Effect of ruminal dosing of mechanical stimulating brush on rumination time, ruminal passage rate and rumen fermentation status in Holstein steers fed a concentrate diet

This experiment was conducted to determine the effect of ruminal dosing of a mechanical stimulating brush on rumination time, ruminal passage rate and rumen fermentation status in steers fed a concentrate diet at maintenance level. Animals were dosed three Rumen Faibu (RF) per head through the rumen fistulae (RF treatment) and not dosed (control) in a change‐over design. The organic cell wall content of the concentrate diet was 12.7% of dry matter. Daily time spent on rumination was very short in both treatments with 24 min in RF treatment and 15 min in control. The turnover rate of ruminal fluid in RF treatment was higher than that in control. There were no differences in ruminal pH and total volatile fatty acid concentration between RF treatment and control. Acetic and butyric acid concentrations were not different between the treatments. Propionic acid concentration tended to be higher in the animals on RF treatment than in control animals. The RF dosing in Holstein steers fed a low fiber diet did not affect the rumination time, but increased rumen digesta passage rate and ruminal propionic acid production.     

Heritability and genetic correlations between rumination time and production traits in Holstein dairy cows during different lactation phases

So far, rumination has been used as a proxy for monitoring dairy cow health at farm level. However, investigating its genetic aspects as well as its correlation with other important productive traits may turn this management tool into a new informative selection criterion. However, scientific evidences on genetic correlation among rumination time (RT) and milk production and milk composition are still scarce. Therefore, the objective of this study was to estimate the heritability of RT across three lactation phases and its genetic correlation with milk production, milk composition and somatic cell count (SCC). Results of our study showed that heritability for RT was 0.34 and was constant across lactation. The mean genetic correlations between RT and milk production and composition traits were 0.07 (milk production), ?0.07 (protein yield), ?0.31 (fat yield), and ?0.32 (fat/protein ratio). The mean genetic correlation between RT and the SCC was 0.05.     

基于声学冲激响应的奶山羊呼吸及反刍同步监测方法

呼吸及反刍是奶山羊最基本的生理活动,及时准确地同步获取奶山羊的呼吸及反刍信息可以为评估奶山羊健康状况提供数据支撑。针对现有方法呼吸及反刍同步监测能力的不足,提出了一种基于声学冲激响应的单只静卧奶山羊呼吸及反刍同步监测方法。该方法首先利用声学在室内空间中的多径效应,实现奶山羊呼吸过程中胸脯起伏及反刍过程中嘴部咀嚼动作全向采集;其次计算收发信号的冲激响应,捕捉由呼吸及反刍运动造成多径信号周期性变化的特征;然后利用呼吸及反刍运动频率差实现呼吸和反刍信号的分离;最后经过幅度归一化、相位同步后实现呼吸及反刍波形的可视化。为了验证该方法的有效性,选用了不同朝向的静卧奶山羊进行呼吸及反刍监测试验,并分析了环境噪声对试验的影响,结果表明：对于不同朝向的奶山羊,该方法呼吸平均相对误差为2.60%,反刍平均相对误差为3.51%,平均漏帧率为2.49%,并对环境噪声有较强的抗干扰能力。     

Energy expenditure for chewing in sheep fed timothy or sudangrass hay at the same intake level

In order to investigate the energy expended in chewing during eating and rumination in sheep fed timothy or sudangrass hay at the same intake level, the energy expenditure of the head was measured using the arterial-venous difference technique and that of the whole body was measured using an open-circuit, indirect respiration calorimeter. There was no difference in the per-chew energy expenditure between timothy hay and sudangrass hay during eating and rumination, but for both types of hay there was a difference in energy expenditure between eating (0.25 J per chew per kilogram body weight) and rumination (0.18 J per chew per kilogram body weight). There was no effect of time period after feeding on the energy expended in one chew during eating and rumination. On average, for a given type of hay, the energy expended in chewing during eating + rumination accounted for 4.9% of the daily energy expenditure of the whole body.     

Using rumination time to manage health and reproduction in dairy cattle: a review

Early detection of disease is the key to successful management of the dairy cattle which leads to timely treatment and prevention of costs associated with prolonged treatment and reduced milk yield. Electronic systems that allow for monitoring of physiological parameters like rumination, are now commercially available. This review paper discusses different aspects of rumination time that could be used to monitor the health and reproduction of dairy cattle. This review paper explored different areas where rumination time could be utilized in monitoring dairy cattle at calving, during the estrus period, during heat stressed conditions, and to detect diseases and transition cow disorders. In conclusion, rumination time could be used as an indicator of the health status in dairy cattle.     

Diet change from a system combining total mixed ration and pasture to confinement system (total mixed ration) on milk production and composition,blood biochemistry and behavior of dairy cows

This study aimed to determine if a diet change from a mixed system to a confinement system affects the milk production and composition, behavior and blood biochemistry of dairy cows. Cows were assigned randomly to one of the two treatments: cows fed with TMR (total‐mixed‐ration) (confined) throughout the period group fed TMR (GTMR, n = 15) and cows that changed their diet from pasture plus TMR to exclusive TMR at 70 ± 14 DIM (GCHD, n = 15). GTMR cows produced more milk and greater lactose and protein yield before the change of diet than GCHD cows (p ≤ .01), but these differences disappeared after the change. GCHD cows decreased the frequency of rumination and lying from before to after the change (p ≤ .03), but in GTMR cows no changes were observed. After diet change, GCHD cows had lower frequency of rumination and lying than GTMR cows (p ≤ .02). Before the change, GCHD cows had greater NEFA (non esterified fatty acids) concentrations than GTMR cows (p = .002). Abrupt change from a mixed system to a confined system was favorable on blood biochemical and milk variables of dairy cows. However, in relation to behavior, the cows expressed difficulties to adapt quickly to the abrupt change of system.     

泌乳奶牛采食、反刍、逍遥行为和日粮纤维性物质表观消化率对比分析

为了对比不同泌乳阶段奶牛的采食、反刍、逍遥行为和日粮营养物质表观消化率,选择体重、胎次相近的8头健康荷斯坦泌乳奶牛,其中,4头处于泌乳盛期(泌乳盛期组),4头处于泌乳后期(泌乳后期组),进行了采食行为观察和消化试验,两组奶牛预饲期20 d,正试期15 d。结果表明,泌乳盛期组奶牛每天的干物质采食量为21.2 kg,极显著高于泌乳后期组的14.1 kg(P<0.01),但两组奶牛的采食时间和采食次数无显著差异(P>0.05),泌乳盛期组奶牛每千克DM采食的时间也极显著低于泌乳后期组奶牛(P<0.01);一昼夜总反刍时间泌乳盛期组奶牛极显著低于泌乳后期组(P<0.01),每千克DMI需反刍时间泌乳盛期组奶牛极显著低于泌乳后期组(P<0.01)。泌乳盛期组奶牛躺卧、走动和站立时间与泌乳后期组奶牛相比无显著差异(P>0.05)。泌乳盛期组奶牛日粮中NDF和ADF的表观消化率极显著低于泌乳后期组(P<0.01),两组奶牛NDF的表观消化率分别为55.8%、67.8%,ADF的表观消化率分别为44.2%、60.7%。     

Presence of contagious yawning in sheep

Contagious yawning is triggered by others yawning, and it has previously been reported in humans, primates and several experimental and companion mammals. Whereas it might be a response to an innate releasing mechanism, contagious yawning is also considered to involve emotional contagion. Here, we demonstrate that sheep, the animal model of livestock animals, also experience contagious yawning. Twelve adult castrated Corriedale sheep were used in this study. Pairs of sheep were adjacently restrained with or without a wooden divider panel to shield them from viewing the other. Their behaviors were video‐recorded for 3 days in each condition. Sheep yawned 2.0 ± 1.1 and 1.2 ± 1.1 times/day/head in the unshielded and shielded conditions, respectively. Unshielded restrained sheep yawned within 1 min after the other one 11.1% of the time, while shielded pairs did not exhibit contagious yawning. Rumination was also highly synchronized under the unshielded condition. These data reveal that contagious yawning and behavioral synchronicity occur in ruminants like sheep, making them a suitable animal model to investigate contagious yawning and the underlying mechanism.     

Effects of substituting kraft pulp with corn silage on dry matter intake,ruminal mat formation,rumen fermentation,and rumination activity in non‐lactating cows

The present study examined the effects of substituting kraft pulp (KP) with corn silage (CS) on dry matter intake (DMI), ruminal mat and rumen fermentation characteristics, and rumination. Four non‐lactating, rumen‐cannulated Holstein cows were fed a CS diet comprising 36% grass silage (GS) and 64% CS or a KP diet comprising 36% GS, 57% KP, and 7% soybean meal. DMI was significantly lower in cows fed the KP diet than in those fed the CS diet (p < 0.05), whereas rumination time did not significantly differ between the treatments. Dry matter content in the rumen immediately before and 3 h after feeding was significantly higher in cows fed the KP diet than in those fed the CS diet (p < 0.05). The consistency and thickness of the ruminal mat did not significantly differ between the treatments. The ruminal mean retention time of feed particles tended to be longer in cows fed the KP diet than in those fed the CS diet (p < 0.10). The ruminal digestion rate of KP was comparable to that of GS and CS. Because ruminal mat was formed and rumination was stimulated, KP was considered to have the equivalent physical effectiveness as CS.     

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.