Michiru Fukasawa

Relationship between milk cortisol concentration and the behavioral characteristics of postpartum cows introduced to a new group.

The objective of this study was to examine the relationship between milk cortisol concentration (MC) and behavioral responses to stress. As a stress response, the behaviors of 37 postpartum cows were observed when they were introduced into a new group. Milk samples for MC measurement and milk trait data were collected on the test day every 2 months after calving. The best linear unbiased prediction (BLUP) was estimated from each behavioral and milk trait data. Behavioral BLUP data were subjected to principal component (PC) analysis and three PCs were extracted. The first PC, with large loadings for eating and allogrooming, was positively correlated with milk yield. Therefore, individual differences in behaviors closely related with PC1 would have been unconsciously paid a lot of attention in terms of productivity. However, the second PC, with large loadings for drinking and self-grooming, uncorrelated with any milk traits, had a negative correlation with MC. The third PC, with large loadings for exploring, fighting and the frequency of agonistic behavior, was uncorrelated with all traits. Both PC2 and PC3 were independent of productivity, and individual differences in behaviors related with these PCs may be scarcely considered.

Depredation of Concentrated Feed by Wild Mammals at a Stock Farm in Japan

Concentrated feed, which contains high levels of digestible nutrients, is widely used as a food source for fattening cattle in Japan. However, it is also a valuable food resource for wild animals. Wild animals such as crows (Kitazaki and Tanida 1996; Nagano et al. 1998), raccoon dogs (Nyctereutes procyonoides) (Murakami and Arata 1998), and Asiatic black bears (Ursus thibetanus) (Maruyama 2003) steal feeds from cattle farms. In the US and UK, wild animals cause economic losses from depredation of cattle feed (Palmer 1976; Johnson and Timm 1987), and sometimes disease transmission (Garnett et al. 2002; Daniels et al. 2003; Palmer et al. 2004). Furthermore, high nutrition cattle feeds may improve the pest’s nutritive status leading to increase of pest populations. Nevertheless, there are few reports on depredation of cattle feed by wild animals. There is no information about which species are more attracted by the concentrated feed than others. Identifying which species steal cattle feed is valuable for developing countermeasures. In this study, the depredation of concentrated feed on a stock farm by wild mammals was investigated to identify which species steal the concentrated feed, and to establish daily and seasonal patterns of depredation.

The calf training for loading onto vehicle at weaning

The aim of this study is to examine whether calf training for loading at the weaning period improves later loading. Five calves were allocated to the trained group and the control group, respectively. Calves in the trained group were loaded onto a livestock trailer for 5 successive days at weaning. Trainers led or hauled the calves by rope only. When loading was completed, trainers fed calves with sugar cubes as rewards. Calves in the control group were weaned without any treatment. Five weeks after weaning, tests were carried out under similar conditions as the trained group. Loading efficiency, physical effort on the handler and handling stress on calves between groups were compared. Trained calves were loaded significantly faster than control calves. Trained calves balked less during loading than control calves. Heart rates of handlers after loading were significantly lower in the trained group than in the control group; however, salivary amylase activity and cortisol concentration was not different between groups. Physical effort and stress on handlers would be almost the same in both groups. Heart rate, plasma cortisol, NEFA and CPK of calves were significantly increased only in the control group after loading. These results show calf training improves loading efficiency and reduces stress on calves.

Physiological changes during feeding and rumination in cows.

In this study, we investigated the physiological changes in cattle during feeding and rumination. We collected blood samples every 5 min by using an automated blood sampling system and simultaneously recorded feeding, ruminating, and other behaviors using a video camera. Plasma non-esterified fatty acid (NEFA) concentrations continuously decreased during feeding and decreased temporarily during rumination. Plasma glucose concentration continuously decreased during feeding and remained stable during rumination. During feeding and rumination, there were no characteristic increases and subsequent decreases in plasma insulin and growth hormone (GH) concentrations, although insulin concentrations were positively correlated with glucose concentration. NEFA concentrations were not correlated with GH and insulin concentrations. In terms of chewing behavior, feeding and rumination are similar; therefore, the changes in metabolites such as NEFA might have been the same. Combination of behavioral observations and application of an automated blood sampling system could contribute to new findings on behavioral and physiological changes regarding the temporary decrease in plasma NEFA concentration during rumination in ruminants.

Genetic parameters for packed red blood cell volume and daily gain during grazing in Japanese Shorthorn calves facing a natural challenge from Japanese theileriosis

Abstract Japanese theileriosis, which is caused by the intraerythrocytic protozoan Theileria orientalis sergenti, is one of the most harmful anemic diseases to grazing calves in Japan. In this paper, we estimated genetic and phenotypic parameters of packed cell volume (PCV) and productivity in 435 Japanese Shorthorn calves, and discussed the feasibility of the genetic improvement for higher anemia tolerance. The heritabilities of PCV at pre-grazing (PrePCV) and minimum PCV during grazing period (MinPCV), age at MinPCV (MinAge), the times of theileriacidal drug treatment (TRT) and daily body weight gain during the grazing period (DG) were 0.54±0.11, 0.13±0.06, 0.21±0.07, 0.35±0.21 and 0.65±0.06, respectively. There were weakly negative genetic correlations between MinPCV and DG. MinAge had a strongly positive genetic correlation with MinPCV, while a strongly negative genetic correlation with DG. TRT had negative phenotypic and genetic correlations with all traits. From the results of simulations of selection, a single improvement in DG would reduce MinPCV and TRT in a population as a correlated response. Although it would lead to a reduction in TRT as a correlated response, it would also lead to temporarily severe anemia. This would require more labor for management of grazing herds and frequent times of sanitary check. On the other hand, a simultaneous improvement in DG and anemia tolerance would be inferior in efficiency of improvement in DG. Instead of a low efficiency of improvement in DG, a simultaneous improvement would decrease TRT more efficiently and increase MinPCV.

The change of sleeping and lying posture of Japanese black cows after moving into new environment

Objective Environmental change is one of the stressful events in livestock production. Change in environment disturbs cow behavior and cows require several days to regain a stable behavioral pattern. Sleeping posture (SP) and lying posture (LP) have been used as indicators for animal that are relaxed and well-acclimated to their environment. The aim of this study was to examine the time required by Japanese black cows for stabilization of SP and LP after moving into new environment. Methods Seven pregnant Japanese black cows were used. Cows were moved into new tie-stall shed and their sleeping and lying posture measured 17 times during 35 experimental days. Both SP and LP were detected by accelerometer fixed on middle occipital and hip-cross, respectively. Daily total time, frequency, and average bout of both SP and LP were calculated. Results Daily SP time was the shortest on day 1 and increased to the highest on day 3. It then decreased until day 9, after that stabilized about 65 min/d till the end of experiment. Daily LP time changed in same manner as daily SP time. The average SP bout was the longest on day 1, and then decreased to stable level on day 7. On the other hand, the average LP bout was the shortest on day 1, and it increased to stable level on day 7. Conclusion These results showed that pregnant Japanese black cows needed 1 week to stabilize their SP. However, there were different change patterns between the average SP and LP bout, even though the change pattern of daily SP and LP time were similar.