Large White Cross Research Articles

Effect of Bread Waste Feeding on Growth Performance and Carcass Traits of Crossbred Pigs

The study was conducted at Pig farm of AICRP on Pigs, Livestock farm, Adhartal, College of Veterinary Science & A.H., Jabalpur (M.P.) for a period of three months. A total of 36 Large White Yorkshire crosses (LWY X Desi) were randomly assigned to six different groups and diets were formulated as per ICAR (1998) standard. All the diets were isoproteinous except group-6, which was formulated as per farmers practice. Composition of the diets (Table-1) are as follows; G-1(Control); concentrate mixture-1, G-2; concentrate mixture-2 (75%)+ bread waste (25%), G-3; concentrate mixture-3 (50%) + bread waste (50%), G-4; concentrate mixture-4 (25%) + bread waste (75%), G-5; wheat bran (19.5%) + bread waste (66%) + GNC (10%) + fish meal (3%) + mineral mixture (1%) + common salt (0.5%), G-6; rice bran (50%) + bread waste (50%). At the end of the experiment, the two animals from each group were slaughtered for carcass evaluation. Daily feed intake was significantly (P<0.05) varied among the groups. Highest daily feed intake (kg/pig/day) was observed in G3 group (1.647) and lowest value observed in G6 group (1.219). Average daily gain (ADG) were significantly (P<0.01) different and highest ADG (kg/pig/day) was observed in group G2 (0.377) and lowest ADG (kg/pig/day) observed in G6 group (0.171). Carcass characteristics were not significantly varied among the experimental groups. Finally, the study concluded that bread waste could be fed to the growing crossbred pigs without affecting performance.

Stocking density affects welfare indicators of growing pigs of different group sizes after regrouping

In recent years, the concept of animal welfare began to be accepted by the Chinese people. On some intensive pig farms, the stocking density for growing pigs is too great, leading to decreased animal welfare. In order to study the relationships between stocking density and welfare indicators and determine the optimal stocking density for growing pigs, a total of 243 Landrace×Large White cross barrows were randomly regrouped at 1.6m2, 1.2m2 or 0.8m2 per pig at 135 days of age. Behavior percentages, lesions on the body and tail, body surface temperature (BST), manure on the body and concentrations of salivary cortisol were measured during the first 15 days after regrouping. Pigs housed at 0.8m2 per animal spent more time drinking (1.89 vs. 1.01%, P=0.0048) and participating in negative social behavior (0.76 vs. 0.26%, P=0.0063) than those housed at 1.6m2 per pig. Pigs housed at 1.2m2 per animal showed more positive social behaviors (1.28 vs. 0.14%, P=0.04) than those housed at 1.6m2. Pigs housed at 0.8m2 per animal had more lesions on the ears (P<0.01), front (P<0.01), middle (P<0.01) and hind-quarters (P<0.01) regions than those housed at 1.6 and 1.2m2. Total scores of lesions on the body were gradually increased (P<0.01) with the increasing stocking density. Pigs housed at 0.8m2 per animal had more manure on their bodies than pigs at 1.6 and 1.2m2 at the 7th, 11th, 13th and 15th day after regrouping. Pigs housed at 0.8m2 per animal had a greater proportion of pigs with an abnormally high BST than those at 1.6 (10 vs. 1.9%, P=0.009) and 1.2 (10 vs. 4%, P=0.037) m2 per pig. Altogether, at the first 15 days after regrouping, pigs housed at 1.2m2 per animal had decreased housing costs compared to those housed at 1.6m2 and improved indicators of animal welfare compared to those housed at 0.8m2.

Analysis of non-synonymous SNPs of the porcine SERPINA6 gene as potential causal variants for a QTL affecting plasma cortisol levels on SSC7.

Recently, the SERPINA6 gene encoding corticosteroid-binding globulin (CBG) has been proposed as a candidate gene for a quantitative trait locus (QTL) affecting cortisol level on pig chromosome 7. The QTL was repeatedly detected in different lines, including a Piétrain × (German Landrace × German Large White) cross (PiF1) and purebred German Landrace (LR). In this study, we investigated whether the known non-synonymous polymorphisms c.44G>T, c.622C>T, c.770C>T, c.793G>A, c.832G>A and c.919G>A of SERPINA6 are sufficient to explain the QTL in these two populations. Our investigations revealed that SNPs c.44G>T, c.622C>T, c.793G>A and c.919G>A are associated with cortisol level in PiF1 (P < 0.01). Haplotype analysis showed that these associations are largely attributable to differences between a major haplotype carrying SNPs c.793G>A and c.919G>A and a haplotype carrying SNPs c.44G>T and c.622C>T. Furthermore, some SNPs, particularly c.44G>T and c.622C>T and the carrier haplotype, showed association with meat quality traits including pH and conductivity (P < 0.05). In LR, the non-synonymous SNPs segregate at very low frequency (<5%) and/or show only weak association with cortisol level (SNPs c.832G>A and c.919G>A; P < 0.05). These findings suggest that the non-synonymous SNPs are not sufficient to explain the QTL across different breeds. Therefore, we examined whether the expression of SERPINA6 is affected by cis-regulatory polymorphisms in liver, the major organ for CBG production. We found allelic expression imbalance of SERPINA6, which suggests that its expression is indeed affected by genetic variation in cis-acting elements. This represents candidate causal variation for future studies of the molecular background of the QTL.

Effect of creatine monohydrate supplementation on carcass traits, meat quality and postmortem energy metabolism of finishing pigs

The objective of this study was to evaluate the effects of creatine monohydrate (CMH) supplementation on meat quality and postmortem energy metabolism of finishing pigs. In total, 48 healthy Duroc–Large White cross castrated male pigs were randomly allocated into two treatments, and fed either a CHM-free basal diet or a basal diet with CMH supplementation (0.8%) for 14 days. At the end of the experiment, six pigs from each treatment were weighed individually and slaughtered. The muscle from longissimus dorsi was collected to evaluate the meat quality and energy metabolism-related parameters. The results showed that CMH supplementation did not affect the loin eye area, back fat depth or dressing percentage (P &gt; 0.05). The muscle pH45 min was higher, whereas drip loss and cooking loss were lower in the CMH supplementation group (P &lt; 0.05). CMH supplementation increased the concentrations of creatine (P &lt; 0.05), adenosine triphosphate (P &lt; 0.05), adenosine diphosphate (P &lt; 0.01) and creatine kinase activity (P &lt; 0.05), and decreased the concentration of lactic acid (P &lt; 0.05), and the activities of lactate dehydrogenase (P &lt; 0.05) and pyruvate kinase (P &lt; 0.05) in muscle postmortem. However, no differences were observed between groups for chemical composition, textural characteristics and glycolytic potential of longissimus dorsi muscle (P &gt; 0.05). These findings suggest that dietary supplementation with CMH during the finishing period in pigs could delay early pH decline and decrease the rate of glycolysis in postmortem longissimus dorsi muscle resulting in a decreased drip loss.

Allelic frequencies of NR6A1 and VRTN, two genes that affect vertebrae number in diverse pig breeds: A study of the effects of the VRTN insertion on phenotypic traits of a Duroc × Landrace–Large White cross

A SNP (748 C>T) in the NR6A1 gene and an insertion (g.20311_20312ins291) in the VRTN gene have been shown to affect vertebrae number in the pig. The allelic frequencies of both genes were investigated in six western breeds and the effects of the VRTN insertion on some phenotypic traits in a Duroc×Landrace/Large White cross. The NR6A1 c. 748T allele, associated with higher number of vertebrae, appeared to be fixed in most studied breeds except in Iberians. The VRTN insertion (Ins allele) shows ample variability in all studied breeds although the allelic frequency of Ins seems to be larger in breeds with a greater history of genetic selection. Ins is associated with an increase in weight at slaughter, in loin and rib primal cut proportions, and with modified meat quality properties such as cooking loss, intramuscular fat content or yield after curing. We discuss the usefulness of both gene markers for pig selection.

Evaluation of dried bread waste as feedstuff for growing crossbred pigs

Aim: The aim was to investigate the effect of bread waste feeding on feed intake, utilization and growth performance of crossbred pigs and to evaluate the economics of bread waste feeding. Materials and Methods: The study was conducted for a period of 3 months (December, 2012-March, 2013). Large White Yorkshire crosses (LWY X Desi) were included in the study. A total of 24 weaned crossbred growing pigs were randomly assigned to four different groups, with six animals in each group. The experimental animals were fed as per their body weight following Indian Council of Agricultural Research requirements. They were fed twice a day according to schedule at 9:00 am and 3:00 pm. The water was kept available to animals round the clock. The cost of the experimental diets was calculated based on the existing price of the ingredients during the experimental period. Samples of feed were collected for analysis of proximate principles as per Association of Official Analytical Chemist. Body weight of all animals was recorded fortnightly basis in the morning before feeding with the use of platform type electronic weighing balance. Feed conversion ratio (FCR) and protein conversion ration was calculated by using a standard formula. Data were analyzed, using one-way analysis of variance (ANOVA). Means showing significant differences in the ANOVA table were compared using the Duncan multiple range test. Results: Crude protein content (%) of the diets was 16.01±0.02, 16.13±0.02, 16.14±0.02, 16.04±0.02, 16.08±0.02 and 12.72±0.03, respectively for the G1, G2, G3 and G4, groups. Proximate compositions (%) of diets used in the experiment were not significantly different. Digestibility coefficients of all the nutrients were significantly varied among the experimental groups. Daily feed intake was significantly (p<0.05) varied among the groups. Average daily gain (kg/pig/day) were significantly (p<0.01) higher in group G2 (0.377). FCR was significantly (p<0.01) higher in the G2 group (4.35). Conclusion: Bread waste can economically supplement up to 50% to the diet of crossbred growing pigs.

Porcine ubiquitin-like 5 (UBL5) gene: genomic organization, polymorphisms, mRNA cloning, splicing variants and association study

Ubiquitin-like 5 (UBL5), which is supposed to be involved in regulation of feed intake, energy metabolism, obesity and type 2 diabetes, is located at position 62.1 cM on the pig chromosome 2 region harbouring quantitative trait loci for carcass and meat quality. The 4,354 bp genomic sequence (FR798948) of the porcine gene encompassing the promoter and entire gene was cloned by polymerase chain reaction. Comparative sequencing revealed 13 polymorphisms in noncoding regions. Synthesis of full-length cDNA sequences using rapid amplification of 5' and 3' ends showed three splice variants. Variants 1 and 2 differ in transcription length for the untranslated part of exon 1 with deduced protein of 73 amino acid (aa) residues and 100 % identities between human, mouse and other species. Variant 3, with 4 bp deletion at the 3' end of exon 2, encodes a truncated protein with 28 aa residues. In a Wild boar×Meishan F2 population (n = 334) with 47 recorded traits, loci FR798948:g.2788G>A and FR798948:g.2141T>C were associated at nominal P < 0.05 with fat deposition, growth and fattening and muscling but after adjustment for multiple testing (Benjamini and Hochberg, J R Stat Soc B 57:289-300, 1995) only eight fat deposition traits showed suggestive association with FR798948:g.2788G>A at adjusted P < 0.10. In a Meishan×Large White (MLW) cross (n = 562) with six trait records available, FR798948:g.2141T>C showed suggestive association with growth (adjusted P = 0.0690). As association mapping conducted in the outbred MLW population is more precise than in the three generation F2 population the UBL5 gene tends to be associated with growth rather than with fat accretion.

Some performance traits of the Calabrian × Large White pig in relation to the housing system (indoor and outdoor): preliminary results

The purpose of the present research was to verify the effect of the “housing system” on some performance traits of the Calabrian × Large White crosses (CA × LW). The research was carried out on 12 subjects of which 7 were housed in “indoor” system and 5 in “outdoor” system. The available area for head was equal to 4.6 m2 for the “indoor” system and 45 m2 per head for the “outdoor” system. The subjects were monitored from birth to slaughter and the following parameters were recorded: weight at typical ages, some relieves at slaughter, fat thickness in three anatomical regions and weight of meat and adipose tissue cuts. Mathematical-statistical elaboration demonstrated that housing system tended to be significant (P &lt; 0.10) only in the case of fat thickness at L6-S region.

Biochemical characterization of meat of Calabrese × Large White pig reared in outdoor or indoor housing system: preliminary results

This work reports some results concerning protein and lipid profiles of pork from 12 subjects of Calabrese Ancient Local Genetic Type (ALGT) × Large White (LW) crosses reared in outdoor or indoor housing system. Aim of this paper is to examine the effect of two housing systems on protein and lipid profiles. Analysis of the proteome of the water soluble fraction (sarcoplasmic) was carried out on meat samples obtained from muscle Caput Longum Tricipitis Brachii (CloTB). The analysis covered a total of 12 samples and 24 two-dimensional gel electrophoresis maps (2 for each sample), which were digitized for subsequent image analysis and used for spot identification by MALDI-TOF mass spectrometry. The comparison of 24 two-dimensional maps was performed by Image Master 2D-Platinum software in order to establish the relative intensity, expressed as vol%, of each spot for each gel. Image analysis produced 12 common spots in all maps analyzed. The housing system did not influence the relative abundance (vol%) of 12 spots detected. These proteins, identified by peptide mass fingerprint, are grouped according to their biological function as metabolic, cellular defense and transport protein. Inter and intra-muscular fatty acid profiles of CloTB was determined by gaschromatography. No significant differences for the fatty acids content were observed between the two housing systems suggesting that intrinsic factors, such as the genetic asset, may be more important than extrinsic factors.

Growth, Carcass and Meat Quality of Casertana, Italian Large White and Duroc x (Landrace x Italian Large White) Pigs Reared Outdoors

To compare growth, skeletal development, carcass traits and meat quality of different genotypes, 10 Casertana (CT), 10 Italian Large White (LW) and 10 Duroc x (Landrace x Italian Large White) (DU) crosses, barrows of 90 days of age, were allotted to the same outdoor rearing and feeding conditions. Live weight was recorded and average daily gain (ADG) was calculated. At slaughter (330-day-old) dressing and lean percentages were determined; backfat thickness and loin eye depth were measured. Carcasses were dissected into commercial cuts. Water holding capacity, pH and colour (45 min and 24 h post-mortem) were measured. Longissimus lumborum muscle samples were collected for cholesterol, α-tochopherol and intramuscular collagen (IMC) analyses. CT compared to DU and LW had the lowest growth rate and skeletal development.Casertana showed higher backfat thickness, lower lean cut/fatty cut ratio and less lean meat (P<0.05). Loin eye depth differed among genotypes with LW>DU>CT (P<0.05). CT showed higher red colour of the meat than DU and LW (P<0.05). CT compared to LW had the highest hydroxylysylpiridinoline (HLP) crosslink concentration and HLP/IMC ratio, and a lower IMC amount (P<0.05). Casertana pigs produced meat that could be tougher than that from the improved breed, but more acceptable from the technological point of view.At eleven months of age bone weight, length and diameter were clearly genetic type-related; differently, the bone maturity was similar among the genotypes studied.

Productive Response of Duroc x Large White and Commercial Hybrid x Large White Crosses Fed High and Low Protein Diets

Thirty five Duroc x Large White (DUxLW) and 43 Commercial Hybrid x Large White (CHxLW) were fed two diets differing for the content of crude protein (CP), with the aim to evaluate the effects of these diets on growth, carcass and thigh traits. Pigs were allotted to two groups and fed high protein (HP) and low protein (LP) diet. Within each dietary group, 3 diets were formulated, for the initial phase of growth (from 79 to 112 days, 17.3% and 15.4% CP as fed basis for the HP and LP diet, respectively), for the intermediated phase of growth (from 113 to 196 days, 15.1% and 13.7% CP as fed basis for the HP and LP diet, respectively) and for the finishing period (from 197 to 272 days, 13.4% and 11.4% CP as fed basis for the HP and LP diet, respectively). HP diets were supplemented with Lysine, LP were supplemented also with Methionine and Threonine. Pigs were slaughtered at nine months of age. Body weight (BW), average daily gain, total feed intake and feed conversion ratio were not affected by diet. Carcass weight, thigh weight, backfat and lean thickness and lean percentage (Fat-O-Meater, FOM) were not affected by dietary treatments, whilst backfat thickness and FOM were significantly higher (P<0.01) in DUxLW and CHxLW pigs genotype respectively. A reduction of about 15% (12% to 17%) of the dietary CP recommended by nutritional requirements does not affect the main productive performances and carcass characteristics of pigs slaughtered at around 160 kg of BW.

Cardiovascular magnetic resonance imaging of isolated perfused pig hearts in a 3T clinical MR scanner

An isolated perfused pig heart model has recently been proposed for the development of novel methods in standard clinical magnetic resonance (MR) scanners. The original set-up required the electrical system to be within the safe part of the MR-room, which introduced significant background noise. The purpose of the current work was to refine the system to overcome this limitation so that all electrical parts are completely outside the scanner room. Four pig hearts were explanted under terminal anaesthesia from large white cross landrace pigs. All hearts underwent cardiovascular magnetic resonance (CMR) scanning in the MR part of a novel combined 3T MR and x-ray fluoroscopy (XMR) suite. CMR scanning included real-time k-t SENSE functional imaging, k-t SENSE accelerated perfusion imaging and late gadolinium enhancement imaging. Interference with image quality was assessed by spurious echo imaging and compared to noise levels acquired while operating the electrical parts within the scanner room. Imaging was performed successfully in all hearts. The system proved suitable for isolated heart perfusion in a novel 3T XMR suite. No significant additional noise was introduced into the scanner room by our set-up. We have substantially improved a previous version of an isolated perfused pig heart model and made it applicable for MR imaging in a state of the art clinical 3T XMR imaging suite. The use of this system should aid novel CMR sequence development and translation into clinical practice.

SNP variation in the promoter of the PRKAG3gene and association with meat quality traits in pig

BackgroundThe PRKAG3 gene encodes the γ3 subunit of adenosine monophosphate activated protein kinase (AMPK), a protein that plays a key role in energy metabolism in skeletal muscle. Non-synonymous single nucleotide polymorphisms (SNPs) in this gene such as I199V are associated with important pork quality traits. The objective of this study was to investigate the relationship between gene expression of the PRKAG3 gene, SNP variation in the PRKAG3 promoter and meat quality phenotypes in pork.ResultsPRKAG3 gene expression was found to correlate with a number of traits relating to glycolytic potential (GP) and intramuscular fat (IMF) in three phenotypically diverse F1 crosses comprising of 31 Large White, 23 Duroc and 32 Pietrain sire breeds. The majority of associations were observed in the Large White cross. There was a significant association between genotype at the g.-311A>G locus and PRKAG3 gene expression in the Large White cross. In the same population, ten novel SNPs were identified within a 1.3 kb region spanning the promoter and from this three major haplotypes were inferred. Two tagging SNPs (g.-995A>G and g.-311A>G) characterised the haplotypes within the promoter region being studied. These two SNPs were subsequently genotyped in larger populations consisting of Large White (n = 98), Duroc (n = 99) and Pietrain (n = 98) purebreds. Four major haplotypes including promoter SNP’s g.-995A>G and g.-311A>G and I199V were inferred. In the Large White breed, HAP1 was associated with IMF% in the M. longissmus thoracis et lumborum (LTL) and driploss%. HAP2 was associated with IMFL% GP-influenced traits pH at 24 hr in LTL (pHULT), pH at 45 min in LTL (pH45LT) and pH at 45 min in the M. semimembranosus muscle (pH45SM). HAP3 was associated with driploss%, pHULT pH45LT and b* Minolta. In the Duroc breed, associations were observed between HAP1 and driploss% and pHUSM. No associations were observed with the remaining haplotypes (HAP2, HAP3 and HAP4) in the Duroc breed. The Pietrain breed was monomorphic in the promoter region. The I199V locus was associated with several GP-influenced traits across all three breeds and IMF% in the Large White and Pietrain breed. No significant difference in promoter function was observed for the three main promoter haplotypes when tested in vitro.ConclusionGene expression levels of the porcine PRKAG3 are associated with meat quality phenotypes relating to glycolytic potential and IMF% in the Large White breed, while SNP variation in the promoter region of the gene is associated with PRKAG3 gene expression and meat quality phenotypes.

Cardiac magnetic resonance imaging of isolated perfused pig hearts in a 3T clinical MR scanner

Purpose: An isolated perfused pig heart model has recently been proposed for the development of novel methods in standard clinical magnetic resonance (MR) scanners. The original set-up required the electrical system to be within the safe part of the MR-room, which introduced significant background noise. The purpose of the current work was to refine the system to overcome this limitation so that all electrical parts are completely outside the scanner room. Methods: four pig hearts were explanted under terminal anaesthesia from large white cross landrace pigs. All hearts underwent cardiovascular magnetic resonance (CMR) scanning in the MR part of a novel combined 3T MR and x-ray fluoroscopy (XMR) suite. CMR scanning included real-time k-t SENSE functional imaging, k-t SENSE accelerated perfusion imaging and late gadolinium enhancement imaging. interference with image quality was assessed by spurious echo imaging and compared to noise levels acquired while operating the electrical parts within the scanner room. Results: imaging was performed successfully in all hearts. The system proved suitable for isolated heart perfusion in a novel 3T XMR suite. No significant additional noise was introduced into the scanner room by our set-up. Conclusions: We have substantially improved a previous version of an isolated perfused pig heart model and made it applicable for MR imaging in a state of the art clinical 3T XMR imaging suite. The use of this system should aid novel CMR sequence development and translation into clinical practice.

Association analyses of porcine SERPINE1 reveal sex‐specific effects on muscling, growth, fat accretion and meat quality

The serpin peptidase inhibitor, clade E (nexin, plasminogen activator inhibitor type 1), member 1 (SERPINE1) gene encodes plasminogen activator inhibitor type 1 (PAI), which is the major physiological inhibitor of tissue-type and urokinase-type plasminogen activators and plays a role in obesity and insulin resistance in women but not in men. We detected SNP FN396538:g.566G>A in intron 3 and a non-synonymous substitution NM_213910:c.612A>G in exon 3 (p.Ile159Val) and mapped the gene to position 8.4 cM on the linkage map of chromosome 3. Association analyses were conducted on the 12th-15th generation of the Meishan × Large White (MLW) cross (n = 565), with records for weight at the end of test, lifetime daily gain, test time daily gain, loin depth and backfat depth, as well as on a European wild boar × Meishan (W × M) F(2) population (n = 333) with 47 traits recorded for carcass composition and meat quality. Analyses performed across the entire MLW population or in the male animals did not show any trait significantly associated with the loci studied. In female animals, both SNPs were associated with loin depth at nominal P < 0.05 with adjusted P values equal to 0.051 (g.566) and 0.057 (c.612). Differences between homozygotes were up to 0.65 SD. In the entire W × M population and female animals, SERPINE1 was significantly associated at adjusted P < 0.05 in descending order with muscling, growth and fat accretion and in male animals with meat quality (R-value). In the studied populations, allele effects were in opposite directions, which implies that the SNPs are markers that are in linkage disequilibrium with a causative mutation.

Porcine insulin receptor substrate 4 (IRS4) gene: cloning, polymorphism and association study

Using PCR and inverse PCR techniques we obtained a 4,498 bp nucleotide sequence FN424076 encompassing the complete coding sequence of the porcine insulin receptor substrate 4 (IRS4) gene and its proximal promoter. The 1,269 amino acid porcine protein deduced from the nucleotide sequence shares 92% identity with the human IRS4 and possesses the same domains and the same number of tyrosine phosphorylation motifs as the human protein. We detected substitution FN424076:g.96C<G in the promoter region that segregates in Meishan and a synonymous substitution FN424076:g.1829T<C in the coding sequence with allele C present only in Meishan. Linkage mapping placed the IRS4 gene at position 82 cM on the current USDA-USMARC linkage map of porcine chromosome X. Association analyses were performed on 555 animals of 12th-15th generation of the Meishan × Large White cross and showed that both SNPs were highly significantly associated with backfat depth (P=0.0005) and that the SNP FN424076:g1829T<C was also associated with loin depth (P=0.017). The Meishan alleles increased back fat depth and decreased loin depth. IRS4 can be considered a positional candidate gene for at least some of the QTL located at the centromeric region of porcine chromosome X.

A novel porcine gene, USP7, differentially expressed in the musculus longissimus from Wujin and Large White pigs

The mRNA differential display technique was performed to investigate differences in the gene expression in the &lt;I&gt;musculus longissimus&lt;/I&gt; from Wujin and Large White pigs. A fragment of one differentially expressed gene was isolated and sequenced. A complete cDNA sequence was obtained using the rapid amplification of cDNA ends (RACE) method. The sequence prediction analysis revealed that the open reading frame of this gene encodes a protein of 1 103 amino acids, which is homologous with the ubiquitin specific peptidase 7 (&lt;I&gt;USP7&lt;/I&gt;) of four species, rat (identity 98%), human (98%), mouse (98%) and chicken (95%), so it can be defined as the porcine &lt;I&gt;USP7&lt;/I&gt; gene. The differences in the USP7 gene expression in muscles from Wujin and Large White pigs were confirmed using semi-quantitative RT-PCR. The gene expression analysis in eight tissues of a Wujin × Large White cross showed that &lt;I&gt;USP7&lt;/I&gt; was expressed in all the tissues, except for fat.

Crossbreeding of large white and Nsukka local pigs: Genotype and age are related changes in haematological parameters

5-Blood samples from 80 pigs of 4 genotypes - the Nsukka local (Lo), the exotic Large White (LW), the one-way F 1 (LW x Lo) and the F 2 crosses belonging to 5 age groups, were analyzed, to determine the mean values of the haematological parameters in the genotypes and different age groups and to check if and how the values are altered by crossbreeding. The local pigs had significantly (P<0.05) higher haemoglobin (Hb, 11.64 g/100 ml), packed cell volume (PCV, 47.00%), red blood cells (RBC, 7.06 x 10 6 /mm 3 ), white blood cells (WBC, 16.50 x 10 3 /mm3) and lymphocytes (61.45%) than the Large White (LW - 10.77g/100ml, 41.55%, 6.26 x 10 6 /mm 3 , 10.65 x l10 3 /mm 3 and 50.59%, respectively), with Fl and F2 crosses intermediate in values. The mean corpscular heamoglobin (MCH), the mean corpuscular heamoglobin concentration (MCHC), monocytes, neutrophils and corpuscular were highest in the LW (17.26 u2g, 25.92%, 6.60%, 39.05%, and 5.20%, respectively) and the lowest in the Lo (16.5 u2g, 24.59%, 4.8%, 30.90% and 2.45%, respectively), with Fl and F2 intermediate. The LW, Lo and Fl were similar in mean corpuscular volume (MCV). There were significant (P<0.05) increases in Hb, PCV, RBC, WBC, lymphocytes and eosinophils with age. However, significant genotype x age interactions were found for RBC, MCH, WBC, lymphocytes, monicytes and eosinophils which limit the inferences made on the main effects. Heterosis estimates based on the one-way Fl were zero, negative or low for most of the parameters. It was concluded that the blood parameters studied are heritable and that additive gene action was important in their inheritance, suggesting that they should respond to selective breeding. Key words: Crossbreeding, genotype, age, blood parameters, pigs

Performance and Linear Measurements of Growing Pigs Fed on Basis of Their Body Weight

The performance of growing pigs fed on basis of percentage of their body weight was evaluated using twenty four growing pigs of Landrace x Large White crosses weighing averagely 35±0.5 kg at the start of the study. The pigs were assigned to four treatments and each treatment was replicated thrice with two pigs per replicate in a Completely Randomized Design. An 18% CP and 11.82 MJME/kg diet was formulated and fed at levels of 10, 8, 6 and 4% of body weights in treatments 1, 2, 3 and 4 respectively. The feeding trial lasted for 56 days. Results showed that treatment effect on the response parameters were significant (P<0.05). As percentage of body weight feeding reduced, final body weight of the pigs increased significantly (P<0.05). Pigs on treatments 2, 3 and 4 had a final body weight of 68.64, 67.62, 67.68 kg respectively which differed from the 60.03 kg observed for pigs on treatment 1. Pigs fed 4% of their body weight (Treatment 4) showed superiority in the response parameters. Pigs on Treatment 4 had a feed cost/kg gain value of 79.56 naira which differed significantly from 263.21 naira, 161.78 naira and 120.67 naira recorded for pigs on T , 1 T and T respectively. Linear body measurement of the pigs followed the same trend as observed in the 2 3 other response parameters. Pigs on T recorded the highest significant (P<0.05) changes in chest girth, 4 height at withers and body length. It is concluded that feeding growing pigs at level of 4% of their body weight leads to optimum performance and better economic returns.

Effects of porcine reproductive and respiratory syndrome virus infection on the performance of commercial sows and gilts of different parities and genetic lines

Objectives: To examine the parity and genetic-line differences and trends for major sow reproductive traits during an outbreak of porcine reproductive and respiratory syndrome (PRRS) and to determine whether specific parities or genetic lines are more severely affected by PRRS virus. Materials and methods: Reproductive performance data (gestation length, total piglets in utero, total piglets born alive, total piglets born dead, total mummified piglets born, total stillborn, and total weaned) were obtained from a commercial herd in China (8098 litters from 1820 sows) from differing genetic lines (Landrace, Large White, Pietrain, Meishan, Duroc composite, and various crosses). The dataset was partitioned into a baseline and a disease phase. Statistical analysis compared performance differences between these two phases for sows of different parities and lines. Results: PRRS caused significant production losses, impacting most reproductive traits. However, the impacts were greater in early parities, eg, the numbers of mummified piglets per litter were greater for sows of lower parities (1 through 5) than older sows (parities 6 through 11), for which there were no differences between disease and baseline data. Line differences and interactions were also detected, highlighting a greater impact of PRRS virus on the Meishan line than on their European counterparts. Implications: Parity should be considered when examining host genetic resistance to PRRS virus and when designing management strategies. The Meishan line may be more susceptible to reproductive PRRS. The use of the Meishan-type line to impact fecundity traits in a disease situation should be reconsidered.