Effects of an intensive experimental protocol on health, fertility, and production in transition dairy cows.

Animal experimentation is required to investigate complex physiological relationships and facilitates development of evidence-based knowledge. However, experimental protocols can interfere with the daily routine of the animals, result in stress and pain, and have adverse effects on health and production. The goal of this study was to investigate the effects of an intensive experimental protocol on health traits and production in transition dairy cows. Eighty experimental dairy Holstein cows (EXP group) underwent serial protocol-based clinical and ultrasonographic examinations, puncture of the jugular vein for blood collection or drug application, and liver biopsy samples, 14 d before until 42 d after parturition. Controls (CTR group) included 206 cows from the same herd, which fulfilled the same inclusion criteria and were kept under the same production management but were not handled for the purpose of this study. Procedure-related effects with a potentially negative effect on health and production were recorded. Furthermore, production, fertility and culling traits of the 2 groups (CTR, EXP) were compared. Most procedure-related adverse effects were associated with transcutaneous liver biopsies and included diffuse inflammation of the skin incision in 11.9% (42 of 320), abscessation of the skin or subcutis in 4.6% (11 of 240), and increased liver echogenicity of the biopsy site in 10.4% (27 of 240). The experimental procedures had a negative effect on milk yield at the start [days in milk (DIM) 5-50, difference: 2.3 kg, standard error (SE): 0.8 kg] and end of lactation (DIM 251-300, difference: 2.0 kg, SE: 1.0 kg; DIM 301-350, difference: 2.3 kg, SE: 1.2 kg) resulting in a lower 305-d milk yield in the EXP group than in the CTR group (difference: 472 kg, SE 214 kg). The milk fat % was higher in the EXP group than in the CTR group from 251 DIM onward (DIM 251-300, difference: 0.20%, SE: 0.09%; DIM 301-350, difference: 0.41%, SE: 0.17%). Also, the somatic cell score was higher in the EXP group than in the CTR group, during early (5-50 DIM, difference: 0.43, SE: 0.22) and from mid-lactation onward (DIM 151-200, difference: 0.43, SE: 0.2; DIM 201-250, difference: 0.49, SE: 0.22; DIM 251-300, difference: 0.55, SE: 0.25; DIM 301-350, difference: 0.61, SE: 0.28). Experimental procedures had no effect on first service conception rate and time to pregnancy, but had a positive effect on stillbirth rate with fewer stillbirths in the CTR group (0%) than in the EXP group (3.9%). Furthermore, experimental handling had no effect on time to culling or type of culling, whereby poor production was a more frequent reason noted for culling in the EXP group. Procedure-associated impairment of production in dairy cows is rarely reported and allows the estimation of the effects of such a study protocol on animal health and production. As a limitation for the interpretation of the results, the number of animals included and conduction in one single herd have to be considered.

[Cortisol concentration before, during and after sham foot trimming in German Holstein cows - the suitability of different matrices]. / Kortisolkonzentration bei Deutsch-Holstein-Kühen vor, während und nach der Klauenbehandlung im Durchtreibestand ­ Eignung verschiedener Matrizes.

OBJECTIVE: The objective of this study was to determine whether changes in cortisol concentration measured in blood serum (KoB) of cows exposed to an acute stressor shows a correlation to cortisol concentrations in saliva (KoS), tears (KoT) and milk (KoM) as well as the concentration of cortisol metabolites in feces (KoK). MATERIALS AND METHODS: In 10 healthy German Holstein cows, sham foot trimming (sKB) including the movement/fixation of the cows through/in a foot trimming chute was used as a model for acute stress. KoB, KoS, KoT, KoM and KoK were measured once a day for 10 days. During sKB, performed on day 4, KoB and KoT were measured at the initiation of foot trimming (minute 0) as well as 15, 25, 30, 40, 50, 60 and 80 minutes later. Additionally, KoK was measured 480, 540, 600 and 660 minutes after the start of sKB. RESULTS: KoB and KoT increased during sKB and reached a maximum at 60 minutes followed by a decrease. KoK increased after sKB and reached a maximum at 660 minutes. There was a significant correlation between KoB and KoT, KoK and KoB and a trend towards a significant correlation between KoK and KoT during sKB. KoB and KoT were significantly correlated (area under the curve, minute 0-10, p = 0.04). KoB decreased significantly from day 1 to day 4 (p < 0.01). On day, 5 KoB (p = 0.03) and KoK (p < 0.01) were significantly higher. KoS and KoT served as good proxies for KoB throughout the study, and KoK and KoB exhibited similar profiles. There were several differences between the profiles of KoM and KoB. During the 10-day measurement period, a significant positive correlation was detected between KoB and KoS (p = 0.002) as well as between KoB and KoT (p = 0.002). CONCLUSIONS AND CLINICAL RELEVANCE: The collection of tear fluid and saliva for determination of cortisol concentrations are non-invasive alternatives to blood sampling. Calm handling of cows may reduce their stress reaction and thus improve animal welfare.

[Effect of different pain management protocols on the health status of German Holstein heifer calves undergoing hot iron disbudding]. / Einfluss der thermischen Enthornung mit unterschiedlichem Schmerzmanagement auf die Gesundheit von Kälbern.

OBJECTIVE: Hot iron disbudding of calves is a stressful and painful procedure. Previous parts of an ongoing comprehensive study on disbudding in dairy calves dealt with various types of pain management and the direct effects of the procedure on physiological, biochemical and behavioral processes. The goal of this study part was to investigate the effects of the disbudding procedure per se, pain management and the age of the calf at the time of disbudding on the health status of the calf. MATERIALS AND METHODS: A total of 337 German Holstein heifer calves were used for this prospective, randomized and triple-blinded study. The calves were disbudded at 4-10 days or at 15-28 days of age. Each calf was randomly assigned to one of 9 treatment groups, which differed with respect to pain management (sedation, local anesthesia, nonsteroidal antiinflammatory drugs, placebo). All but the sham-disbudded calves underwent hot iron disbudding and all calves were monitored clinically before and until 4 weeks after the procedure. The findings were analyzed using valuation scores and a threshold model of the SAS software. RESULTS: Disbudding exhibited adverse effects on respiratory health. Calves undergoing sham disbudding experienced the lowest incidence of respiratory disease and calves that did not receive any anesthesia or pain medication displayed the highest frequency. All treatments showed mitigating effects on the incidence of respiratory tract diseases, however the effects varied with the type of pain management. Fever was less common in calves that were disbudded early in life than calves that underwent disbudding at an older age. CONCLUSION: Disbudding of young calves poses a risk to respiratory health. If breeding of polled offspring is not possible or when farming of horned cattle is not feasible, the risk of respiratory disease induced by disbudding can be minimized by adequate pain management. Disbudding of very young calves is feasible and recommended. CLINICAL RELEVANCE: The present study underlines the importance of optimal pain management during disbudding of dairy calves.

[Assessment of different pain management methods for the treatment of claw lesions in Meat Merino ewes]. / Bewertung verschiedener Methoden des Schmerzmanagements während der Behandlung von Klauenlederhaut-Läsionen bei weiblichen Merinofleischschafen.

OBJECTIVE: Pain management during veterinary procedures is a significant component of animal welfare and has legal as well as ethical implications. Even though regional intravenous anaesthesia (RIVA) is an accepted method for painful procedures involving the distal digits of sheep, this anaesthetic technique is rarely applied in the field. The primary goal was to investigate the feasibility, safety and efficacy of RIVA in sheep. A secondary goal was to examine whether the anaesthetic procedure can be improved by combining RIVA with sedation and whether these methods have a positive effect on the postoperative wellbeing of the animals. METHODS: A total of 36 Meat Merino sheep with contagious interdigital dermatitis and 12 healthy control sheep were used. Behaviour was observed during treatment of the lame sheep using various pain management protocols and during routine claw trimming of the healthy sheep, and all the sheep were observed after the procedures. The observed behaviours were assessed using scores and the scores compared among the animals of the 4 study groups (RIVA, sedation with xylazine hydrochloride + RIVA, placebo, control). RESULTS: RIVA was successfully conducted in sheep. Local reactions at the application sight and in the tourniquet area in 2 animals resolved completely. A significant reduction in defensive movements during the painful procedure confirmed the efficacy of RIVA. Stress-associated behaviours, including head shaking and idle chewing, occurred with a similar frequency in RIVA and placebo animals, leading to the conclusion that stress levels due to the handling in dorsal recumbency were comparable between these 2 groups. Sedation reduced the frequency of pain- and stress-associated behaviours, including guarding, favouring limbs, vocalisation, idle chewing and bruxism. Xylazine hydrochloride-RIVA animals displayed better weight-bearing in the affected limb, better food uptake and ruminated more postoperatively than sheep from the other study groups. CONCLUSION: RIVA in sheep is straightforward, safe and effective. Additional sedation reduces the stress and pain response. This pain and stress management has a positive effect on the postoperative wellbeing of sheep.

[Detection and assessment of acute and chronic pain in Meat Merino ewes using ethological parameters]. / Erfassung und Bewertung von akutem und chronischem Schmerz anhand ethologischer Merkmale bei weiblichen Merinofleischschafen.

OBJECTIVE: The assessment of pain in sheep is a clinical challenge, because being a prey species, they tend to mask it. Since pain in animals cannot be measured directly, various methods are applicable to detect its effects on physiological, biochemical and ethological processes. Clinicians experienced in behavioural assessment are able to reliably determine the level of pain endured by an animal. The objective of this study was to identify behaviours that reflect acute and chronic pain as well as stress in sheep. METHODS: The behaviour of 36 Meat Merino ewes with contagious footrot (contagious interdigital dermatitis) was analysed during normal activities in the flock and during footrot treatment, which included claw trimming to remove abnormal horn. The behaviour during treatment was compared with that of 12 healthy control sheep of the same breed during routine foot trimming. Grading of the observed behaviours was made using a numerical score. The occurrence of footrot was defined as, and equated with, chronic pain, and treatment was equated with acute pain. For the assessment of stress induced by the manipulative treatment, the data of the healthy sheep were taken as a comparison. RESULTS: The strongest indications of chronic pain were non-weight bearing lameness of an affected limb, shifting of weight and abnormal gait patterns. Additionally, sheep with footrot urinated more frequently than healthy animals. Stress-related bruxism occurred in healthy and ill sheep during foot trimming, but not during normal activities in the flock. Tail wagging and strong defensive movements of all limbs commonly occurred during footrot treatment. Head shaking appeared to be primarily stress-related in association with dorsal recumbency on the tilt table, but was exacerbated by pain elicited by hoof trimming. CONCLUSION: The behaviours selected in this study were useful for the identification of chronic and acute pain in sheep; however, correct interpretation of behavioural changes requires an experienced individual.