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Effects of feeding regiments on meat qualit1 (1)

  1. Effects of feeding regiments on meat quality By: - ABHINAVA BANERJEE
  3. >>Nutrition is the powerful component of livestock production system that controls several aspects of meat quality. Consumer oriented demands in meat quality has motivated the meat producers to concentrate on the nutritional aspects of the livestock rearing. The animal feed mostly affects hygienic, sanitary & nutritional characteristics of meat. Particularly, various meat quality attributes that are affected by the amount and the type of nutrients intake of the animal shall include dressing yield, meat: bone ratio, protein: fat ratio, fatty acid composition, calorific value, color, physicochemical & processing properties, shelf life & sensory attributes. In this regards, even the American Dietetic Association has endorsed beef & lamb as functional foods. So it has been imperative to develop nutritional strategies to produce meat more as a functional food than an ordinary source of animal protein. The strategies for quality meat production will include genetic selection & gene manipulation, balanced nutrition & use of approved growth promoting agents. The meat quality can also be improved through utilization of natural antioxidants, mineral supplements & probiotics.
  5. When animals are fed forages, growth rate is slower, animal attain slaughter weight at later age & the carcass has less fat. The meat is leaner, darkens in color & has more species’ specific flavor. Beta-carotene is present in high concentrations in the fresh leaf tissues & is responsible for the undesirable yellow color of the fat in pasture fed beef. An undesirable grassy flavor may results from the compounds found in for-age. Consumption of the wild onions & garlic can also give the undesirable flavor to the meat. This can be decreased or eliminated by feeding high concentrate diet up to 90 days before slaughter. Grass feeding produces a stronger flavored meat, preferred in UK & NEW ZEALAND; whereas a cereal produces a milder flavored meat that is preferred in SPAIN & USA. The difference is generally attributed to whether the main dietary
  6. fatty acid is alpha-linoleic, which produces a stronger flavor, or linoleic acid which produces a mild flavor. Feeding grass or concentrates containing linseed in the diet increases the content of 18: 3n-3 & is longer chain derivative eicosapentaenoic acid in beef muscle & adipose tissue, resulting in lowering n-6: n-3 ratio. Grass feeding also increases docosahexaenoic acid. However, grass feeding not only increases n-3 polyunsaturated fatty acids and conjugated linoleic acid (CLA) (TABLE 1) but, due to its high concentration of vitamin E, color & shelf-life is also improved. The American Dietetic Association has endorsed beef & lamb as functional food because of the antitumor genic properties of CLA they contains.
  8. When diets have a high fibre & low-energy content, carcasses are less fattened, the skeleton is more developed & the lipid content of the carcass is very low, but water & protein content seems to be high. Higher crude fibre feeding leads to lower energy content of the meat.
  10. In general, as the energy density of the diet increases, either through the use of high quality of grains that replaces the forages or by adding fat, the growth rate of the animals reach slaughter weight at younger age, the resultant carcass is heavier & higher in overall fatness & marbling. The percentage of muscular tissue is lower & that of fat is higher, in the animals of high planes of nutrition than those on the power planes. When the proteins: energy ratio is increased, the fastest growing animals may become leaner. The meat is juicier & the fat flavors the mask the meat flavor of the species. (TABLE1) On high plane of nutrition, a greater proportion of fat is synthesized from carbohydrate; & such fat has consequently a lower iodine number. Higher plane of nutrition increases the % of the intramuscular fat & decreases the % of the moisture in animal. Intensive feeding of high concentrate diets prior to slaughter improves marbling scores & palatability rating of the meat.
  12. In sub maintenance diets, fat is mobilized rather than deposited from muscles. Undernutrition causes a marked increase in the water content of the muscle (83% compared to 74% in well-nourished animals). This is also associated with the increase in % of intramuscular collagen & a decrease in its salt soluble proteins, a factor conducive to toughness. Sub- maintenance feeding to growing broilers from 4 to 8 weeks of age reduced yield of breast & thigh muscle weights by 30% to 35% then those fed ad libitum.
  14. Although inadequacy of many nutrients is bound to have repercussion on the meat quality, only a few are of consistent concern in practice. Protein inadequacies affect the amount of meat more than its quality. A failure to provide the sufficient amounts of essential amino acids also impairs the meat formation. Lysine is of particular concern because of its very high proportions in muscle proteins & its usual marginal levels in most feeds. Such inadequacies are likely to occur prior to marketing and results in additional carcass fat & decreased breast meat yield. The development of glycolytic metabolism is limited & the fall of the pH during the processing of the muscle into meat is restricted & this meat has a better water holding capacity.
  16. Fat is the main content of meat that is most affected by nutrition. When the fat is present in the diet of animal at higher levels (more than 9%), the dressing % is increased, carcasses are fatter, the carcass length to circumference ratio is reduced, & the fat content of hind leg meat is increased, while the water & the protein content is reduced. However, in some studies different feeding plans & fat enriched diets do not show variation in chemical composition of the longissimus dorsi muscle of animals. Feeding high levels of unsaturated fats have resulted in problems of carcass fat softness & oxidative instability of meat. Increasing the content of n-3 PUFA improves “greasy” & “fishy” flavor in beef, whereas, color & shelf life are reduced. Under these situations, high levels of VIT-E are necessary to help to stabilize the effect of incorporating high level of long chain PUFA into meat.
  18. IN PIGS: -Higher oleate diet fed growing pigs was found with higher muscle & adipose tissue oleate levels. The longissimus muscle chops were juicier & is tenderer. Attempts to reduce the fat content of porcine carcasses by nutritional manipulations can cause in increase softness & loss of cohesiveness in fatty tissue, leading to separation of sub- cutaneous fat into layers. This undesirable effects is due to a decrease in the size of the fat cells & an increase in the ratio of linoleic to stearic acids in fat. The more unsaturated the fatty acid, the greater its propensity to undergo peroxidation & it is well established that feeding high levels of fish oils containing EPA & DHA results in the fishy taints in the meat.
  19. IN POULTRY: - A significant increase in TBA number & rancid flavor scores (TABLE 2) for broilers fed 150g/kg full fat linseed compared with bird fed animal diet were recorded. Raised alpha-linoleic concentration was contributing to the oxidative instability. Nutritional effects on flavor of poultry meat are mainly negative & stem from feeding excessive quantities of n-3 PUFA derived from fish or linseed. This high susceptibility to peroxidation results in rapid production of off-odors & flavors that reduce shelf life of both raw & cooked meat. Fish meal & fish oil in broiler diets should not exceed 12% & 1% weight, respectively, if fishy taints are to be avoided. Other factors that “taint” the meat are the use of certain ingredients in rations.
  21. Supplemental feeding of nutrients produces heavier carcass, higher dressing %, first quality cuts, enhanced muscle proportion, slight increase in the fat deposition & desirable organoleptic traits. Niacin supplementation improved ultimate pH & color score but decrease carcass shrink & drip loss %. Dietary chromium methionine chelate supplementation is an alternate regimen to produce novel animal products such as low cholesterol, high lean & low fat meat.
  23. Feeding of VITAMIN E improves color stability/freshness, tenderness, juiciness, (TABLE 3) oxidative stability & extends the shelf life of meat. VITAMIN E is not synthesized in animal cells & must be obtained from plants through diet. Green plant tissue has high concentration of VITAMIN E than mature senescent tissue. Grains have low concentration of VITAMIN E. supplementation of VITAMIN E @0.5g/day for 126 days doubly increases the display life of meat from grain finished animals. It also helps to prevent lipid oxidation & retards meta-myoglobin formation in meat exposed to air, so improving quality (TABLE 4). Retardation of browning by VITAMIN E is linked to an inhibition of lipid oxidation. VITAMIN C & E are the natural anti-oxidants in meat that are
  24. derived from diet & may contribute to color stability. Also, they are individually effective at slowing meta-myoglobin formation, whereas, when applied simultaneously, they completely inhibited meta-myoglobin formation over 7 days. An excess of dietary VITAMIN A increases proteolytic activity of the muscle, perhaps by increasing the permeability of the membrane within which catheptic enzymes are contained. Increased VITAMIN D may increase tenderization via increased calcium levels in muscle tissue at harvest. This increased muscle pool then activates proteolytic enzymes that degrade certain muscle protein.
  26. Feed supplemented with SELENIUM & ZINC fairly improved the acceptability & decreased the oxidative rancidity of the cooked chicken or meat product (TABLE 5). When the diet is high in iron, the meat will be a very dark red & cause metallic taste when the meat is cooked. Poor nutrition diet with inadequate levels of CALCIUM, PHOSPHOROUS & the major VITAMINS A & D causes multi- colored muscle meat in animals. Some muscles are dark red & some are nearly pink in color. This causes a problem with ground meat.
  28. It is a live microbial feed supplement which improves the intestinal microbial balance in favor if the host animal. Public disapproval & banning of anti-biotic & growth hormones as feed additives in certain parts of the world has renewed commercial interest in probiotics production & its use in poultry feeding. These are neither absorbed in the gut nor do they reach the general circulation i.e. without any residual effect in meat. A most widely used probiotic bacterium is Lactobacillus acidophilus, which acts as natural substitutes for feed anti-biotic. Dietary yeast components, such as whole yeast & cell wall supplementation improved tenderness & reduced oxidation of meat. Lowest supplementation significantly improves liver weight in broilers.
  30. The commonly used β-ADRENERGIC agonists include cimaterol, etc. β-ADRENERGIC has shown enormous potential to alter the muscularity & ratio of lean to fat in meat animals. The orders of efficacy of this drugs in livestock is CATTLE>SHEEP>TURKEY> PIG>POULTRY. Unlike anabolic steroids hormones, Β-ADRENERGIC are effective in all sexes to the same extent. It also reduces the amount of fat in the body & increases Protein accretion, so promoting muscular development. Fat reduction is done by both fat production & fat breakdown. Protein accretion is through reducing breakdown & favoring normal protein turnover. Particularly, high proportion of type II, glycolytic, Fast contracting fibres is most affected. (TABLE 6)
  32. Carcasses from B-adrenergic agonists administered animals showed increased glycolysis that resulted in decreased muscle glycogen that ultimately increased the pH. The less fat cover resulted in faster cooling of carcass. The increase in the rate of pH fall resulted in decreased WHC causing increased drip loss in veal.
  34. CIMATEROL resulted in a lighter meat due to decreased WHC caused by increased reflectance by moist surface (TABLE 7). A significant decrease in HEAM pigment was observed due to increased % of white muscle fibres.
  36. The meat obtained from these animals showed decrease in tenderness or increase in shear force due to decrease in % of heat soluble collagen (22-40%) & rapid maturation of connective tissues. There was an increase in size &/or % of white muscle fibres with larger diameters. A decreased calpain activity in the carcasses of young bulls resulted decreased proteolysis, which combined with changes in muscle fibres size decreases the tenderness.
  38. TABLE 1: - Carcass & meat quality characteristics of steers… Characteristics Pasture (n=10) Concentrates (n=20) Hot carcass weight, (kg) 225.6a 240.10b Degree of finishing 1.5a 2.0b Fat depth, (mm) 3.8a 6.1b Rib eye area, (cm2 ) 55.20a 62.9b Total lipid 1.68a 3.18b Total Conjugated Linoleic Acid 0.53b 0.25a Saturated Fatty Acids 49.08b 47.62a Mono-Unsaturated Fatty Acids 40.96a 46.36b Poly-Unsaturated Fatty Acids 9.96b 6.02a PUFA:SFA 0.20b 0.13a n6:n3 1.44a 3.00b
  39. TABLE 2: - Effect of dietary factors on consumer acceptability & TBA values- of cooked dark chicken meat … Factors studied 74 days of storage at -200 C Acceptability score* TBA #(µg MDA/kg) Fat source Fish oil 4.9 86 Linseed oil 5.0 84 Animal fat 5.1 74 *Sensory scores based on 9 point scale #Thiobarbituric acid (TBA) value . Malonaldehyde (MDA)
  40. TABLE 3: - Effect of VITAMIN E on taste characteristics of cooked roast beef… Characteristics Vitamin Treatment Vit E (E+) Control (E-) SEM Tenderness 10.25 10.53 0.20 Saltiness 1.23 1.50 0.13 Juiciness 6.45b 7.15a 0.19 Beef flavor 8.11 8.50 0.26 Scale: 15 cm semi-structured line scale where, 0=none & 15=intense
  41. TABLE 4: - Quality of buffalo meat pre-blended with natural antioxidants… Treatment Day 0 Day 4 Day 8 Mean Color scores (5 Points) Control 4.60 2.67 1.0 2.74a Sodium ascorbate 4.77 4.70 4.33 4.60b Alpha-Tocopherol acetate 4.67 2.97 1.13 2.87a SA+TA 4.70 4.60 3.90 4.39c Met myoglobin (%) Control 57.67 59.80 74.27 63.87a Sodium ascorbate 52.07 53.97 60.0 55.25b Alpha-Tocopherol acetate 55.77 58.80 68.87 60.73ac SA+TA 54.33 55.17 60.20 50.05bc TBARS Number (mg malonaldehyde/kg meat) Control 0.355 0.663 1.313 0.733a Sodium ascorbate 0.276 0.313 0.551 0.367b Alpha-Tocopherol acetate 0.310 0.440 0.709 0.469b SA+TA 0.291 0.318 0.705 0.420b
  42. TABLE 5: - Effect of dietary factors on consumer acceptability & TBA values- of cooked dark chicken meat… Factors studied 74 days of storage at -200 c Acceptability score* TBA#(µg MDA/kg) Zn supplementation 0 mg/kg 4.9 93 600 mg/kg 5.1 71 Se supplementation 0 mg/kg 5.0 91 Selenite, 1.2 mg/kg 5.2 73 Se yeast, 0.20 mg/kg 4.8 83 *Sensory scores based on 9 point scale #Thiobarbituric acid (TBA) value . Malonaldehyde (MDA)
  43. TABLE 6: - Effect of Oral administration of β-adrenergic Agonists… Animal Weight gain (%) Feed Consumption (%) Feed/Gain (%) Muscle (%) Fat (%) Cattle +10 -5 +15 +10 -30 Chicken +2 - +2 +2 -7 Pigs +4 -5 -5 +4 -8 Sheep +15 +2 +15 +25 -25
  44. TABLE 7: - Effect of Cimaterol on Meat Quality of LD Muscle… Treatments Control Cimaterol Glycogen 93 75.5 Protein 22.5 23.3 Intramuscular fat 0.86 0.58 Soluble collagen 23.9 24.2 Shear force 5.8 17.7 Meat Color Lightness 40.6 42.4 Hue 31 33.2 Saturation 21.2 19.9
  45. ARTICLES BY WHICH THE INFORMATIONS ARE TAKEN….. 1) G/view?usp=drivesdk 2) M/view?usp=drivesdk
  46. RESOURCES… 1) 2) 3) 4) 5) 6) men_on_meat_quality_MyHC_isoforms_AMPK_and_PGC- 1a_genes_expression_in_the_biceps_femoris_muscle_of_Mongolia_sheep 7)