Hampshire Crosses Research Articles

Effects of Cricket Powder on Growth Performance, Carcass Traits, Pork Quality, Physicochemical, and Sensory Analyses of Finishing Swine

Feeding pigs, a balanced diet is an important factor to promote growth performance and results in higher yield and quality pork. Alternative ingredients such as cricket powder (CP) can be used as a substitution to provide high-quality protein for swine. Therefore, this experiment was investigated the effects of cricket powder on growth performance, carcass traits, pork quality, physicochemical, and sensory analyses of finishing swine. Eight finishing hogs (Hampshire cross) were allotted to two treatments: 1) control (0% CP) and 2) control + 2% CP (CP replaced SBM), for 34 days. All treatments were analyzed for growth and carcass performance (ADG, ADFI, G: F, LEA, BF, HCW, and DP), sensory evaluation (9-point hedonic scale with 14 trained panelists), physicochemical (nutrition content, pH, moisture (%), ash content, color (L*, a*, b*), lipid oxidation (TBARS)), and microbiological analysis (aerobic heterotrophs (AH), E. coli, Enterobacteriaceae). Pork loin samples coated with 2% CP were used for all treatments, except the control treatment. Each treatment was prepared and stored at 3°C for 9 days. The results showed that the control diet pigs outgained pigs fed 2% CP 1.03 kg/d vs. 0.62 kg/d. There was no difference (p>0.05) in ADFI or G: F regardless of treatment. Pigs fed 2% CP tended to have greater DP (80.10% vs. 78.21%). The 2% CP treatment obtained the highest scores for all sensory attributes, acceptability (85.71%), and purchase intent (71.43%). Adding 2% CP improved the crude fiber (4.44%), iron (13.60 ppm), and zinc contents (21.50 ppm). Pigs fed 2% CP had increased (p<0.05) a* redness (10.51), pH value (5.91), and moisture content (73.03%). No E. coli and Enterobacteriaceae were detected in this experiment. In addition, samples with 2% CP increased redness values, decreased lipid oxidation, and decreased aerobic heterotrophs counts compared to the control treatment. Thus, our results suggest that adding cricket powder in swine production can be used to promote sustainability, enhance meat color, decrease undesirable microorganism growth, and prolong the shelf-life of pork loin.

Aural hematoma in lambs associated with Otobius megnini (Ixodida: Argasidae) infestation

In this report we described a case of aural hematomas in three lambs associated with Otobius megnini (Ixodida: Argasidae) infestation. From April to May 2021, five 3-month-old Hampshire cross lambs presented with unilateral aural hematomas. Upon otoscopic examination, engorged soft ticks (O. megnini) were observed in the external ear canals of three of the five lambs. The remaining two lambs had lesions consistent with infestation and were in a shared environment and deemed likely to have been infected. The treatment of all animals was based on the drainage of the serosanguinous fluid through an incision in the internal space of the ear pinna. Upon physical inspection of the entire flock (n = 310), O. megnini infestation was observed in one additional animal that did not have a hematoma. Following animal and environmental ectoparasiticide treatment with permethrin, no recurrences or additional cases of aural hematomas were observed in the flock in the following two-year period. To the authors' knowledge, this is the first description of aural hematomas in lambs associated with O. megnini infestation with successful recovery after surgery and off-label acaricide treatment.

Fattening performance and carcass characteristics of lambs supplemented with condensed tannins from Acacia mearnsii extract

Tannins are polyphenolic compounds with some beneficial properties for ruminants as they act as antioxidants, antimicrobials, and anthelmintics, which may improve animal performance. However, the results are variable, depending on the type, source, and dose. The objective of this research was to determine the effect on fattening performance and carcass characteristics of lambs supplemented with condensed tannins (CTs) from Acacia mearnsii extract. Thirty-six, three-month-old Dorset x Hampshire cross lambs of 20.8 ± 3.3 kg live weight were used in a completely randomized design with four treatments (n = 9), namely T1: basal diet, 0.0 g CT/kg DM-1; T2: T1 + 1.75 g CT/kg DM-1; T3: T1 + 3.5 g CT/kg DM-1; and T4: T1 + 5.25 g CT/kg DM-1. The daily weight gain was higher in T2 and T3 than in T1. The weight at slaughter and empty weight at slaughter were higher in T2 than in T1. The hot carcass weight was higher in T3 than in T1, but no different from T2 or T4. The hot carcass yield was higher in T3 than in the other treatments. The meat pH at slaughter and 24 hours postmortem was higher in T4 than in T1 and the meat protein percentage was higher in T3 than in T1. The inclusion of CTs from Acacia mearnsii extract in the diet of fattening lambs increased their daily weight gain, yield, and carcass weight.

Evaluation of Two SNP Markers in DPPA2 and SYTL3 Genes for Association with Host Response against Visna/Maedi Infection in Turkish Sheep

Visna/maedi (VM) is an incurable viral disease of sheep causing serious production losses across the globe. Classical control measures against VM such as screening and culling are costly and time-consuming. Breeding VM resistant sheep could provide an opportunity for struggling with the VM and decreasing the economic loss. In this study, we aimed to investigate possible associations between two previously reported single nucleotide polymorphisms (SNPs) in the ovine DPPA2 and SYTL3 genes and VM serostatus, and evaluate implementation of selective breeding strategies against VM in Karacabey merino, Kivircik, Imroz, and composite breeds; Bandirma, Hampshire crosses (HAMP), Ramlic and Black-headed German mutton crosses (SBA) which are reared in Marmara region of Turkey. For this purpose, we genotyped the sheep which VM serostatus were determined previously. The genotyping results showed that these SNPs in the DPPA2 and SYTL3 genes are polymorphic. We have conducted an association analysis with an experimental design using case-control matched pairs. Finally, a power analysis was performed to determine the power of the statistical analysis. According to our findings, within our detection limits (the minimum odds ratio 2.5 to 2.8; CI 95; statistical power 0.96; p-value < 0.05), there was no significant association between the SNPs in the DPPA2 and SYTL3 genes and VM serostatus. Therefore, these SNP markers are not useful to selective breeding against VM in Turkish sheep.

EFFECT OF REPLACING CORN AND SOYBEAN MEAL WITH BREWERS RICE AND DRIED DISTILLERS BREWERS YEAST ON PERFORMANCE OF GROWING-FINISHING PIGS

The objective of this study was to determine the ef fect of replacing corn and Soybean Meal (SBM) with Brewers Rice (BR) and Dried Distillers Brewers Yeast (DDBY), respectively, on ADG, G:F, Apparent Total Tract Digestibility (ATTD), fecal DM output and fecal loss of N and P of growingfinishing pigs. Sixty four Yorkshire x Duroc x Hamp shire crosses (BW = 73±5.7 kg) were randomly assigned to corn/SBM (CSM), BR/SBM (RSM), corn/DDBY (CBY) or BR/DDBY (RBY) diets. Compared with pigs finished on corn based diets, pi gs fed BR based diets gained faster (0.868 vs. 0.730 kg.pig -1 ; p<0.01) and had better gain to feed ratio (0.30 v s. 0.25; p<0.01). Pigs finished on RBY diet had the least fecal DM output (0.245, 0.352, 0 .575, 0.639 kg.pig -1 ; p<0.001) and greatest ATTD (91.5, 87.8, 80.0, 77.9%; p<0.001) followed by RSM, CBY and CSM pigs, respectively. Pigs finished on RBY diet lost the least (p<0.001) amount of N (0 .010, 0.013, 0.019, 0.021 kg.pig -1 ) and P (0.010, 0.014, 0.016, 0.019 kg.pig -1 ) in the feces followed by pigs finished on RSM, CB Y and CSM, respectively. In conclusion, BR and DDBY can replace all corn and SBM in swine diets with no negative effects on performance of growing-finishin g pigs.

DIET MODIFICATION TO REDUCE FECAL EXCRETION OF NITROGEN AND PHOSPHORUS IN GROWING-FINISHING PIGS

An experiment was conducted to determine whether brewers rice can replace all corn in diets for swine and reduce fecal excretion of Nitrogen (N) and Phosphorus (P) without compromising performance and carcass quality of growing-finishing pigs. Sixteen Yorkshire x Duroc x Hampshire crosses (BW = 77±2.5 kg) were randomly assigned to either corn/soybean meal (CSM; control) or brewers rice/soybean meal (RSM) diet. Both diets were formulated to contain 14% CP. The RSM pigs had a greater reduction (p<0.001) in daily fecal loss of N (0.007 Vs. 0.011 kg pig-1) and P (0.007 Vs. 0.008 kg pig-1), lower (p<0.001) fecal output (0.171 Vs. 0.322 kg pig-1), than CSM pigs. Compared with CSM pigs, RSM pigs gained faster (0.712 Vs. 0.581 kg pig-1 per day; p<0.01) and had better gain to feed ratio (0.30 Vs. 0.25; p<0.01). Furthermore, RSM pigs had greater (p<0.001) Apparent Total Tract Digestibility (ATTD; 91.5 Vs. 84.1%). Diet did not (p>0.10) affect carcass yield and Loin Eye Area (LEA), however, RSM pigs tended (p<0.10) to lay more back fat than CSM pigs. In conclusion, brewers rice can replace all corn in diets for growing-finishing pigs, reduce fecal excretion of N and P, increase pig performance with no effect on carcass quality. Consequently, feeding brewers rice instead of corn may help reduce environmental pollution attributed to excessive fecal excretion of N and P in growing-finishing pigs.

Association study and expression analysis of porcine ESR1 as a candidate gene for boar fertility and sperm quality

Male fertility is impaired through the lack of ESR1 (Estrogen Receptor 1) but little is known about the ESR1 roles in boar spermatogenesis and fertility. Therefore, this research was aimed at investigating the association with sperm quality and boar fertility traits in a total of 300 boars both from purebred Pietrain and Pietrain × Hampshire crosses. A SNP in coding region of ESR1 g.672C > T in exon 1 was associated with sperm motility ( P < 0.05) and plasma droplet rate ( P < 0.01) while the polymorphism in non-coding region of ESR1 g.35756T > C in inton 1 was associated with non-return rate ( P < 0.05). Furthermore, to analyse the mRNA and protein expression of ESR1 in boar reproductive tissues, a total of six boars were divided into two groups [Group I (G-I) and Group II (G-II)], where G-I had relatively better sperm quality. ESR1 expression was higher in tissues collected from G-I boars than those of collected from G-II boars, and the difference in mRNA expression was significant ( P < 0.01) in head of epididymis. The ESR1 protein expression results from western blot coincided with the results of qRT-PCR. The ESR1 protein localization observed a strong staining in the cytoplasm of Sertoli cell in the testis, in the epithelial cells in head and tail of epididymis, in smooth muscle in tail of epididymis, and in the post acrosomal region and tail of the spermatozoa. These results will improve the understanding of the functions of the ESR1 in spermatogenesis within the reproductive tract and will shed light on ESR1 as a candidate in the selection of boar with good sperm quality and fertility.

Association study and expression analysis of CD9 as candidate gene for boar sperm quality and fertility traits

Cluster-of-differentiation antigen 9 ( CD9) gene expressed in the male germ line stem cells is crucial for sperm–egg fusion, and was therefore selected as candidate gene for boar semen quality. The association of CD9 with boar sperm quality and fertility trait was analyzed using a total of 340 boars both from purebred Pietrain and Pietrain × Hampshire crosses. A single nucleotide polymorphism (g.358A>T) in intron 6 was significantly associated with sperm motility (MOT) ( P < 0.001), plasma droplet rate (PDR) ( P < 0.001) and abnormal spermatozoa rate (ASR) ( P < 0.01). Boars were divided into two groups with group 1 (G-I) boars having a higher SCON and SMOT, lower SVOL (sperm volume) and group 2 (G-II) having a lower SCON and SMOT, higher SVOL. The mRNA and protein expression levels were evaluated in reproductive, non-reproductive tissues and spermatozoa from G-I and G-II animals by using quantitative real-time PCR and western blotting. When both reproductive and non-reproductive tissues were examined, highest mRNA was expressed in prostate gland, then in the body of the epididymis, vas deferens and tail of the epididymis. In case of reproductive tissues, CD9 expression was higher in tissues and spermatozoa collected from G-I boars than those collected from G-II boars. The mRNA expression was significantly different ( P < 0.05) in body of epididymis from G-I and G-II boars. The CD9 protein expression results from western blot were coincided with the results of qRT-PCR. Moreover, CD9 protein localization in Leydig cells, Sertoli cells, epithelial cells and spermatozoa was remarkable which indicated the important role of CD9 in spermatogenesis process. By using mRNA and protein expression profiles, it could be shown that CD9 plays a crucial role during sperm development, especially within the epididymis where the maturation of the sperm, a key process for the sperm quality and motility takes place. These results will improve the understanding of the functions of the CD9 in spermatogenesis within the reproductive tracts and will shed light on CD9 as a candidate gene in the selection of good sperm quality boars.

Effects of different dietary fat sources on the fatty acid profile of backfat and intramuscular fat of pigs of various sire breeds

The aim of the feeding trial was to compare the effects of four different dietary fat supplementations (2.5% of tallow, olive oil, soyabean oil or linseed oil), three sire breeds and both sexes upon pig growth and usual carcass traits, but especially upon several meat and fat quality traits. Ninety-six weaners from different German and foreign sire breeds were tested for their ability to improve the quality of market products. The experiment was carried out with 48 barrows and 48 female growing/fattening pigs. They were progeny of German hybrid sows mated to Duroc, Hampshire x Duroc crosses or Pietrain x Hampshire crosses. The animals were individually kept from 30 to 120 kg liveweight. Growth and slaughter performances of pigs were not significantly influenced by the supplemented fat source. The overall mean of intramuscular fat of loin reached only 1.3%, varying between the sire breeds. The fatty-acid composition of backfat and intramuscular fat showed much smaller differences between sire breeds and sexes than between fat supplements to the diets. There were strong correlations between intake (x) and concentration of polyunsaturated fatty acids in backfat (y=3.73 x - 0.91; r(2)=0.85). Similar correlations were calculated for oleic acid. The results demonstrate that the fatty-acid profile in backfat and muscle can be substantially influenced by fat sources in the diet

Potential for small-scale farmers to produce niche market pork using alternative diets, breeds and rearing environments: Observations from North Carolina

With the extensive focus on lean conformation in the finished hog over the past 25 years, there is some indication that pork quality has suffered and taste has been bred out of today’s pork. Similar to the Certified Angus Beef program (a breed noted for intramuscular fat), small-scale farmers can promote a different ‘upscale’ pork by using breeds that will focus on pork taste exclusively, and feeding diets (possibly apart from corn and soybeans) to enhance flavor. Two experiments were devised to examine the influence of breed, rearing environment and diet on fresh pork quality and flavor. In Trial 1, three sow breed groups (Tamworth, Tamworth · Landrace, or Hampshire · Landrace) were mated to Duroc boars. Littermates (91 pigs total) were assigned randomly at weaning to one of three treatments: (1) confinement, (2) dry-lot and (3) pasture. All pigs were full fed a 16% crude protein (CP) grow-finish ration. Pasture pigs were allowed access to plots consisting of predominately white and crimson clovers with warm-season grasses (Bermuda grass and crab grass). Hampshire crosses had higher Minolta L* scores, indicating a paler, less desirable loin. Pork quality was similar across rearing environments except for lower initial pH levels observed in the pasture system and higher drip-loss percentage recorded in both outdoor systems. In Trial 2, 42 Tamworth · Duroc littermates were randomly assigned to one of two rearing environments (confinement or pasture) at 55 kg and full fed a 14% CP diet. Pigs finishing on pasture had access to standing, mature barley. Pork from the pasture system was darker than that from pigs reared in confinement. No differences were observed in sensory evaluation of the pork for the rearing environments examined. For both trials, intramuscular fat levels (< 2%) and visual color scores were too low to be considered for ‘upscale’ markets. Alternative diets to produce niche-market pork are unlikely to influence flavor without adequate levels of marbling.

Potential for small-scale farmers to produce niche market pork using alternative diets, breeds and rearing environments: Observations from North Carolina

With the extensive focus on lean conformation in the finished hog over the past 25 years, there is some indication that pork quality has suffered and taste has been bred out of today's pork. Similar to the Certified Angus Beef program (a breed noted for intramuscular fat), small-scale farmers can promote a different ‘upscale’ pork by using breeds that will focus on pork taste exclusively, and feeding diets (possibly apart from corn and soybeans) to enhance flavor. Two experiments were devised to examine the influence of breed, rearing environment and diet on fresh pork quality and flavor. In Trial 1, three sow breed groups (Tamworth, Tamworth×Landrace, or Hampshire×Landrace) were mated to Duroc boars. Littermates (91 pigs total) were assigned randomly at weaning to one of three treatments: (1) confinement, (2) dry-lot and (3) pasture. All pigs were full fed a 16% crude protein (CP) grow-finish ration. Pasture pigs were allowed access to plots consisting of predominately white and crimson clovers with warm-season grasses (Bermuda grass and crab grass). Hampshire crosses had higher Minolta L* scores, indicating a paler, less desirable loin. Pork quality was similar across rearing environments except for lower initial pH levels observed in the pasture system and higher drip-loss percentage recorded in both outdoor systems. In Trial 2, 42 Tamworth×Duroc littermates were randomly assigned to one of two rearing environments (confinement or pasture) at 55 kg and full fed a 14% CP diet. Pigs finishing on pasture had access to standing, mature barley. Pork from the pasture system was darker than that from pigs reared in confinement. No differences were observed in sensory evaluation of the pork for the rearing environments examined. For both trials, intramuscular fat levels (&lt;2%) and visual color scores were too low to be considered for ‘upscale’ markets. Alternative diets to produce niche-market pork are unlikely to influence flavor without adequate levels of marbling.

Effects of genotype and rearing system on sensory characteristics and preference for pork ( M. Longissimus dorsi)

The study concerns sensory quality, consumer preference, and thawing and cooking losses of loin muscle ( M. Longissimus dorsi) from Hampshire crosses of different genotypes. Half of the pigs were organically reared, the others conventionally reared. A selected and trained panel carried out descriptive tests showing that loin from organically reared pigs scored lower for juiciness and higher for crumbliness than loin from conventionally reared pigs. Loin from RN − carriers compared with loin from non-carriers scored higher for tenderness, juiciness, acidulous taste and meat taste and lower for crumbliness. Loin from gilts scored higher for juiciness and lower for off-flavour than loin from castrated males. Two consumer tests were performed. Rearing system did not influence the consumer preference for pork loin, while RN − loins were preferred to loins from non-carriers. Neither rearing system nor genotype affected thawing or cooking losses. Loin from females, however, had higher thawing loss than loin from castrated males.

Sensory quality and cooking loss of ham muscle ( M. biceps femoris) from pigs reared indoors and outdoors

The aim of this study was to evaluate the sensory characteristics and cooking loss of ham from pigs of different genotype and sex and on different rearing systems. Half of each litter was reared indoors in a large pen (120 mm 2), and the other half outdoors. Ham muscles ( M. biceps femoris) from 48 Hampshire crosses (carriers or non-carriers of the RN − allele) were subjected to sensory evaluation by means of descriptive analysis by a selected and trained nine-member panel. Ham from RN − carriers scored higher than that from non-carriers with regard to smell intensity and meat taste, also it was more tender and tended to have a more acidulous taste. Ham from pigs reared indoors had a juicier and more acidulous taste than that from pigs reared outdoors. Ham from castrates was more tender and more juicy than ham from gilts.

Die Fleischbeschaffenheit von Schweinekreuzungen mit besonderen Qualitätseigenschaften im Vergleich zum heutigen Standard- und Markenschweineangebot*

Abstract. Title of the paper: Meat Quality in Pig Crosses with special quality characteristics as compared to present Standard and Brand Pork Supply In a field experiment in Niedersachsen products of six sire lines mated to BHZP hybrid sows of one herd were compared. They were fattened in 4 BEG-farms and slaughtered at the Premium abattoir Zeven, where meat quality traits were measured on about 3000 pig carcasses (300–800 per genetic group). It is shown that the present market Standard from stress susceptible PI(PP)-boars produces 20% PSE carcasses and the present quality brand Standard from PI*HA(NP) boars still 10%, whereas all stress resistent (NN) products ränge below 2% PSE. Hampshire crosses cause higher water –, reduced protein contents and lower final pH values among their progeny because of their disturbed glucose metabolism (RN-defect gene). Only in progeny of Danish Duroc boars the intramuscular fat content reached the desired 2%, German products ranged between 1.2–1.5 %. Recommendations for breeding more uniform endproducts with higher quality Standards are given.

Effects of red clover silage and ageing time on sensory characteristics and cooking losses of loin ( M. longissimus dorsi) from Hampshire crosses with and without the RN − allele

The study concerns the effects of red clover silage (silage) and ageing time on sensory characteristics and cooking loss of loin from Hampshire crosses with and without the RN − allele. Half of each litter received conventional feed and the other half conventional feed with admixed red clover silage. Loins were aged at 4°C (4 and 8 days), prepared at 150° to 68°C and sensory evaluated by descriptive analyses. RN − carriers had loins of higher meat taste intensity and a more acidulous taste than non-carriers. Meat taste intensity and tenderness increased as ageing time increased while acidulous taste decreased. Loins, aged 4 days, from conventionally fed pigs were juicier than those of silage-fed pigs. RN − carriers had a greater total cooking loss than non-carriers. ©

Sensory and technological meat quality in carriers and non-carriers of the RN − allele in Hampshire crosses and in purebred Yorkshire pigs

The effect of the dominant RN − allele on technological and sensory meat quality of loin and ham from pigs, crossbred from Landrace × Yorkshire sows and one Hampshire sire heterozygous for the RN − allele was studied. The non-carriers of the RN − allele and the purebred Yorkshire pigs were similar regarding most of the technological traits. In comparison with the RN − carriers, they had higher values for pH u, Napole yield, dry matter and protein content, but lower values for drip loss, filter paper wetness, cooking loss, internal reflectance, residual glycogen and glycolytic potential. The three groups did not differ concerning lactate content, intramuscular fat or ash content. Shear-force values did not differ between the two RN genotypes, but both genotypes had lower shear-force values than the purebred Yorkshire pigs. Non-carriers had higher processing yield for cured cooked ham than RN − carriers. The RN − allele had little effect on the sensory attributes, as assessed by a trained panel using a descriptive test, but there was a tendency to lower chewing time for meat from the crossbreds compared to the purebred Swedish Yorkshire. RN − carriers produced more acidic fresh loin than non-carriers and purebred Yorkshire pigs, and juicier cured cooked ham than non-carriers.

Effect of the RN gene on technological and sensory meat quality in crossbred pigs with Hampshire as terminal sire

The effect of the dominant RN gene (Rendement Napole) was studied in Hampshire crosses (Hampshire sires × Swedish Landrace—Swedish Yorkshire dams). The present material comprised 107 entire male and 52 female pigs slaughtered at 106 kg live weight. Carriers and non-carriers of the RN gene were distinguished on the basis of the glycolytic potential (GP) in post-mortem longissimus muscle, or with the Napole yield (yield after curing and cooking). Compared with the glycolytic potential classification, Napole classification gave 16% misclassified samples. In comparison with non-carriers of the RN gene, gene carriers showed the following significant differences in m. longissimus dorsi meat quality traits: lower pH, higher surface and internal reflectance values, lower protein extractability, lower water-holding capacity, lower Napole yield and greater cooking loss. The high correlation ( r = −0.73; p < 0.001) which was found between GP and Napole yield in the total material, was absent in muscle from individuals carrying the RN gene. In addition to the detrimental effect on meat quality, the RN gene also had beneficial effects. Thus RN carriers had a lower ( p = 0.02) shear force value (Warner-Bratzler) and, at sensory testing, a stronger taste and smell and greater acidity (9-member untrained panel). No difference was found in sensory evaluated tenderness.

Effects of ractopamine on adipose tissue metabolism and insulin binding in finishing hogs. Interaction with genotype and slaughter weight

Twenty-four barrows were divided among eight treatments in a 2 × 2 × 2 design to quantify the influence of ractopamine (0 or 20 mg/kg diet) over the final 40 kg of gain on metabolic activity in adipose tissue. Interactions with genotype (Hampshire cross or Landrace cross) and slaughter weight (100 or 127 kg) were investigated also. Backfat was removed at slaughter and rates of lipolysis and fatty acid synthesis (FS), activities of malic enzyme (ME) and fatty acid synthetase (FAS), and insulin binding to adipocytes were assessed. Adipocytes from ractopamine-fed pigs were less sensitive (EC 50 increased 90%) and had a lower maximum lipolytic response (40%) to ractopamine stimulation. Rates of basal and insulin-stimulated FS were decreased 40% in ractopamine-fed pigs and were reflected in lower activities of ME (50%) and FAS (15%). Breed and slaughter weight had no consistent influence on the ractopamine response. Landrace-cross pigs had greater insulin binding capacity (30–60%) whether data were expressed on a cell or surface area basis. Ractopamine feeding did not consistently affect insulin binding capacity. Results suggest that ractopamine interacts in vivo with the β-adrenergic receptor of swine adipocytes, decreasing lipogenic capacity and diminishing responsiveness to β-adrenergic stimulation.

A comparison of the Duroc, Hampshire, Landrace, and Large White as terminal sire breeds of crossbred pigs slaughtered at 85 kg liveweight

Abstract An on-farm study was undertaken, firstly, to compare the Duroc and Hampshire as terminal sires in a three-way cross including the Landrace and Large White breeds and, secondly, to evaluate the latter cross against a two-way backcross involving the White breeds. Three boars of each sire breed were mated with crossbred sows of Large White, Landrace breeding and the progeny were grown to 85 kg liveweight on ad libitum feeding. Duroc- and Hampshire-sired litters had relatively fewer still births but breed of sire did not influence the number of live births in the litter or litter size at weaning. Duroc and Hampshire-crosses reached slaughter weight 4 days earlier than the Large White- and Landrace-crosses. They also had similar killing-out percentages and back fat measurements and these were higher and lower respectively than the crosses of the White breeds. Hampshire crosses had the largest eye muscles in cross-sectional area. Tissue composition of the carcass was not significantly different in Duro...

Comparative growth performance, carcass characteristics, and meat quality of pigs sired by Hampshire and Landrace boars

Abstract The performance (25 – 85 kg liveweight) of Hampshire x (Landrace x Large WhIte) and Landrace x (Landrace x Large White) progeny was compared under three feeding regimes, namely ad libitum, restricted according to liveweight, and one in which all pigs received the same amount of feed over the same period of time. On each feeding regime, growth performance was similar for the two types of crossbreds, but Hampshire crosses had relatively higher carcass yields, lower backfat measurements, and larger ‘eye muscles’ in cross-section. The eye muscles of Hampshire crosses were paler and had higher drip losses than those of Landrace crosses but only a few carcasses of each breed type had pale, soft, exudative musculature. Breed of sire did not significantly influence the intramuscular fat content of eye muscle tissue.