This study examined the effects of 4 genotypes of chicken, all suitable for extensive fattening, on carcass and meat quality using 320 chickens divided into 4 equally sized groups. The comparison included 2 indigenous chicken strains from Thailand, Black-boned and Thai native (Thai), and 2 imported chicken breeds, Bresse and Rhode Island Red (Rhode, a layer breed). The animals were fed until 16 wk of age. Breast (pectoralis major) and thigh (biceps femoris) muscles were studied in detail. Chickens of the imported breeds were heavier at slaughter than indigenous strains, especially Black-boned chickens. Proportions of retail cuts with bones were similar among genotypes, whereas deboned breast meat and lean:bone ratio were lowest in the layer breed (Rhode). The meat of the Black-boned chickens was darker than that of the other genotypes. Thai and Rhode chickens had a particularly yellow skin. The ratio of red and intermediate to white fibers was higher in the thigh muscle, and the diameter of all muscle fiber types in both muscles was smaller in the indigenous compared with the imported breeds. The meat of the 2 indigenous Thai strains had lower contents of fat and cholesterol compared with that of the imported breeds, especially relative to the Rhode chickens (thigh meat). The meat of the indigenous origins, especially of the Thai chickens, was higher in shear force and collagen content (thigh only) than meat of the imported breeds. The meat lipids of the Thai chickens had particularly high proportions of n-3 fatty acids and a favorably low n-6/n-3 fatty acid ratio compared with the other genotypes. In conclusion, meat of indigenous chickens has some unique features and seems to have more advantages over imported breeds than disadvantages, especially when determined for a niche market serving consumers who prefer chewy, low-fat chicken meat.

The present study aimed to assess the possible effects of Assam tea (Camellia sinensis) extract (ATE) on growth performances, immune responses, and disease resistance of Nile tilapia, Oreochromis niloticus against Streptococcus agalactiae. Five levels of ATE were supplemented into the based diet at 0, 1, 2, 4, and 8 g kg-1 feed of Nile tilapia fingerlings (10.9 ± 0.04 g initial weight) in triplicate. After four and eight weeks of feeding, fish were sampled to determine the effects of the tea supplements upon their growth performance, as well as serum and mucosal immune responses. A disease challenge using S. agalactiae was conducted at the end of the feeding trial. Fish fed ATE revealed significantly improved serum lysozyme, peroxidase, alternative complement (ACH50), phagocytosis, and respiratory burst activities compared to the basal control fed fish (P<0.05). The mucus lysozyme and peroxidase activities were ameliorated through ATE supplementation in the tilapia diets. Supplementation of ATE significantly (P<0.05) enhanced final body weight, weight gain, and specific growth rate; while a decreased feed conversion ratio was revealed at 2 g kg-1 inclusion level, after four and eight weeks. Challenge test showed that the relative percent survival

Abstract. The study of carcass and meat quality of four male genotypes namely: Thai native (TH), crossbred (Thai native x Barred Plymouth Rock; THB), Barred Plymouth Rock (BPR) and Shanghai (SH) chickens was conducted. Three hundred and twenty birds receiving from four equal groups were allotted in Completely Randomized Design (CRD). They were fed from one day and slaughtered at 16 weeks of age. Breast (M. pectoralis major) and thigh (M. biceps femoris) muscles were investigated for meat quality. TH had lower slaughtered weight (P<0.001) but higher lean : bone as well as less bone percentage (P<0.05) than all groups. Thigh muscle fiber of TH had higher type I and lower type IIB whereas there were similar in breast muscle fiber. Meat quality in terms of IMF, cholesterol and triglyceride contents as well as n-3 fatty acid and the ratio of n-6/n-3 of Thai indigenous male strain was more favorable compared to those all genotypes. Breast and thigh muscle were higher in shear force value and collagen content but the sensory evaluation was not significantly different. Since they were similar in sensory evaluation, the male layer and the male crossbred chickens have the potential to substitute TH in a market serving consumers who prefer chewy chicken meat.

Fish skin, a by-product from fish processing industries, still contains a significant amount of protein-rich material. Gelatin was extracted from Nile tilapia skin with the yield 20.77±0.80 % wet weight. Gelatin was then separately hydrolyzed by proteases, including bromelain, papain, trypsin, flavourzyme, alcalase and neutrase. Low molecular weight gelatin hydrolysate (<10 kDa) has a great potential as an antioxidant agent. Flavourzyme hydrolysate has potent activity on ABTS radical scavenging (1,413.61±88.74 μg trolox/ mg protein) and also inhibits the oxidation of linoleic acid at a high level (59.74±16.57 % inhibition). The greatest reducing power is in alcalase hydrolysate (4.951±1.577 mM trolox/mg protein). While, bromelain hydrolysate has the highest ferrous ion chelating activity (86.895±0.061 %). Evaluation of the angiotensin-I-converting enzyme's inhibitory activity indicates that all hydrolysates have great potency as an antihypertensive agent. All studied tilapia skin gelatin hydrolysates contain potent antioxidant and anti-hypertensive effects.

Twenty-four male 1-year old swamp buffaloes (Bubalus bubalis) were randomly allocated to 4 groups. One group grazed on guinea grass (GG) and another on guinea grass and the legume Stylosanthes guianensis (GL). The other two groups were kept in pens and fed freshly cut guinea grass and concentrate at an amount of 1.5% (GC1.5) and 2.0% (GC2.0) of body weight, respectively. The effect of the different feeding intensities on carcass characteristics and meat quality were assessed. The mean body weight at slaughter was 398 (±16) kg. Average daily gain was higher in concentrate-supplemented groups (570 and 540 g/d in GC1.5 and GC2.0, respectively) when compared to GG (316 g/d) and GL (354 g/d) (p<0.01). Likewise, the warm carcass weight was higher in GC1.5 and GC2.0 compared to GG and GL. Dressing percentage was 48.1% and 49.5% in GC1.5 and GC2.0 in comparison to 42.9% and 44.8% observed in GG and GL, respectively. Meat of Longissimus throracis from GC1.5 and GC2.0 was redder in color (p<0.01), while water holding capacity (drip and thawing loss) was improved in pasture-fed groups (p<0.05). Protein and fat content of Longissimus thoracis was higher in animals supplemented with concentrate (p<0.01), as was cholesterol content (p<0.05), whereas PUFA:SFA ratio was higher and n-6/n-3 ratio lower (p<0.01) in pasture-fed buffaloes. Results of the present study showed that the supplementation of pasture with concentrate enhances the growth and carcass characteristics of swamp buffaloes expressed in superior dressing percentage, better muscling, and redder meat with a higher content of protein and fat, whereas animals grazing only on pasture had a more favorable fatty acid profile and water holding capacity. In conclusion, the supplementation of concentrate at a rate of about 1.5% of body weight is recommended to improve the performance and carcass quality of buffaloes.

No abstract

A total of 600 crossbred pigs, whereof 56 were randomly selected for more in-depth studies of carcass and pork quality, were employed to test different tuna oil feeding regimens. The focus was put on the efficiency to enrich lean and adipose tissue with n-3 fatty acids and the expression of adverse side-effects on performance, carcass, and pork quality. The 4 treatments were 0% tuna oil in diet (T0; control), 1% of unrefined tuna oil in diet fed from 35 to 90 kg of BW (T1), and 3% of unrefined tuna oil in diet offered during the early (35 to 60 kg of BW; T3-E) or late stage of fattening (75 to 90 kg of BW; T3-L). With this arrangement, pigs consumed equal lifetime amounts of tuna oil (approximately 1.6 kg per pig). None of the tuna oil treatments had significant effects on performance. There were no differences in carcass quality among tuna oil groups except for group T3-E where carcasses and loin chops were fatter than those of the other groups. Water-holding capacity and texture of the loin as well as firmness and melting properties of the backfat remained widely unaffected by the treatments. Tuna oil feeding resulted in a lighter, less red and less yellow backfat and was found to increase the proportion of n-3 fatty acids to total fatty acids in all treatments. This especially concerned eicosapentaenoic acid and docosahexaenoic acid, but not alpha-linolenic acid. There was also a slight increase in oleic acid, whereas n-6 fatty acids largely decreased. Feeding tuna oil during a short period at the end of fattening (T3-L) or permanently during fattening (T1) proved to be similarly efficient in increasing n-3 fatty acid content of lean and adipose tissue (to about 1.6-fold of T0). By contrast, only two-thirds of this increase was found when the same amount of tuna oil had been fed exclusively during early fattening (T3-E). The decreased efficiency in T3-E was associated with better sensory flavor, overall acceptability grading, and oxidative status. The results show that, particularly under the condition of a continuous supply, much of the n-3 fatty acids ingested in early fattening can be recovered in pork. These findings give farmers flexibility as to when and how pork can be enriched in n-3 fatty acids with fish oil.

Native chickens are slowly growing indigenous chicken (Gallus domesticus) breeds; many of them were developed from jungle fowl, which is found in every part of Asia. These breeds are disease resistant, easy adapting to tropical climates, and have a low mortality. In Thailand, a distinct sector of consumers prefers to eat meat from native chickens rather than that from broilers because it is more tasty and chewy. In addition, studies have shown that it has a low content of fat which may be helpful for people susceptible to coronary heart diseases. This review also compiles evidence for further indicators of a special meat quality such as more oxidative (Type I) muscle fibres, a higher collagen content (promoting the preferred chewiness), an elevated content of certain flavor-relevant compounds, as well as high ratio of polyunsaturated to saturated fatty acids.