Interactive effects of dietary fat source and slaughter weight in growing-finishing swine: I. Growth performance and longissimus muscle fatty acid composition

Effect of feeding high oleic soybean oil to finishing pigs on growth performance, carcass characteristics, and meat quality

This study aimed to evaluate the effects of dietary fat source and feeding duration on growth performance, carcass characteristics, and meat quality of finishing pigs. A total of 450, 21-wk-old finishing pigs with an average body weight of 113.7 ± 8 kg were housed in 90 pens assigned to one of five dietary treatments in a 2 × 2 + 1 factorial design. Dietary treatments consisted of two fat sources (CWG: 4% inclusion of choice white grease and HOSO: 4% inclusion of high oleic soybean oil) each provided 2 or 4 wk before marketing. The "+1" diet was corn-based without fat inclusion (CON). Observations included growth performance, carcass characteristics, fatty acid (FA) profile, and sensory evaluation. Data was analyzed using PROC MIXED in SAS considering dietary treatment as a main effect, feeding duration, and their interactions. Preplanned contrasts were used to compare dietary treatments with the control. From day 14 to 28 and the overall experimental period (day 0-28), pigs fed fat-supplemented diets had a greater (P < 0.05) average daily gain and gain-to-feed ratio than CON-fed pigs. There was no significant difference (P > 0.05) in growth performance when comparing fat sources or feeding periods. Pigs supplemented with either CWG or HOSO showed a tendency to have a greater (P < 0.10) belly weight and belly yield, and a lesser (P < 0.10) loin yield and loin muscle area when compared with CON pigs. The loin from pigs fed fat sources had greater (P < 0.05) oleic acid and eicosenoic acid concentration when compared with CON. When CWG was compared with HOSO, pigs fed CWG had a higher (P < 0.05) concentration of palmitic acid and stearic acid, while the HOSO pigs had a higher concentration of oleic acid and linolenic acid in the loin. In the belly, CON had a higher (P < 0.05) concentration of palmitic acid and stearic acid compared to HOSO, while pigs fed fat sources had a higher concentration of oleic acid and eicosenoic acid. Bellies from HOSO had higher (P < 0.05) oleic acid and α-linolenic acid methyl ester concentrations, while CWG had higher concentrations of g-linolenic acid. For the sensory evaluation, the palatability and acceptability of pork were not affected (P > 0.05) by dietary treatments. In conclusion, supplementation with HOSO not only improved performance but tended to improve some carcass characteristics and increased the concentration of oleic acid, and some other unsaturated FA with a concomitant decrease in the concentration of some saturated FA in pork.

Replacing yellow maize with Illipe nut (Shorea stenoptera) improves growth performance and meat quality of porker pigs

The effects of incorporating Illipe nut into the diet of pigs, in replacement of yellow maize, on their growth performance and meat quality was investigated in a 60 days feeding trial. Twenty-four male pigs were divided into two treatments and fed diets with 0% (T1) or 15% (T2) Illipe nut inclusion. Feed intake, live weight (LW) and backfat thickness (BFT) were taken and used to calculate average daily feed intake (ADFI), average daily gain (ADG), feed conversion ratio (FCR) and increase in backfat (IBF). At the end of the trial, final LW and BFT were measured. Pigs were then slaughtered and hot carcass weight (HCW), pH45mins, pH24hrs and dressing percentage (DP) were determined. Other analysis, including total moisture, thawing loss (TL), cooking loss (CL) and water holding capacity (WHC), were conducted on pork samples. Nutritional content and fatty acid (FA) composition of pork samples were analyzed, and nutritional indices were calculated. Improvements (P < 0.05) in final LW, ADG, final BFT, IBF and FCR were seen in pigs fed the T2 diet. Additionally, the T2 pork was superior (P < 0.05) in HCW, DP, pH24hrs, TL, CL, total moisture and WHC than T1 pork. The FA composition of T2 pork was also improved, with a higher (P < 0.05) PUFA:SFA ratio, indicating lower SFA and higher PUFA levels than T1 pork. Along with this, T2 pork had lower (P < 0.05) index of atheroginicity (IA) and higher (health promoting index) HPI levels, indicating that the T2 pork is a healthier choice for consumption. These findings indicate that the inclusion of 15% Illipe nut into the diet of porker pigs improved their overall growth performance and meat quality.

Effects of an extra-high slaughter weight and a low-lysine diet on growth and meat quality of finishing gilts

The present study aimed to find out the feasibility of increasing the meat quality of finishing gilts by increasing their slaughter weight (SW) to an extra-high (XH) level and also by using a low-lysine (lys) diet in XH-weight pig production. Twenty-four gilts and eights barrows were divided into four treatments (T) by gender, SW, and diet: T1 (barrow; 116-kg SW; Medium [Med]-lys [0.80%] diet), T2 (gilt; 116-kg SW; Med-lys), T3 (gilt; XH [150 kg] SW; Med-lys), and T4 (gilt; XH SW, Low-lys [0.60%]). Growth performance from 85 kg of body weight to SW was measured only for T3 and T4. All animals were slaughtered at their target SW, followed by physicochemical analyses and sensory evaluation on the Longissimus lumborum muscle (LL). Average daily gain did not differ between T3 and T4. Dressing percentage was greater for T3 vs. T2. Backfat thickness was greater for T1 vs. T2 and T3 vs. T2, not being different between T3 and T4. The LL pH was lower and Warner-Bratzler Shear force value was greater for T3 vs. T2. Other physicochemical measurements including the intramuscular fat content were not different or different narrowly if different at all (p < 0.05) between T3 and T2 or T4, but not between T1 and T2. The percentages of major fatty acids including 16:0, 18:0, 18:1, and 18:2 in LL, which did not differ between T2 and T3, differed between T3 and T4 apparently resulting from a difference in composition of the ingredients of the two diets. The sensory texture score was greater for T3 vs. T2 in fresh LL; in cooked LL, juiciness and umami scores were greater for T3 vs. T2, flavor score being less for T4 vs. T3. The gender effects on physicochemical and sensory pork quality were small, if any. Overall, the meat quality of finishing gilts could be improved by increasing the SW to the XH level, but not by using the Low-lys diet, suggesting that it will be feasible to produce XH-weight market gilts if the increased meat quality can make up for the expected decrease in production efficiency accompanying the increased SW.

Carcass and meat quality traits and their relationships in Duroc × Landrace × Yorkshire barrows slaughtered at various seasons

To understand characteristics of carcass traits and meat quality in pig population, 22 indicators of carcass characteristics and meat quality traits were measured on 278 Duroc × Landrace × Yorkshire barrows that were slaughtered in different seasons (spring, summer, autumn and winter). The effects of body weight and season on carcass characteristics and meat quality were analyzed by GLM procedure, followed the Bonferroni multiple test. The phenotypic correlations among those traits were calculated by employing the CORR procedure. In addition, the linear regression equations were constructed by stepwise regression model in REG procedure. The results showed that pigs slaughtered in spring had the heaviest body weight among the four seasons (P < 0.05), pigs slaughtered in summer had the lowest backfat depth and shear force (P < 0.05), and pigs slaughtered in winter had the lowest drip loss (P < 0.05). The results showed more variation in backfat depth, drip loss, intramuscular fat content, and shear force, compared with other indicators across pigs. Body weight had a significant association with loin eye area, average backfat depth and L^⁎_{24 h} (P < 0.05). Furthermore, regression equations for drip loss, cooking loss, shear force, and intramuscular fat content were constructed using more accessible indicators. Collectively, this study provided an overall view of carcass and meat quality traits in a commercial pig population in China, and illustrated that season significantly affected carcass characteristics and meat quality traits independently of body weight.

Dietary Valine/Isoleucine Ratio Impact Carcass Characteristics, Meat Edible Quality and Nutritional Values in Finishing Crossbred Duroc × Landrace × Yorkshire Pigs With Different Slaughter Weights

The aim of this study was to investigate effects of dietary ratio of valine to isoleucine [R(V/I)] on carcass characteristics and meat quality of finishing pigs and whether slaughter weight influence the effect. We carried out a 2 × 3 factorial trial with two slaughter weight (105 vs. 130 kg) and three R(V/I) (0.58, 1.23, and 2.60 at 75–100 kg body weight, and 0.70, 1.24, and 2.39 at 100–135 kg body weight for L-, N- and H-R (V/I), respectively). Data show that increasing slaughter weight significantly increased meat color (a*_{45 min} and b*_{45 min}), drip loss and shear force (P < 0.05). Meanwhile, increasing slaughter weight reduced sarcomere length, the proportion of protein-bound water, and most kinds of muscular total amino acid contents except for tryptophan and arginine, while increased contents of muscular free lysine, tryptophan, leucine, isoleucine, valine, alanine, and arginine in the M. longissimus thoracis (P < 0.05). Health lipid indices based on fatty acid composition of intramuscular lipid were improved as the slaughter weight increased (P < 0.05). Notably, pigs received N-R (V/I) diet improved carcass traits in terms of thinner backfat thickness and higher fat-free lean index, as well as increased meat flavor-contributing amino acids at the cost of reduced intramuscular fat content and increased shear force of cooked meat compared with the pigs fed L-R (V/I) and H-R(V/I) diets (P < 0.05). H-R (V/I) diet decreased ultimate pH value and sarcomere length of the skeletal muscle but increased the proportion of free water (T₂₃), consequently, increased drip loss and cooking loss of fresh meat in pigs (P < 0.05). In conclusion, both slaughter weight and dietary ratio of valine to isoleucine exerted significant impacts on carcass characteristics, meat quality and nutrition values. In particular, carcass traits and meat color of lighter pigs were more susceptible to the influence of dietary R (V/I) relative to heavier pigs.

Effects of dietary vitamin E and fat supplementation in growing-finishing swine fed to a heavy slaughter weight of 150 kg: II. Tissue fatty acid profile, vitamin E concentrations and antioxidant capacity of plasma and tissue

The study aimed to assess the effects of vitamin E (VE) supplementation and fat source on fatty acid (FA) composition, VE concentrations, and antioxidant capacity in plasma and tissues of pigs fed to a heavy slaughter weight (150 kg). A total of 64 pigs (32 barrows, 32 gilts; 28.41 ± 0.83 kg) were blocked by sex and weight, and randomly assigned to one of eight dietary treatments (n = 8 per treatment) in a 4 × 2 factorial arrangement. Fat sources included corn starch (CS), 5% tallow (TW), 5% distiller’s corn oil (DCO), and 5% coconut oil (CN); VE supplementation levels were 11 and 200 ppm. Five-phase diets were formulated to meet requirement estimates of NRC (2012) and fed to pigs for each period of 25 kg from 25 to 150 kg. Increasing VE supplementation level increased C16:1 (P < 0.05) content but decreased C20:0 (P < 0.05) content in backfat and belly fat, while in liver, it increased C17:0 (P < 0.05) but decreased C18:0 (P < 0.05). Compared to the pigs fed the CS diet, the pigs fed the CN diet had greater (P < 0.05) content of total saturated FA, the pigs fed the DCO diet had greater (P < 0.05) content of total polyunsaturated FA content and iodine value, and the pigs fed the TW diet had greater (P < 0.05) content of total monounsaturated FA in backfat, belly fat, and liver. Plasma VE concentrations increased linearly (P < 0.05) with increasing length of feeding but faster (P < 0.05) in the pigs fed the CN and TW diets compared with the CS and DCO diets within the 200 ppm VE level; the pigs fed the DCO diet had the highest plasma VE concentrations (P < 0.05) from Phase 2 to Phase 5 within the 11 ppm VE level. The VE concentrations in liver and loin muscle (P < 0.05) increased with increasing dietary VE level from 11 to 200 ppm, but it was not affected by dietary fat source. There was no effect of VE supplementation and fat source on antioxidant capacity in plasma and liver except that pigs fed the DCO diet had greater liver SOD activity (P < 0.05) than the pigs fed the CN diet. In conclusion, dietary VE supplementation did not affect FA profile in backfat, belly fat, and liver consistently, while dietary FA composition with different fat sources affected much of the FA profile in backfat, belly fat, and liver. The higher level of VE supplementation increased liver and muscle VE concentrations and dietary fat sources affected plasma VE concentrations differently (P < 0.05), wherein the TW and CN diets increased the VE absorption greater than the DCO diet.

Effect of Concentration of Flaxseed (Linum usitatissimum) and Duration of Administration on Fatty Acid Profile, and Oxidative Stability of Pork Meat

Flaxseed is a common ingredient used for livestock feed. The aim of this work was to study the effect of a diet supplemented with flaxseed at 5% and 10% concentrations in the intervals of 3 and 6 weeks prior slaughter on fatty acid profile and oxidative stability of pork meat. Meat samples were collected after slaughter from each animal (five groups, n = 6). Samples of the musculus longissimus dorsi (MLD) and the musculus gluteobiceps (MGB) were selected. Chemical composition, fatty acid profile and oxidative stability during the storage of meat under chilling conditions (4 °C, 7 days) was analyzed. The addition of flaxseed significantly affected the composition of fatty acid profile and the shelf life of the produced meat. The fat content was changed in the experimental groups with 10% flaxseed supplementation (10.84% in MGB and 9.56% MLD) versus the control group. Despite the different concentrations of flaxseed, the best EPA/AA ratio was observed in the experimental groups fed with flaxseed supplementation for 3 weeks. The worst oxidative stability of meat samples (p < 0.05) was recorded in the experimental groups with the addition of flaxseed for 6 weeks, which was related to higher PUFA content in samples of the experimental groups and higher susceptibility of PUFAs to lipid oxidation. The oxidative stability of meat in the experimental group fed 5% flaxseed supplementation for 3 weeks was not affected.

Dietary soybean oil modulates fatty acid composition of pork

This study was conducted to evaluate the impact of soybean oil level on performance and fatty acid profile of backfat and longissimus lumborum muscle of gilts. Forty-eight gilts with an initial weight of 21.75 ± 0.138 kg and final weight of 98.65 ± 2.106 kg were subjected to one of the following six dietary soybean oil inclusions (0.00, 1.086, 2.173, 3.259, 4.345, and 5.432%). Experimental design was completely randomized block with six treatments and four replicates of two animals each. Lipid profile of backfat and longissimus lumborum muscle was analyzed by gas chromatography. Increasing dietary soybean oil levels did not influence final weight, daily weight gain, and feed intake (P > 0.05) but improved feed to gain ratio (P < 0.05). The inclusion of soybean oil modified the lipid profile of backfat and muscle, reduced saturated and monounsaturated fatty acids, and increased polyunsaturated fatty acids concentration, mainly linoleic and α-linolenic acids (P < 0.05). Increasing dietary soybean oil inclusion decreased atherogenic and thrombogenic indexes, and the omega-6:omega-3 ratio of the backfat and longissimus lumborum muscle (P < 0.05). The level of soybean oil in swine diets influenced backfat and longissimus lumborum lipid profile.

The Effect of Replacement of Soybean Meal with Corn Dried Distillers Grains with Solubles (cDDGS) and Differentiation of Dietary Fat Sources on Pig Meat Quality and Fatty Acid Profile

Simple Summary

The growing demand for protein and the reluctance of consumers to use genetically modified feeds necessitate the use of other protein feeds. Corn dried distillers grains with solubles (cDDGS) is a well-digested protein feed; however, it is rich in unsaturated fatty acids and can negatively affect the meat quality and oxidative stability. The negative influence of dietary unsaturated fatty acids on meat quality can be balanced by feed additives, e.g., a dietary saturated fat source increasing the iodine value of fat. To reduce the detrimental effect of corn DDGS in the present experiment, the beef tallow and coconut oil in a feed mixture were studied, as both of them are more saturated than corn DDGS and rapeseed oil. The aim of the study was to investigate mixtures comprising corn DDGS as a partial replacer for soybean meal as well as different dietary saturated fat sources to determine their effect on the meat quality and fatty acid profile. The relationships between dietary fatty acid profile and meat fatty acid profile and between various meat quality parameters were analyzed.

Abstract

The aim of the study was to investigate mixtures comprising corn distillers dried grain with solubles as a partial replacer for soybean meal (SBM) and different dietary fat sources, in order to determine their effect on the meat quality and fatty acid profile. Thirty-two crossbred fatteners were divided into four groups: I–SBM + rapeseed oil, II–cDDGS + rapeseed oil, III–cDDGS + beef tallow, IV–cDDGS + coconut oil. The experiment took place from 60 to 118 kg. At the end of fattening, all pigs were slaughtered and samples of meat (musculuslongissimus lumborum) were taken. The fatty acid profile, texture, and quality traits were analyzed. Corn DDGS affected drip loss. Beef tallow and coconut oil improved water holding capacity and drip loss and increased fat content, compared to the control group. The dietary fat type affected the fatty acid composition, iodine value, and consequently some quality traits of meat. However, these relationships varied. Fat content in the meat was inversely correlated with shear force and texture parameters, but positively with tenderness and juiciness. The fatty acid profile significantly influenced cohesiveness, chewiness, resilience and sensory traits, which were the most beneficial in meat with higher fat content and higher fat saturation index.

The effect of sex and slaughter weight on performance, carcass quality and gross margin, assessed on three commercial pig farms

Economic margins on pig farms are small, and changing slaughter weights may increase farm profitability. However, one can question if the optimal slaughter weight is the same for each sex. On three farms, crossbred pigs (n = 1128) were used to determine the effect of sex and slaughter weight on performance, carcass quality and gross margin per pig place per year. On each farm, an equal number of entire males (EMs), barrows (BAs), immunocastrates (IC) and gilts (GIs) were housed separately in group pens. Pens were randomly divided into three categories of different slaughter weights: 105, 117 and 130 kg BW. In BA, the high average daily feed intake (ADFI) and the lower capacity to gain muscle led to a higher feed conversion ratio (FCR) and lower lean meat percentage in comparison to EM and IC. In all sexes, ADFI and FCR increased with an increasing slaughter weight but the effect of slaughter weight on carcass quality varied between sexes. In BA and GI, slaughter weight had no effect on carcass quality, but in EM and IC, carcass quality improved at higher slaughter weights. Gross margin per pig place per year was calculated as gross margin per pig × barn turnover per year, taking into account fixed costs per round, feed costs and output price per pig. The slaughter weight that gained the highest gross margin per year differed between sexes. Slaughtering BA and GI at 130 kg BW, compared to 105 or 117 kg BW, decreased the gross margin per pig place per year due to the lower margin per pig and barn turnover at higher weights. In IC and EM, no difference in gross margin per pig place per year could be demonstrated between slaughtering at 105, 117 or 130 kg BW. In IC, the increasing gross margin per pig with increasing slaughter weights counteracted with the lower barn turnover. In EM, gross margin per pig did not differ between slaughter weights, but the effect of barn turnover was too small to demonstrate significant differences between slaughter weights on gross margin per pig place per year. In conclusion, slaughter weight has an impact on profitability in BA and GI: they should not be slaughtered at 130 kg BW but at lower weights, but no effect could be demonstrated in EM and IC.

BEEF TALLOW AND EMULSIFIER IN GROWING-FINISHING PIG DIETS

Two trials were aimed to evaluate beef tallow in diets with and without emulsifier on performance of pigs at growing-finishing phases. In the first trial, 15 barrows (22.03±0.62 kg) were distributed among three treatments: reference diet; test diet 1 (5% beef tallow) and test diet 2 (10% beef tallow). Beef tallow presented average value of 7130.97 kcal ME/kg. For the performance trail, 30 barrows (24.85±1.18 kg) were distributed among five treatments: T1 - diet with soybean oil and 3230 kcal ME /kg; T2 - diet with beef tallow and 3230 kcal ME/kg; T3 - diet with beef tallow and 3080 kcal ME/kg; T4 - diet with beef tallow, 3080 kcal/kg and 0.1% emulsifier; T5 - diet with beef tallow, 2930 kcal ME/kg and 0.1% emulsifier. Feed conversion was worse in animals fed diet with 3080 kcal ME/kg containing beef tallow and with 2930 kcal ME/kg with beef tallow and emulsifier. For economic availability, animals fed diet with beef tallow and 3230 kcal ME/kg and those fed diet with 3080 kcal ME/kg containing beef tallow and emulsifier, did not differ from animals fed diet with soybean oil, which enables the reduction up to 150 kcal ME/kg be compensated by emulsifier addition.

Effect of time interval between the second Improvest® dose and slaughter and corn dried distillers grains with solubles feeding strategies on carcass composition, primal cutout, and pork quality of immunologically castrated pigs

Effects of dried distillers grains with solubles (DDGS) feeding strategies on carcass composition, primal cutout, and lean quality of immunologically castrated (IC; n=863) pigs were evaluated, and consisted of: 1) corn-soybean meal (CS) diet (PCon); 2) CS+40% DDGS (NCon); 3) CS+40, 30, 20, or 10% DDGS fed in phases 1 to 4, respectively (SD); or 4) CS+40% DDGS fed in phase 1 to 3 and CS in phase 4 (WD). All pigs received the first dose of Improvest® at 11weeks. of age, and the second dose was administered at either 9, 7, or 5weeks. before slaughter at 24weeks. of age. The SD and WD improved carcass dressing percentage and resulted in intermediate primal cut yields and pork loin quality compared with pigs fed PCon and NCon. Increasing the time interval between second dose of Improvest® and slaughter increased adipose tissue accretion but did not affect lean quality of pork.

Influence of dietary fat source and feeding duration on finishing pig growth performance, carcass composition, and fat quality

A total of 160 finishing pigs (PIC 327 × 1050; initially 45.6 kg) were used in an 84-d experiment to evaluate the effects of dietary fat source and feeding duration on growth performance, carcass characteristics, and carcass fat quality. There were 2 pigs per pen with 8 pens per treatment. The 10 dietary treatments were a corn-soybean meal control diet with no added fat and a 3 × 3 factorial with main effects of fat source (4% tallow, 4% soybean oil, or a blend of 2% tallow and 2% soybean oil) and feeding duration (d 0 to 42, 42 to 84, or 0 to 84). The control corn-soybean meal diet was fed in place of added fat diets when needed for duration treatment purposes. On d 0, 1 pig was identified in each pen and fat biopsy samples of the back, belly, and jowl were collected on d 0, 41, and 81 for fatty acid analysis. At the conclusion of the study, all pigs were harvested, carcass characteristics were determined, and back, belly, and jowl fat samples were collected for analysis. Overall (d 0 to 84), there were no differences among pigs fed the different fat sources for growth and carcass characteristics; however, pigs fed diets with added fat for the entire study had improved ( = 0.036) G:F compared with pigs fed the control diet without added fat. Pigs fed supplemental fat throughout the entire study also had improved ( < 0.05) ADG and G:F as well as heavier d-84 BW ( = 0.006) compared with pigs fed additional fat during only 1 period. Adding fat for the entire study increased ( = 0.032) backfat and tended to reduce ( = 0.079) the fat free lean index compared with pigs fed the control diet without added fat. Added fat also increased ( < 0.05) the iodine value (IV) when compared with pigs fed the control diet. Increasing the feeding duration of soybean oil lowered MUFA and increased PUFA concentrations for all fat depots, whereas these values remained relatively unchanged by the addition of tallow (duration × fat source interactions, < 0.05). Our study failed to show any feeding period × fat source interactions ( < 0.05) in fatty acid composition or IV for jowl fat, whereas this interaction occurred for belly fat and backfat, which would indicate a longer turnover rate for jowl fat. In conclusion, feeding additional fat improved ADG and G:F; however, feeding soybean oil for an increased duration, either alone or in combination with tallow, negatively affected the fatty acid composition and IV of different fat depots.

Effects of the ratio of unsaturated fatty acid to saturated fatty acid on the growth performance, carcass and meat quality of finishing pigs

The effects on finishing pigs (80–100 kg BW) fed diets supplemented with oil sources containing different ratios of unsaturated to saturated fatty acids (UFA:SFA ratio) were evaluated in 15 barrows and 15 gilts (Duroc × Large White × Landrace). Three experimental diets were evaluated using a randomized complete block design, with broken rice, soybean meal and rice bran as the main feedstuffs in the control diet. Diets 2 and 3 consisted of the control diet supplemented with 3% oil, with UFA:SFA ratios of 2.5:1 and 5:1, respectively. Overall, there was no significant difference (P > 0.05) found in the average daily gain (ADG) of the pigs fed the treatment diets; however, the pigs fed the control diet and diet 3 had better (P < 0.05) feed conversion ratios (FCR) than the pigs fed diet 2. The pigs fed diets 2 and 3, which were supplemented with oil at UFA:SFA ratios of 2.5:1 and 5:1, had greater (P < 0.05) average daily feed intakes (ADFI) than the pigs in the control group. Additionally, it was found that the gender of the pigs had an effect (P < 0.05) on the FCR. Interaction effects between the experimental diets and the gender of the pigs (P < 0.05) were found in the ADFI and FCR. There were no significance differences (P > 0.05) among the treatment groups with regard to the carcass quality of the pigs; however, it was found that the gilts had greater (P < 0.01) loin eye areas than the barrows fed diets 2 and 3 and the loin eye area of pig fed diet 2 was the largest (P < 0.05). In the case of the meat quality parameters, it was clearly found that the pigs fed the control diet had a greater (P < 0.05) lightness (L^∗) in the meat colour, and the lowest cooking loss was found in the pigs fed the diet supplemented with fat containing the UFA:SFA ratio of 5:1. Overall, the dietary treatment did not significantly affect the drip loss, thawing loss and shear force of the pork. In conclusion, the supplementation of oil with UFA:SFA ratios of 2.5:1 and 5:1 has the potential to improve pork quality.

The impact of dietary fat withdrawal on carcass iodine value, belly characteristics, and changes in body fat over time

The inclusion of unsaturated fats in pig diets has raised issues related to pork carcass fat quality. The objective of this experiment was to understand how withdrawal from the diet of unsaturated dietary fat before slaughter impacts the composition of jowl fat during the growth cycle and at market. Fifty individually housed pigs (PIC 337 × C22/29; initial BW = 59.3 ± 0.55 kg) were allotted based on sex and initial BW to 10 treatments for an 82-d experiment as follows: 3 dietary fat withdrawal times before slaughter (21, 42, or 63 d) by 3 dietary fat unsaturation loads (DFUL), which includea high intake of unsaturated fatty acids supplied through an inclusion of 5% corn oil (HIGH), a high intake of a mixture of saturated and unsaturated fatty acids supplied through an inclusion of 5% animal-vegetable blend (MED), and a moderate intake of unsaturated fatty acids supplied through an inclusion of 2.5% corn oil (LOW). Pigs were weighed and jowl adipose samples were collected on d 0, 21, 42, and 63 and at harvest on d 82. Data were analyzed using PROC MIXED with treatment and sex as fixed effects. At market (d 82), increasing the withdrawal of dietary fat further away from market increased 18:1 (P = 0.045) and tended to increase 14:0 concentrations (P = 0.054). It also significantly decreased 18:2 (P < 0.001) and tended to decrease 18:3 concentrations (P = 0.081). A HIGH DFUL resulted in the greatest 18:2 concentrations in jowl fat followed by LOW; MED resulted in the lowest 18:2 levels (P < 0.001). Dietary fat withdrawal before market significantly reduced carcass iodine value (IV) measured at d 82 (P = 0.006). In conclusion, elevated 18:2 intake makes lowering carcass IV in the depot fat very difficult and may take as long as 61 d. The withdrawal of unsaturated dietary fat apparently altered the fat depot to be more reflective of fat synthesized de novo, resulting in a more saturated depot fat. Importantly, this alteration of deposited fat composition did not translate into improved belly firmness, depth, weight, or fat color.

The effect of slaughter weight on the carcass characteristics of pork with sex type as co-variable

A study was conducted with 192 pigs of three sex types with treatments according to slaughter weight (65 kg to 144 kg). The main statistical differences observed were for slaughter weight with significant (P < 0.05) and highly significant (P < 0.01) differences describing more than 10% of variance observed for all characteristics (liveweight, warm carcass weight, dressing percentage, eye muscle area, subcutaneous fat thickness, intramuscular fat area, subcutaneous fat : eye muscle area, intramuscular fat : eye muscle area, fat thickness, muscle depth, carcass length, ham circumference, ham length and chest depth) measured. Sex differences (P < 0.05) were also observed for dressing percentage, fat measurements and muscle depth measured between the 5th and 6th lumbar vertebrae. Sex type differences, in all instances, accounted for 10% or less variance except for subcutaneous fat : eye muscle area ratio (18.47%). It was shown that although significant sex type differences (P < 0.05) existed; slaughter weight had the largest effect on carcass characteristics in the given circumstances accounting for most of the observed variance.

Regression analysis to predict growth performance from dietary net energy in growing-finishing pigs

Data from 41 trials with multiple energy levels (285 observations) were used in a meta-analysis to predict growth performance based on dietary NE concentration. Nutrient and energy concentrations in all diets were estimated using the NRC ingredient library. Predictor variables examined for best fit models using Akaike information criteria included linear and quadratic terms of NE, BW, CP, standardized ileal digestible (SID) Lys, crude fiber, NDF, ADF, fat, ash, and their interactions. The initial best fit models included interactions between NE and CP or SID Lys. After removal of the observations that fed SID Lys below the suggested requirement, these terms were no longer significant. Including dietary fat in the model with NE and BW significantly improved the G:F prediction model, indicating that NE may underestimate the influence of fat on G:F. The meta-analysis indicated that, as long as diets are adequate for other nutrients (i.e., Lys), dietary NE is adequate to predict changes in ADG across different dietary ingredients and conditions. The analysis indicates that ADG increases with increasing dietary NE and BW but decreases when BW is above 87 kg. The G:F ratio improves with increasing dietary NE and fat but decreases with increasing BW. The regression equations were then evaluated by comparing the actual and predicted performance of 543 finishing pigs in 2 trials fed 5 dietary treatments, included 3 different levels of NE by adding wheat middlings, soybean hulls, dried distillers grains with solubles (DDGS; 8 to 9% oil), or choice white grease (CWG) to a corn-soybean meal-based diet. Diets were 1) 30% DDGS, 20% wheat middlings, and 4 to 5% soybean hulls (low energy); 2) 20% wheat middlings and 4 to 5% soybean hulls (low energy); 3) a corn-soybean meal diet (medium energy); 4) diet 2 supplemented with 3.7% CWG to equalize the NE level to diet 3 (medium energy); and 5) a corn-soybean meal diet with 3.7% CWG (high energy). Only small differences were observed between predicted and observed values of ADG and G:F except for the low-energy diet containing the greatest fiber content (30% DDGS diet), where ADG and G:F were overpredicted by 3 to 6%. Therefore, the prediction equations provided a good estimation of the growth rate and feed efficiency of growing-finishing pigs fed different levels of dietary NE except for the pigs fed the low-energy diet containing the greatest fiber content.

Effects of adding supplemental tallow to diets containing 30% distillers dried grains with solubles on growth performance, carcass characteristics, and pork fat quality in growing-finishing pigs

Crossbred pigs (n = 315) were blocked by initial BW (6.8 ± 1.1 kg) and randomly assigned to 1 of 4 dietary treatments to evaluate the effects of dietary inclusion of tallow and corn distillers dried grains with solubles (DDGS) on pig growth, carcass traits, and pork fat quality. Diets consisted of a corn-soybean meal control diet (CON) and another 3 corn-soybean meal diets containing 5% tallow (T), 30% DDGS (D), or 5% tallow plus 30% DDGS (TD) in a 2 × 2 factorial arrangement of treatments. Diets were formulated to contain similar levels of available P and standardized ileal digestible Lys:ME among treatments. Pigs were housed in 40 pens, with 7 to 8 pigs per pen, to provide 10 replicates per treatment. Overall ADG did not differ among treatments. Compared with CON (2.76 kg/d) and T (2.59 kg/d), feeding 30% DDGS reduced the ADFI (interaction, P > 0.05) of pigs when fed with 5% tallow (2.45 kg/d for TD) but not when fed alone (2.76 kg/d for D). There was no effect of DDGS on overall G:F, but pigs fed diets with tallow had greater (P < 0.01) G:F (0.4) than pigs fed no tallow (0.37). Feeding tallow increased (P < 0.01) HCW, carcass yield, and backfat depth of pigs independent of DDGS. Feeding DDGS reduced (P < 0.01) belly firmness, as measured by belly flop angle, independent of tallow (D = 71.8° and TD = 57.7° vs. CON = 134.0° and T = 113.4°) and tallow also tended to reduce belly firmness (P < 0.10). Feeding DDGS and tallow reduced the concentration of SFA in belly fat, while the concentration of MUFA were increased (P < 0.01) by feeding tallow but not DDGS. Conversely, feeding DDGS increased (P < 0.01) the concentration of PUFA in belly fat but there was no effect of tallow. An interaction (P = 0.03) between DDGS and tallow for iodine value (IV) of belly fat was observed, in which addition of tallow or DDGS increased the IV of belly fat (64.22 for T and 71.22 for D vs. 59.01 for CON) but addition of both reduced IV (67.88 for TD). The IV of belly fat and backfat were correlated (P < 0.01) with the IV product of the diet fed in phase 3 (r = 0.49 and r = 0.81, respectively). In conclusion, adding 5% tallow to 30% DDGS diets improved G:F and carcass yield while reducing the IV of belly fat. However, pork fat firmness as measured by belly flop angle was not improved.

Impact of dietary fat source and concentration and daily fatty acid intake on the composition of carcass fat and iodine value sampled in three regions of the pork carcass

The increased inclusion of unsaturated fats in pig diets has raised issues related to pork carcass fat quality. The objective of this experiment was to more precisely measure how differing levels of daily fatty acid intake alters the fatty acid composition in 3 different fat depots. A total of 42 gilts and 21 barrows (PIC 337×C22/29) with an average initial weight of 77.80±0.38 kg were allotted randomly based on sex and BW to 7 treatments: 3 and 6% of each of tallow (TAL; iodine value [IV]=41.9), choice white grease (CWG; IV=66.5), or corn oil (CO; IV=123.1) and a control (CNTR) corn-soybean meal-based diet with no added fat. Pigs were individually housed to allow accurate measurement of individual feed intake, in particular, daily dietary fatty acid and energy intake. Fat samples were collected from the jowl, belly, and loin at slaughter. Diet and carcass fat samples were analyzed for IV. Belly weights were recorded at slaughter along with a subjective belly firmness score (1=firmest to 3=least firm). Carcass lipid IV was increased (P<0.001) by increasing the degree of unsaturation of the dietary fat source (66.8, 70.3, and 76.3 for TAL, CWG, and CO, respectively). Carcass lipid IV for TAL and CWG was not affected (P>0.05) by inclusion levels; however, carcass lipid IV was greater (P<0.001) in pigs fed 6 than 3% CO (80.0 vs. 72.6), and carcasses of gilts had greater IV (P<0.001) than carcasses of barrows (71.5 vs. 69.1). Increasing the level of TAL and CO but not CWG from 3 to 6% decreased the apparent total tract digestibility of GE, resulting in a source×level interaction (P<0.05). Dietary fat source had no effect (P≥0.66) on apparent total tract digestibility of either DM or GE, but feeding 6% dietary fat increased G:F (P=0.006) over pigs fed 3% fat (0.358 vs. 0.337). Of all the fatty acids measured, only linoleic acid intake presented a reasonable coefficient of determination (R2=0.61). Overall, IV product (IVP) was approximately equal to linoleic acid intake as a predictor of carcass IV (R2=0.93 vs. R2=0.94). When inclusion of dietary fat and PUFA intake increased, IVP placed more emphasis on the dietary fat inclusion level rather than the dietary fat composition. Linoleic acid intake corrected the overemphasis placed on dietary fat inclusion by IVP. To conclude, linoleic acid intake showed a strong relationship with carcass IV and can be used as a predictor.

Effects of dietary lysine/protein ratio and fat levels on growth performance and meat quality of finishing pigs

This study aimed to evaluate the effects of dietary lysine/protein ratio and fat levels on the growth, carcass characteristics and meat quality of finishing pigs fed feed made from food waste, including noodles and chocolate. Four dietary treatments, 2 levels of lysine/protein ratio (0.035 and 0.046) and 2 levels of fat (3.3% and 6.0%), were adapted to a 2 × 2 factorial arrangement. Each diet for the finishing pigs contained the same levels of adequate crude protein (16%) and lysine (0.58-0.75%), and similar levels of high total digestible nutrients (90.2-92.6%). In total, 32 LWD pigs with an average body weight of 57.2 kg were assigned to 4 dietary groups. The pigs were slaughtered at about 115 kg. Growth performance was not influenced by the dietary treatments. Carcass characteristics were slightly influenced by the dietary fat level. As the dietary lysine/protein ratio decreased, the marbling score of Longissimus dorsi muscle increased and the intramuscular fat (IMF) increased from 6.82% to 9.46%. Marbling score was not significantly influenced by the dietary fat level. These results indicate that IMF increased without adverse effects on growth, carcass characteristics and meat quality, when pigs were fed a diet with low lysine/protein ratio.

Comparison of hematologic and serologic profiles of broiler birds with normal and severe degrees of white striping in breast fillets

White striping is the white striation occasionally observed parallel to the direction of muscle fibers in broiler breast fillets and thighs at the processing plant. Broiler breast fillets can be categorized as normal (NORM), moderate (MOD), or severe (SEV) based on the degree of white striping. Histologically, SEV fillets are characterized by the highest degree of degeneration of muscle fibers along with fibrosis and lipidosis when compared with NORM. The present study was undertaken to compare the hematologic and serologic profiles of broilers with NORM and SEV degrees of white striping to get more information on the systemic changes associated with the condition. Day-old male broiler chicks of a commercial strain were grown on the same diet in 6 replicate pens (n = 32 birds/pen). Blood samples (5 mL) were collected from the wing vein of each bird on the day before processing for analyzing hematologic and serologic profiles. At 63 d, the birds were weighed and processed in a commercial inline processing system. Weight of the butterfly fillets, liver, and abdominal fat pad were recorded. Left-side fillets were scored to obtain the degree of white striping for each bird. Representative samples for NORM (n = 24) and SEV (n = 17) categories were selected to compare the hematologic and serologic profiles. The SEV birds had greater (P < 0.05) live, fillet, and liver weights, as well as fillet yield, compared with the NORM birds, but the abdominal fat yield was less (P < 0.05) in SEV birds. The NORM and SEV birds did not show any differences in various hematological parameters, including the differential leukocyte count. Conversely, SEV birds had elevated (P < 0.05) serum levels of creatine kinase, alanine transaminase, aspartate aminotransferase, and lactate dehydrogenase. These results suggest that there is no systemic infectious or inflammatory condition associated with a SEV degree of white striping. The elevated serum enzyme levels confirm the muscle damage associated with the degenerative myopathy in SEV birds.

Effects of genotype and dietary oil supplementation on performance, carcass traits, pork quality and fatty acid composition of backfat and intramuscular fat

A 42-day study was conducted to evaluate the effect of genotype: terminal sire line Duroc×F1 (DC×F1); terminal sire line Embrapa MS-115×F1 (MS-115×F1); and MS-115×Moura (MS-115×MO) and three dietary oil sources: soybean; canola; and canola+flax, on performance, carcass traits, pork quality, and fatty acid composition. Genotype affected the technological quality of pork and fatty acid profile. MS-115-sired pigs had better meat color and Duroc-sired pigs had higher intramuscular fat content, more saturated fat and better omega-6/omega-3 ratio. Moura breed influenced positively meat tenderness and intramuscular fat. Diet did not affect the technological quality of the meat. Canola or canola+flax oil diet supplementations increased monounsaturated and C18:3 and decreased C18:2 fatty acids, reducing the omega-6/omega-3 ratio. The best omega-6/omega-3 ratio was obtained through supplementation with canola+flax.

Poultry fat decreased fatty acid transporter protein mRNA expression and affected fatty acid composition in chickens

Background

A study was undertaken to examine the effects of poultry fat (PF) compared with those of soybean oil (SBO) on intestinal development, fatty acid transporter protein (FATP) mRNA expression, and fatty acid composition in broiler chickens. A total of 144 day-old male commercial broilers were randomly allocated to 2 treatment groups (6 replicates of 12 chicks for each treatment) and fed isocaloric diets containing 3.0% PF or 2.7% SBO at 0 to 3 wk and 3.8% PF or 3.5% SBO at 4 to 6 wk, respectively.

Results

PF had no influence on intestinal morphology, weight, or DNA, RNA, or protein concentrations at 2, 4, and 6 wk of age. However, compared with SBO, PF significantly decreased FATP mRNA abundance at 4 wk (P = 0.009) and 6 wk of age (P < 0.001); decreased liver fatty acid-binding protein (L-FABP) mRNA abundance at 6 wk of age (P = 0.039); and decreased C18:2 (P = 0.015), C18:3 (P < 0.001), C20:2 (P = 0.018), Σ-polyunsaturated fatty acids (Σ-PUFA) (P = 0.020), and the proportion of PUFA (P < 0.001) in the intestinal mucosa and decreased C18:2 (P = 0.010), C18:3 (P < 0.001), C20:2 (P < 0.001), Σ-PUFA (P = 0.005), and the proportion of PUFA (P < 0.001) in breast muscle at 6 wk of age.

Conclusions

PF decreases FATP and L-FABP mRNA expression and decreased the proportion of PUFA in the intestinal mucosa and breast muscle.

Effects of corn dried distiller's grains with solubles and enzyme premix supplements on growth performance, carcass characteristics and meat quality parameters in finishing pigs

The objective of the present study was to investigate the effects of corn dried distiller's grains with solubles (DDGS) and enzyme premix (mannanase + phytase) supplementation on the growth performance, carcass and meat quality parameters in finishing pigs. Sixty hybrid pigs (L × LW × D) with initial weight of 63.92 ± 1.50 kg were used in a 3 × 2 factorial design with main effects of DDGS levels (0, 10 and 20%) and enzyme premix levels (0% vs. 0.14%). Average daily gain (ADG, P < 0.01) and average daily feed intake (ADFI, P < 0.05) were decreased due to an increased level of DDGS additive while the feed conversion ratio was improved (P < 0.05) by adding enzyme premix. The diet cost/gain (won/kg) was saved (P < 0.01) due to an increased level of DDGS additive. There were no significant differences in carcass characteristics and meat quality parameters of Longissimus dorsi muscle by DDGS level and enzyme premix. Palmitoleic acid, oleic acid and monounsaturated fatty acid (MUFA) decreased (P < 0.05) according to DDGS level. The results indicate that DDGS may be used in feeds for finishing pig as a replacement of corn and soybean meal without affecting their carcass characteristics and meat quality.