Influence of feed restriction and sex on growth performance and carcass and meat quality of Iberian pigs reared indoors

Impact of Rearing Strategies on the Metabolizable Energy and SID Lysine Partitioning in Pigs Growing from 90 to 200 kg in Body Weight

The current nutrient recommendations focus on pigs fed ad libitum up to 140 kg in body weight (BW). It remains unclear whether this applies to pigs weighing above 140 kg in BW under different rearing conditions. This study aimed to estimate protein (Pd) and lipid (Ld) depositions and the metabolizable energy (ME), standardized ileal digestible lysine (SID lysine) requirement and partitioning in 224 C21 Goland pigs (90−200 kg in BW). The control pigs (C) received diets limiting ME up to 170 kg in slaughter weight (SW) at 9 months of age (SA); older (OA) pigs had restricted diets limiting ME and SID lysine up to 170 kg in SW at >9 months SA; younger (YA) pigs were fed nonlimited amounts of ME and SID lysine up to 170 kg in SW at <9 months SA; and greater weight (GW) pigs were fed as the YA group, with 9 months SA at >170 kg in SW. The estimated MEm averaged 1.03 MJ/kg0.60. An 11% increase in MEm was observed in OA pigs compared to the controls. Energy restriction had negligible effects on the estimated MEm. The marginal efficiency of SID lysine utilization for Pd averaged 0.725, corresponding to a SID lysine requirement of 9.8 g/100 g Pd.

A Comparative Analysis of Metabolic Profiles of Embryonic Skeletal Muscle from Lantang and Landrace Pigs

Simple Summary

The pig is one of the most important domesticated meat animals. Some studies have revealed that pigs with low meat production show more intense myogenesis at the early stage of embryonic muscle development than pigs with high meat production. Here, by gas chromatography–mass spectrometry GC–MS based metabolomics, we concluded that the nucleotide metabolism and energy metabolism of the longissimuslumborum (LL) were increased in Lantang pigs compared with Landrace pigs, indicating rapid synthesis of nucleic acids and ATP to meet the material and energy requirements of rapid cell proliferation and differentiation in Lantang pigs.

Abstract

Elucidation of the complex regulation of porcine muscle development is key to increasing pork output and improving pork quality. However, the molecular mechanisms involved in early porcine embryonic muscle development in different pig breeds remain largely unknown. Here, GC–MS based metabolomics and metabolomic profiling was used to examine the longissimus lumborum (LL) of the Lantang (LT) and the Landrace (LR) pig at embryonic day 35 (E35). Metabolites showed clear separation between LT and LR, with 40 metabolites having higher abundances in LT and 14 metabolites having lower abundances in LT compared with LR. In addition, these metabolic changes were mainly associated with nucleotide metabolism and energy metabolism, such as purine metabolism, pyrimidine metabolism, the pentose phosphate pathway, and the TCA cycle. More interestingly, the contents of DNA, RNA, and ATP per unit mass of LL tissues were higher in LT, indicating rapid synthesis of nucleic acids and ATP, to meet both the material and energy requirements of rapid cell proliferation and differentiation. Furthermore, enzyme activity associated with the TCA cycle and pentose phosphate pathway, including α-ketoglutaric dehydrogenase (KGDH), malate dehydrogenase (MDH), pyruvate dehydrogenase (PDH), succinate dehydrogenase (SDH), and glucose-6-phosphate dehydrogenase (G6PDH), were higher in LT. Based on these results, we conclude that there are significant differences in nucleotide metabolism and energy metabolism of LL between LT and LR, and we speculate that the enhanced nucleic acid metabolism and energy metabolism in LT can meet the material and energy requirements of rapid cell proliferation and differentiation, making myogenesis more intense in LT compared to LR which might be the metabolic mechanism underlying the distinct skeletal muscle development in the two breeds.

The Implications of Changing Age and Weight at Slaughter of Heavy Pigs on Carcass and Green Ham Quality Traits

Simple Summary

Conventional rearing systems for heavy pigs intended for Italian dry-cured ham production require pigs to be slaughtered at 160 ± 16 kg and a minimum age of 9 months. With the current animal genetic trends providing progressively leaner animals, the conventional rearing system fails to provide pigs with optimal characteristics for the dry-cured ham industry. In this research, new combinations of age and weight at slaughter were explored, using different feeding conditions, as possible alternative rearing strategies for heavy pigs. Such alternative rearing strategies aimed to manipulate the growth rate of pigs, first allowing them to reach 160 ± 16 kg slaughter weight at a younger age; second, allowing pigs to maximize their slaughter weight at 9 months of age; and third, inducing slow growth in the pigs to reach the 160 ± 16 kg body weight at an older age. The first two strategies were the most promising alternatives as they improved the rate of gain, feed efficiency, and ham adiposity of the pigs. While the first strategy was the most economically convenient, the second produced the hams with the highest quality.

Abstract

Italian dry-cured ham production requires pigs to be slaughtered at 160 ± 16 kg at 9 months of age (control, C). The study explored three alternatives, based on different feeding conditions: (1) allowing pigs to express their growth potential by letting them reach 160 ± 16 kg slaughter weight (SW) at younger slaughter age (SA) (younger Age, YA); (2) allowing pigs to express their growth potential by maximizing their SW at 9 months SA (greater weight, GW); (3) increasing the SA required to reach 160 ± 16 kg SW (older age, OA). Pigs (336 C21 Goland, 95 kg initial body weight) were slaughtered on average at 257, 230, 257, and 273 d SA and 172.7, 172.3, 192.9, and 169.3 SW kg for the four treatments, respectively. C pigs had an average daily gain (ADG) of 715 g/d and feed efficiency (FE) of 0.265 (gain to feed). Compared to C, YA pigs had higher ADG (+32%), FE (+7.5%), and better ham adiposity; GW pigs had higher carcass weight (+12%), ADG (+25%), trimmed ham weight (+10.9%), and better ham adiposity. OA treatment affected ADG (−16.4%), FE (−16.6%), and trimmed ham weight (−3.6%). YA and GW could be promising alternatives to C as they improved FE and ham quality traits.

Feeding Crude Glycerin to Finishing Iberian Crossbred Pigs: Effects on Growth Performance, Nutrient Digestibility, and Blood Parameters

A total of 192 Iberian × Duroc pigs kept under intensive conditions were used to investigate the effects of feeding crude glycerin on growth performance, nutrient digestibility, and blood parameters. Animals were blocked by initial body weight (96.0 ± 11.3 kg) and allotted to pens (16 pigs per pen). Pens were assigned randomly to one of three dietary treatments (four pens per treatment). Dietary treatments contained 0, 5, or 10% of crude glycerin proportionally substituting for wheat (G0, G5, and G10, respectively). Diets were formulated to be isoenergetic and isoaminoacidic. No significant effect of crude glycerin was observed on average daily gain, average feed intake, or feed conversion ratio. The apparent total tract digestibility of dry matter, organic matter, and crude protein was no different between treatments. Total serum protein, albumin, glucose, insulin, and IGF-1 were not affected by glycerin inclusion. In conclusion, crude glycerin up to 100 g/kg can be included in the diets of finishing Iberian crossbred pigs without any negative effect on growth performance, digestibility, or serum metabolic parameters.

Pork Quality of Two Lithuanian Breeds: Effects of Breed, Gender and Feeding Regimen

Simple Summary

A few highly selected commercial pig breeds have been developed and many different local breeds have been replaced by these modern breeds. With the aim to preserve rare local breeds, the necessity has arisen to find and create the conditions under which local breeds could be more widely used. Therefore, the performance and production qualities of local breeds should be evaluated and highlighted. As the quality of pig production is associated with breeds and effects of other different conditions, the objective of this experiment was to investigate the effects of breed, gender, and feeding level in the finishing phase on the carcass and meat quality of Lithuanian White and Lithuanian Indigenous Wattle pigs reared indoors. Feed restriction during the finishing phase and gender both affected the growth and fatness of pigs. The breed and gender appeared to have an effect on the parameters of meat quality including fatty acid composition. The breed and gender effects on fatty acid composition showed more favorable lipid indices in relation to healthy nutrition in the ham muscles of Lithuanian White pigs compared with Lithuanian Indigenous Wattle pigs and also in the ham muscle and backfat of females compared with castrated males.

Abstract

The diversity of breeds is an important factor influencing carcass and meat quality traits that are also associated with other different effects. The objective of this study was to investigate the effects of breed, gender, and feeding level in the finishing phase on the carcass and meat quality of Lithuanian White and Lithuanian Indigenous Wattle pigs reared indoors. After 60 kg weight, half of the animals from both breeds were fed a restricted diet of approximately 82% of average ad libitum feeding intake, and the other half of pigs were further fed ad libitum to the end of the experiment. Feed restriction during the finishing phase decreased daily gain and weight of pigs at slaughter, and backfat thickness at the tenth rib (p ˂ 0.001, p ˂ 0.01, and p ˂ 0.05, respectively). Lithuanian White pigs demonstrated higher (p ˂ 0.001) growth rate, live body weight at slaughter and carcass weight, and had a higher (p ˂ 0.01) length of carcass and loin area and lower (p ˂ 0.05) backfat thickness at the last rib and at two points at the lumbar area compared with Lithuanian Indigenous Wattle pigs. The semimembranosus muscle of Lithuanian White pigs had relatively (8.1%) lower (p ˂ 0.001) proportions of saturated and 41.2% higher (p ˂ 0.001) proportions of polyunsaturated fatty acids compared with the pigs of the Lithuanian Indigenous Wattle breed, whereas in the longissimus muscle and subcutaneous tissue, the breed only affected the n-6/n-3 ratio (p ˂ 0.01 and p ˂ 0.001, respectively). Gender showed an effect on saturated fatty acids in all the studied tissues, however, the effects on polyunsaturated fatty acids were found in the semimembranosus muscle and subcutaneous tissue (p ˂ 0.05 and p ˂ 0.001) and the effects on monounsaturated fatty acids was found only in the semimembranosus muscle (p ˂ 0.01). These differences in the fatty acid composition of the semimembranosus muscle and subcutaneous tissue of females exhibited more favorable lipid quality indices compared with castrated males (p ˂ 0.001). The semimembranosus muscle of Lithuanian White pigs also showed more favorable lipid quality indices in relation to healthy nutrition compared with Lithuanian Indigenous Wattle pigs (p ˂ 0.001). This study is one of the steps toward the development and utilization of endangered breeds. The obtained information can be used to increase choice in pork production and consumption, and provides new insights for research into the conservation of local breeds.

Genetic parameters of meat quality, carcass composition, and growth traits in commercial swine

Swine industry breeding goals are mostly directed towards meat quality and carcass traits due to their high economic value. Yet, studies on meat quality and carcass traits including both phenotypic and genotypic information remain limited, particularly in commercial crossbred swine. The objectives of this study were to estimate the heritabilities for different carcass composition traits and meat quality traits and to estimate the genetic and phenotypic correlations between meat quality, carcass composition, and growth traits in 2 large commercial swine populations: The Maschhoffs LLC (TML) and Smithfield Premium Genetics (SPG), using genotypes and phenotypes data. The TML data set consists of 1,254 crossbred pigs genotyped with 60K SNP chip and phenotyped for meat quality, carcass composition, and growth traits. The SPG population included over 35,000 crossbred pigs phenotyped for meat quality, carcass composition, and growth traits. For TML data sets, the model included fixed effects of dam line, contemporary group (CG), gender, as well as random additive genetic effect and pen nested within CG. For the SPG data set, fixed effects included parity, gender, and CG, as well as random additive genetic effect and harvest group. Analyses were conducted using BLUPF90 suite of programs. Univariate and bivariate analyses were implemented to estimate heritabilities and correlations among traits. Primal yield traits were uniquely created in this study. Heritabilities [high posterior density interval] of meat quality traits ranged from 0.08 [0.03, 0.16] for pH and 0.08 [0.03, 0.1] for Minolta b* to 0.27 [0.22, 0.32] for marbling score, except intramuscular fat with the highest estimate of 0.52 [0.40, 0.62]. Heritabilities of primal yield traits were higher than that of primal weight traits and ranged from 0.17 [0.13, 0.25] for butt yield to 0.45 [0.36, 0.55] for ham yield. The genetic correlations of meat quality and carcass composition traits with growth traits ranged from moderate to high in both directions. High genetic correlations were observed for male and female for all traits except pH. The genetic parameter estimates of this study indicate that a multitrait approach should be considered for selection programs aimed at meat quality and carcass composition in commercial swine populations.

The effect of periodic energy restriction on growth performance, serum biochemical indices, and meat quality in sheep

Energy is a key factor regulated by the neuroendocrine system. The objective of this study was to compare growth performance, serum biochemical indices, carcass traits, meat quality, and nutrient composition of lambs fed restricted metabolizable energy (ME) intakes to mimic the seasonal changes of the natural grasslands of northwest China. Nineteen male Dorper × Small Tailed Han lambs were assigned to treatments, control (CON) fed at 1.0 MJ/W0.75 × d-1 throughout the 180 d study, and restricted ME (RES) fed by sequentially restricting ME every 30 d (0.56, 0.84, 1.0, 0.84, 0.56, and 0.28 MJ/W0.75 × d-1). Lambs were harvested at the end of the study. Lambs fed the CON diet demonstrated higher (P < 0.05) average daily gain (ADG) compared with RES-fed lambs (158.79 and 57.01 g/d, for CON and RES, respectively), although ADG were lower in each period with the last period being a negative ADG for RES-fed lambs resulting in a loss of body weight. Both treatments demonstrated lower ADG in the last 3 study periods compared with the first 2 periods, which may be explained by cold stress (<-3 °C) increasing the lamb's energy requirement. Feeding lambs a restricted ME diet resulted in lower (P < 0.05) blood serum glucose, triglycerides, total protein, calcium, phosphorus, immunoglobulin G, immunoglobulin M, and immunoglobulin A concentrations compared with CON-fed lambs, but both treatments were similar (P > 0.05) for cholesterol and high-density lipoprotein-cholesterol. Feeding lambs a restricted ME diet increased (P < 0.05) meat pH, while reducing the cooked meat rate compared with CON-fed lambs. Thus, the carcass yield, rib eye muscle area, and shear force were lower (P < 0.05) for RES-fed lambs compared with CON-fed lambs. The meat water concentration was higher (P < 0.05), whereas the concentrations of dry matter, crude fat, crude protein, and carbohydrate were lower (P < 0.05) for lambs fed a RES ME diet compared to CON-fed lambs. These results demonstrate that sequentially restricting ME intake, as natural grasslands might experience during seasonal forage quality and quantity changes, resulted in a reduction of body weight because lambs were mobilizing body reserves as a source of ME. The reduction in concentrations of key serum nutrients, as well as carcass traits and meat composition, demonstrate the body is responding to the meet the lambs ME requirements, which has implications for both meat quality and the animal's physiological functions.

Reduction of androstenone perception in pan-fried boar meat by different masking strategies

BACKGROUND

Consumers highly sensitive to androstenone María (AND) will probably reject meat from entire male pigs, which tends to have high levels of this hormone. To avoid this, the effect of different masking strategies (sprinkling with mixed spices or fennel, marinating and breading with garlic-parsley or curry) on the sensory parameters of pork loin chops obtained from entire animals with high levels of AND (1.0-2.9 mg kg^-1 AND in fat) and castrated animals (<0.4 mg kg^-1 AND in fat), both with low levels of skatole (<0.1 mg kg^-1 skatole in fat) was investigated.

RESULTS

The garlic-parsley breadcrumbs led to the highest reduction in the perception of AND compared with the other masking strategies used, and preserved the juiciness of the product. There was a negative correlation between AND and fat content.

CONCLUSION

AND odor and flavor can be reduced in meat from entire male pigs by using suitable strategies, the best strategy being the garlic-parsley breadcrumbs. © 2017 Society of Chemical Industry.

The effect of the dietary protein restriction and re-feeding on the content of leptin, IGF-I and urea nitrogen in the blood plasma and growth performance in pigs

The aim of the present study was to examine the effect of the dietary protein restriction on the plasma concentrations of leptin, insulin-like growth factor (IGF-I), blood urea nitrogen (BUN) and growth performance in growing pigs. A total of 12 gilts were divided into experimental (ET) and control (CT) treatments. After the 14-day dietary restriction period during which the ET fed a low-protein diet (LPD, 5% of crude protein) and the CT fed a standard diet (SD, 16% of crude protein) the second 14-day re-feeding period followed, in which LPD was replaced by a SD that was fed by the both treatments. During the dietary protein restriction reduced (P < 0.05) N intake, average daily gain (ADG), concentration of BUN and tendency (P = 0.084) to the lower IGF-I in ET compared with CT were observed. Feed to gain ratio was greater (P < 0.05) in ET. During the subsequent re-feeding period, there was a tendency to the greater daily feed intake (P = 0.068) and N intake (P = 0.070), greater (P < 0.05) ADG, BUN and plasma leptin but no IGF-I in ET. These observations suggest that dietary protein restriction promotes body growth in pigs, which is associated with increase in blood leptin and BUN level in ET during the re-feeding, indicating that the increased ADG can be due to increased fat deposition but not of protein synthesis.

Effect of feeding restriction on growth and dressing percentages in Mexican hairless pig

Twenty-four male Mexican hairless pigs, weighing 16 ± 1.12 kg, were used to evaluate growth performance and carcass yield in pigs fed 2 (L), 3 (M) and 4 (H) times the Metabolizable Energy (ME) required for maintenance. The pigs were assigned randomly to two experimental rearing systems (indoors and outdoors). They were fed daily according to their respective feeding regimen (FR). The indoor pigs were fed ad libitum with chopped star grass forage (Cynodon nlemfuensis). The outdoor pigs had access during 16 h to a paddock of star grass. The pigs were slaughtered when they achieve 70 kg of live weight. No significant differences between indoors and outdoors were observed in any of the variables evaluated (P > 0.05). A significant reduction of daily live weight gain (P < 0.05) was observed conforming to FR reductions (0.501, 0.438 and 0.300 kg/day for H, M and L, respectively). Days to achieve 70 kg of live weight increase (P < 0.05) as FR reduces (110, 124 and 180 days for H, M and L, respectively) were recorded. Forage consumption in pigs reared indoors reduces (P < 0.05) conforming to FR increases (0.092, 0.121 and 0.307 kg DM/day for H, M and L respectively). Fat carcass yield reduces significantly (P < 0.05) according FR reductions (24.5, 22.8 y 18.9 kg, for H, M and L respectively). Also, carcass meat yield was higher (P < 0.05) in pigs from L regimen (25.0 kg) than in pigs from M and H regimen (22.0 and 22.8 kg, respectively). Results obtained indicate a reduction in daily live weight gain conforming to daily feed intake reductions; however, improvement in carcass meat yield, accompanied with a reduction in carcass fat yield, was observed.

Composition and quality characteristics of carcasses from pigs divergently selected for residual feed intake on high- or low-energy diets

The objective was to determine the extent to which feeding low-energy, high-fiber (LEHF) and high-energy, low-fiber (HELF) diets impacts meat quality and carcass composition of pigs divergently selected for residual feed intake (RFI). Two experiments were conducted in the divergently selected Iowa State University RFI lines: Exp. 1 evaluated carcasses of generation (G) 8 pigs fed on commercial feeders; Exp. 2 evaluated composition, pork quality, sensory, and postmortem proteolysis of pigs fed on electronic single-space feeders in G 8 and 9. Pigs (N = 177) in Exp. 1 were randomly assigned a pen (mixed sex and line; N = 8). Groups (n = 3) of pigs were slaughtered at a mean BW of 121.5 kg. Pigs in Exp. 2 (G8: n = 158; G9: n = 157) were randomly assigned to 1 of 6 pens of each diet per G. Pigs from G8 were slaughtered at a mean BW of 122.5 kg and G9 at a mean of 128.4 kg. Data were analyzed using the mixed procedure of SAS. Fixed effects were line, diet, sex, and all appropriate interactions. Random effects were group, pen, litter, and sire and covariate of off-test BW. For Exp. 2, G was added as a fixed effect and sensory day was added as a random effect when applicable. In Exp. 1, carcasses from low RFI (LRFI) pigs were leaner and had less fat depth (P < 0.01). Carcasses from pigs fed the LEHF diet had a lighter HCW and greater estimated percent lean than pigs fed HELF diet (P < 0.01). In Exp. 2, LRFI pigs on the HELF diet had the greatest loin depth (P < 0.01). Chops from HRFI pigs had greater drip loss, color scores, lean tissue a*, and percent lipid and lesser percent moisture than LRFI ( P< 0.05). Chops from pigs on the LEHF diet had lesser muscle L* values and greater percent moisture than chops from pigs fed the HELF diet (P < 0.05). Chops from LRFI pigs were juicer than those from HRFI pigs (P < 0.05). Protein extracted at d 2 postmortem from LRFI pigs on the LEHF diet had a greater 38 kDa desmin degradation product than protein from LRFI pigs fed the HELF diet (P < 0.05). Day 5 postmortem extracted protein from HRFI pigs had greater 38 kDa desmin degradation product than LRFI (P = 0.05). Pigs fed LEHF (P < 0.01) had adipose with a greater iodine value than adipose from HELF fed pigs. Pork sensory quality from pigs differentially selected for residual feed intake was not influenced by energy content of the diet the pigs were fed.

Effect of sex, dietary glycerol or dietary fat during late fattening, on fatty acid composition and positional distribution of fatty acids within the triglyceride in pigs

The effect of sex, source of saturated fat (lard v. palm oil) and glycerol inclusion in the fattening diet on composition and fatty acid positional distribution in the triglyceride molecule was studied in pigs from 78 to 110 kg BW. Average daily gain and carcass characteristics, including ham and loin weight, were not affected by dietary treatment but sex affected backfat depth (P < 0.01). A significant interaction between sex and glycerol inclusion was observed; dietary glycerol increased lean content in gilts but not in barrows (P < 0.05 for the interaction). Individual and total saturated fatty acid (SFA) concentrations were greater in barrows than in gilts. In contrast, the concentration of total polyunsaturated fatty acids (PUFA) and of C18:2n-6, C18:3n-3, C20:3n-9 and C20:4n-6 in the intramuscular fat (IMF) was higher (P < 0.05) in gilts than in barrows. Sex did not affect total monounsaturated fatty acids (MUFA) concentration in the IMF. The proportion of SFA in the subcutaneous fat (SF) was higher in barrows than in gilts (P < 0.001). Within the individual SFA, sex affected only the concentrations of C14:0 and C16:0 (P < 0.001). Dietary fat did not affect total SFA or PUFA concentrations of the IMF but the subcutaneous total MUFA concentration tended to be higher (P = 0.079) in pigs fed lard than in pigs fed palm oil. Dietary glycerol increased total MUFA and C18:1n-9 concentration in the IMF and increased total MUFA and decreased C18:2n-6, C18:3n-3 and total PUFA concentrations in the SF. The data indicate that altering the fatty acid composition of the triglyceride molecule at the 2-position, by dietary intervention during the fattening phase, is very limited.

Feeding Iberian × Duroc cross pigs with crude glycerine: Effects of diet and gender on carcass and meat quality

Ninety (45 castrated males and 45 gilts) Iberian × Duroc pigs were used in this study. During the finishing period (95-160 kg body weight, 74 days) animals received conventional feed (control G0) or the same feed plus 5% (G5) or 10% (G10) of crude glycerine to partially replace wheat. In general, neither the diet nor gender affected ultrasound, carcass or meat quality parameters. The G10 had lower values of cooking loss and a* than the G5 and G0 groups. The fatty acids, C10:0, C12:0 and C18:3, in intramuscular fat were lower in both glycerine groups. Polyunsaturated fatty acids and 18:2 decreased and C20:0 increased at the subcutaneous fat of G10 animals. Castrated males produced carcasses with higher backfat thickness and fat content. Castrated males had a higher SFA content in subcutaneous fat than females (P<0.001). In conclusion, up to 10% crude glycerine could be used in the Iberian × Duroc diet.

Qualidade da carne de suínos com uso de glicerina na alimentação

O objetivo deste trabalho foi avaliar os efeitos do fornecimento de diferentes níveis de glicerina na alimentação sobre a qualidade da carne de suínos em terminação. Foram utilizados 30 machos castrados e 30 fêmeas que apresentaram peso inicial de 79,3±4,0kg. Utilizou-se delineamento em blocos casualizados (peso inicial) em esquema fatorial 2 × 4 + 2, sendo duas categorias sexuais (macho castrado e fêmea), quatro níveis de glicerina bruta (50, 100, 150 e 200g/kg) e dois grupos controle (macho castrado e fêmea alimentados com dieta sem glicerina), totalizando dez tratamentos com seis repetições e a unidade experimental representada por um animal. Após o abate, foram realizadas as análises físico-químicas e centesimais dos músculos Longissimus dorsi (lombo) e Semimembranosus (pernil) do lado esquerdo das carcaças. Os resultados mostraram interação entre os níveis de glicerina e sexo para a intensidade de vermelho e cinzas no pernil. Observou-se que, nos corte do lombo, o pH final dos machos castrados foi maior do que o das fêmeas suínas. Os resultados indicaram que suínos machos castrados apresentaram maior teor de extrato etéreo no pernil e no lombo quando comparados às fêmeas. No pernil, o teor de cinzas das fêmeas suínas foi superior ao dos machos castrados. Entretanto, no lombo, não se verificou influência dos níveis de glicerina sobre a composição centesimal. Contudo, apesar de o uso da glicerina ter ocasionado modificação na cor vermelha e teor de cinzas no pernil de machos castrados, de forma geral não provocou mudanças relevantes sobre as características físico-químicas e centesimais da carne de suínos, podendo ser utilizada até o nível de 200g/kg na alimentação desses animais.

Effect of sex and final fattening on ultrasound and carcass traits in Iberian pigs

A hundred and twenty-five castrated Iberian pigs (61 males and 64 females, from 106.9 kg of live weight at star to 160.3 kg at slaughter) was used to investigate the effect of feeding system on carcass attributes (backfat thickness and loin area measured with ultrasound before slaughter, and intramuscular fat and weights and yields of hams, forelegs and loins after slaughter). Pigs were fattened outdoor under extensive conditions. There were 4 treatments: "montanera", M; "recebo", R; "cebo a campo", C; and high oleic fed, O). Ultrasound images were collected at two rib locations (10th and 14th). M and O groups had the highest fat thickness and loin area was lower in M than in C group. M and O showed higher carcass weight and yield than the other groups. The largest ham weight was for C and the lowest for M groups. Loin weight and yield were higher in M and R than the other two groups (O and C).

Influence of crude protein content, ingredient complexity, feed form, and duration of feeding of the Phase I diets on productive performance and nutrient digestibility of Iberian pigs

The influence of CP content and ingredient complexity, feed form, and duration of feeding of the Phase I diets on growth performance and total tract apparent digestibility (TTAD) of energy and nutrients was studied in Iberian pigs weaned at 28 d of age. There were 12 dietary treatments with 2 type of feeds (high-quality, HQ; and low-quality, LQ), 2 feed forms (pellets vs. mash), and 3 durations (7, 14, and 21 d) of supply of the Phase I diets. From d 7, 14, or 21 (depending on treatment) to d 35, all pigs received a common diet in mash form. Each treatment was replicated 3 times (6 pigs/pen). For the entire experiment, ADG (P < 0.05) and ADFI (P < 0.01) were less with the HQ than the LQ Phase I diets, but G:F was not affected. Pelleting of the Phase I diets did not affect ADG but improved G:F (P < 0.01). Feeding the Phase I diets from d 0 to 21 improved G:F (P < 0.05) but decreased ADG (P < 0.01) as compared with 7 or 14 d of feeding. Postweaning diarrhea (PWD) tended to be greater (P = 0.06) for pigs fed the HQ diets than pigs fed the LQ diets and pigs fed pellets than those fed mash (P < 0.001). Also, PWD was greater for pigs fed the Phase I diet for 14 or 21 d than those fed the diet for 7 d (P < 0.01). From d 0 to 21, ADG and G:F were not affected (P > 0.10) by feed quality, but feeding pellets or increasing the duration of feeding the Phase I diets improved G:F (P < 0.01). Also, in this period, PWD was greater with pellets than with mash and for pigs fed the Phase I diets for 14 or 21 d than for pigs fed the diet for only 7 d (P < 0.01). From d 21 to 35, pigs previously fed the LQ diet had greater ADG than pigs fed the HQ Phase I diets (P < 0.001). Also, pigs fed the Phase I diets for 21 d had decreased ADG (P < 0.05) and ADFI (P < 0.001) and reduced G:F (P < 0.05) than pigs fed these diets for 7 or 14 d. Organic matter digestibility was greater for pigs fed the HQ Phase I diets than pigs fed the LQ Phase I diets (P < 0.05). Pelleting improved TTAD of all nutrients (P < 0.01). It is concluded that HQ Phase I diets increased TTAD of nutrients but not feed efficiency of Iberian pigs from d 0 to 35. Also, pelleting improved energy and nutrient digestibility and feed efficiency. Increasing the duration of supply of the Phase I diets from 7 to 21 d improved feed efficiency but reduced ADG. Therefore, the use of LQ Phase I diets in pellet form for no more than 7 d after weaning is recommended in Iberian pigs.

Epitope selection to male specific antigens for sex selection in swine

Immunological approaches to gender selection have been contemplated since the discovery of the family of male-specific H-Y antigens found only on the surface of male cells. H-Y antigens are able to elicit an immune reaction when cells or tissues from a male donor are grafted to a female recipient. We describe here the development and testing of an inexpensive approach using polyclonal antibodies against four specific H-Y outer membrane proteins male enhanced antigen 1 (MEA 1), male enhanced antigen 2 (MEA 2), sex determining region Y (SRY) and testis determining factor (TDF). Epitopes based on hydrophilic primary sequences of the proteins were synthesized, N-terminal biotin-labeled, linked to streptavidin and mixed with a Ribi adjuvant prior to immunization in rabbits. The antiserum was tested to determine affinity to swine spermatozoa using anti-motility, flow cytometry and motility and sedimentation chambers. Fluorescent microscopy and fluorescent in situ hybridization (FISH) was used to identify the percentage of motile spermatozoa that contained the Y chromosome. We found that the polyclonal antibodies had high affinity to the spermatozoa leading to a cessation of motility. Furthermore, the majority of these non-motile spermatozoa contained the Y chromosome. We conclude that the use of polyclonal antiserum against synthetic H-Y peptide antigens may be an inexpensive and simple means to inhibit the motility of swine spermatozoa bearing the Y chromosome.