Nutritive value of sun-dried grape pomace, incorporated at a low level in complete feed for the rabbit bred under Magrebian conditions

[EN] The nutritive value and potential use of sun-dried grape pomace (g/kg as fed: 140 of crude protein (CP), 529 of neutral detergent fi bre (NDF), 460 acid detergent fi bre , 293 acid detergent lignin) for fattening rabbits was studied by comparing 3 experimental diets containing a low but increasing incorporation rate of grape pomace (GP): 0% (control, GP0), 3% (GP3), and 6% (GP6) in substitution to the control diet (251 g NDF and 175 g CP/kg) formulated with raw materials available in the area of Tiaret (Algeria): barley, wheat bran and straw, soybean meal and faba bean. Three groups of 30 rabbits (individually caged) were fed ad libitum the three diets from weaning (35 d, mean weight 460±83 g) to 77 d of age. The dry matter digestibility was obtained from total and individual faecal collection on all animals (3 x 30), during four consecutive days each week from 42 to 77 d of age. Then, faeces from 10 rabbits per group were selected for nutrient analyses. Intake and weight gain were recorded twice a week during the whole fattening period. Incorporating 3 or 6% of GP in a low fi bre diet impaired from 35 to 77 d growth rate (-8.8% for GP3 and GP6 vs. GP0, P<0.01), feed conversion (+8.5% for GP6 vs. GP0, P<0.01), and dressing out percentage (-2.5% for GP3 and GP6 vs. GP0, P<0.001). The digestibility of organic matter was linearly reduced from 72.8 to 70.0% with the GP incorporation rate (P<0.01), while crude protein digestibility remained unaffected and averaged 78.7%. The predicted nutritive value of sun-dried GP calculated by regression was high but highly variable for digestible energy (9.33±2.01 MJ DE/Kg, raw basis), and particularly for the digestible protein content (81.8±77.2 g DCP/kg). Thus, the sun-dried whole grape pomace could be considered as an alternative fibre source for the rabbit feeding in Magrebian area.Guemour, D.; Bannelier, C.; Dellal, A.; Gidenne, T. (2010). Nutritive value of sun-dried grape pomace, incorporated at a low level in complete feed for the rabbit bred under Magrebian conditions. World Rabbit Science. 18(1):17-25. doi:10.4995/wrs.2010.18.03172518

Technical characteristics of elite youth female soccer match-play: position and age group comparisons between under 14 and under 16 age groups

The purpose of this study was to quantify the technical characteristics of U14 and U16 elite youth female soccer match-play and compare position-specific differences between and within these age groups. A total of 449 match observations from 45 matches were undertaken on 189 players representing Regional Talent Centres in The Football Association’s Girls’ England Talent Pathway league. Linear mixed modelling determined position-specific differences for 24 technical and 4 possession-based variables. Results showed similar team possession-based characteristics at both age groups. Interceptions (U14 = 4.6 ± 0.3, U16 = 3.9 ± 0.3) and tackles (U14 = 4.2 ± 0.3, U16 = 3.2 ± 0.3) were the most common defensive actions. Passes were the most common offensive action (U14 = 21.8 ± 1.8, U16 = 25.1 ± 1.9). In possession, U14 central players performed more actions than wide players, whilst actions were more evenly distributed amongst positions at U16, suggesting a variation in playing style between age groups. Technical performances of players were position-dependent, and differences in offensive and defensive variables were observed between age groups across all positions. These findings may assist practitioners in informing specific coaching practice, training programme design or talent identification processes within this population

Interpreting physical performance in professional soccer match-play: Should we be more pragmatic in our approach?

Academic and practitioner interest in the physical performance of male professional soccer players in the competition setting determined via time-motion analyses has grown substantially over the last four decades leading to a substantial body of published research and aiding development of a more systematic evidence-based framework for physical conditioning. Findings have forcibly shaped contemporary opinions in the sport with researchers and practitioners frequently emphasising the important role that physical performance plays in match outcomes. Time-motion analyses have also influenced practice as player conditioning programmes can be tailored according to the different physical demands identified across individual playing positions. Yet despite a more systematic approach to physical conditioning, data indicate that even at the very highest standards of competition, the contemporary player is still susceptible to transient and end-game fatigue. Over the course of this article, the author suggests that a more pragmatic approach to interpreting the current body of time-motion analysis data and its application in the practical setting is nevertheless required. Examples of this are addressed using findings in the literature to examine: a) the association between competitive physical performance and ‘success’ in professional soccer, b) current approaches to interpreting differences in time-motion analysis data across playing positions and, c) whether data can realistically be used to demonstrate the occurrence of fatigue in match-play. Gaps in the current literature and directions for future research are also identified

Variable Levels Of Drift In Tunicate Cardiopharyngeal Gene Regulatory Elements

Background: Mutations in gene regulatory networks often lead to genetic divergence without impacting gene expression or developmental patterning. The rules governing this process of developmental systems drift, including the variable impact of selective constraints on different nodes in a gene regulatory network, remain poorly delineated. Results: Here we examine developmental systems drift within the cardiopharyngeal gene regulatory networks of two tunicate species, Corella inflata and Ciona robusta. Cross-species analysis of regulatory elements suggests that trans-regulatory architecture is largely conserved between these highly divergent species. In contrast, cis-regulatory elements within this network exhibit distinct levels of conservation. In particular, while most of the regulatory elements we analyzed showed extensive rearrangements of functional binding sites, the enhancer for the cardiopharyngeal transcription factor FoxF is remarkably well-conserved. Even minor alterations in spacing between binding sites lead to loss of FoxF enhancer function, suggesting that bound trans-factors form position-dependent complexes. Conclusions: Our findings reveal heterogeneous levels of divergence across cardiopharyngeal cis-regulatory elements. These distinct levels of divergence presumably reflect constraints that are not clearly associated with gene function or position within the regulatory network. Thus, levels of cis-regulatory divergence or drift appear to be governed by distinct structural constraints that will be difficult to predict based on network architecture

Sports teams as complex adaptive systems: manipulating player numbers shapes behaviours during football small-sided games

Small-sided and conditioned games (SSCGs) in sport have been modelled as complex adaptive systems. Research has shown that the relative space per player (RSP) formulated in SSCGs can impact on emergent tactical behaviours. In this study we adopted a systems orientation to analyse how different RSP values, obtained through manipulations of player numbers, influenced four measures of interpersonal coordination observed during performance in SSCGs. For this purpose we calculated positional data (GPS 15 Hz) from ten U-15 football players performing in three SSCGs varying in player numbers (3v3, 4v4 and 5v5). Key measures of SSCG system behaviours included values of (1) players’ dispersion, (2) teams’ separateness, (3) coupling strength and time delays between participants’ emerging movements, respectively. Results showed that values of participants’ dispersion increased, but the teams’ separateness remained identical across treatments. Coupling strength and time delay also showed consistent values across SSCGs. These results exemplified how complex adaptive systems, like football teams, can harness inherent degeneracy to maintain similar team spatial–temporal relations with opponents through changes in inter-individual coordination modes (i.e., players’ dispersion). The results imply that different team behaviours might emerge at different ratios of field dimension/player numbers. Therefore, sport pedagogists should carefully evaluate the effects of changing RSP in SSCGs as a way of promoting increased or decreased pressure on players

Rehabilitation of Watson-Jones proximal tibial avulsion injury in elite academy level football: A report of two separate cases in one season

© 2020 Elsevier Ltd Objectives: Watson-Jones proximal tibial avulsion injuries occur more frequently in athletic and muscular adolescent males. However, they are rare and therefore infrequently described in the medical literature. Two of these injuries occurred in a Category 1 football academy in the same season within a six-month period. We have described the cases with the hope of better informing other clinicians should they encounter this injury. Methods: This case report describes the injury mechanism, surgical management and rehabilitation for the two cases [Players A and B]. Outcomes measures including player speed, agility and power were compared with scores from players of the same age group at the time of injury in the Premier League academies. Risk factors are also discussed. Results: Both players were managed surgically, initially. Player B had the surgical fixation removed during rehabilitation. Player A still has the fixation in situ. Post-surgery, player A returned to full play at thirty-two weeks and thirty-eight weeks for player B. No critical incidents occurred during rehabilitation. Conclusion: Watson-Jones avulsion fractures, although rare, can be managed successfully. Athletes can achieve a successful return to play at their previous level

Movement characteristics, physiological and perceptual responses of elite standard youth football players to different high intensity running drills

This is an Accepted Manuscript of an article published by Taylor & Francis in Science and Medicine in Football on 06/04/2018, available online: https://doi.org/10.1080/24733938.2018.1461235Purpose: To examine responses to high intensity running drills in youth football players. Methods: Seventeen players completed the YoYo Intermittent Recovery test level one (YYIR1) and a 15 m maximal sprint to quantify target running speeds. Players performed three conditions on separate occasions comprising: 12 x 15 s high intensity runs at 100% of the final YYIRT1 speed, 12 x ~4 s repeated sprints with ~26 s recovery, and combination running using both modalities. Heart rate was monitored continuously with PlayerLoadTM and movement characteristics using microtechnology. Ratings of perceived exertion and blood lactate responses were measured 2 min after the final repetition. The ratio of Flight:contraction time was calculated from a countermovement jump before and at 2 min and 14 hours after each condition. Data analysis used magnitude based inferences and effect sizes statistics. Results: Peak speed (1.1%; ES 0.23 ± 0.44) and mean speed over the initial 4s (6.3%; ES 0.45 ± 0.46) were possibly faster during combination compared to high intensity running with unclear differences when compared to repeated sprinting. This was despite most likely (21.6%; ES 7.65 ± 1.02) differences in prescribed speeds between conditions. There were likely reductions in F:C at 14 hours ratio after high intensity (-5.6%; ES –0.44 ± 0.32) and combination running (-6.8%; ES -0.53 ± 0.47). Changes in the repeated sprinting condition were unclear. Conclusions: Actual movement characteristics of high intensity running drills may not reflect those used to prescribe them whilst reductions in F:C ratio are still evident 14 hours after their completion