Swine Production and Challenges in Vietnam after African Swine Fever: A Case Study in Peri-Urban Hanoi, Vietnam

The goal of this paper was to identify major challenges in rebuilding the swine industry in Vietnam, using the Chuong My district, Hanoi as a case study. Primary data was gathered in 2020 mainly through a survey of 97 swine producers in the district. Analysis tools were descriptive and comparative statistics. Results show that after the ASF outbreak, the recovery of the swine industry in Vietnam faced several challenges, including the issues of piglet quantity and quality, changing consumer preferences which were worsened by the current Covid-19 pandemic, relatively cost disadvantage of domestic production under the context of new free trade agreements, disease risk (ASF under the condition of no effective and safe vaccine), insufficient resources of farms to restock, and environmental issues caused by swine production in rural areas. The paper proposed several recommendations to rebuilding the swine herd in order to address the issues and overcome the challenges, mainly focus on improving sow quality, market information and linkages, good practices in production, training for labor, and address environmental issues.

Draft Genome Sequences of Two Virulent Streptococcus equi subsp. zooepidemicus Swine Isolates from Pennsylvania

ABSTRACT Draft genome sequences of two outbreak isolates of Streptococcus equi subsp. zooepidemicus from a Pennsylvania swine herd affected with high mortality and morbidity are reported here. The genome analysis revealed that the isolates are closely related to a virulent strain originally identified in China.

Atypical Porcine Pestivirus Circulation and Molecular Evolution within an Affected Swine Herd

Atypical porcine pestivirus (APPV) is a single-stranded RNA virus from the family Flaviviridae, which is linked to congenital tremor (CT) type A-II in newborn piglets. Here, we retrospectively investigated the molecular evolution of APPV on an affected herd between 2013 and 2019. Monitoring was done at regular intervals, and the same genotype of APPV was found during the entire study period, suggesting no introductions from outside the farm. The nucleotide substitutions over time did not show substantial amino acid variation in the structural glycoproteins. Furthermore, the evolution of the virus showed mainly purifying selection, and no positive selection. The limited pressure on the virus to change at immune-dominant regions suggested that the immune pressure at the farm might be low. In conclusion, farms can have circulation of APPV for years, and massive testing and removal of infected animals are not sufficient to clear the virus from affected farms.

Comparison of four serological tests for the diagnosis of swine brucellosis

The purpose of this article is to present results of a research in which the results of four serological tests were compared for the diagnosis of swine brucellosis in pigs from Brazilian herds in which the outbreak occurred in relation to other brucellosis-free. Rose Bengal (RBT), complement fixation (CFT), agglutination plus 2-mercaptoethanol test (TAT+ME), and commercial fluorescence polarization assay (FPA) were used to test 333 sera (271 sows and 62 finishing pigs) from a Brucella suis infected swine herd and 1,100 swine sera from brucellosis free pigs taken at a slaughterhouse. Considering infected all the 271 sows from the outbreak, and interpreting results of the FPA according to the manufacturer directions, sensitivities observed were 95.94% for FPA, 94.83% for RBT, 93.73% for CFT, and 92.25% for TAT+ME. Considering infected all the pigs from the infected herd with a positive result in at least one test, sensitivities observed were 98.92% for RBT, 97.13% for CFT, 96.06% for FPA, and 94.98% for TAT+ME. Specificities of the tests were CFT and TAT+ME, 100%; FPA, 99.55%; and RBT 99.27%. Results indicated a good performance of all the tests, and the agreement among them was almost perfect.

Full genome sequence analysis of a 1-7-4-like PRRSV strain in Fujian Province, China

PRRS virus (PRRSV) has undergone rapid evolution and resulted in immense economic losses worldwide. In the present study, a PRRSV strain named FJ0908 causing high abortion rate (25%) and mortality (40%) was detected in a swine herd in China. To determine if a new PRRSV genotype had emerged, we characterized the genetic characteristics of FJ0908. Phylogenetic analysis indicated that FJ0908 was related to 1-7-4-like strains circulating in the United States since 2014. Furthermore, the ORF5 sequence restriction fragment length polymorphism (RFLP) pattern of FJ0908 was 1-7-4. Additionally, FJ0908 had a 100 aa deletion (aa329–428) within nsp2, as compared to VR-2332, and the deletion pattern was consistent with most of 1-7-4 PRRSVs. Collectively, the data of this study contribute to the understanding of 1-7-4-like PRRSV molecular epidemiology in China.

The impact of dietary supplementation of arginine during gestation in a commercial swine herd: II. Offspring performance

Arginine (Arg) is an important amino acid of pig fetal development; however, whether Arg improves postnatal performance is ill-defined. Therefore, the influence of Arg supplementation at different gestational stages on offspring performance was evaluated in a commercial swine herd. Sows (n = 548) were allocated into 4, diet by stage of gestation treatments: Control (n = 143; 0% suppl. Arg), or dietary treatments supplemented with 1% L-Arg (free-base; Ajinomoto Animal Nutrition North America, Inc., Chicago, IL): from 15 to 45 d of gestation (n = 138; Early-Arg); 15 d of gestation to farrowing (n = 139; Full-Arg); and from day 85 of gestation to farrowing (n = 128; Late-Arg). All offspring were individually identified and weighed at birth; at weaning, a subset was selected for evaluation of carcass performance at market. All data were analyzed using birth weight (BiWt) and age as covariates. Wean weights (WW) and prewean (PW) ADG tended to increase (P = 0.06) in progeny from sows supplemented with Arg, as compared to progeny from Control sows. Preplanned contrast comparisons revealed an increased (P = 0.03) BiWt for pigs from sows receiving 1% L-Arg prior to day 45 of gestation (Early-Arg and Full-Arg; 1.38 kg/pig), as compared to pigs from sows not supplemented prior to day 45 of gestation (Control and Late-Arg; 1.34 kg/pig). No difference in BiWt was observed (1.36 kg/pig; P = 0.68) for Arg supplementation after day 85 of gestation (Full-Arg and Late-Arg), as compared to those not receiving Arg supplementation after day 85 (Control and Early-Arg); although WW and PW ADG were greater (P = 0.02), respectively. A 3.6% decrease (P = 0.05) in peak lean accretion ADG occurred when dams received 1% L-Arg prior to day 45 of gestation (Early-Arg and Full-Arg), however, no other significant differences were detected in finishing growth parameters or carcass characteristics (P ≥ 0.1). Pig mortality rates tended (P = 0.07) to decrease in progeny of dams supplemented Arg after day 85 (3.6%) compared to dams not provided additional Arg during late gestation (4.9%). Collectively, these data suggest that Arg provided during late gestation may improve WW and PW ADG, however, finishing performance was not affected. While Arg supplementation provided some moderate production benefits, further investigation is warranted to comprehensively understand the gestational timing and biological role of Arg supplementation during fetal and postnatal development in commercial production systems.

The impact of dietary supplementation of arginine during gestation in a commercial swine herd: I. Gilt reproductive performance

Supplemental arginine (Arg) during gestation purportedly benefits fetal development. However, the benefits of a gestational Arg dietary strategy in commercial production are unclear. Therefore, the objectives of this study examined Arg supplementation during different gestational stages and the effects on gilt reproductive performance. Pubertal gilts (n = 548) were allocated into 4 treatment groups: Control (n = 143; 0% supplemental Arg) or 1 of 3 supplemental Arg (1% as fed) treatments: from 15 to 45 d of gestation (n = 138; Early-Arg); from 15 d of gestation until farrowing (n = 139; Full-Arg); or from 85 d of gestation until farrowing (n = 128; Late-Arg). At farrowing, the number of total born (TB), born alive (BA), stillborn piglets (SB), mummified fetuses (MM), and individual piglet birth weights (BiWt) were recorded. The wean-to-estrus interval (WEI) and subsequent sow reproductive performance (to third parity) were also monitored. No significant effect of supplemental Arg during any part of P0 gestation was observed for TB, BA, SB, or MM (P ≥ 0.29). Offspring BiWt and variation among individual piglet birth weights did not differ (P = 0.42 and 0.89, respectively) among treatment groups. Following weaning, the WEI was similar among treatments (average of 8.0 ± 0.8 d; P = 0.88). Litter performance over 3 parities revealed a decrease (P = 0.02) in BA for Early-Arg fed gilts compared with all other treatments, whereas TB and WEI were similar among treatments over 3 parities (P > 0.05). There was an increased proportion of sows with average size litters (12 to 16 TB) from the Full-Arg treatment sows (76.8% ± 3.7%) when compared with Control (58.7% ± 4.2%; P = 0.01); however, the proportion of sows with high (>16 TB) and low (<12 TB) litters was not different among treatments (P = 0.20). These results suggest that gestational Arg supplementation had a minimal impact on reproductive performance in first parity sows. These data underscore the complexity of AA supplementation and the need for continued research into understanding how and when utilizing a gestational dietary Arg strategy can optimize fetal development and sow performance.

Identification of Marbling Gene Loci in Commercial Pigs in Canadian Herds

We examined the amount of marbling and tested the genome of boars from 5 breeds of Duroc, Iberian, Lacombe, Berkshire and Pietrian that were commercially available for a swine herd in Canada. The marbling was ranked according to the amount of intramuscular fat % obtained in loin chops consisting of the longissimus dorsi muscle. The genetics were analysed by genome wide association study using 80,000 single nuclear polymorphism (SNP) microarrays. Our samples had pork that achieved > 7 % IMF from 110kg animals. Meta-analysis revealed SNP markers that were associated with the highest marbled pork chops on chromosomes 5, 7, and 16. Using the susScr 11.1 map, we determined that the nearest genes were SSNP, Rh glycoprotein and EGFLAM. We tested a sub-population of Duroc sired animals and found a different set of markers close to GRLB and KCNJ3 on chromosomes 8 and 15. Based on our sample, we can achieve pork with good marbling from animals conventionally raised to standard market weights of 110kg. The choice of a good marbling line of pig is not necessarily breed specific.