The objective of this study was to determine the effects of physically effective neutral detergent fiber (peNDF) content in total mixed ration (TMR) on dry matter intake, digestibility, and chewing activity in fattening Hanwoo (Bos taurus coreanae) heifers. The experiment was designed as a replicated 3×3 Latin square using 12 heifers. Fattening heifers were offered one of three diets [high (T1), medium (T2), and low (T3) peNDF] obtained by different mixing times (3, 10, and 25 min) for the same TMR feed. The peNDF content of TMR was determined by multiplying the proportion of dry matter retained by a 1.18 mm-screen in a Penn State Particle Separator by the dietary NDF content. The peNDF1.18 content was 30.36%, 29.20%, and 27.50% for the T1, T2, and T3 diets, respectively (p<0.05). Dry matter intake was not affected by peNDF content in TMR. Total weight gain in T1 group was significantly higher (p<0.05) than in T2 and T3 groups. However, weight gain did not differ between T2 and T3 groups. The feed conversion ratio decreased with an increase in the peNDF content (T1: 12.18, T2: 14.17, and T3: 14.01 g/g). An increase in the peNDF content of TMR was associated with a linear increase in the digestibility of dry matter, crude protein, crude fiber, neutral detergent fiber, and acid detergent fiber (p<0.05). Also, an increase in peNDF content of the TMR resulted in a linear increase in the number of chews in eating and ruminating (p<0.05), and consequently in the number of total chews (p<0.05). These results indicate that peNDF content affects digestibility and chewing activity. Consequently, the peNDF content of TMR should be considered for improving feed efficiency, digestibility, body weight gain, and performance in fattening heifers.

ObjectiveThis experiment was to determine proper physical traits in the diet for goats by investigating the effects of physically effective neutral detergent fiber (peNDF) content on dry matter intake (DMI), digestibility, and chewing activity in black goats fed with total mixed ration (TMR).MethodsSix growing wethers of Korean native black goats (Capra hircus coreanae) aged 8 months and weighing between 26.9 kg and 27.1 kg (27.03±5.05 kg) were used in this experiment. Three diets of varying peNDF content were obtained by original TMR (T1), 12,000 rpm grinding (T2), and 15,500 rpm grinding (T3) of the same TMR diet. The peNDF1.18 content of the experimental diets was 23.85%, 21.71%, and 16.22% for T1, T2, and T3, respectively.ResultsAverage daily gain (ADG) was higher in T2 group compared to those of the control and T3 groups, but ADG and DMI were not affected by the dietary particle size and peNDF content. Also, there was no difference between apparent nutrient digestibility of dry matter, crude fiber, ether extract, neutral detergent fiber, and acid detergent fiber. Although there was no significant difference, rumination and total chewing time were associated with decreased peNDF content.ConclusionThe feeding of peNDF-based TMR showed no impact on apparent nutrient digestibility and nitrogen balance. Further studies are required with a wider range of dietary peNDF level and particle size to better identify the effect of dietary peNDF and particle size on chewing activity and performance in goats.

Our aim in this study was to determine the effects of physically effective neutral detergent fibre (peNDF) in a total mixed ration (TMR) on feed intake, digestibility and chewing activity in beef cattle. The experiment had a replicated 3 × 3 Latin square desig, using three fattening Hanwoo (Bos taurus coreanae) steers with ruminal cannulas. Steers were offered one of three diets (high, medium or low peNDF content) obtained by mixing the same TMR for different periods of time (5, 13 and 25 min). peNDF content of TMR was calculated as [total chewing time/NDF intake (kg)] × dietary NDF content, and the proportion of sample dry matter (DM) collected in a ≥1.18-mm sieve is commonly used as the physical effectiveness factor in the equation. The peNDF1.18 contents of the high, medium and low diets were 25.97%, 21.10% and 17.94% (P < 0.05). In addition, the proportion of particles collected on the 19-mm, 1.18-mm, and pan sieves changed linearly with an increase of TMR mixing time. Mean particle-size distributions of diets were 11.43, 24.11, 30.70 and 33.68 for 19 mm, 8 mm, 1.18 mm and pan, respectively. Eating rate and ruminating and chewing efficiencies were significantly decreased with reduced peNDF content, and DM intake was increased significantly (P < 0.05). Lower peNDF content reduced the total number of chews significantly (P < 0.05). Total time spent chewing associated with eating was not affected by peNDF contents. Digestibility of DM, crude protein and crude fat decreased with reducing peNDF content in the diet, but there was no significant difference among the three groups. These results indicated that peNDF affects intake, digestibility and chewing activity in beef cattle. Therefore, high levels of peNDF appears to improve TMR, as it can increase efficiency and may prevent ruminal disorders in Hanwoo steer.

Purpose The purpose of this study is to review the definition, perspective, measurement and context of workplace learning and explored workplace learning to identify its role in quantitative research. Design/methodology/approach Through an integrative review of the literature, the following four roles that workplace learning has played in these studies were identified: workplace learning as an antecedent, a mediator, a moderator and an outcome. Findings This paper synthesized results for workplace learning in 45 studies. A total of 88 variables related to workplace learning were identified after four overlapped variables (autonomy, social support, work engagement and workload) in multiples areas were excluded from a total of 92 variables (56 antecedents, 8 mediators, 7 moderators and 21 outcomes). Research limitations/implications Because this study identified four roles of workplace learning (as antecedent, mediator, moderator and outcome), this study did not focus on the process of learning in the workplace. Additional study is needed to investigate how workplace learning can lead to outcomes and how this process can link workplace learning and its consequences. Originality/value This paper synthesized the antecedents, mediators, moderators and outcomes for workplace learning by integrating the findings in this study. This provided a comprehensive framework that could be used by researchers to continue the empirical research on this topic to develop the dynamics between individual, group, job and organizational variables on the one hand and workplace learning on the other.

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