Dietary inclusion of tomato pomace improves meat oxidative stability of young pigs

The aim of this study was to assess the nutritional effect of tomato pomace, in combination with two distinct fat sources (lard or soya bean oil), on longissimus lumborum muscle, subcutaneous fat and liver of young pigs. Forty male pigs of 4 weeks old were randomly assigned to four dietary treatments using two fibre sources (wheat bran or 5.0% tomato pomace) and two fat sources (lard or soya bean oil), in a 2 × 2 factorial design for a 5‐week trial. Tomato pomace did not improve colour, fatty acid profile, cholesterol content or lipid oxidation, nor did it yield detectable levels in lycopene or β‐carotene in the meat (p > 0.05). However, a positive increase in α‐tocopherol content of meat and liver was observed in pigs fed tomato pomace (p < 0.05). Compared with lard, soya bean oil increased MUFA and PUFA proportions and decreased the percentage of SFA (p < 0.05). Our results indicate that 5.0% of tomato pomace increases pork oxidative stability and that 5.0% of soya bean oil, compared with lard, improves its nutritional quality.     

Effects of Inulin Supplementation in Low‐ or High‐Fat Diets on Reproductive Performance of Sows and Antioxidant Defence Capacity in Sows and Offspring

This experiment was conducted to investigate the effects of inulin supplementation in low‐ or high‐fat diets on both the reproductive performance of sow and the antioxidant defence capacity in sows and offspring. Sixty Landrace × Yorkshire sows were randomly allocated to four treatments with low‐fat diet (L), low‐fat diet containing 1.5% inulin (LI), high‐fat diet (H) and high‐fat diet containing 1.5% inulin (HI). Inulin‐rich diets lowered the within‐litter birth weight coefficient of variation (CV, p = 0.05) of piglets, increased the proportion of piglets weighing 1.0–1.5 kg at farrowing (p < 0.01), reduced the loss of body weight (BW) and backfat thickness (BF) during lactation (p < 0.05) and decreased the duration of farrowing as well as improved sow constipation (p < 0.05). Sows fed fat‐rich diets gained more BW during gestation (p < 0.01), farrowed a greater number of total (+1.65 pigs, p < 0.05) and alive (+1.52 pigs p < 0.05) piglets and had a heavier (+2.06 kg, p < 0.05) litter weight at birth as well as a decreased weaning‐to‐oestrous interval (WEI, p < 0.01) compared with sows fed low‐fat diets. However, it is worth noting that the H diet significantly decreased the serum activities of superoxide dismutase (T‐SOD) and glutathione peroxidase (GSH‐Px) and increased the serum malondialdehyde (MDA) levels in sows and piglets (p < 0.05). In contrast, HI diet enhanced the activities of T‐SOD and GSH‐Px and decreased the serum MDA concentrations (p < 0.05) in sows and piglets. In summary, the fat‐rich diets fed to sows during gestation had beneficial effects on reproductive performance, but aggravated the oxidative stress in sow and piglets. Inulin‐rich diets fed to sow during gestation had beneficial effects on within‐litter uniformity of piglet birthweight and enhanced the antioxidant defence capacity of sows and piglets.     

Effect of dietary mono- and polyunsaturated fatty acids on the fatty acid composition of pigs' adipose tissues.

In two experiments with growing-finishing pigs six different dietary fats were added to a conventional diet (control--C) to study the effects of dietary monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) on the fatty acid composition of backfat and kidney fat at similar amounts of double bonds in feed (Exp. 1:7% pork fat--PF, 4.95% olive oil--OO, 3.17% soybean oil--SO) or a constant amount of 5% of processed fats (Exp. 2: partially hydrogenated fat--SAT, fractionated pork fats: olein--OLE, stearin--STE). Compared with the control, PUFA were only slightly increased in backfat of pigs fed PF, OLE, STE or OO, although dietary PUFA intake was up to 70% higher. With SO PUFA were significantly increased in adipose tissues, predominantly at the expense of MUFA. Consequently, a non-linear relationship was found between PUFA intake and proportion in backfat. MUFA were incorporated at the expense of SFA, therefore, adipose tissues of OO fed animals were lowest in SFA. Despite comparable amounts of double bonds in feed (Exp. 1), the degree of unsaturation measured as fat score (sum of double bonds) was in the order SO > OO > PF > C. In contrast, the proportion of SFA was C > PF = SO > OO. Regarding the decisive role of SFA for fat consistency it may be concluded that MUFA should also be considered in feeding recommendations for pigs. Furthermore, in case of a high dietary supply of MUFA, a simple index of double bonds might not be sufficiently conclusive to judge pig fat quality.     

Proteome changes in renal cortex and medulla induced by dietary supplementation with inulin‐type fructans in growing pigs

The aim of the study was to evaluate the influence of dietary supplementation with inulin extract from chicory root and dried chicory root on the protein profile of the renal cortex and medulla of growing pigs. The experiment was carried out on renal cortex and medulla tissue collected from 24 50‐day‐old PIC x Penarlan P76 crossbred piglets (males). Animals were divided into three dietary groups (n = 8) and fed with a control diet, diet supplemented with 2% inulin extract from chicory root and a diet supplemented with 4% dried chicory root. Kidney samples were collected after 40 days of feeding, and renal cortex and medulla proteins were separated by two‐dimensional electrophoresis. Protein identification was performed using MALDI‐TOF mass spectrometry. The diet supplemented with 2% chicory inulin induced significant expression changes of 20 and 26 protein spots in the renal cortex and medulla respectively. Supplementation with 4% dried chicory root triggered changes in the expression of 44 and 24 proteins in the renal cortex and medulla respectively. Both forms of chicory inulin‐type fructans effectively affected the expression of proteins involved in energy metabolism, heat shock proteins and other chaperones, cytoskeletal and cytoskeleton‐related proteins, as well as other proteins. Additionally, changes in transferrin abundance in both experimental groups suggested the significance of chicory fructan supplementation for iron absorption and bioavailability. In conclusion, 2% inulin extract from chicory root and 4% dried chicory root exerted a similar effect on changes in renal protein expression; however, more pronounced alterations were induced by dried chicory root. Nevertheless, further studies are needed for better understanding the mechanism underlying the effect of chicory inulin‐type fructans and their fermentation end products on the kidneys of growing pigs.     

Effect of dietary kapok oil supplementation on growth performance,carcass traits,meat quality and sensory traits of pork in finishing‐pigs

Kapok seed and oil from the tropical zone are widely used as pig feed to harden porcine fat in Japan. This study evaluated the effect of dietary kapok oil supplementation on pork quality and sensory traits. Five Duroc pigs each were assigned to an experimental group supplemented with kapok oil and a control group. Dietary kapok oil supplementation had no effect on growth performance and intramuscular fat content in the Longissimus dorsi muscle (LM). Supplemental kapok oil increased saturated fatty acid contents in subcutaneous and intramuscular fat and decreased monounsaturated fatty acid levels (P < 0.05). Off‐flavor detection by a trained panel was higher in the experimental than the control group (P < 0.05), but tenderness, juiciness, texture and flavor intensity of LM chops were similar in both groups. The overall palatability of pork as judged by a consumer panel decreased with kapok oil supplementation (P < 0.01). These results indicate that while growth performance, intramuscular fat contents and carcass characteristics were unchanged, while dietary kapok oil supplementation makes firm fat to prevent inferior soft fat in pork, it can lower the palatability of pork due to a decrease in monounsaturated fatty acids.     

Comparison of grain sources for swine diets and their effect on meat and fat quality traits

A study was conducted to evaluate the effect of dietary grain sources on various compositional and quality characteristics of pork from pigs reared in a commercial environment. Pigs were fed 1 of 5 dietary treatments containing the following single or blended grain sources throughout most of the grow-finish period: 1) yellow corn, 2) white corn, 3) 1/3 yellow corn and 2/3 white corn, 4) 2/3 yellow corn and 1/3 white corn, and 5) barley. Pigs were from 2 sire genetic types, Duroc and Hampshire x Duroc, mated to PIC 1055 females. A total of 1,040 pigs were included in the study in a 2 x 2 x 5 factorial arrangement with 2 genetic types, 2 sexes (barrows and gilts), and 5 dietary treatments. Eight pigs were randomly selected from each pen of 26 (n = 320) for meat and fat quality evaluation. Pigs were 27.6 kg at the beginning of the experiment and were fed to 130.2 kg. All animals were held overnight at a commercial abattoir before slaughter. One whole, skin-on, boneless loin was collected from each carcass and held at -1 degrees C in a cryovac-sealed bag at the Iowa State University Meat Laboratory. At 25 to 27 d postslaughter, loins were evaluated for meat and fat quality. Dietary treatment had no effect (P > 0.05) on 24-h pH, sensory tenderness, sensory chewiness, Instron tenderness, loin purge, or cook loss. At 25 to 27 d postslaughter, pigs fed diet 4 had a greater (P < 0.05) loin pH than pigs fed diet 1, and diets 2, 3, and 5 were not different from all treatment means. Pigs fed diet 4 had a greater (P < 0.05) Japanese color score than pigs fed diets 2, 3, and 5, and diet 1 was not different from all treatment means. Pigs fed diet 3 had a greater percentage of intramuscular fat than pigs fed diets 1 and 2, although diets 1, 4, and 5 and diets 1, 2, and 5 were not different (P > 0.05). No differences among dietary treatments were found for fat color values on a subjective basis. Pigs fed diet 5 had a more desirable objective fat color than pigs fed all white corn, and diets 1, 3, and 4 were not different (P > 0.05). Pigs fed diet 5 had greater levels of SFA and MUFA, and lower levels of unsaturated fatty acids and PUFA, in the subcutaneous fat than pigs fed all other diets. These results indicate that the energy sources evaluated in this study had little effect on eating quality of pork that was held for 25 to 27 d postslaughter.     

Interactive effect of ractopamine and dietary fat source on quality characteristics of fresh pork bellies

Crossbred pigs (n = 216) were used to test the interaction, if any, of ractopamine (RAC) and dietary fat source on the characteristics of fresh pork bellies. Pigs were blocked by BW (77.6 +/- 6.5 kg) and allotted randomly to pens (6 pigs/pen). After receiving a common diet devoid of RAC for 2 wk, pens within blocks were assigned randomly to 1 of 4 treatments arranged in a 2 x 2 factorial design, with 5% fat (beef tallow vs. soybean oil) and RAC (0 vs. 10 mg/kg). At the conclusion of the 35-d feeding period, pigs were slaughtered at a commercial pork packing plant (average BW of 108.8 +/- 0.6 kg), and fresh bellies were captured during carcass fabrication. Neither RAC (P = 0.362) nor fat source (P = 0.247) affected belly thickness. Subjective (bar-suspension) or objective (compression test) measures of belly firmness were not (P > or = 0.148) affected by the inclusion of RAC in the diet; however, bellies from pigs fed soybean oil (SBO) were softer than those from pigs fed beef tallow (BT), as indicated by perpendicular (P < or = 0.005) and parallel (P < 0.001) suspensions. Moreover, bellies from BT-fed pigs required more (P = 0.096) force to compress 50% of their thickness than bellies from SBO-fed pigs (52.29 vs. 43.51 kg). Color (L*, a*, and b* values) of the belly lean and fat was not (P > or = 0.131) affected by RAC, and lean color was similar (P > or = 0.262) between fat sources; however, belly fat from BT-fed pigs was lighter (P = 0.030) and redder (P = 0.013) in color than belly fat from SBO-fed pigs. Bellies of SBO-fed pigs had greater (P < 0.001) proportions of PUFA and lower (P < 0.001) proportions of SFA and MUFA than belly fat from pigs fed BT. Regardless of the RAC inclusion level, PUFA:SFA and iodine values were lower in belly fat from pigs fed BT than SBO; however, within SBO-fed pigs, PUFA:SFA and iodine values were further increased by feeding RAC (RAC x fat source, P < 0.001). As expected, dietary fat source altered the fatty acid composition of fresh pork bellies, which subsequently impacted fresh belly firmness. Interestingly, including RAC in swine finishing diets exacerbated the effect of feeding SBO on pork fat polyunsaturation.     

Investigation of carryover effect of prior fibre consumption on growth,serum and tissue metabolic markers in Ossabaw pigs fed a high‐fat diet

Carryover effect of prior fibre consumption on metabolic markers was investigated. Treatments were arranged in 2 × 2 factorial with 2 fibre sources, 4% inulin or cellulose (Solka‐Floc®) and fat levels (5 or 15%) for the low‐fat diet (LFD) and high‐fat diet (HFD) respectively. Pigs were fed the two fibre diets for the first 56d (nursery phase), and thereafter fed either the LFD or HFD containing no added fibre source from d56 to 140 (growing phase). Pigs on the HFD were heavier (p = .05) than those on LF (64.61 vs. 68.38 kg), regardless of prior fibre type consumed. Pigs that were fed cellulose during the nursery and later fed the HFD had the highest ADG (p < .05). Feeding the HFD resulted in higher back fat (BF) (13.41 and 18.18 ± 0.12 mm for LFD and HFD, respectively; p < .01). The HFD resulted in higher (p < .01) insulin (0.014 and 0.016 ± 0.001 mg/L for LF and HF respectively) and glucose (100.89 and 125.03 ± 4.39 mg/dl for LF and HF respectively) concentrations in the serum. Inulin increased (p ≤ .02) jejunal expression of SREBP‐1c and CL‐4, but reduced (p < .05) TNFɑ and IL‐6 expression in the ileum. Alpha‐diversity was significantly different (p < .05) between the inulin and cellulose fed pigs at the end of the nursery and finishing phases. Therefore, inulin feeding before a HFD may lead to reduction in ADG and inflammatory markers in the small intestine of pigs, and thus prevent future metabolic disorders.     

多株益生菌复合饲料发酵剂的应用效果试验

选择180头"外三元"肥育猪,分小、中、大猪三个试验组,同时饲喂3种试验日粮(即三组饲料原料的发酵产品),每种试验日粮的饲喂量分成3个水平,并以饲喂基础日粮(即全价配合饲料)为对照。饲喂45 d(正试期30 d)后,统计日增重,并屠宰大猪测定猪肉品质。结果表明:与单纯饲喂基础日粮相比,添加试验日粮Ⅰ、试验日粮Ⅱ、试验日粮Ⅲ的育肥猪的生产性能明显提高,日均增重分别提高了13.6%～17.1%(P<0.05)、1.8%～8.9%、3.5%～13.8%,肉质明显改善,猪肉滴水损失分别降低了33.72%、16.17%2、2.61%,且肌肉粗蛋白、肌肉脂肪含量有不同程度的提高。     

Interactive effect of ractopamine and dietary fat source on pork quality characteristics of fresh pork chops during simulated retail display

Crossbred pigs (n = 216) were used to test the interactive effect, if any, of ractopamine (RAC) and dietary fat source on the performance of finishing pigs, pork carcass characteristics, and quality of LM chops during 5 d of simulated retail display (2.6 degrees C and 1,600 lx warm-white fluorescent lighting). Pigs were blocked by BW and allotted randomly to pens (6 pigs/pen), and, after receiving a common diet devoid of RAC for 2 wk, pens within blocks were assigned randomly to 1 of 4 diets in a 2 x 2 factorial arrangement, with 5% fat [beef tallow (BT) vs. soybean oil (SBO)] and RAC (0 vs. 10 mg/kg). Diets were formulated to contain 3.1 g of lysine/Mcal of ME and 3.48 Mcal/kg of ME. Across the entire 35-d trial, pigs fed RAC had greater (P < 0.01) ADG and G:F, but RAC did not affect (P = 0.09) ADFI; however, performance was not affected (P >or= 0.07) by dietary fat source. Carcass weight, LM depth, and lean muscle yield were increased (P < 0.01), whereas fat depth was decreased (P = 0.01), in carcasses from RAC-fed pigs; however, carcass composition measures were similar (P >or= 0.27) between fat sources. Feeding 10 mg/kg of RAC reduced (P 相似文献   

Live weights at slaughter significantly affect the meat quality and flavor components of pork meat

One‐hundred‐twenty crossbred pigs finished at 175–185 days of age were used to investigate the effects of live weights at slaughter on the meat quality, volatile flavor compounds, and sensory attributes of pork meat. Based on the live weights at slaughter, three weight groups (n = 36 per group) were classified as follows: light weight (LW: 100 kg), medium weight (MW: 110 kg), and heavy weight (HW: 120 kg). After slaughter, longissimus dorsi muscle samples were taken and used for the analyses of aforementioned parameters. The HW group had higher fat content and water holding capacity compared to the LW or MW group (p < 0.05). The HW group also showed higher levels for majority of unsaturated fatty acids and total polyunsaturated fatty acids than the LW group (p < 0.05). The slaughter weight significantly affected the amounts of 11 among the 47 flavor compounds identified. Significantly higher amounts of fatty acids oxidation‐derived flavor compounds (aldehydes) were found in the HW group than in the other groups. Noticeably, increasing slaughter weight was associated with higher sensorial scores for flavor, juiciness, and acceptance scores (p < 0.05). Based on the obtained results, 120 kg body weight is recommended as the market weight for this commercial breed without compromising the meat quality.     

Improving pork quality by feeding supranutritional concentrations of vitamin D3

Duroc-cross pigs (n = 25) were assigned to one of three experimental finishing diets containing 0 (control), 40,000 (40), or 80,000 (80) IU of supplemental vitamin D3/kg of feed (as-fed basis)to test the effects of vitamin D3 on pork quality traits. Experimental diets were fed for 44 or 51 d before slaughter, and days on feed were blocked in the experimental design. A trend existed for pigs receiving the highest concentration of vitamin D3 supplementation to have a lower (P = 0.08) ADG (0.77 kg/d) compared with pigs fed either the 40-diet (0.88 kg/d) or control (0.92 kg/d). Diet did not (P > 0.10) affect backfat thickness measured along the midline, 10th-rib fat depth, longissimus muscle area, muscle score, or hot carcass weights. Longissimus pH, measured at 0.5, 1, 2, 3, 4, and 24 h postmortem, was higher (P < 0.05) for pigs on the 80-diet than those fed the control diet. Longissimus muscle color, measured at 24 h postmortem, from pigs fed either the 40- or 80-diet were darker (lower L* values; P < 0.05) than those fed the control diet. Objective longissimus color scores were higher (P < 0.01), and firmness/wetness scores lower (P < 0.05), for pigs on the 80-diet as compared to those on the 40-diet or control diet. The diet had no (P > 0.10) effect on Warner-Bratzler shear force values; percentage of cook loss; or trained sensory panel evaluations for tenderness, juiciness, and flavor. Feeding the 80-diet increased (P < 0.05) plasma vitamin D3 and calcium after 2, 4, and 6 wk on feed compared with the control diet. Vitamin D3 and 25-hydroxy vitamin D3 concentrations in the longissimus muscle increased (P = 0.001) with increasing vitamin D3 levels in the diet; however, muscle calcium concentrations and fiber type were not (P > 0.30) affected by diet. These results indicate that feeding supranutritional levels of vitamin D3 for at least 44 d improves pork color and increases pH, but may retard growth if fed at 80,000 IU/kg of feed.     

Effects of an immune stimulant,inactivated Mycobacterium phlei,on the growth performance as well as meat quality of fattening pigs

Inactivated mycobacterium phlei (M. phlei) is well known for its immune‐stimulatory functions in humans and livestock, but less information is available about the influence on meat quality of pigs when used as a feed additive. This study was designed to evaluate the effects of inactivated M. phlei on growth performance as well as meat quality of fattening pigs. A total of 240 cross‐bred pigs ([Landrace × Yorkshire] × Duroc) with initial body weight of 80.14 ± 0.29 kg were randomly allocated to five treatments, each of which consisted of eight replicates with 6six pigs per replicate. The basal diet supplemented with five levels of inactivated M. phlei preparations (0, 3.5 × 10⁹ [0.1% w/w], 7 × 10⁹ [0.2%], 1.4 × 10¹⁰ [0.4%] or 2.1 × 10¹⁰ [0.6%] colony‐forming units/kg) was respectively fed to the control group and four treatment groups for 30 days. Adding 0.4% of inactivated M. phlei to diet increased the average daily feed intake and average daily gain of pigs. Importantly, intramuscular fat percentage in the Longissimus dorsi (LD) was increased by feeding diet containing 0.2%, 0.4% and 0.6% of inactivated M. phlei, despite the pH value, drip loss, cooking loss and filter paper fluid uptake not being influenced. Analysis of the fatty acid components showed that some saturated fatty acids were decreased in LD after feeding inactivated M. phlei, but some monounsaturated fat acids (MUFAs) and polyunsaturated fatty acids were increased (PUFAs), which induced the total contents of MUFAs and PUFAs were improved. RT‐PCR assay revealed that feeding inactivated M. phlei up‐regulated genes implicated in fat metabolism in muscle, including ELOVL6, FASN, SCD1 and H‐FABP. This study revealed that feeding inactivated M. phlei not only increased growth performance of fattening pigs, but also improved the meat quality by increasing intramuscular fat content, thus inactivated M. phlei probably has high utilization value in modern pig production.     

Effects of soyabean meal‐ or whey‐based diets on lipid metabolism in weaned piglets

The present study aimed to test the hypothesis that dietary protein source influences lipid metabolism‐related parameters weaned piglets. The effects of soyabean meal (SB) and whey proteins (WP) on gene expression of several genes involved in the lipogenic process in liver, visceral (VAT) and subcutaneous (SAT) adipose tissues, plasma insulin concentration and fatty acid (FA) profile were investigated in 18 weaned piglets. Weaned piglets were fed one of two diets containing either SB or WP as the main protein source. Following a 10‐h fasting period, plasma insulin concentration and FA profile were assessed at 56 and 72 days of age, whereas gene expression in liver, VAT and SAT was assessed at 72 days of age. Plasma insulin concentration was not affected by diet, although it was 40% lower in SB fed pigs. The SB pigs had lower 14:0 (p < 0.01) and higher 18:3n‐3 (p < 0.001) levels in plasma in comparison with WP pigs. However, these changes were attributed to background differences in the dietary FA profile and not to a direct protein source effect. Gene expression of sterol regulatory element‐binding protein 1 (SREBP‐1) in liver and VAT were lower (p < 0.01 and p < 0.05, respectively) in SB compared to WP fed piglets, but no differences occurred in SAT. No changes were observed in sterol regulatory element‐binding protein 2, liver X receptor, peroxisome proliferator‐activated receptors α and γ and plasminogen activator inhibitor 1 mRNA levels, either in liver or in adipose tissues. In conclusion, dietary protein source, accompanied likely by side alterations in the dietary composition, affects lipid metabolism in pigs through the downregulation of SREBP‐1, which is a crucial determinant of lipogenic process.     

Effects of beta‐glucans ingestion (Saccharomyces cerevisiae) on metabolism of rats receiving high‐fat diet

We investigated the effects of beta‐glucans (Saccharomyces cerevisiae) ingestion on metabolic parameters of Wistar rats receiving high‐fat diet. The experimental period was divided into two stages: in the first one, the animals were divided into two groups containing 12 animals each. The first group received commercial feed and the second received high‐fat diet containing 20% of pork fat during 60 days. At the end of this period, body weight, blood glucose and Lee index were assessed. In the second stage, those 24 animals were redivided into four groups: (C) – control diet; (CB) – control diet and treated with Beta‐glucan (BG); (O) – obese animals and (OB) – obese animals treated with BG. Animals from groups CB and OB received 30 mg/kg of BG dissolved in saline solution by gavage. Animals from groups C and O received only saline solution for 28 days. The design used was totally randomized in 2 × 2 factorial scheme. Data were submitted to analysis of variance (anova ). Animals from OB group showed inferior levels (p < 0.05) of total cholesterol (13.33%), triacylglycerols (16.77%) and blood glucose (23.97%) when compared to the animals from group O. The use of BG has provided smaller increase in Lee index (p < 0.05), without promoting alteration in feed and water consumption, organs weight, HDL‐C, LDL+VLDL‐C, carcass composition, villus/crypt ratio, and pancreas, kidney and stomach histology. BG from S. cerevisiae promoted beneficial metabolic effects in rats receiving high‐fat diet.     

Effects of L-carnitine supplementation on quality characteristics of fresh pork bellies from pigs fed 3 levels of corn oil

Crossbred pigs (n = 216) were used to test the effect of supplemental L-carnitine (CARN) on the fatty acid composition and quality characteristics of fresh pork bellies from pigs fed diets formulated with different inclusion levels of corn oil. Pigs were blocked by BW (43.6 ± 1.0 kg) and allotted randomly to pens of 6 pigs within blocks. Then, within blocks, pens were assigned randomly to 1 of 6 dietary treatments in a 2 × 3 factorial arrangement, with either 0 or 100 mg/kg of supplemental CARN and 3 dietary inclusion levels (0, 2, or 4%) of corn oil (CO). When the lightest block weighed 125.0 kg, all pigs were slaughtered, and left-side bellies were captured during carcass fabrication for quality data collection. Fresh pork bellies were evaluated for length, width, thickness, and firmness (bar-suspension and Instron-compression methods) before a 2.5-cm-wide strip of belly was removed and subsequently dissected into subcutaneous fat, primary lean (latissimus dorsi), secondary lean (cutaneous trunci), and intermuscular fat for fatty acid composition determination. Although belly length, width, and thickness of fresh pork bellies were not affected by CARN (P ≥ 0.128) or CO (P ≥ 0.073), belly firmness decreased linearly (P < 0.001) with increasing dietary CO, but there was no (P ≥ 0.137) effect of CARN on any belly firmness measure. Dietary CARN increased (P < 0.05) the proportion of total SFA in the intermuscular fat layer, increased (P < 0.05) the proportion of total MUFA in the primary and secondary lean layers, and decreased (P < 0.05) the proportion of total PUFA in the intermuscular fat and secondary lean layers of pork bellies. Moreover, the SFA and MUFA compositions decreased linearly (P < 0.001) with increasing dietary CO, and the rate of the decrease in SFA composition was greater (P < 0.001) in the fat layers than the lean layers. Conversely, the PUFA content increased linearly (P < 0.001) with increasing dietary CO, and the rate of the increase in PUFA was greater (P < 0.001) in the fat than the lean layers, and greater (P = 0.022) in the primary than secondary lean layer. Results from this study would indicate that differences in the amount and rate of fatty acid deposition associated with feeding increased amounts of CO, along with moisture differences among the belly layers, combine to negatively affect fresh pork belly firmness.     

Effects of choice white grease or poultry fat on growth performance, carcass leanness, and meat quality characteristics of growing-finishing pigs.

Eighty-four crossbred gilts were used to evaluate the effects of dietary choice white grease (CWG) or poultry fat (PF) on growth performance, carcass characteristics, and quality characteristics of longissimus muscle (LM), belly, and bacon of growing-finishing pigs. Pigs (initially 60 kg) were fed a control diet with no added fat or diets containing 2, 4, or 6% CWG or PF. Diets were fed from 60 to 110 kg and contained 2.26 g lysine/Mcal ME. Data were analyzed as a 2 x 3 factorial plus a control with main effects of fat source (CWG and PF) and fat level (2, 4, and 6%). Pigs fed the control diet, 2% fat, and 4% fat had greater (P < 0.05) ADFI than pigs fed 6% fat. Pigs fed 6% fat had greater (P < 0.05) gain/feed (G/F) than pigs fed the control diet or other fat levels. Subcutaneous fat over the longissimus muscle from pigs fed CWG had more (P < 0.05) moisture than that from pigs fed PF. Feeding dietary fat (regardless of source or level) reduced (P < 0.05) the amount of saturated fats present in the LM. Similarly, 4 or 6% fat decreased (P < 0.05) the amount of saturated fats and increased unsaturated fats present in the bacon. No differences (P > 0.05) were observed for ADG, dressing percentage, leaf fat weight, LM pH, backfat depth, LM area, percentage lean, LM visual evaluation, LM waterholding capacity, Warner-Bratzler shear and sensory evaluation of the LM and bacon, fat color and firmness measurements, or bacon processing characteristics. Adding dietary fat improved G/F and altered the fatty acid profiles of the LM and bacon, but differences in growth rate, carcass characteristics, and quality and sensory characteristics of the LM and bacon were minimal. Dietary additions of up to 6% CWG or PF can be made with little effect on quality of pork LM, belly, or bacon.     

低聚木糖对生长肥育猪血浆生化参数和肌肉脂肪酸组成的影响

本试验旨在研究低聚木糖(XOS)对生长肥育猪血浆生化参数和肌肉脂肪酸组成的影响。选取70日龄、平均体重约为30kg的杜×长×大三元杂交猪110头,随机分为11组,每组10头(公母各占1/2),单栏饲养。试验设对照组(饲喂基础饲粮),抗生素组(饲喂在基础饲粮中添加0.04kg/t速大肥、0.2kg/t抗敌素的饲粮),30~65kg阶段100、250和500g/t XOS添加组(在30~65kg阶段分别饲喂在基础饲粮中添加100、250和500g/t XOS的饲粮,在66~100kg阶段均饲喂基础饲粮),66~100kg阶段100、250和500g/t XOS添加组(在30~65kg阶段均饲喂基础饲粮,在66~100kg阶段分别饲喂在基础饲粮中添加100、250和500g/t XOS的饲粮)以及30~100kg阶段100、250和500g/t XOS添加组(分别饲喂在基础饲粮中添加100、250和500g/t XOS的饲粮)。于试猪平均体重达100kg(约170日龄)时,前腔静脉采血,离心分离血浆,测定生化参数;屠宰后取背最长肌和股二头肌样品,测定其脂肪酸组成。结果表明:与对照组相比,30~65kg阶段,饲粮添加100或500g/t XOS可显著降低股二头肌中十七烷酸(C17∶0)含量(P0.05);66~100kg阶段,饲粮添加250g/t XOS可显著增加股二头肌中饱和脂肪酸(SFA)+单不饱和脂肪酸(MUFA)含量(P0.05),添加100或500g/t XOS可显著增加股二头肌中花生烯酸(C20∶1)含量(P0.05);30~100kg阶段,饲粮添加100g/t XOS可显著增加背最长肌中油酸/亚油酸以及股二头肌中C20∶1、MUFA和SFA+MUFA含量(P0.05),添加100或250g/t XOS可显著降低血浆总胆固醇浓度(P0.05),添加500g/t XOS可显著增加血浆高密度脂蛋白-胆固醇浓度(P0.05)。综上所述,饲粮添加一定剂量的XOS可通过调控与脂代谢相关的血浆生化参数、增加肌肉中MUFA和SFA+MUFA含量而改善猪肉的风味和营养价值,且以30~100kg阶段添加100g/t XOS为最佳。     

Effects of dietary ramie powder at various levels on growth performance,antioxidative capacity and fatty acid profile of finishing pigs

This study was conducted to evaluate the effects of ramie (Boehmeria nivea, previously known as a fibre crop and also called “China grass”) included in diets on growth performance, antioxidative capacity and muscular fatty acid profile of finishing pigs. A total of 180 Xiangcun Black pigs (initial body weight =70.71 ± 1.21 kg) were randomly allotted to 1 of 5 dietary treatments with six pens of six pigs per pen. The pigs were provided a basal diet or a diet contained 3%, 6%, 9% or 12% of ramie powder during a 50‐day experiment period. The results showed that the inclusion of ramie increased (quadratic, p < 0.05) the average daily gain (ADG) and gain:feed ratio (G:F) with the highest value of ADG and G:F in 3% ramie group, but ramie content in the diet up to 9% reduced the growth performance of the pigs compared with that of 3% ramie group. The activity of serum total superoxide dismutase (SOD) was increased (linear, p < 0.05) by ramie, while content of malondialdehyde was decreased (linear, p < 0.05). As increasing the dietary ramie level, the mRNA expression level of SOD1 was increased quadratically (p < 0.05) in muscle tissues. Moreover, the addition of ramie linearly increased (p < 0.05) polyunsaturated fatty acids content, whereas it linearly reduced (p < 0.05) the lipid indices of atherogenicity (AI) and thrombogenicity (TI) in muscle tissues, and lower values of AI and TI reflect a “healthier” fat composition. The results indicated that ramie in a diet not more than 9% may improve antioxidative capacity with no detrimental impact on growth performance of Chinese native finishing pigs; meanwhile, it could beneficially change the pork fatty acid pattern which has a positive impact on consumer's health.