Durant aquesta tesis es varen realitzar sis estudis en vedells joves amb l’objectiu de conèixer estratègies per incrementar el consum de concentrat al voltant del deslletament. En primer lloc, es realitzà un estudi per desenvolupar un mètode per determinar preferències oro-sensorials en vedells deslletats, aquest mètode va consistir en registrar el consum d’un grup mínim de 20 animals individualitzats, als quals se’ls ofertà una doble opció de dos ingredients o concentrats durant un període de 6 h. Amb aquest mètode es realitzà el segon estudi, on es van determinar les preferències oro-sensorials entre 8 ingredients energètics (arròs, blat, blat de moro, corn gluten feed, civada, melca, ordi i segones de blat) i 6 ingredients proteics (colza, DDG de blat, corn gluten meal, girasol, pèsol i soja). El blat i la soja van ser els ingredients preferits, mentre que el corn gluten feed, l’arròs i el corn gluten meal van ser els ingredients menys preferits a curt termini. En el tercer estudi, es testà l’efecte d’addicionar un edulcorant amb aroma al lactoremplaçant i al concentrat. Al addicionar l’aroma s’observà un increment en el consum de concentrat en aquells vedells que presenten un baix consum al moment del deslletament. El quart estudi avaluà la capacitat de regulació dels requeriments nutricionals en vedells nounats. En aquest estudi un grup de vedells van rebre un concentrat convencional i es van comparar amb un altre grup als quals se’ls ofertà una bateria de diferents ingredients que composaven el concentrat. Els vedells que tenien accés a la bateria d’ingredients van descriure un consum total i creixement similar als vedells que rebien concentrat. Però en canvi van descriure un major consum de proteïna i greix, i un menor consum de carbohidrats. Aquestes diferències es van deure principalment a la predilecció cap a la soja i la soja grassa que van mostrar els animals que podien escollir entre diversos ingredients. El cinquè estudi va analitzar el paper de la mida de partícula del farratge en vedells lactants. En aquest estudi es comparaven dos tipus de dietes, composades per un concentrat convencional al qual se li addicionava un 10% de farratge. Aquestes dues dietes diferien en la mida de partícula del farratge, molturat (2mm) o trinxat (3-4cm). Es va observar que els animals que rebien el farratge més groller (3-4 cm) incrementaven més el seu consum la setmana desprès del deslletament, millorava la seva digestibilitat de matèria seca, proteïna, fibra neutra detergent i àcid detergent, i també reduïa la realització de conductes orals no-nutritives. Es va realitzar un sisè estudi on es va avaluar el paper que tenen els opioids en la regulació de la ingesta mitjançant l’estimulació o inhibició del plaer. En aquest estudi es va provar l’efecte de la naloxona, un antagonista opioide, sobre l’elecció de concentrats preferibles en vedells deslletats, i les seves possibles interaccions amb altres metabòlits relacionats amb la regulació de la ingesta. Es va observar que en animals saciats la naloxona podria reduir el consum, indicant que els opioids intervenen en la regulació de la ingesta total, però a més es va observar redueix la preferència per concentrats amb edulcorants, que prèviament s’havien observat altament preferibles. Pel que fa als metabòlits analitzats només es va observar una interacció entre la naloxona i els nivells de glucagon-like peptide-1. Resumint, els vedells lactants van mostrar preferència pels edulcorants al voltant del deslletament, tant a curt termini com a llarg termini. La soja va ser un ingredient d’elecció, mentre que la civada no va ser desitjada, tant a curt termini com a llarg termini. El fet d’addicionar un mateix aroma amb edulcorant al concentrat com a la llet va incrementar el consum d’aquells animals que presentaven un consum baix prèviament al deslletament. La mida de partícula del farratge va condicionar el creixement, consum, digestibilitat i comportament dels vedells al voltant del deslletament. Finalment, es va observar que els opioides juguen un paper important en la regulació de la ingesta mitjançant l’hedonisme o el plaer. / In this thesis, six studies in young calves were performed in order to find strategies to increase concentrate intake around weaning. The first study was conducted to develop a method to determine oro-sensory preferences in weaned calves. This method consist on measure the solid feed consumption of a minimum group of 20 calves, which recieve two options of concentrates or ingredients during a period of 6 h. Using this method, the second study was performed, where the oro-sensory preferences between 8 energetic ingredients (rice, wheat, corn, corn gluten feed, oats, sorghum, barley and second wheat) and 6 protein ingredients (canola, corn DDG, corn gluten meal, sunflower, soybean and pea) were determined. Wheat and soybean meal were the favorite ingredients for weaned calves, while the corn gluten feed, rice and corn gluten meal ingredients were less preferred in this short term study. The third study was conducted to evaluate the effect of flavoring a starter concentrate in a same manner as a milk replacer on intake and performance of young calves. This study claims, that offering a starter concentrate flavored as the milk replacer enhances solid feed consumption of those calves that have a low intake around weaning. The fourth study evaluated the ability of calves to meet their nutrient requirements when different ingredients were offered indepently in newborn calves. In this study a group of calves received a conventional concentrate whereas another group received a battery of different ingredients. The calves that had access to the free-choice of ingredients described a similar total consumption and growth compared to calves that received concentrate. However, calves that had access to all ingredients described a higher consumption of protein and fat, and lower consumption of carbohydrates that those receiving concentrate. These differences in nutrient intake were mainly due to the preference toward soybean meal and soybean full fat described by the animals that had access to all ingredients. The fifth study analyzed the role of particle size of forage in lactating cattle. This study compared two diets, composed of a conventional concentrate with a 10% of forage added. These two diets were different in the particle size of forage, ground (2 mm) or choped (3-4cm). It was observed that animals receiving chopped forage (3-4 cm) increased solid feed consumption the week after weaning, improved the apparent digestibility of dry matter, crude protein, neutral detergent fibre and acid detergent fibre, and reduce undesired behaviors, such as non-nutritive oral behaviors. The sixth study was conducted to evaluate the role of opioids in the regulation of food intake by stimulation or inhibition of pleasure. This study tested the effect of naloxone, an opioid antagonist, on preferred concentrates consumption in weaned calves, and their possible interactions with other metabolites related to the regulation of food intake. It was observed that satiated animals treated with naloxone reduced solid feed consumption, indicating that opioids are involved in the regulation of total intake. Furthermore, calves treated with naloxone reduced their preference for concentrate with sweetener, which had been previously observed as a preferred concentrate. Regarding the analyzed metabolites, GLP-1 was influences by naloxone administration. In summary, calves showed preference for sweeteners around weaning, either in short term or long term assays. Soybean meal was a preferred ingredient, while oats was not desired, both in short term and long term. Adding a sweetener with the same aroma in concentrate and in milk replacer increased consumption of animals that had a low intake prior to weaning. The particle size of forage influenced the growth, consumption, digestibility and performance of calves around weaning. Finally, we observed that opioids play an important role in the regulation of food intake by hedonism or pleasure.

It is direct response on a pure reaction that a leader took a learning and visiting. And it means that all of the spirit and style deep in his mine will explosion at any time and any where. Even though account a character later, will be described included a real; aconcept and the other spirit also be exploded and you will find some philosophy of management that you never found before if you carefully. The leader visited to the site of manufacturing that different from around the table in the office and will contact and feel all of the men; products; facilities; the environment and every thing around the site directly. The feeling is really, the reaction is true and the response normally representing the spirit of the leader. The spirit including something will feed back to the men, whom interact with the leader. You will found that a success leader all ways have some character form the feed backs. On the observation we have found some conclusions as follow: 1. A success leader has the modest and studious characters. 2. A success leader has the conscientious and never stop till find out the cause curiously characters. 3. A success leader will sight on the future and carry out the strategies for the futures. 4. A success leader will seek the truth from the facts and take streamlining. 5. A success leader will try to get all of the information and disseminate the useful news in time. 6. A success leader is a disseminator of experience and never limited in the organization or the countries.

The Cattle Value Discovery System (CVDS) was developed to predict growth and feed requirements of individual cattle fed in groups based on animal, diet, and environment information (Tedeschi et al., 2006). Evaluations of the CVDS using several databases of finishing cattle were conducted to determine the accuracy and precision of the model in predicted dry matter required (DMR) of pen-fed cattle. As well, the sensitivity of the model’s predictions to deviations from actual ration metabolizable energy (ME) value was conducted. A meta-analysis of growing and finishing steers evaluated to model’s accuracy in predicting DMR of individually fed steers, and the relationships between several model-predicted variables and actual performance and efficiency measures. Results for the first CVDS model evaluation involving pen-fed Santa Gertrudis cattle fed finishing diets revealed that accurate predictions of DMR are possible. The average mean bias for both steers and heifers was 2.43%. The sensitivity analysis of dietary ME values revealed that the model tends to consistently over- and under-predict DMR when the ME values are under- and over-estimated, respectively. However the ranking of pens was not affected by this mis-estimation of diet ME. In the second evaluations, both methods (mean body weight; MBW, dynamic iterative model; DIM) of CVDS were highly accurate and precise in allocating feed to pens of steers fed diverse types of diets and environmental conditions, with both models having a mean bias under 4%. The DIM model was slightly more accurate than the MBW model in predicting DMR. An evaluation of sources of variation revealed that for both models a large portion of the error was random, indicating that further work is needed to account for this variation. The meta-analysis study revealed that the model was able to account for 64% and 67% of the variation in observed dry matter intake (DMI) for growing and finishing steers, respectively. The two model-predicted efficiency measures, the ratio of DMR to average daily gain (ADG) and predicted intake difference (PID), were strongly to moderately correlated with their observed efficiency counterparts. In growing and finishing steers, DMR: ADG was able to account for 76% and 64% of the variation in observed feed conversion ratio (FCR) in growing and finishing studies, respectively. Strong correlations were also found between residual feed intake (RFI) and PID, suggesting that there may also be some similarity on these two measurements.

Objectives of this study were 1) to characterize the relationship between beef cattle efficiency, namely residual feed intake (RFI), and digestive, microbial, and fermentation parameters in growing beef calves and 2) to examine the effects of added dietary hydrolysable or condensed tannin on animal performance and efficiency, fermentation and carcass and non-carcass traits. To accomplish the first objective, multiple RFI studies were conducted and in all studies RFI was calculated as the difference between actual and expected dry matter intake (DMI) based on average gaily gain (ADG) and body weight0.75(BW). A total of 187 head selected out of a population of 600 head of growing beef calves were evaluated for diet and nutrient digestibility, ruminal and fecal volatile fatty acids (VFA) concentrations and methane producing activity (MPA). Low RFI calves consumed less DMI and had lower feed conversion ratios (FCR) as compared to high RFI calves. Low RFI calves also had higher diet and nutrient digestibilities compared to high RFI calves. Residual feed intake was negatively correlated with diet and nutrient digestibilities such that more efficient animals had higher digestibilities. Low RFI calves tended to have lower ruminal propionate and higher acetate:propionate ratios when fed a high-forage diet. Calves with divergent RFI did not have different gross microbial populations as evidenced by the Firmicute:Bacteriodetes ratio, but low RFI calves tended to have higher fecal Prevotella spp. and lower fecal Spirochaetes and ruminal Cyanobacteria. The importance of these subtle shifts in microbial ecology is not evident at this time and more research is needed to fully elucidate the interaction of host and microbes to fully grasp the importance of minor microbial deviations. No differences in 3 h MPA were detected in low vs. high RFI calves but low RFI calves had higher fecal MPA when sampled at 24 h; however, calculated methane emissions were lower for low RFI calves. Tannin supplementation had no effect on animal performance and efficiency, ruminal fermentation VFA concentrations, MPA, or ammonia concentrations in finishing beef steers. There was also no detrimental effect of tannins on carcass traits; however, hydrolysable tannin supplementation resulted in increased empty rumen mass. Results from these studies indicate that diet and nutrient digestibility are affected by RFI such that more efficient calves had higher DMD, microbial ecology is responsive to RFI such that minor microbial shifts were observed, and tannin supplementation, at the current inclusion rate, had no effect on animal and carcass performance.

These studies were designed to evaluate the relationships between residual feed intake (RFI) and performance of growing heifers and Brahman cows. Residual feed intake was determined for 77 heifers of diverse breedtypes (Angus, Brahman, Hereford, Holstein, Jersey and F1 crosses) during both the pre- and post-pubertal periods. Heifers were individually fed and allowed ad libitum access to feed for 84 +/- 6 d during the prepubertal feeding trial and 90 +/- 4 d during the post-pubertal feeding trial. Brahmaninfluenced heifers had lower RFI than heifers without Brahman influence during both the pre-pubertal (P < 0.05) and post-pubertal (P < 0.0001) periods. Residual feed intake determined during the pre-pubertal period was only a moderate predictor (r = 0.48; P < 0.0001) of RFI determined during the post-pubertal period. Residual feed intake was determined for 38 Bonsmara heifers over a 70-d feeding period. Heifers were fed a high roughage diet at 2.65% of body weight (BW). Weekly blood serum samples were analyzed for progesterone concentration by radioimmunoassay (RIA) to determine puberty. There were no observed differences between efficient and inefficient heifers for performance traits, age at puberty or conception, or cumulative achievement of puberty and conception. The postpartum performance of Brahman primiparous (n=16) and multiparous (n=38) cows previously evaluated postweaning for RFI was investigated. Females were weighed and evaluated for body condition score (BCS) at 28-d intervals prior to the start of the 2008 calving season. Weekly weights and BCS were collected beginning 21 d after calving. Blood serum samples were also collected weekly for progesterone analysis by radioimmunoassay (RIA), non-esterified fatty acid (NEFA) analysis by enzymatic colorimetry, and insulin-like growth factor-I (IGF-I) analysis by RIA. Females were exposed to vasectomized marker bulls after calving to aid in estrus detection. Eight and ten d following observed estrus, females were evaluated using ultrasonography via rectal palpation to determine the presence of a corpus luteum (CL). Efficient cows exhibited estrus, developed functional corpora lutea, and exhibited estrus with CL formation earlier (P < 0.05) than inefficient cows. Furthermore, a greater percentage (P < 0.05) of efficient than inefficient cows were pregnant at the end of the breeding season.

These studies were designed to evaluate the relationships that exist between residual feed intake, parity, rate of return to estrous cyclicity and nonesterified fatty acid (NEFA) concentrations, as well as changes in both body weight (BW) and body condition score (BCS) during the prepartum and postpartum time periods in Brahman females. Residual feed intake classification was evaluated for all females during the course of 70-d trials conducted prior to these experiments. Heifers (n = 30) and cows (n = 63) were evaluated for BW and BCS, as well as by collection of weekly blood samples beginning five weeks prior to calving. Blood serum samples were utilized to assay for NEFA concentrations by enzymatic colorimetry both pre- and postpartum. Multiparous females (n = 44) were sampled weekly for five weeks following parturition. Beginning 28d postpartum, weekly blood samples were collected and assayed for progesterone concentrations by radioimmunoassay to determine return to estrous cyclicity. Following calving, females were exposed to epididymectomized bulls fitted with chin-ball markers to aid in estrus detection. After detection, estrus females were evaluated for presence of a corpus luteum by trans-rectal ultrasonography. Prepartum, it was found that inefficient females had a greater BCS than efficient females (P < 0.05), significant BW changes occurred during the sampling period (P < 0.05) and moderate to low correlations existed between BW and BCS. Additionally, it was found that the interaction between RFI x parity had a significant affect upon NEFA concentrations, BW and BCS (P < 0.05). During the postpartum period it was found that efficient females were lower in both BW and BCS (P < 0.05), no change occurred over time in NEFA concentrations (P > 0.1) and a greater pregnancy rate was achieved in efficient females, as well as in females that returned to estrous cyclicity rapidly (< 90d) following calving.

The first objective of this study was to validate the feeding behavior measurements from a radio frequency electronic system (GrowSafe (TM) System Ltd., Airdrie, AB, Canada) and examine the software sensitivity to different parameter settings (MPS) to quantify feeding behavior traits. Data was continuously recorded 24 h per day using the GrowSafe™ system for 32 heifers over 81-d. Ten animals were randomly selected and evaluated over 6-d using time-lapse video recordings. Different parameter settings (MPS) from the electronic system (GrowSafe (TM)) used to record feeding behavior data, bunk visits (BV) frequency and BV duration, were compared with the observed (video) values. The second objective of this study was to quantify meal criterion; examine the associations between feeding behavior traits, performance, and feed efficiency; and the effects of breed type on feed efficiency (residual feed intake - RFI) and feeding behavior traits in heifers fed high-grain diets. Results from study one demonstrated that the GrowSafe (TM) system 4000E could accurately predict BV and meal data compared to observed data. The 100 s, used for the maximum duration between consecutive EID recordings to end an uninterrupted BV, was the appropriate MPS to predict BV frequency and duration, and meal frequency and duration compared to observed data using the GrowSafe (TM) 4000E system. The system’s ability to detect the animal’s presence or absence at the feed bunk was 86.4 and 99.6 percent, respectively. Results from the second study demonstrated that the meal criterion for heifers fed high-grain diets was 13.8 min. The 4 methods to calculate meal criterion demonstrated no differences in results of frequencies and durations of meal and the number of bunk visits per meal. Similar phenotypic correlations were found between the feeding behavior traits with RFI derived from the base model or with adjustments for final back fat. The adjustment of RFI to final back fat changed the RFI rank between breeds. The addition of feeding behavior traits to the RFI base model could accounted up to 40.4 percent of the variation in DMI not explained by ADG or MBW.

Cattle classified as having low residual feed intake (RFI) phenotypes are those that consume less feed than expected based on body weight and growth performance. Mechanisms contributing to the variation in RFI are not fully understood. Previous studies have shown that cattle of divergent RFI phenotypes have different levels of energy expenditures, which are associated with heat increment, basal metabolism, thermoregulation responses, and physical activity. The objectives of this experiment were to characterize residual feed intake (RFI) in growing heifers and to determine if variation in whole-animal energy expenditure contributes to differences in RFI. Brangus heifers (n =120) were individually fed a roughage-based diet (1.93 Mcal ME/kg DM) diet twice daily and feed refusals measured weekly. Heifers were weighed once weekly for 70 d and RFI calculated as the difference between actual and expected DMI from linear regression of DMI on ADG and mid-test BW0.75. Immediately following the 70 d study, oxygen pulse rate (mL O2/heart beat) and 48-h heart rates were measured on 8 high and 8 low RFI heifers to estimate energy expenditure. Daily heart rates and oxygen pulse rates were higher (P < 0.05) in heifers with high RFI compared to those with low RFI. As a result, energy expenditure (kcal/BW0.75) was estimated to be 17.4 percent greater (P < 0.05) in high-RFI heifers then low-RFI heifers. Mortality and morbidity losses caused by bovine respiratory disease (BRD) continue to negatively impact the net revenues of the beef cattle industry. Stress can predispose calves arriving at feedlots to BRD by impairing their immune system with calves having more excitable temperaments possibly having a greater risk. The objectives of the second study was to examine the effects of metaphylactic treatment and temperament on performance, feed intake, feed efficiency, and feeding behavior traits in steers. Santa Gertrudis steers (n =119) were weighed and randomly to control (CON; no antimicrobial treatment) or metaphylactic (MET; 1.5 mL/45 kg BW of ceftiofur crystalline free acid) treatments. Steers were weighed at 14-d intervals and individual intakes and feeding behavior traits measured using a GrowSafe sytems while fed a roughage-based diet (2.21 Mcal ME/kg DM). Objective (relative exit velocity; REV) and subjective (chute score; CS) measurements of temperament were measured on arrival and on day 28 of the study. Steers with higher REV weighed less, grew slower, consumed less feed, spent less time consuming feeding, had more feeding bouts per meal, had less backfat, smaller longissimus muscle area, and higher cortisol levels. Steers treated with MET had higher ADG than those receiving CON. Cattle with higher REV that received MET had less of a decrease in ADG, DMI, time spend consuming feed, and less of an increase in feeding bouts compared to high REV steers receiving CON. Results from this study suggest that process-control strategies, which quantify and manage inter-animal variation in calf temperament may facilitate more judicious use of antimicrobial products and provide more consistent and predictable responses to metaphylactic strategies.

While lean manufacturing has greatly improved the efficiency of production operations, it has left US enterprises in an increasingly risky environment. Causes of manufacturing disruptions continue to multiply, and today, seemingly minor disruptions can cause cascading sequences of capacity losses. Historically, enterprises have lacked viable tools for addressing operational volatility. As a result, each year US companies forfeit billions of dollars to unpredictable capacity disruptions and insurance premiums. In this dissertation we develop a number of stochastic models that capture the dynamics of capacity disruptions in complex multi-tier flow-matching feed-forward networks (FFN). In particular, we relax basic structural assumptions of FFN, introduce random propagation times, study the impact of inventory buffers on propagation times, and make initial efforts to model random network topology. These stochastic models are central to future methodologies supporting strategic risk management and enterprise network design.

The Cattle Value Discovery System (CVDS) was developed to predict growth and feed requirements of individual cattle fed in groups based on animal, diet, and environment information (Tedeschi et al., 2006). Evaluations of the CVDS using several databases of finishing cattle were conducted to determine the accuracy and precision of the model in predicted dry matter required (DMR) of pen-fed cattle. As well, the sensitivity of the model's predictions to deviations from actual ration metabolizable energy (ME) value was conducted. A meta-analysis of growing and finishing steers evaluated to model's accuracy in predicting DMR of individually fed steers, and the relationships between several model-predicted variables and actual performance and efficiency measures. Results for the first CVDS model evaluation involving pen-fed Santa Gertrudis cattle fed finishing diets revealed that accurate predictions of DMR are possible. The average mean bias for both steers and heifers was 2.43%. The sensitivity analysis of dietary ME values revealed that the model tends to consistently over- and under-predict DMR when the ME values are under- and over-estimated, respectively. However the ranking of pens was not affected by this mis-estimation of diet ME. In the second evaluations, both methods (mean body weight; MBW, dynamic iterative model; DIM) of CVDS were highly accurate and precise in allocating feed to pens of steers fed diverse types of diets and environmental conditions, with both models having a mean bias under 4%. The DIM model was slightly more accurate than the MBW model in predicting DMR. An evaluation of sources of variation revealed that for both models a large portion of the error was random, indicating that further work is needed to account for this variation. The meta-analysis study revealed that the model was able to account for 64% and 67% of the variation in observed dry matter intake (DMI) for growing and finishing steers, respectively. The two model-predicted efficiency measures, the ratio of DMR to average daily gain (ADG) and predicted intake difference (PID), were strongly to moderately correlated with their observed efficiency counterparts. In growing and finishing steers, DMR: ADG was able to account for 76% and 64% of the variation in observed feed conversion ratio (FCR) in growing and finishing studies, respectively. Strong correlations were also found between residual feed intake (RFI) and PID, suggesting that there may also be some similarity on these two measurements.