The present study evaluated the use of haptoglobin (Hp) as an indicator of health and performance in 166 Holstein heifer calves reared in an intensive production system. Calves were evaluated at D6-9; D10-13; D20-23; D35-38 and D65-68, corresponding to the days of life. The absence or presence of diseases was evaluated by physical examination and classification of scores. The performance parameters evaluated were body weight, height at withers and hind width. Hp was measured by spectrophotometric technique. The highest prevalence of diarrhea (59.4%; 98/165) was observed in D10-13, bovine respiratory disease (BRD) was on D35-38 (25.8%; 42/163), and umbilical inflammations in D6-D9 (7.8%; 13/166). Highest values of Hp were observed in animals with diarrhea (P=0.02), and umbilical inflammation (P=0.057), in comparison with the group of healthy calves. A significant negative correlation was observed between Hp and performance index. This protein presented an important relation with diarrhea and performance of the calves, opening perspectives on its utilization as a biomarker of diseases.

The aim of this study was to evaluate secondary clinical disease, milk production efficiency and reproductive performance of heifers and cows persistently infected (PI) with bovine viral diarrhea virus type 2 (BVDV type 2). PI animals (n = 25) were identified using an antigen capture ELISA of ear notch samples. They were distributed into three age groups: ≤ 12 (n = 8), 13 to 24 (n = 6) and 25 to 34 (n = 11) months old. A control group of BVDV antigen ELISA negative female cattle that were age matched to the PI animals was utilized from the same herd. The PI group had a 1.29 higher odds ratio for diarrhea than controls (p = 0.001, IC95% = 1.032–1.623) and 1.615 greater chance of developing bovine respiratory disease (BRD) (p = 0.012, IC95% = 1.155–2.259). The age at first insemination (p = 0.012) and number of insemination attempts required to establish the first pregnancy (p = 0.016) were both higher for PI than controls. Milk production was higher for control cows than PI cows during most of the sampling periods. Somatic cell counts (SCC) were higher in PI cows than the controls at all sampling points across lactation (p ≤ 0.042). PI cattle had a higher incidence of disease, produced less milk, a higher SCC, and poorer reproductive performance than control cattle in this study.

This study evaluated the associations between estimated distance from farms' locations to auction markets, and health indicators of surplus dairy calves sold during summer 2019 and winter 2020 in Québec, Canada. A total of 3,610 animals from 1,331 different farms were used in this cross-sectional cohort study. Geographic coordinates (latitude and longitude) were obtained for each farm and the 2 participating livestock auction markets. Calves' abnormal physical signs (APS) were noted upon arrival at the auction market as they were examined by trained research staff. The haversine distance between the farm and the auction market was evaluated using geographic coordinates and categorized. Generalized linear mixed models were used for statistical analyses. The main APS observed were ocular discharge (34.9%), abnormal hide cleanliness (21.2%), swollen navel (17.2%), dehydration score 1 (at least one of the 2 following clinical signs: persistent skin tent or sunken eye, 12.9%), and dehydration score 2 (both clinical signs mentioned above, 6.5%). Calves from farms located at greater distances from the auction markets (≥110 km) had a higher risk ratio (RR: 1.08, 95% CI: 1.03, 1.13) for dehydration than those from lesser distances (0-25 km). During the summertime, a-RR of 1.18 (95% CI: 1.15, 1.22) was observed for dehydration compared with wintertime. A 2-way interaction between estimated distance and season showed a higher prevalence of ocular discharge for calves from farms at distances greater than or equal to 110 km during the summer (RR: 1.11, 95% CI: 1.04, 1.20) than for calves from farms located at lesser distances (0-25 km). These results demonstrate that calves from farms located at greater distances from the auction markets had more APS, mainly during the summer. A better understanding of the transport conditions and interaction with management at the farm of origin is determinant to mitigate the impact of the journey on surplus calf health.

The early use of antimicrobial therapy has been introduced in many farms to prevent diarrhea and respiratory disease in young calves; however, there is controversy about whether this practice has a beneficial effect on the health of these animals. This study evaluated the influence of the early use of antimicrobials on the health and performance of neonatal Holstein calves. Twenty-six Holstein calves were screened and divided into two groups, according to the administration (ATB+), or not (ATB-) of tulathromycin (2.5mg/kg, subcutaneously) within the first 12 hours of life. Calves were evaluated by general clinical examination, fecal score, respiratory score, and external palpation of the umbilical region, besides fecal output of dry matter. Anemia was determined by using an automatic system and, also, using a commercial kit for iron dosage. Diarrhea was diagnosed by a centrifuge-flotation technique using a sugar solution (Cryptosporidium) and multiplex semi-nested RT-PCR (rotavirus/coronavirus). The performance of the calves was estimated by Daily Weight Gain (DWG). The young dairy calves were evaluated within 12 hours of birth (≤12h) and at 3-5th (D3-5), 7-9th (D7-9), 13-15th (D13-15), 20-23rd (D20-23), and 27-30th (D27-30) days of life. No difference was noted between the ATB+ and ATB- groups concerning heart rate, respiratory frequency, and rectal temperature. Erythrogram showed a higher frequency of anemia in ATB- group (P=0.016) at the D3-5 check-up; lower values of serum iron were also observed simultaneously (P=0.051). Thirteen cases of respiratory disease were detected during this study; however, no significant difference was observed between the groups in this regard. The frequency of diarrhea (fecal score 2-3) was high in both groups, peaking at D13-D15. No differences were noted between the groups regarding the frequency of diarrhea when considering the dry fecal matter. The predominant etiological agent for diarrhea was Cryptosporidium spp.. The DWG was similar between groups, with maximum weight reduction on D13-15. The administration of tulathromycin in prophylactic dose (2.5mg/kg) at birth decreased the frequency of anemia but did not influence weight gain or the prevalence of diarrhea.

This research evaluated the effect of milking on the physical exam of the mammary gland (MG) and milk examination in Saanen goats. Six properties were selected, four farms were used after evaluation of criteria selection and distributed in two groups according to the milking method: manual or mechanical. The physical examination of MG was performed using the techniques of inspection and palpation, in addition to the examination of the milk by strip cup, California Mastitis Test, somatic cell count, and bacteriological exam. It was possible to detect an association between the milking method with the most of physical exam of the MG: inspection of the MG (p = 0.001), inspection of the teat (p = 0.002), palpation of the MG (p = 0.054) and palpation of the teat (p = 0.036). The machine milking had an association with the reduction of the volume of MG (OR = 6.00), reduction of the teat size (OR = 16.19), and firm consistency of mammary parenchyma (OR = 2.39). The use of machine milking represented a less risk for an increase of the volume of the MG volume (OR = 0.288) and the presence of cisternitis (OR = 0.490). The association between the SCC and the type of milking was also detected (p = 0.002). Machine milking was associated with changesin the physical exam of MG and milk examination compatible with traumatic lesions. This information indicates inappropriate use of milking equipment in the dairy goat’s properties.

Dairy calf welfare assessment tools focusing on the pre-weaning period have been proposed in recent research. Despite the existence of these tools, assessing the welfare and health-related quality of life (HRQoL) of dairy calves remains challenging. These difficulties may stem from the complexity of assessing all dimensions of calf welfare and the validity, reliability, and feasibility of the indicators used in assessment tools. This review aims to discuss welfare and HRQoL concepts and integrate them into a framework to facilitate the understanding of dairy calf welfare and HRQoL. The review also identifies on-farm dairy calf welfare indicators and explores how their validity, reliability, and feasibility have been evaluated. HRQoL, as a component of the quality of life concept, is used to determine how an animal feels during illness using behavioral expressions of affective states. In this review, we adapted a human HRQoL framework for dairy calves, illustrating the interconnection of 3 domains of animal welfare (behavior, mental state and health) in assessing calves' HRQoL. It is worth noting that a limited number of HRQoL assessment tools have been developed for dairy calves, and there is no standard way to assess the welfare of pre-weaned dairy calves. Some studies focus on specific aspects of animal welfare, while others address this concept more broadly. While behavioral indicators have been explored in dairy science, they often remain disconnected from the concept of HRQoL. After reviewing various welfare assessment tools focusing on pre-weaned dairy calves, 44 welfare indicators were selected. Considering the selected welfare indicators, we observed that their validity, reliability, and feasibility have not been extensively explored. This review contributes to understanding welfare and HRQoL concepts for pre-weaned dairy calves and highlights opportunities to enhance the assessment of welfare and HRQoL for these animals.