the use of ARC. The odds of remaining inside the hutch were 1.33 (1.03–1.70) times greater for calves housed in control compared with covered hutches. Overall, the average of hutch interior temperature was higher in covered compared with control hutches in both studies (SG1, 23.2 ± 0.06 vs. 22.8 ± 0.06°C; SG2, 17.1 ± 0.07 vs. 16.9 ± 0.07°C). Hutch THI was higher in covered empty hutches compared with control hutches in both study groups (SG1: 68.6 ± 0.06 vs. 67.6 ± 0.06°C; SG2: 60.2 ± 0.08 vs. 59.6 ± 0.08°C). Average temperature (measured at 1200 h) of the inner surface of the hutch wall was lower in covered compared with control hutches by 1°C (24.4 ± 0.13 vs. 25.4 ± 0.13°C), whereas the temperature of the sand bedding did not differ between groups. Our results suggest that the use of ARC did not generate a hutch microclimate that resulted in significant improvements on health and performance of pre-weaned dairy calves under these specific study settings.     

The effect of individual versus pair housing of dairy heifer calves during the preweaning period on measures of health,performance, and behavior up to 16 weeks of age

Pair housing of dairy heifer calves during the preweaning period helps meet the natural social needs of the calf and has been shown to improve growth and starter intake during the preweaning period as compared with individual housing. However, there is little evidence to suggest that pair-housed calves maintain their social and growth advantages past the weaning phase. The objective of this study was to investigate the effect of pair housing on measures of calf performance, health, and behavior up to 16 wk of age. Healthy Holstein and crossbred heifer calves were enrolled in the study after colostrum feeding, with the first calf randomly assigned to 1 of 2 housing treatments: pair (PR; 2 hutches with common outdoor space) or individual (INDV; 1 hutch plus outdoor space). All calves were bucket fed 4 L of milk replacer twice daily and weaned at 50 d of age. Weaned calves (6/group) remained with their treatment group until exit from the study at 16 wk. A venous blood sample was collected from each calf between 24 h and 7 d of age to test for serum total protein (g/dL). Body weights (kg) were obtained at birth, weaning, and 16 wk. Each enrolled calf was scored for health each week and calf health treatments were also collected. A hair sample was collected from the left shoulder at birth and 16 wk to assess hair cortisol (pg/mL). At enrollment, each calf was fitted with a triaxial accelerometer on the left hind leg for continuous recording of standing and lying time (min/24 h) for 16 wk. Latency to find feed, water, and lie down (min) at entrance to the weaned pen were recorded by continuous video observation. Open field testing with a novel object was performed at 5, 10, and 16 wk. Behaviors analyzed by video observation included latency to approach the object (s), vocalizations (n), and time spent immobile, walking, or running (s/10 min). Linear mixed models were used to determine the effect of treatment (INDV or PR) on calf growth, activity, and behavioral outcomes, which accounted for time, breed, the interaction of time and treatment, the random pen, and variability in testing day and repeated measurements within calf when appropriate. Twenty-four Holstein and crossbred calves (PR: n = 12, 6 pairs; INDV: n = 12) were enrolled from November 2 to December 23, 2018. The PR calves were 7.1 kg heavier at weaning and gained 0.15 kg/d more during the preweaning period as compared with INDV calves. In the 24 h after movement to the postweaning pen, PR calves lay down for longer periods of time (14.3 vs. 11.0 ± 0.4 h/d), and PR calves urinated more during novel object testing at 5 wk of age. Our study demonstrated benefits, such as better growth and increased lying time, of pair housing calves during the preweaning period.     

Effect of maternal exercise on calf dry matter intake,weight gain,behavior, and cortisol concentrations at disbudding and weaning

The objective of this study was to determine the effect of maternal physical activity during late gestation on calf dry matter intake, weight gain, behavior, and cortisol concentration during disbudding and weaning. Fifty-five Holstein and 5 Jersey × Holstein crossbred calves were enrolled into the study during gestation. Calves were born from pregnant, nonlactating Holstein (n = 58) and Jersey × Holstein crossbred (n = 2) dairy cows. Cows were assigned to either confinement (n = 20 cows; 13 female calves, 7 male calves), exercise (n = 20 cows; 8 female calves, 12 male calves), or pasture (n = 20 cows; 11 female calves, 9 male calves) treatments at dry-off from January to November 2015. Enrollment in treatment was balanced by parity (1.8 ± 0.9), projected mature-equivalent fat-corrected milk (13,831 ± 2,028 kg/lactation), dam breed, and projected calving date. Cows assigned to confinement remained in the pen throughout the dry period. Cows assigned to exercise were walked 5 times/wk at a targeted 1.5 h at 3.25 km/h. Cows assigned to pasture were turned out 5 times/wk for a targeted 1.5 h/d. Treatments were terminated on the expected due date or at signs of calving. Calves were removed from cows immediately once observed by farm staff and subsequently weighed and moved into a straw deep-bedded hutch. Data loggers were attached to the rear fetlock of each calf ?3 d to +6 d relative to disbudding and weaning to monitor changes in lying behavior. Calves were weighed on d ?7, ?5, ?3, ?1, 0, 1, 3, 5, and 7, and grain was weighed the 7 d preceding and following disbudding and weaning. Blood was collected 24 h before and 0, 1, and 4 h after disbudding and d ?1, 0, 1, and 2 relative to weaning to determine cortisol concentrations. Data were analyzed using mixed linear model in SAS (SAS Institute Inc., Cary, NC). Calf weight gain decreased the day after disbudding and calves tended to have elevated cortisol concentrations 1 h after disbudding, regardless of maternal treatment. Calf weight gain decreased the day of and after weaning; calves had elevated cortisol concentrations the day after weaning, regardless of treatment. Behavior did not differ by treatment at disbudding, but calves from pasture cows lay down for less time compared with confinement and exercise maternal treatments and less frequently than exercise maternal treatments at weaning. More research investigating the significance of lying time and restlessness around stressful events is needed to further understand the implications of such behavioral responses.     

The effect of milk-feeding method and hay provision on the development of feeding behavior and non-nutritive oral behavior of dairy calves

We investigated the interactive effects of common feeding management factors on the development of feeding and non-nutritive oral behaviors in preweaned calves through the weaning transition. Calves were randomly assigned to 1 of 3 treatments that differed by milk-feeding method (teat or bucket) and ad libitum access to chopped timothy hay: control, milk provided by bucket and no access to hay (CON; n = 10); milk provided by bucket and access to hay (H; n = 10); milk provided via a teat and access to hay (TH; n = 10). Calves had ad libitum access to concentrate and water, and were fed 6 L/d of pasteurized waste milk, divided into 2 meals. All calves were weaned by removing the second milk meal for 9 ± 2 d, beginning at 36 d of age. Daily concentrate and hay intake were recorded, and calves were weighed weekly to measure growth. We recorded the behavior of all calves using 2 s time-lapse video during time periods that encompassed milk meals, from 6000 h to 1000 h and 1600 h to 2000 h, on 2 consecutive focal days in wk 2 and 4. We continuously monitored lying time and activity using electronic data loggers. During the preweaning period, hay selection by H and TH calves was subject to a treatment × week interaction, with TH calves increasing hay intake to a greater extent over time. Similarly, we observed a tendency for a treatment × week interaction for hay dry matter intake. Before weaning, concentrate intake was subject to a treatment × week interaction, increasing to a greater extent over time for H and TH calves, but was greater overall for CON calves. As predicted, milk-feeding method and hay provision influenced the proportion of time devoted to feeding and non-nutritive behaviors. The CON calves spent the greatest amount of time performing non-nutritive sucking directed at the pen, TH calves the least, and H calves intermediate amounts. Considering the time TH calves sucked on their teat when milk was not present in addition to the time they spent sucking on pen fixtures, the total amount of time spent performing sucking behavior was similar between treatments. Although intake was similar across the weaning transition, CON calves had greater average daily gain than H calves, and TH calves were intermediate. Providing access to hay and milk via a teat during the milk-feeding stage decreased non-nutritive oral behaviors and influenced feeding behavior.     

The effect of rearing substrate and space allowance on the behavior and physiology of dairy calves

The objective of this study was to investigate the effect of rearing substrate and space allowance on the behavior and physiology of dairy calves. At 1 wk of age, 72 calves were moved into 1 of 18 experimental pens (n = 4 calves/pen) where they remained until 6 wk of age. Half of the pens had floors covered with quarry stones (QS) and the other half were covered with sawdust (SW). For each substrate type, calves were reared at 1 of 3 space allowances: 1.0, 1.5, or 2.0 m²/calf. Behavior was video-recorded continuously for 24 h in the home pen at 2, 4, and 6 wk of age; the time calves spent lying, standing, walking, and running were estimated using 1-min instantaneous scan sampling. Body weight, cleanliness, fecal fluidity, and skin surface temperature were recorded at 1, 4, and 6 wk of age. Escherichia coli numbers were assessed on the skin surface of the shoulder and in feces of calves at 4 and 6 wk of age. Blood samples were taken at 1, 4, and 6 wk of age to measure cortisol, creatine kinase, immunoglobulin G, serum amyloid A, and total protein concentrations. Calves reared on QS spent less time lying and walking and more time standing at 4 and 6 wk of age compared with calves reared on SW. Furthermore, calves reared at a space allowance of 2.0 m²/calf spent less time lying and more time standing and walking compared with calves reared at a space allowance of 1.0 and 1.5 m²/calf. Calves reared on QS had lower skin surface temperatures compared with calves reared on SW. Fecal fluidity scores were lower in calves reared on QS than SW at 2 wk of age. Fewer E. coli were recovered from the shoulder of calves reared on QS than those of calves reared on SW, but fecal E. coli counts were similar between rearing substrates and space allowances. Serum amyloid A concentrations were lower in calves reared on QS than SW. We detected no effect of rearing substrate or space allowance on body weight, cleanliness, or concentrations of cortisol, creatine kinase, immunoglobulin G, and total protein. In conclusion, lower skin temperature in combination with reduced lying behavior may reflect reduced comfort of calves reared on QS. Furthermore, a space allowance of 2.0 m²/calf may provide calves with more opportunity to perform active behaviors.     

Short communication: The effect of diarrhea and navel inflammation on the lying behavior of veal calves

Many veal calves arrive to growing facilities with diseases, including diarrhea and navel inflammation. Observing neonatal calf behavior, such as lying behavior, can be used to better detect and determine the implications of these diseases. The aim of this study was to determine the effect of navel inflammation and diarrhea on lying behavior in neonatal veal calves. This study was part of a larger experiment that included a total of 360 male Holstein calves from 3 cohorts; from these calves, we selected a subset of 125 calves (every third calf as they entered the barn) to be fitted with 3-dimensional accelerometers (Hobo Pendant G data loggers; Onset Computer Corp., Bourne, MA) on 1 hind leg to continuously measure lying time, number of lying bouts, and lying bout duration. Calves were housed individually on slatted flooring (Tenderfoot; Tandem Products Inc., Minneapolis, MN) in 3 rooms of a mechanically ventilated barn. Health exams were conducted twice weekly for 2 wk starting the day after arrival. Exams included rectal temperature, navel score (0 = normal, 1 = mildly inflamed, 2 = moderately inflamed, 3 = severely inflamed), and fecal score (0 = normal, 1 = semiformed, 2 = loose, 3 = watery). Calves were considered to have navel inflammation (n = 22) or diarrhea (n = 15) if they scored ≥2 during at least 3 of the 4 health exams. The lying behavior of these calves was compared with that of normal calves (n = 18) that had no signs of illness and rectal temperatures <39.4°C during at least 3 of the 4 health exams. Data were analyzed using a repeated-measures ANOVA; models included cohort (1, 2, or 3), health status (normal, navel inflammation, or diarrhea), week (1 or 2), and a health by week interaction. There was an effect of health status on lying time, whereby normal calves spent more time lying compared with calves with inflamed navels and tended to spend more time lying compared with calves with diarrhea. There was no effect of health status on the number of lying bouts per day or on the duration of lying bouts. There were no health by week interactions. Results indicate that neonatal veal calves with navel inflammation and diarrhea may be less comfortable than calves without these conditions. Veal producers should consider adapting their facilities to create more comfortable lying environments to help calves better recover from disease, such as by adding a hospital pen with comfortable bedding.     

Effects of gradual and later weaning ages when feeding high milk replacer rates on growth,textured starter digestibility,and behavior in Holstein calves from 0 to 4 months of age

The objectives of this study were to evaluate calf performance, diet digestibility, and behaviors when feeding 4 milk replacer (MR) programs with different MR rates, weaning ages, and MR reduction steps. Male Holstein calves (n = 96; 40 ± 1 kg of body weight; 1 to 2 d of age) were housed in individual pens for 56 d. Feeding programs for MR were 0.66 kg for 35 d; then 0.33 kg for 7 d fed only in the a.m. (0.6 kg); 0.66 kg for 7 d, 0.82 kg for 35 d, 0.33 kg for 4 d in a.m. only, and 0.22 kg for 3 d in a.m. only (0.8 kg); 0.66 kg for 7 d, 0.82 kg for 7 d, 1.1 kg for 21 d, 0.82 kg for 7 d, 0.33 kg for 4 d in a.m. only, and 0.22 kg for 3 d in a.m. only (1.1 kg); and ad libitum allowance for 35 d, 0.82 kg for 7 d, 0.44 kg for 4 d in a.m. only, and 0.22 kg for 3 d in a.m. only (ad lib). Calves were fed a common MR [25% crude protein, 17% fat, dry matter (DM) basis]. A textured calf starter with whole corn and oats (20% crude protein and 39% starch, DM basis) and water were fed for ad libitum intake during the nursery trial. Daily behavior duration (rumination, eating, and activity) was continuously recorded from d 1 to 55 for 4 calves/treatment using ear tag accelerometers (CowManager SensOor; Agis, Harmelen, the Netherlands). All calves were moved into groups by MR program (4 calves/pen) at 56 d and fed the same starter blended with 5% grass hay. Fecal samples were collected from individual calves between d 52 to 56 and from pen floors on d 66 to 70 to estimate total-tract digestibility. Data were analyzed as a randomized complete block design with repeated measures when appropriate. Intake of MR averaged 25.3, 35.3, 40.9, and 46.5 kg of DM per calf for 0.6 kg, 0.8 kg, 1.1 kg, and ad lib treatments, respectively. Starter intake was greatest for 0.6 kg compared with others and average daily gain (ADG) differed among all 4 programs with 0.6 kg < 0.8 kg < 1.1 kg < ad lib during d 0 to 56. Intake of MR for ad lib was highly variable and was reflected in ADG. Daily rumination, eating, and activity durations did not differ among treatments from d 1 to 55 of the nursery trial. Digestibility of DM, organic matter, acid and neutral detergent fiber, and sugar at d 52 to 56 were greater for 0.6 kg versus ad lib. Digestibility of DM at d 66 to 70 differed for all treatments with 0.6 kg > 0.8 kg > 1.1 kg > ad lib and was mostly influenced by fiber digestibility. During the grower trial (d 56 to 112), ADG was greater for 0.6 kg versus 1.1 kg and ad lib. Hip width change was greater for 0.6 kg versus other treatments. Feeding more than 0.6 kg/d of MR increased ADG preweaning, but reduced diet digestibility postweaning resulted in similar calf BW and frame size by 4 mo of age among MR feeding programs.     

The effect of increasing the nutrient and amino acid concentration of milk diets on dairy heifer individual feed intake,growth, development,and lactation performance

Increasing early (<3 mo) nutrient feeding levels and growth rate of dairy calves has been found to increase their milk production potential. The objective of this study was to compare the effect of offering milk diets with or without added carbohydrates and amino acids on calf growth, weaning age, and subsequent growth and milk yield of dairy heifers in their first lactation. Friesian calves born at Massey University (n = 57) were selected at random, weighed, and allocated to receive 1 of 3 diets. All calves were fed colostrum from 1 to 3 d of age, followed by 4 L of whole milk (WM) per head per day and probiotics between 3 and 18 d of age. At 18 d of age, calves were weighed to ensure mean body weight (BW); then, at 19 d of age, calves changed diets to 1 of 3 treatments, which reached full treatment rate at 21 d of age. The diets were 4 L/head per day of WM (M); 4 L/head per day of WM plus 200 g of plant carbohydrates (MP); and 4 L/head per day of WM plus 200 g of plant carbohydrates with amino acids (MPA). Calves were weaned upon reaching a BW of 90 kg. During this period, BW, body condition, and hip height and width were measured. The heifers were commingled and grazed on ryegrass and white clover pastures until calving at 23 mo of age, when BW, body condition, and hip height and width were measured again. Milk yield and composition were measured throughout first lactation. At weaning, calves fed MPA had greater mean BW gain, a lower number of days to target BW, and a greater mean hip width gain compared with calves in the M group, although mean gain in hip height did not differ among treatments. Total calf starter intake during the milk period was lower for MPA-fed calves compared with those offered M, mainly due to a shorter milk feeding period required to attain the 90-kg weaning weight, whereas mean daily starter intake and straw intake did not differ. No difference was observed in the calving rate or calving age of heifers in any of the dietary feeding groups. First lactation fat-corrected milk yield, milk fat percentage, and total milk fat and protein yields were greater for animals reared on MP and MPA compared with M. Body weight, hip height and width at parturition, milk protein percentage, somatic cell count, or days in milk did not differ among treatments. Increasing nutrient intake, during the milk feeding period, improved the BW gain of calves and milk production of dairy heifers during first lactation.     

The effects of teat bar design and weaning method on behavior, intake, and gain of dairy calves

The aim of the present study was to investigate the effects of teat-feeding method and weaning method on behavior, milk and concentrate intake, and weight gain of group-housed dairy calves. Forty-eight calves were housed in groups of 4 and offered 6 L of whole milk per calf in 2 daily feedings. In 6 of the 12 group pens, the calves were offered the milk in a teat bar with a separate milk compartment for each teat, whereas in the remaining 6 pens, the calves were offered the milk in a teat bar with all teats connecting to 1 shared milk compartment. Calves were gradually weaned off milk by reducing the volume of milk over a 10-d period, starting at an average age of 47 d. In 6 pens (3 pens with each of the 2 milk-feeding treatments), calves were weaned by volume reduction, whereas in the remaining pens, the calves were weaned by diluting the milk with water (WD) and maintaining the same total volume of liquid. Daily concentrate intake per pen was recorded during weaning and 1 wk after weaning. Behavior was recorded around milk feeding, by direct observation on 1 occasion before and on 1 occasion during weaning, and by video on 1 occasion before and 2 occasions during weaning. Furthermore, the behavior was recorded during the 15 h of light on 1 occasion during weaning. Individual milk intake was measured twice by weighing the calves immediately before and after milk feeding. The calves fed via a separate teat bar switched between teats more often than calves fed with a shared teat bar. There was greater variation in the duration of ingesting milk within groups fed via a separate teat bar, but no effect of teat bar design was found on the variation in milk intake within the groups. Calves fed via a separate teat bar took longer to start eating concentrate after milk feeding than calves fed with a shared teat bar. The WD calves had a lower concentrate intake during weaning than weaned by volume reduction calves. The WD calves were lying down less during the 30 min after milk feeding and during the 15 h of light, although they had a shorter latency to lie down after milk feeding. In conclusion, a separate teat bar increased teat switching, increased variation in duration of ingesting milk, and increased the latency to eat concentrates after milk feeding. There was no effect of the teat bar design on feed intake or weight gain. However, weaning the calves by gradually diluting the milk with water reduced lying during weaning and reduced the concentrate intake during and after weaning.     

Characterizing social behavior,activity, and associations between cognition and behavior upon social grouping of weaned dairy calves

Weaned dairy calves are commonly exposed to changing physical and social environments, and ability to adapt to novel management is likely to have performance and welfare implications. We characterized how behavioral responses of weaned heifer calves develop over time after introduction to a social group. Previously individually reared Holstein heifer calves (n = 15; 60 ± 5 d of age; mean ± standard deviation) were introduced in weekly cohorts (5 ± 3 new calves/wk) to an existing group on pasture (8 ± 2 calves/group). We measured activity and behavior on the day of initial introduction and after 1 wk, when calves were exposed to regrouping (addition of younger calves and removal of older calves from the pen). Upon introduction, calves had 2 to 3 times more visits to each region of the pasture; they also spent more time at the back of the pasture, closest to where they were introduced and furthest from the feeding area (25.13 vs. 9.63% of observation period, standard error = 5.04), compared with behavior after 1 wk. Calves also spent less time feeding (5.0 vs. 9.6% of observation period, standard error = 0.82) and self-grooming (0.52 vs. 1.31% of observation period; standard error = 0.20) and more time within 1 to 3 body lengths of another calf (16.3 vs. 11.9% of observation period, standard error = 2.3) when initially grouped. We also explored whether behavioral responses to initial postweaning grouping might be associated with individual differences in behavioral flexibility. To evaluate this, we assessed cognition of individually housed calves (n = 18) at 5 wk of age using a spatial discrimination task conducted in a T-maze to measure initial learning (ability to learn the location of a milk reward) and reversal learning (ability to relearn location of the milk reward when it was switched to opposite arm of the maze). Calves were categorized by reversal learning success (passed, n = 6, or failed, n = 8). Calves that passed the reversal learning stage of the cognitive task spent less time at the back of the pen (9.3 vs. 27.4% of observation period, standard error = 5.5) and tended to have lower latency to feed (121.8 vs. 306.2 min; standard error = 96.4) on the day of introduction compared with calves that failed reversal learning. Overall, we found that initial introduction to social grouping had a marked influence on behavior of weaned calves that decreased over time. Further, these results suggest that individual variability in cognitive ability may be predictive of behavioral responses and ability to adapt to a novel environment.     

Health,physiology, and behavior of dairy calves reared on 4 different substrates

The objective of this study was to compare the health, physiology, and behavior of group-housed calves reared on wood shavings with those reared on alternative surfaces. At 1 wk of age, 80 calves were moved into 1 of 20 experimental pens (n = 4 calves/pen) where they remained until 6 wk of age. Pens had floors covered with pea gravel (PG), rubber chip (RC), sand (SA), or wood shavings (WS; n = 5 pens/substrate). Body weight, cleanliness, health, and skin surface and vaginal temperature were recorded at 1, 3, and 6 wk of age. Escherichia coli numbers were assessed on the skin surface of the shoulder and in the feces of calves at 3 and 6 wk of age. Blood samples were taken at 1, 3, and 6 wk of age to measure hematological values and cortisol, IgG, and lactate concentrations. Behaviors (lying, running, and self-grooming) were recorded in the home pen at 1, 3, and 6 wk of age using video recorders and accelerometer data loggers. At 6 wk of age, calves were tested individually in an arena test and behavior was recorded continuously for 20 min. Body weight did not differ among calves reared on PG, RC, SA, or WS, regardless of age. All calves were clean and no calves displayed any signs of lameness, leg lesions, or injuries at wk 1, 3, or 6, regardless of substrate. The number of E. coli recovered from a surface area of 100 cm² on the shoulder of each calf was affected by rearing substrate, with more E. coli recovered from calves reared on WS than PG, RC, or SA at 3 and 6 wk of age. Fecal E. coli counts were not affected by rearing substrate at 3 or 6 wk of age. Over the entire study period, calves reared on PG and SA had lower skin temperatures than calves reared on RC or WS, but skin temperature was similar between calves reared on PG and SA. However, vaginal temperature did not differ among calves reared on different substrates at 1, 3, or 6 wk of age. Hematology values and cortisol, IgG, and lactate concentrations of calves were similar among rearing substrates over the 6-wk study period. In the home pen, rearing substrate did not influence time spent lying; however, calves reared on WS performed more lying bouts than calves reared on PG or SA. In addition, rearing substrate did not influence the time calves spent running; however, calves reared on WS spent more time self-grooming than calves reared on PG, RC, and SA. During a 20-min arena test, running, bucks, jumps, and kicks performed by calves was not affected by rearing substrate. In conclusion, the physiology and behavior of calves reared on PG, RC, and SA was similar to WS, which is considered the preferred rearing substrate to use when rearing calves. Therefore, PG, RC, and SA may be acceptable substrate options when rearing group-housed dairy calves.     

The effect of colostrum storage conditions on dairy heifer calf serum immunoglobulin G concentration and preweaning health and growth rate

The objective of the present study was to compare serum IgG concentration, weight gain, and health characteristics in Irish spring-born dairy calves fed colostrum stored using a range of conditions. Immediately after birth, 75 dairy heifer calves were assigned to 1 of 5 experimental colostrum treatments: (1) fresh pasteurized colostrum, fed immediately after pasteurization; (2) fresh colostrum, fed immediately after collection but not pasteurized; (3) colostrum stored unpasteurized at 4°C in a temperature-controlled unit for 2 d before being fed to calves; (4) colostrum stored unpasteurized at 13°C in a temperature-controlled unit for 2 d before being fed to calves; and (5) colostrum stored unpasteurized at 22°C in a temperature-controlled unit for 2 d before being fed to calves. All colostrum had IgG concentrations >50 g/L and was fed to calves promptly after birth. Blood samples were obtained from calves via the jugular vein at 0 h (before colostrum feeding) and at 24 h of age to determine the rate of passive transfer of IgG; individual calf live-weights were recorded to monitor weight gain (kg/d) from birth to weaning. Colostrum stored in warmer conditions (i.e., 22°C) had >42 times more bacteria present and a pH that was 0.85 units lower and resulted in a serum IgG concentration that was almost 2 times lower compared with colostrum that was pasteurized, untreated, or stored at 4°C for 2 d. Colostrum stored at 4°C for 2 d had more bacteria present than pasteurized and fresh colostrum but did not result in reduced calf serum IgG concentrations. Average daily weight gain from birth to weaning did not differ among treatments. Even if colostrum has sufficient IgG (>50 g/L) but cannot be fed to calves when freshly collected, storage at ≤4°C for 2 d is advisable to ensure adequate passive transfer when it is consumed by the calf.     

Measurement of dairy calf behavior prior to onset of clinical disease and in response to disbudding using automated calf feeders and accelerometers

We determined if feeding and lying behavior, recorded by automatic calf feeding systems (ACFS) and accelerometers, could be used to detect changes in behavior before onset of neonatal calf diarrhea (NCD) or in response to disbudding pain in dairy calves. At 4 d of age, 112 calves had accelerometers attached to their hind leg and were housed in pens with ACFS. Calves were examined daily for signs of illness or injury. Of the 112 calves monitored, 18 were diagnosed with NCD; activities of calves with NCD were then compared with those of 18 healthy controls (calves that had no symptoms of NCD, other illnesses, or injury). Feeding (milk consumption and the number of rewarded and unrewarded visits to the feeder) and lying behavior during the 5 d leading up to calves displaying clinical signs of NCD were analyzed. Calves with NCD performed fewer unrewarded visits and consumed less milk than healthy calves during the 2- and 4-d periods before diagnosis with NCD, respectively. Calves with NCD tended to perform fewer lying bouts than healthy calves over the 5-d period before diagnosis with NCD. At 3 wk of age, a subset of 51 healthy calves were allocated to 1 of 5 treatment groups: (1) sham handling (SHAM, n = 10), (2) cautery disbudding (DB, n = 11), (3) administration of local anesthetic (LA) and DB (LA+DB, n = 11), 4) administration of a nonsteroidal anti-inflammatory drug (NSAID) and DB (NSAID+DB, n = 9), and (5) administration of LA, NSAID and DB (LA+NSAID+DB, n = 10). Feeding and lying behavior were recorded continuously for 24 h pre- and postdisbudding. We found no effect of treatment on the number of rewarded or unrewarded visits to the feeder and milk volume consumed 24 h before administration of treatments. During the 24-h postdisbudding period, SHAM calves performed more unrewarded visits than DB, LA+DB, and NSAID+DB calves, but the number of unrewarded visits did not differ between SHAM and LA+NSAID+DB calves. During the first hour of the posttreatment period we noted a difference in lying times among treatments, with DB and NSAID+DB calves spending less time lying than SHAM calves and lying times being similar between SHAM, LA+DB, and LA+NSAID+DB calves. The ACFS and accelerometers have the potential to automatically gather valuable information regarding health status and pain in calves. Therefore, it may be advantageous to combine both of these measures (ACFS and accelerometers) when evaluating NCD on farm or pain in calves in future research.     

The influence of 3 different navel dips on calf health,growth performance,and umbilical infection assessed by clinical and ultrasonographic examination

The objectives were to investigate the effect of 3 navel dips on (1) umbilical infection, (2) health events (pneumonia, diarrhea, and arthritis), and (3) average daily gain (ADG) in newborn dairy calves. A secondary aim was to compare the agreement of standardized ultrasonographic examination with clinical examination for the diagnosis of umbilical infection. In a randomized block design, newborn calves were assigned by birth order to 3 treatment groups: Navel Guard (NG; SCG-Solutions Inc., McDonough, GA), 7% iodine tincture (SI), and 2% chlorhexidine gluconate (CH). Treatment consisted of a single dip administration of the umbilicus immediately after removal of the newborn from the calving pen with 1 of the 3 navel dips. Weekly clinical examinations were carried out during the first 4 wk of life with special attention being paid to the umbilicus, joints, respiratory tract, and fecal consistency, and included ultrasonographic evaluation of the umbilical structures. Body weight was assessed by using a girth tape at first and last evaluation. Multivariable logistic regression demonstrated no statistical differences in umbilical infection or health events. Multivariable linear regression analysis showed statistical differences in ADG (least squares means ± standard errors) between groups, with 494 ± 29, 571 ± 29, and 516 ± 29 g/d in groups NG, SI, and CH, respectively. Overall mortality during the study period was 9.5% (n = 40). Postmortem examination identified diarrhea (80%) as the main disorder with 19, 4, and 9 calves in groups NG, SI, and CH, respectively. Kappa values yielded fair [0.30 (95% CI: ?0.03–0.63)], good [0.61 (95% CI 0.46–0.75)], moderate [0.53 (95% CI 0.31–0.74)], and moderate [0.49 (95% CI 0.19–0.79)] agreement for detection of omphalitis between clinical and ultrasonographic evaluation in wk 1, 2, 3, and 4, respectively. Agreement was very good for detection of omphaloplebitis, with kappa values (95% CI) of 0.91 (0.80–1.00), 0.87 (0.75–0.98), and 0.90 (0.76–1.00) in wk 2, 3, and 4, respectively, when omphalophlebitis was diagnosed. We detected no difference in the effectiveness of the 3 treatments in the prevention of umbilical infection, pneumonia, diarrhea, or arthritis.     

An observational analysis of twin births, calf sex ratio, and calf mortality in Holstein dairy cattle

A data set of Holstein calving records from January 1996 to September 2004 comprising 4,103 herds with 2,304,278 calving events representing 1,164,233 cows and 96,069 twin births was extracted from Minnesota Dairy Herd Improvement Association archives to assess reported twinning trends and calf mortality across time. Overall, the reported twinning rate was 4.2%, and twinning increased with parity [1.2% for nulliparous vs. 5.8% for multiparous cows; odds ratio (OR) = 4.9], and with time (3.4% in 1996 to 4.8% in 2004), with a parity by time interaction. Independent of parity, the greatest twinning rate was observed when conception occurred from August to October compared with other seasons (OR = 1.2). Calf mortality was greater after twin births, with 28.2% of twin calving events reporting one or both calves as dead, compared with 7.2% for singleton births (OR = 6.5). Calf mortality for primiparous and multiparous cows was 5.0% after a single birth and 25.5% after twin births, whereas for nulliparous heifers, mortality was 10.4% for singletons and 38.0% for twins (OR = 3.4). Calf sex ratio (male, M; female, F) was 53.3% M and 46.7% F for singleton calves, and 30.1% MM, 43.6% MF, and 26.3% FF for twin calves. Although specific factors cannot be implicated, the increase in twinning across time suggests a concurrent change in one or more causative factors associated with twinning during the 9-yr study period.     

An observational analysis of twin births, calf stillbirth, calf sex ratio, and abortion in Iranian holsteins

Calving records of Holstein dairy cows from April 1998 to September 2006 comprising 16 herds with 104,572 calving events representing 4,045 twin births were used to evaluate reported twinning rate, calf sex ratio, stillbirth, and abortion rates in single and twin births. Overall, the reported twinning rate was 3.9%, and twinning increased with parity [1.1% for primiparous cows vs. 5.7% for cows in their fourth or greater lactation; odds ratio (OR) = 5.50]. Regardless of parity, the greatest twinning rate was observed when conception occurred in fall season from September to December (OR = 1.17). Calf stillbirth was greater after twin births, with 18.8% of twin calving events resulting in one or both calves as stillborn, compared with 4.0% for singleton births (OR = 7.58). Calf stillbirth for multiparous cows was 2.9% for single births and 18.0% for twin births (OR = 7.08), whereas for primiparous cows, stillbirth was 6.6% for singletons and 27.7% for twins (OR = 5.85). Calf sex ratios (male, M; female, F) were 52.4% M and 47.6% F for singleton calves and 28.2% MM, 48.9% MF, and 22.9% FF for twin calves. The mean abortion rate was 13.4%, with 13.8% for single births and 4.2% for twin births (OR = 1.22). Abortion rate for multiparous cows was 15.9% for single births and 4.0% for twin births (OR = 4.31), whereas for primiparous cows, abortion rate was 9.4% for single births and 5.4% for twin births (OR = 1.89). Although milk production, as a causative factor associated with twinning, increased in recent years, twinning rate decreased over the years.     

Effect of supplementing essential fatty acids to pregnant nonlactating Holstein cows and their preweaned calves on calf performance,immune response,and health

The objective was to evaluate the effect of supplementing saturated or unsaturated fatty acids (FA) during late gestation of cows and during the preweaning period of calves on growth, health, and immune responses of calves. During the last 8 wk of pregnancy, Holstein cattle (n = 96) were fed no fat supplement (control), a saturated FA (SFA) supplement enriched in C18:0, or an unsaturated FA supplement enriched in the essential FA linoleic acid. Newborn calves were fed a milk replacer (MR) with either low linoleic acid (LLA; coconut oil) or high linoleic acid (HLA; coconut oil and porcine lard) concentration as the sole feedstuff during the first 30 d. A grain mix with minimal linoleic acid was offered between 31 and 60 d of life. At 30 and 60 d of life, concentrations of linoleic acid in plasma were increased in calves born from dams supplemented with essential FA compared with SFA (44.0 vs. 42.5% of total FA) and in calves consuming HLA compared with LLA MR (46.3 vs. 40.8% of total FA). Total n-3 FA concentration was increased in plasma of calves fed HLA compared with LLA MR (1.44 vs. 1.32%) primarily due to increased α-linolenic acid. Prepartum supplementation with SFA tended to improve dry matter intake (48.8 vs. 46.7 kg) and improved average daily gain (0.50 vs. 0.46 kg/d) by calves without affecting efficiency of gain or circulating concentrations of anabolic metabolites or hormones. Increasing mean intake of linoleic acid from approximately 4.6 to 11.0 g/d during the first 60 d of life increased average daily gain (0.50 vs. 0.45 kg/d) without a change in dry matter intake, thus improving feed efficiency (0.63 vs. 0.59 kg of gain/kg of dry matter intake). Improved weight gain in calves fed HLA MR was accompanied by increased or tendency to increase plasma concentrations of glucose (92.7 vs. 89.9 g/dL) and insulin-like growth factor I (59.5 vs. 53.2 g/dL), increased hematocrit (36.0 vs. 34.4%) and concentration of blood lymphocytes (4.61 vs. 4.21 × 10³/μL), lowered plasma concentrations of acid-soluble protein (78.8 vs. 91.3 mg/L) and blood platelets (736 vs. 822 × 10³/μL), and increased production of IFN-γ by peripheral blood mononuclear cells at 30 d of age (48.1 vs. 25.6 pg/mL), possibly indicating an earlier development of the immune system. Partial replacement of coconut oil with porcine lard in MR improved calf performance and some aspects of immunity.     

Effects of additional milk replacer feeding on calf health, growth, and selected blood metabolites in calves

The objective of the experiment was to evaluate effects of increased milk replacer feeding on growth, intake, feed efficiency, and health parameters in stressed calves. Holstein bull calves (n = 120; approximately 3 to 8 d of age) were purchased from sale barns and dairy farms and housed in fiberglass hutches. In addition, wood shavings contaminated with coronavirus were mixed with clean shavings and added to each hutch before the start of the experiment. Calves were fed either a fixed amount (454 g/d) of a 20% crude protein (CP), 20% fat milk replacer to weaning at 28 d or a variable amount (454, 681, 908, and 454 g/d on d 0 to 7, 8 to 14, 15 to 31, and 32 to 41, respectively) of a milk replacer containing 28% CP and 17% fat without or with added dietary supplement containing bovine serum. Calves were also fed commercial calf starter and water ad libitum. Plasma IgG concentration in most calves on arrival at the facility was < 10 g/L. Intake, change in body weight, feed efficiency, morbidity and mortality, and selected plasma metabolites were determined. Body weight at 28 d, 56 d, daily body weight gain, intake of milk replacer, fecal scores, days with diarrhea, and days treated with antibiotics were increased with feeding variable amount of milk replacer over the 56-d study. Starter intake from d 1 to 56 was reduced from 919 to 717 g/d in calves fed fixed and variable amounts of milk replacer, respectively. Morbidity, measured as the number of days that calves had diarrhea, was increased by 53% when a variable amount of milk replacer was fed. Calves fed variable milk replacer were treated with antibiotics for 3.1 d compared with 1.9 d for calves fed 454 g of milk replacer/d. Concentrations of plasma glucose, urea N, and insulin-like growth factor-I were increased when calves were fed variable amount of milk replacer. Dietary supplement containing bovine serum had no effect on any parameter measured. There was no effect of milk replacer feeding on concentrations of nonesterified fatty acids, total protein, or growth hormone concentrations. Plasma tumor necrosis factor-α was highest in calves with the highest plasma IgG concentrations on the day of arrival and might be related to the calf's ability to identify pathogens in the environment. Under conditions of this study, calves fed variable amount of milk replacer and exposed to immunological challenge before weaning had greater BW gain, but also increased incidence of diarrhea that required added veterinary treatments.     

Effects of roughage source,amount, and particle size on behavior and gastrointestinal health of veal calves

The European Union 1997 Directive, stipulating that veal calves should be fed a minimum of 50 to 250 g of fibrous feed from 8 to 20 wk of age, is vague. A fibrous feed ration maximum of 250 g has been implicated in welfare issues, namely the occurrence of abnormal oral behaviors and poor gastrointestinal health. Past research suggests that this amount is insufficient to prevent the development of abnormal oral behaviors and enabling good rumen development. Different sources and particle sizes of roughage could lead to very different welfare outcomes. In a 3 × 2 × 2 factorial design, 240 group-housed calves (10 ± 1 d; 46.1 ± 0.1 kg) were fed different roughage sources (straw, maize silage, or maize cob silage; the latter 2 were dried and provided no extra moisture compared with straw) in 2 amounts (250 or 500 g of dry matter per day), and 2 particle sizes (chopped or ground). Roughage was supplemented to milk replacer (MR) from 2 wk after arrival. In addition, 60 calves were fed 1 of 3 additional control treatments: MR only (n = 20), MR plus an iron supplement (n = 20), or MR plus ad libitum hay (n = 20). Oral behaviors were recorded using instantaneous scan sampling at 2-min intervals for 2 h in 3 periods per day, at 12 and 22 wk of age. Calves were slaughtered at 24 wk of age and rumen and abomasal health parameters were recorded. Limited provision of straw resulted in behavior comparable with that from unlimited provision of hay, with reduced tongue playing and oral manipulation of the environment, as well as increased chewing compared with diets with no roughage supplement. Straw prevented ruminal hairballs, but impaired rumen development and increased abomasal damage. A higher ration of roughage increased chewing (12 wk), decreased oral manipulation of the trough (12 and 22 wk) and the pen (22 wk), and increased rumen weight. However, more roughage led to increased abomasal damage for certain parameters. Longer feed particles had no obvious benefits for behavior, but decreased hairball prevalence. Overall, unlimited hay had the highest benefit for both behavior and gastrointestinal health. Adding iron to the MR did not alter behavior or gastrointestinal health compared with MR without iron supplement. This study demonstrated that different roughage sources, amounts, and particle sizes have different effects on veal calf behavior and gastrointestinal health, and hence on veal calf welfare.     

Systematic early obstetrical assistance at calving: II. Effects on dairy heifer calf growth,health, and survival to weaning

Good calving management should not only ease the transition of cows into lactation, but also contribute to providing healthy replacement animals for the herd. Difficulty during parturition has been found to be detrimental to the offspring. Because of the association of obstetrical intervention with undesirable outcomes, the general management recommendation for calving is to let cows give birth unassisted whenever possible. Unfortunately, very few studies have investigated the effects of planned early assistance during calving, regardless of whether or not another problem exists. To investigate the effects of early assistance during apparently normal calvings, a clinical trial was conducted on 257 Holstein cows. They were observed through the second stage of calving, and before calving they were divided randomly between 2 assigned interventions: not assisted or early assistance during the second stage of parturition. After calving, the animals were classified into 4 actual calving intervention groups: too quick to be assisted, not assisted, early assistance, and late assistance (for cows in the not assisted group that did not calve unassisted within the 1 h maximum time allowed). Early assistance was given 15 min after first sight of both front hooves of the calf and done using human force only. Heifer calves (n = 129) born from enrolled dams were followed until weaning to assess the effect of assigned and actual calving interventions on their growth, health, and survival. Heifer calves’ weight at birth was positively associated with weight at 7 wk, but the effect varied by assigned and actual intervention. As a routine management practice, giving early assistance during calving to dairy cows did not influence average daily gain, health, or survival in dairy heifer calves up to weaning at 7 wk of age.