Management of dairy heifers: Can operant conditioning be an effective and feasible tool to decrease stress and ease animals' close contact and handling?

Besides health monitoring, a regular check of dairy heifers' growth rate is desirable, but it is rarely done because procedures that require restraint and handling can be associated with substantial stress for both animals and farmers. Inexperienced heifers, especially if they are highly responsive to humans, may find restraint and handling potentially aversive. This study investigated whether training heifers of different age and responsiveness toward humans (RTH), through operant conditioning, could reduce stress in animals, ease close contact and handling, and be feasible in terms of farmers' effort. We assessed 60 Holstein heifers of 2 age classes (young, n = 29, 291 ± 39 d; old, n = 31, 346 ± 62 d) according to the avoidance distance test and classified them as confident (n = 20), neutral (n = 21), or nonconfident (n = 19). Half of the heifers of each age and RTH class were trained (n = 29), whereas the other half was not (n = 31). The trained heifers were subjected to target training for 8 sessions and positively reinforced with feed to allow being touched on the muzzle, rump, and perineum. If a heifer refused positive reinforcement, the trainer stepped back as negative reinforcement. In the last week of the experiment, the effect of training on the reaction to handling was assessed in all heifers. We measured heart rate, root mean square of successive interbeat interval differences (RMSSD), and fecal cortisol metabolites (FCMet). The presence of behavioral distress signs was recorded as well. The avoidance distance test was performed a second time 24 h after the measuring session. All of the trained heifers, regardless of RTH class, successfully accomplished the target training task in 6 sessions, each spending on average 25.3 s per session. All of the trained heifers allowed touches on the rump and perineum at the end of the fourth session. Training nonconfident heifers required more time compared with the others. Trained heifers showed higher RMSSD than nontrained heifers (14.2 vs. 16.9 ms, respectively), indicating a lower vagal tone, and thus, a slightly lower stress level than nontrained heifers. Training did not lead to differences in HR, FCMet, or presence of stress behavioral signs. Nonconfident heifers had the highest mean baseline FCMet values compared with neutral and confident heifers (38.4 vs. 30.3 vs. 29.1 ng/g, respectively). Nonconfident heifers also showed the lowest value of FCMet 12 h after the measuring session (36.7 vs. 44.6 vs. 49.7 ng/g), likely due to a decreased responsiveness of the adrenal gland to a stressor. The average avoidance distance decreased between the beginning and the end of the experiment, especially for neutral and nonconfident heifers, regardless of whether they were trained or not. These results show how using operant conditioning on some heifers not only decreased their vagal tone, but also reduced the responsiveness to humans of all the animals, trained and not trained; in the latter case, this reduction was through nonassociative learning, such as habituation.

A survey on sensor systems used in Italian dairy farms and comparison between performances of similar herds equipped or not equipped with sensors.

Sensor systems (SS) were developed over the last few decades to help dairy farmers manage their herds. Such systems can provide both data and alerts to several productive, behavioral, and physiological indicators on individual cows. Currently, there is still a lack of knowledge on both the proportion of dairy farms that invested in SS and type of SS installed. Additionally, it is still unclear whether the performances of herds equipped with SS differ from those of similar herds managed without any technological aid. Therefore, the aims of this study were (1) to provide an insight into SS spread among Italian dairy farms and (2) to analyze the performances of similar herds equipped or not equipped with SS. To reach the former goal, a large survey was carried out on 964 dairy farms in the northeast of Italy. Farmers were interviewed by the technicians of the regional breeders association to collect information on the type of SS installed on farms and the main parameters recorded. Overall, 42% of the surveyed farms had at least 1 SS, and most of them (72%) reared more than 50 cows. Sensors for measuring individual cow milk yield were the most prevalent type installed (39% of the surveyed farms), whereas only 15% of farms had SS for estrus detection. More sophisticated parameters, such as rumination, were automatically monitored in less than 5% of the farms. To reach the latter goal of the study, a subset of 100 Holstein dairy farms with similar characteristics was selected: half of them were equipped with SS for monitoring at least individual milk yield and estrus, and the other half were managed without any SS. Average herd productive and reproductive data from official test days over 3 yr were analyzed. The outcomes of the comparison showed that farms with SS had higher mature-equivalent milk production. Further clustering analysis of the same 100 farms partitioned them into 3 clusters based on herd productive and reproductive data. Results of the Chi-squared test showed that the proportion of farms equipped with SS was greater in the cluster with the best performance (e.g., higher milk yield and shorter calving interval). However, the presence of a few farms equipped with SS in the least productive cluster for the same parameters pointed out that although the installation of SS may support farmers in time- and labor-saving or in data recording, it is not a guarantee of better herd performance.

An insight into the dairy chain of a Protected Designation of Origin cheese: The case study of Asiago cheese.

The Protected Designation of Origin (PDO) label of the European Union safeguards and guarantees top-quality traditional agri-food products that must be manufactured in a specific region according to traditional production methods. Production specifications of PDO cheeses are often focused on the cheese-making process and lack information on the dairy farming system that is upstream of the chain. This case study aimed to analyze and cluster the dairy farms that supply milk to the chain of Asiago, an internationally known PDO cheese of northeastern Italy. A large survey involving all of the cheese factories of the Asiago PDO chain was made in 2017. Each cheese factory submitted a questionnaire to its supplying dairy farmers concerning (1) farm facilities and herd management and (2) feeding program of lactating cows. Results from 517 farms were processed; there were 67 ± 27% (mean ± standard deviation) respondents per cheese factory. Four clusters of dairy farms were identified by hierarchical clustering analysis. Cluster 1 (8% of the surveyed farms) and cluster 2 (22%) are small in size and low in yield, representing the traditional milk production system; farms are mainly located on mountains or hills and have autochthonous dual-purpose breeds mostly housed in tiestall barns. By rearing cattle of endangered breeds and feeding cows primarily with forages produced on-farm together with the use of pasture, these clusters, and especially cluster 1, have shown to provide essential ecosystem services for landscape and biodiversity preservation in the alpine areas. Clusters 3 and 4 (34 and 36% of the surveyed farms, respectively) gather medium-scale farms mainly located in the lowland that operate according to modern management and housing systems and rear high-producing dairy cows. These cows are mainly fed total mixed rations based on corn silage, but the dietary forage:concentrate ratio is kept relatively high, as farmers are more interested in producing high-quality milk for cheese-making than pushing for yield. Regardless of the cluster allocation, a considerable cow longevity, which is a recognized "iceberg indicator" of cattle well-being, was highlighted. This study showed that different farming systems may lay behind a single PDO cheese. The knowledge of their characteristics is important to reinforce the PDO production specifications as well as to distinguish and protect niche products that come from specific groups of farms that provide essential ecosystem services.

Health, behaviour and growth performance of Charolais and Limousin bulls fattened on different types of flooring.

Intensive fattening of late-maturing breeds on concrete or rubberized slatted floors is the prevalent beef production system in mainland Europe. The rationale behind this study is that specific beef breeds with different slaughter weights might have a diverse response to different flooring systems. The study aimed at assessing whether growth performance, health, behaviour and claw condition of two beef breeds, Charolais (CH) and Limousine (LIM), would be affected by their housing on concrete (CS) or rubber-covered (RCS) fully slatted floor. A total of 228 CH (116 on CS; 112 on RCS) and 115 LIM (57 on CS; 58 on RCS) were housed in four and two commercial farms, respectively, in groups of 9.0 ± 2.1 animals/pen with an average space allowance of 3.1 ± 0.2 m2. Draining gaps of CS and RCS pens were 16.9 ± 1.7% and 11.6 ± 1.2% of the total surface, respectively. Bulls of both breeds had similar initial body weight (429.4 ± 31.5 kg for CH; 369.6 ± 31.7 kg for LIM), and they were slaughtered when they reached suitable finishing. Charolais had a higher final body weight (BW) than LIM (750.8 ± 8.6 v. 613.7 ± 10.9 kg; P < 0.01), and bulls of both breeds on RCS had higher average daily gain than on CS (1.47 ± 0.02 v. 1.39 ± 0.02 kg/day; P < 0.05). The percentage of bulls early culled or treated for locomotor disorders were reduced by RCS only for LIM, while RCS tended to prevent the occurrence of bursitis for both breeds. During two 8-h behavioural observations, bulls on RCS performed more head butt/displacements and chases than on CS, and they reduced the frequency of abnormal lying down events. The use of RCS increased mounts' frequency only in LIM, while its reduced drainage capacity impaired only the cleanliness of CH. Postmortem hoof inspection showed longer claw dorsal wall and diagonal lengths, and sharper toe angles for CH on RCS than LIM on both floors. Results of this study point out that fully slatted floors, regardless of being rubberized or not, are not suitable for bulls finished at a final BW above 700 kg due to their detrimental effects on health and welfare. The use of RCS could be recommended as an alternative to CS only if bulls are slaughtered at a lower final BW (around 600 kg), like in the case of LIM breed.

Effect of a ceiling fan ventilation system on finishing young bulls' health, behaviour and growth performance.

This research aimed at assessing the effects of a ceiling fan ventilation system on health, feeding, social behaviour and growth response of finishing young bulls fattened indoors during a mild summer season. A total of 69 Charolais young bulls were housed in six pens without any mechanical ventilation system (Control) and in six pens equipped with ceiling fans. The experimental period lasted 98 days from June until mid-September 2014. Four experimental days were considered in order to assess the effect of the ventilation system under two different microclimatic conditions: 2 alert days at monthly interval with temperature humidity index (THI) between 75 and 78, and 2 normal days with THI⩽74. Health and behaviour of the bulls were evaluated through 8-h observation sessions starting after morning feed delivery. The study was carried out during a rather cool summer with a climate average THI of 68.9 and 4 days with average THI>75. Despite these mild climate conditions, ceiling fans lowered litter moisture and acted as a preventive measure for bulls' dirtiness (odd ratio=47.9; 95% CI 19.6 to 117.4). The risk of abnormal breathing was increased for Control bulls (odd ratio=40.7; 95% CI 5.4 to 304.2). When exposed to alert THI conditions, respiration rate and panting scores increased and rumination duration dropped in Control bulls compared with bulls provided with a ceiling fan. During observations under alert THI, bulls spent less time eating, more time being inactive and consumed more water compared with normal THI conditions. Bulls' daily dry matter intake measured during the observation sessions decreased on alert compared with normal THI days (P<0.001) due to a drop of intake during the daylight hours. Ceiling fan treatment had no effect on bulls' growth performance or water consumption but these results most likely depended on the mild climate conditions. Ceiling fans proved to mitigate some of the negative effects of heat stress on bulls' behaviour (rumination, lying down and drinking water) and respiration rate, however. The lack of a significant improvement of bulls' growth response should not discourage beef farmers from using ceiling fans in indoor systems, considering the likely increase in frequency and intensity of heat waves in the planet's temperate areas induced by global warming.

Study of progesterone and cortisol concentrations in the Italian Friesian claw.

The present research was conducted to study progesterone and cortisol concentrations in the claw of cattle and to verify whether the cattle claw could be considered an efficient matrix to provide retrospective information regarding progesterone and cortisol concentrations related to pregnancy and peripartum periods. These 2 steroids are involved in hoof growth. The study was performed on 32 calves and 24 pregnant milking cows of the Holstein breed, which were clinically healthy and lacking any claw disorders. Samples of at least 0.5cm in thickness were taken from the sole. Progesterone and cortisol concentrations were determined by RIA. The cortisol concentration in the horny shoe of calves from 0 to 30 d of age was significantly higher than the concentration at 31 to 60 and 61 to 120 d of age. Conversely, the progesterone concentration showed no statistically significant difference in relation to age. The horn progesterone concentrations recorded in the milking dairy cows at 7 mo of pregnancy showed high variability in the horizontal sections of the sole (the individual coefficient of variation ranged between 0.09 and 1.11). In 6 cows, genuine extreme values (genuine outliers) of the progesterone level were found. Moreover, significant differences existed among the progesterone concentrations of the sole's transverse sections. We detected a significant positive correlation between the weight of the horn samples after freeze-drying and their weight after hydration. The cortisol and progesterone levels in soaked horn samples were found to be significantly lower than in the same dry samples. These results show that cortisol and progesterone can be measured in the cattle claw horn. The claws of mature dairy cows could not be used as a matrix to provide a retrospective measure of cumulative hormone secretion, whereas the analysis of the calves' claw horns showed retrospective hormonal information similar to hair samples.

The natural history of pre-type 1 (insulin-dependent) diabetes mellitus in patients with autoimmune endocrine diseases.

An 11-year prospective study was carried out in 180 non-diabetic patients with organ-specific autoimmune diseases to evaluate islet cell antibodies in predicting Type 1 (insulin-dependent) diabetes mellitus. Islet cell antibodies were characterised according to titres, persistence, complement-fixing ability, and pattern. During follow-up, 14 of 46 patients with islet cell antibodies persistently greater than 5 Juvenile Diabetes Foundation Units (JDF-U) (30.4%), none of 23 with islet cell antibodies between 2.5 and 5 JDF-U or fluctuating, and 3 of 109 without islet cell antibodies (2.7%), developed diabetes. The cumulative risk of developing diabetes was 70%, 0%, and 4%, respectively. All the patients who developed diabetes were females. Eight progressed to insulin-dependence acutely, four showed a transient period of non-insulin-dependence, while two were still insulin-free. No difference was found in titres of islet cell antibodies for the risk of diabetes. Complement-fixing islet cell antibodies enhanced the cumulative risk for the disease in patients with conventional islet cell antibodies at low-middle (> or = 2.5-40 JDF-U), but not at high (> or = 80 JDF-U) titres. Forty-two patients with islet cell antibodies were investigated for the whole or the selective pattern. In the presence of the whole pattern the cumulative risk for diabetes rose to 100%, while with the selective pattern it declined to 34%. The whole pattern was found in 83% of patients who developed Type 1 diabetes acutely. In patients with organ-specific autoimmune diseases, the whole islet cell antibody pattern greatly enhances the prediction for diabetes.

Islet cell surface antibodies by an ELISA method in diabetic and nondiabetic patients.

Islet cell surface antibodies (ICSA) were investigated by an ELISA method using a commercial kit in 146 subjects with and without islet cell antibodies (ICA): 28 with insulin-dependent diabetes mellitus (IDDM), 24 with noninsulin-dependent diabetes mellitus (NIDDM), 22 first-degree relatives (FDR) of IDDM patients, 31 organ-specific autoimmune patients (OSAP), 21 nonautoimmune hospitalized patients (NAP), and 20 ICA-negative normal controls. Furthermore, insulin autoantibodies (IAA) were evaluated in 87 of these subjects. ICSA were found in 11% of IDDM patients and in 14% of their FDR, in 4% of NIDDM patients, in 10% of OSAP, in 10% of NAP, and in 5% of normal controls. After absorption with rat liver powder, ICSA were detected in 7% of IDDM patients, in 5% of their FDR, in 4% of NIDDM, in 6% of OSAP, in 5% of NAP and in none of normal controls. ICSA were also detected in 4% of IAA-positive compared to 3% of IAA-negative sera. Neither correlation was found between ICSA and ICA in each group of subjects, nor between ICSA and IAA, suggesting that these autoantibodies recognize different pancreatic targets. Moreover, no significant difference was observed for ICSA prevalence in the various groups of patients studied when compared with normal controls. The prevalence of ICSA assessed by this ELISA method has been compared to that reported by other workers, who employed different techniques.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of insulin autoantibodies using an ELISA technique in first-degree relatives of IDDM patients and in autoimmune patients.

We have improved an ELISA technique for the detection of IgG and IgM class IAA demonstrating the sensitivity and the specificity of antigen-antibody reaction. In sera of 135 first degree relatives of IDDM patients and of 128 autoimmune patients "at risk" for IDDM either positive or negative for islet cell antibodies (ICA), the prevalence of IAA IgG/IgM in all groups studied was significantly (p less than 0.001) higher than in controls, but the highest frequency of IAA was observed in the ICA-positive subjects. A similar association was also observed in complement-fixing ICA (CF-ICA) positive subjects. Future prospective studies will be necessary to establish the role of IAA as marker of B-cell damage.