Call number: LD2668 .T4 1978 K85 / Master of Science

Call number: LD2668 .T4 1964 W42 / Master of Science

Photocopy of typescript. / Digitized by Kansas Correctional Industries

Pork quality is an important issue for the whole meat chain, from producers, abattoirs, retailers through to costumers and is affected by a web of multi-factorial actions that occur throughout the pork production chain. A vast amount of information is available on how these diverse factors influence different pork quality traits. However, results derived from individual studies often vary and are in some cases even contradictory due to different experimental designs or different pork quality assessment techniques or protocols. Also, individual influencing factors are often studied in isolation, ignoring interacting effects. A suitable method is therefore required to account for a range of interacting factors, to combine the results from different experiments and to derive generic response-laws. The aim of this thesis was to use meta-analyses to produce quantitative, predictive models that describe how diverse factors affect pork quality over a range of experimental conditions.

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Made available in DSpace on 2014-06-11T19:28:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-01Bitstream added on 2014-06-13T18:34:26Z : No. of bitstreams: 1 endo_v_me_jabo.pdf: 582582 bytes, checksum: 3464bf8d019728c103eb70fb996f52cc (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Foram utilizados 24 cordeiros Ile de France confinados dos 15 kg aos 32 kg de peso corporal em baias individuais com controle diário do alimento fornecido e das sobras. Os tratamentos, IN: cana-de-açúcar in natura + concentrado, AER: cana-de-açúcar hidrolisada com 0,6% de óxido de cálcio (CaO) em ambiente aeróbico + concentrado e ANA: cana-de-açúcar hidrolisada com 0,6% de CaO em ambiente anaeróbico + concentrado em um delineamento inteiramente casualizado, com oito repetições cada tratamento. Cordeiros alimentados com cana-de-açúcar hidrolisada em ambiente anaeróbico apresentaram maior balanço de nitrogênio (29,46 g/dia e 2,80 g/kg0,75/dia), teor de nitrogênio absorvido (2,98 g/kg0,75/dia), teor de vermelho (a*) aos 45 minutos (10,48) e extrato etéreo (2,77%) no músculo Longissimus lumborum. O maior coeficiente de digestibilidade da fibra em detergente neutro corrigido para cinzas e proteína foi observado para cordeiros alimentados com cana-de-açúcar hidrolisada (aeróbico, 51,70% ou anaeróbico, 53,75%). O maior comprimento da perna in vivo (32,21 cm), menor altura do posterior (55,23 cm) e perdas na dissecação do lombo (1,83%) foram encontrados para cordeiros terminados com cana-de-açúcar hidrolisada em ambiente aeróbico. Menor teor de gordura intermuscular (4,77%) e peso corporal vazio (24,84 kg) foram observados para cordeiros alimentados com cana-de-açúcar in natura. O fornecimento da cana-de-açúcar na forma in natura se torna viável por dispensar o processo de preparo da solução da calda e do revolvimento para homogeneização dos amontoados de cana-de-açúcar, além de não haver necessidade da compra do agente alcalinizante / It were used 24 lambs Ile de France, non-castrated, fed with diets containing in nature or hydrolyzed sugar cane in aerobic and anaerobic environments on a roughage: concentrate ratio, 50:50. The lambs were confined to 15 kg body weight, which received the diet in individual stalls in the trough, with control of food offered and the leftovers, and were slaughtered at 32 kg body weight. Lambs fed with hydrolyzed sugar cane in anaerobic environment had higher nitrogen balance (29.46 g / day and 2.80 g/kg0, 75/day), ratio of nitrogen absorbed (2.98 g/kg0, 75/day), level of value for red (a*) at 45 minutes (10.48) and ether extract (2.77%) of Longissimus lumborum muscle. The higher digestibility of neutral detergent fiber corrected for ash and protein was observed for lambs fed with hydrolyzed sugar cane independently of the environment of hydrolysis (aerobic, 51.70% or anaerobic, 53.75%). There was a greater length of leg in vivo (32.21 cm), smaller posterior (55.23 cm) and loss (1.83%) for lambs fed with hydrolyzed sugar cane in aerobic environment. Lower content of intermuscular fat (4.77%) and empty body weight (24.84 kg) for lambs fed sugar cane in nature. The hydrolyzed sugar cane provided better utilization of the fibers, but did not affect performance of animals in nature sugar cane in lambs feeding was shown to increase the quantitative traits in vivo of the lambs, but did not improve and/or damaged in carcass quantitative traits when compared with treatment with hydrolyzed sugar cane, so the use of hydrolyzed sugar cane is feasible to waive daily cuts, consequently, reduces workmanship. The supply of in nature sugar cane becomes feasible to waive the process of the preparation of the solution and revolving for homogenization of the piles of sugar cane and there is no need to purchase the alkalizing agent

Background: Meat tenderness is the consumer's most preferred sensory attribute. This trait is affected by a number of factors, including genotype, age, animal sex, and pre-and post-slaughter management. In view of the high percentage of Zebu genes in the Brazilian cattle population, mainly Nellore cattle, the improvement of meat tenderness is important since the increasing proportion of Zebu genes in the population reduces meat tenderness. However, the measurement of this trait is difficult once it can only be made after animal slaughtering. New technologies such as RNA-Seq have been used to increase our understanding of the genetic processes regulating quantitative traits phenotypes. The objective of this study was to identify differentially expressed genes related to meat tenderness, in Nellore cattle in order to elucidate the genetic factors associated with meat quality. Samples were collected 24 h postmortem and the meat was not aged. Results: We found 40 differentially expressed genes related to meat tenderness, 17 with known functions. Fourteen genes were up-regulated and 3 were down-regulated in the tender meat group. Genes related to ubiquitin metabolism, transport of molecules such as calcium and oxygen, acid-base balance, collagen production, actin, myosin, and fat were identified. The PCP4L1 (Purkinje cell protein 4 like 1) and BoLA-DQB (major histocompatibility complex, class II, DQ beta) genes were validated by qRT-PCR. The results showed relative expression values similar to those obtained by RNA-Seq, with the same direction of expression (i.e., the two techniques revealed higher expression of PCP4L1 in tender meat samples and of BoLA-DQB in tough meat samples). Conclusions: This study revealed the differential expression of genes and functions in Nellore cattle muscle tissue, which may contain potential biomarkers involved in meat tenderness.

Effects of feeding Moringa oleifera leaf meal as an additive on growth performance of chicken, physico- chemical shelf-life indicators, fatty acids profiles and lipid oxidation of broiler meat The main objective of the study was to determine the effect of M.oleifera leaf meal (MOLM) as an additive on growth performance, carcass characteristics, physico-chemical shelf-life indicators (colour, ultimate pH, driploss), fatty acids profiles and lipid oxidation of meat from broilers. A total of 432 1day old unsexed broiler chicks (Aviane 48) were randomly allocated to four dietary treatments (TRTS) in 72 cages. There were 18 cages per treatment and each cage allocated 6 chicks. Water and feed was provided at ad libitum. The feeding phases were, prestarter (0-7 Days), starter (8-18 Days), grower (19-28 Days), finisher (29-35 Days). The four TRTS contained graded levels of MOLM at 1000g/ton, 750g/ton, 500g/ton, and 0g/ton (control), respectively. The birds were slaughtered at 35 days of age. Breast muscles were sampled for meat, ultimate pH (pHu ), colour, drip loss over a 7 days shelf-life test. After each day’s test sub-samples were dipped in liquid nitrogen and kept at -180 C for thiobarbituric acid reactive substances determination. On Day1 and Day 7 extra sub-samples were also kept at -180 C for fatty acids analysis.The TRTS had no effect on average feed intake (AFI), feed conversion efficiency (FCE), and on average daily gain (ADG). Slaughter weight (SW), carcass weight (CW), dressing percentage and gizzard weight (GW) values were similar in all TRTS. Liver weight (LW), heart weight (HW), and gastro-intestinal fat (GIF) differed in all the TRTS, with treatment 2 having the highest value of HW (28.3±2.55), and LW (44.2±1.60) was the highest on treatment 4 . The pH values in all TRTS were constant from Day1 to Day5, reached peak on Day6, and then declined on Day7. Meat from broilers given treatment 1 with MOLM (1000g/ton) had the highest lightness (L*) values. The redness (a*) values were the highest in meat from treatment 2 (750g/ton MOLM). Treatments had no effect on yellowness (b*) values and on drip loss of the breasts. During storage L* values were high from Day1 to Day5 and decreased from Day6 to Day7. Drip loss increased with storage time as expected. Treatment 4 (control) had the highest proportions of poly-unsaturated fatty acids (PUFA) (30.3±1.87). Treatment 1 (1000g/ton) had the highest proportion of saturated fatty acids (SFA) (60.9±1.87). Treatment 1 (1000g/ton) had the highest proportion of SFA (60.9±4.30). Treatment 2 (750g/ton) had the highest n-6/n-3 ratio than other TRTS. Days had no effect (P>0.05) on PUFA, SFA, and n-6/n-3 ratio. Treatment 1 had a highest amount of malondialdehyde (MDA), treatment 4 had no effect (P>0.05) on MDA . Storage time had an effect (P<0.05) on MDA levels, except for on Day1 and Day7. Day2 had the highest amount of MDA (0.7±0.08). The use of MOLM as an additive in broiler diets reduced lipid oxidation in meat, and maintained the quality of the broiler meat during storage. It also did not have any adverse effects on the growth performance of broilers. Therefore, it has the potential to be used as an additive in broiler diets.

The objective of this study was to determine if increasing the forage level and feeding grain whole as opposed to dry-rolled is a feasible alternative to high energy rations with a similar age at time of slaughter. Steers were fed either twenty or forty percent forage, with whole or dry-rolled corn. There were no differences in fat thickness, longissimus area, KPH, marbling, USDA quality grade, Warner-Bratzler shear force, or cook loss. Cattle fed high forage and whole corn tended to have lower hot carcass weights. Additionally, the forty percent forage treatment tended to have lower USDA yield grades, and had darker colored steak. Also, steaks from the dry-rolled corn treatment had steaks that were redder, and more yellow. Results from this study suggest that increasing forage level, and corn processing might not result in significant differences in carcass characteristics or meat tenderness, but could negatively impact meat color.

Piglets that are born with low viability have increased mortality during early life, result in increased labor by personnel and potential animal welfare concerns. Producers focused on improving ovulation rates with the outcome of increased number of piglets with the average of piglets born increasing from 8.0 pigs/litter/sow to 10.3 pigs/litter/sow (NASS, 2016). This may not be advantageous, as number of piglets born per litter increased the weight of each piglet decreased. It is hypothesized this is due to decreased uterine blood flow available per piglet in larger litters, resulting in lower viability piglets at birth. Two studies with the intent of improving uterine blood flow will be discussed. The first study will investigate how pharmaceuticals could enhance uterine blood flow in the gilt. The second study will discuss the postnatal outcome of offspring, who experienced greater umbilical blood flows, born from dams that were exercised during gestation.