The aim of the study was to determine the fatty acid composition, colour stability and lipid oxidation of fresh mince produced from fallow deer and to evaluate the effect of frozen storage duration on the retail display shelf life of the mince. A total of 31 fallow deer carcasses were used in the study. After cooling for 24hrs, the carcasses were deboned, external fat from the fore and hindquarter muscles removed and individually vacuum packed. For the first trial, seven fallow deer carcasses were used. Meat from the hind and fore-quarters of each carcass was divided into two equal batches per animal. One batch was minced (through a 5 mm die) and packed into oxygen permeable overwraps and refrigerated at 4°C for a period of eight days under retail display conditions. The second batch was vacuum packed and frozen at -20°C for 2 months at the end of which mince was also produced and monitored over an eight-day period under the same conditions that were used for the fresh mince. Colour, pH, lipid and myoglobin stability was determined. Proximate and fatty acid composition was also determined. No differences (P>0.05) were noted between proximate composition of fresh and frozen/thawed minced meat. The lipid content of fallow deer was 2.4 percent (±0.04). Total n3 fatty acids differed (P<0.05) between treatments and decreased with increased storage and display day. There were significant (P<0.05) treatment and time interactions on all measured colour parameters, TBARS and myoglobin forms. Fresh mince was lighter and had higher redness (a*) and yellowness (b*) values than mince from two months frozen stored meat. Hue angle for fresh mince remained stable throughout display whereas it increased for frozen/thawed mince. Fresh mince had lower TBARS values than frozen/thawed mince. Minced meat produced from frozen/thawed deer meat had higher surface met-myoglobin and total met-myoglobin percentages. Surface and total oxy-myoglobin percentage was higher in fresh mince. The first trial clearly showed colour and lipid stability differences between fresh mince and mince from frozen/thawed meat. It also showed that fresh mince has a longer retail display life than mince produced from frozen/thawed meat (six days and four days, respectively). In the second trial, the effects of frozen storage duration on colour and lipid stability were investigated. Twenty-four fallow deer were used. Twelve were harvested in June (6male 6female) and the other twelve in August (6 male 6female) of the same year.Twenty four hours after harvesting, the fore and hindquarter muscles of the carcasses were deboned, vacuum packed and kept at -20°C until October (i.e. 2months and 4months frozen storage period). Upon thawing, the meat was processed into mince following the same procedure used for the first trialand displayed for a fiveday period under retail display conditions. Frozen duration and gender had no effect (P>0.05) on the proximate composition of fallow deer meat. The total amount of saturated fatty acids (SFA) increased and total amount of poly unsaturated fatty acids (PUFA) decreased as frozen duration and display day increased (P<0.05). Frozen duration affected (P<0.01) lipid oxidation and percentage oxy-myoglobin. Mince pH and all colour parameters (L*, a*, b*,hue and chroma) differed (P<0.05) between treatments on day zero and three. Display day was a significant factor (P<0.05) on all measured parameters. By day three all parameters except pH showed signs of extended oxidation and discolouration as evidenced by reduced redness, decreased colour intensity and high TBARS values. This study showed that prolonged frozen storage negatively affects the colour and lipid stability of meat and increases oxidation of PUFAs during frozen storage. However, the study also suggests that although frozen/thawed meat has a shorter retail display shelf life; the proximate composition of the meat remains unchanged.

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 pre-slaughter handling on pork quality from a smallholder abattoir By Christian Sabelo Gajana A total of 158 pork samples from Landrace and Large White pigs were collected from Nxuba Municipal abattoir to determine the effects of pre-slaughter handling on pork quality. Technological quality attributes of pork such as pHu, L*, a*, b*, WBSF values, TL%, CL% EL% were determined. Breed differences were observed in ultimate pH (pHu) and redness (a*) with meat from the Large White having higher pHu and lower a* values than meat from the Landrace. Meat from pigs slaughtered in spring season had the highest (P<0.05) shear force values (27.6±1.58) while the lowest shear force values (18.5±1.58) were found in meat from pigs that were slaughtered in the autumn season. The lowest pHu and highest a* values were found in meat from 9 month-old pigs (5.3±0.07). The 6, 9 and 10 months had highest (P<0.05) than 7 and 8 months old pigs. Cooking loss and evaporation loss increased with age groups. Only distance and transportation time had a positive relationship to TL% of pork whilst no significant relationship was reported between all the other pre-slaughter variables and technological quality attributes of pork. Highest risks of PSE occurrences were observed with more space allowance of 0.4 m2 per 100 kg during transportation. Reduced risks of PSE occurrences were observed with space allowance of 0.35 m2 per 100 kg. The pHu were positively correlated to WBSF values (P < 0.001). The L* values were positively correlated to b* (P < 0.001), and negatively correlated to a* while CL and EL were positively correlated to L*. In the current study, a* values were positively correlated to b* (P < 0.001) but negatively correlated to EL (P < 0.01). There were iv positive correlations between CL and EL, Both CL and EL were positively correlated to WBSF values. The first four principal components (PCs) explained about 95% of the total variability for technological quality attributes of pork. It can be concluded that pig breeds vary in pHu and considerations should be made on different seasons of slaughter when assessing pork quality. Precautions should also be made on age categories of animal when improving the quality of pork. Transportation time, distance, stocking density, temperature and lairage time did not show significant relationship with technological quality attributes measured; except for transportation time and distance travelled which had a positive relationship with TL%. The risk of PSE increased with more space availability more than 0.4 m2 per 100 kg pig, but stocking density of 0.35 m2 per 100 kg was an ideal reduce the risk of PSE pork.

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 effect of pasteurizing dose levels of irradiation on the lipid and protein fractions of raw bovine muscle was studied by chemical amalysis and taste panel evaluation. The following storage conditions were evaluated: (a) Long term anaerobic storage at 39°F (b) Short term aerobic storage at 39°F (c) Frozen storage at -10°F (d) Cooking and short term aerobic storage at 39°F. Free fatty acid content increased with time of storage at 39°F. Irradiation with 1 Mrad of γ irradiation depressed free fatty acid development. During frozen storage the unirradiated sample was significantly higher in free fatty acids than the irradiated samples (0.1 Mrad and 0.5 Mrad). The quantity of phospholipid was reduced by both aerobic and anaerobic storage but no significant difference was evident between irradiated and unirradiated samples. The formation of free amino acids during storage was retarded by irradiation. A significant difference in flavour between control samples and those which received 0.5 Mrad of irradiation was found consistently by taste panel evaluation. The flavour difference resulted from characteristic irradiation odour. Rancid flavours were not detected by the panel. Thiobarbituric reactive substances (TBRS) increased during short term aerobic storage, however a significant difference did not exist between irradiated and unirradiated samples. During long term anaerobic storage the TBRS of irradiated samples increased faster than that of unirradiated samples, but the difference was relatively small. During frozen storage TBRS increased in direct proportion to the level of irradiation. Aerobic storage of cooked meat at 39°F resulted in a rapid increase of TBRS but the level was not affected by irradiation. / Land and Food Systems, Faculty of / Graduate

M.Tech. (Biotechnology) / Please refer to full text to view abstract

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.

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