An epidemiological investigation into the association between biomarkers and growth performance in nursery pigs

Comparative analysis of productive performance and fattening efficiency of commercial pigs in China for two consecutive years

THE PURPOSE OF THIS STUDY

(1) propose an evaluation indicator of the fattening efficiency of commercial pigs (Yorkshire × Landrace × Duroc)-fattening efficiency index (FEI). (2) Analyze the correlation to find the main productive factors affecting the FEI. (3) Compare and analyze the yearly/monthly/different piglets' sources of productive performance in 2020 and 2021. The data included 2592 commercial pig batches in 2020 and 3266 in 2021, with a total of 6,134,234 commercial pigs. Descriptive statistics and difference analysis were carried out on 16 productive factors of a whole year and single/multiple sources for two consecutive years. The same period difference between the monthly data and the annual average were also analyzed. The top six productive factors correlated with FEI were average daily gain (ADG) (0.8080), feed conversion rate (FCR) (- 0.7203), survival rate (SR) (0.6968), number of deaths (- 0.4103), feeding days (- 0.3748) and body weight (BW) of marketing pigs (0.3369). The overall productive performance in 2021 was lower than that in 2020, which was reflected in more piglet sources and a lower BW of piglets, more deaths, a lower SR, longer feeding days, a lower ADG, a higher FCR and a lower FEI. The productive performance of a single source was better than that of multiple ones. The contrastive results of monthly data in 2020 and 2021 showed significant differences in most factors except for the number of marketing pigs, the number of piglets and feed consumption. The monthly trend of 15 factors for two consecutive years revealed similar trends only in the month of piglets purchasing, number of piglets sources, number of deaths and ADG. Compared with the annual average, the ADG significantly increased in May. The FEI of multiple sources was markedly lower than that of a single source. FEI may be suitable for evaluating the fattening efficiency of commercial pigs. The annual and monthly productive performance and fattening efficiency in 2021 were significantly lower than those in 2020. Single source was represented better productive performance and fattening efficiency than multiple ones.

The Novel Structural Variation in the GHR Gene Is Associated with Growth Traits in Yaks (Bos grunniens)

The growth hormone receptor (GHR) is a member of the cytokine/hematopoietic factor receptor superfamily, which plays an important role in the growth and development, immunity, and metabolism of animals. This study identified a 246 bp deletion variant in the intronic region of the GHR gene, and three genotypes, including type II, type ID, and type DD, were observed. Genotype analysis of structural variation (SV) was performed on 585 individuals from 14 yak breeds, and it was found that 246 bp deletion was present in each breed. The II genotype was dominant in all yak breeds except for SB yak. The association analysis of gene polymorphisms and growth traits in the ASD yak population showed that the 246 bp SV was significantly associated with body length at 6 months (p < 0.05). GHR messenger RNA (mRNA) was expressed in all the tested tissues, with significantly higher levels in the liver, muscle, and fat than in other organs. The results of transcription activity showed that the luciferase activity of the pGL4.10-DD vector was significantly higher than that of the pGL4.10-II vector (p < 0.05). Additionally, the transcription-factor binding prediction results showed that the SV in the runt-related transcription factor 1 (Runx1) transcription-factor binding site may affect the transcriptional activity of the GHR gene, regulating yak growth and development. This study showed that the novel SV of the GHR gene could be used as a candidate molecular marker for the selection of the early growth trait in ASD yak.

Study on the effect of seasonal variation on expression of serum biochemicals in pigs

Pigs are particularly susceptible to heat stress because of their more sub-cutaneous fat with little or non-functional sweat glands. Pigs depend on panting as primary mechanism of heat dissipation and/or wallowing. Therefore, a study was conducted to generate basic information on certain blood biochemicals of pigs reared in high humid climatic condition. For the purpose, blood samples were collected randomly from 400 female pigs (6–12 month of age) during summer and winter of the year. The analysis of THI has shown an increase in the study area since 2012 to 2018. The hematological study of the pigs revealed a variation in respect of Hb and TEC with the season. Estimation of different enzymes showed increase with the increase of THI. The activity of enzyme, hormones except leptin was accelerated. Expression of IGF 1, HSP 70 and HSP 90 was also affected with the change of THI. The level of Kisspeptin and FSH β receptor showed difference between two seasons of the year. However, the level of Kisspeptin and FSH β receptor in serum of the experimental animals was found to be insufficient to initiate puberty till 12 months of age. It can be concluded that the pigs reared in semi-intensive system under high humid climatic condition did not attain puberty up to one year of age.

Effects of duration of betaine supplementation on growth performance and blood IGF-1 in light- and normal-weight weaner pigs under commercial conditions

Context Betaine supplementation has been reported to increase insulin-like growth factor 1 (IGF-1) in pigs. Betaine is not generally added to weaner pig diets due to a lack of knowledge on the duration of supplementation and effect on targeted bodyweight class. Light-weight weaners, known for their inferior growth performance, may benefit from betaine supplementation during the early days post-weaning. Aims This experiment aimed to identify the timing of betaine supplementation over the weaner phase (early (0–7 days) or late (7–35 days) post-weaning periods) and targeted weaning weight class (light vs normal). Methods The experiment followed a 2 × 2 × 2 factorial arrangement for studying the effects of 0.1% betaine supplementation during early (0–7 days post-weaning) and late (7–35 days post-weaning) weaner phase in light-weight and normal-weight weaners. One hundred and forty-four pens (18 pigs/pen) of weaned pigs (26 days age) were allocated into a 2 × 2 × 2 factorial arrangement on the basis of weaning weight class ((light (3.6 ± 0.75 kg, mean ± s.d.) vs normal (6.6 ± 0.84 kg, mean ± s.d.)), early weaner phase diet (control vs 0.1% betaine) and late weaner phase diet (control vs 0.1% betaine). Basal diets contained sufficient methionine and choline as per industry practice. Growth performance during early, late and whole weaner phase were recorded. Blood IGF-1 was measured at 7 days and 35 days post-weaning. Key results Supplementing 0.1% betaine during the early weaner phase reduced (P &lt; 0.05) growth rate over the early post-weaning period (0–7 days) in both light- and normal-weight weaners, although blood IGF-1 concentration (7 days post-weaning) was not affected. Betaine supplementation during early or late weaner phase did not affect growth performance over the late weaner phase (7–35 days), whole weaner phase (0–35 days) or blood IGF-1 concentration (35 days) of light- or normal-weight weaners. Light-weight weaners had a lower feed intake, and a lower average daily gain than did the normal-weight weaners during the early, late and whole post-weaning periods (all P &lt; 0.01). Conclusions Light-weight weaners had inferior production performance during the weaner phase, which was not improved by betaine supplementation. Implications Betaine supplementation is not recommended in the weaner phase when other dietary methyl donors are sufficient.

Serial Optical Coherence Tomography at Baseline, 7 Days, and 1, 3, 6 and 12 Months After Bioresorbable Scaffold Implantation in a Growing Porcine Model

BACKGROUND

Little is known about serial changes in lumen and device dimensions after bioresorbable scaffold implantation in a growing animal model. Methods and Results: ABSORB (n=14) or bare metal stents (ICROS amg [Abbott Vascular, Santa Clara, CA, USA], Winsen-Luhe, Germany; n=15) were implanted in the coronary arteries of domestic swine (a hybrid of Finnish-Norwegian Landrace swine) weighing 30-35 kg. Angiography and optical coherence tomography (OCT) were performed immediately after implantation and repeated at 7 days, 1, 3, 6 and 12 months after the index procedure. One month after implantation, mean lumen area decreased relative to baseline in both groups (relative area change from baseline, -41.4±15.6% for ABSORB vs. -20.9±18.6% for ICROS) while mean device area decreased only in the ABSORB group (relative area change: -11.1±9.4% vs. +0.14±7.95%, respectively). At 12 months, mean lumen area increased relative to baseline in both groups (relative area change from baseline, +55.6±22.4% vs. +32.3±83.6%, respectively) in accordance with the swine growth weighing up to 260-300 kg. Mean device area in the ICROS group remained stable whereas that in the ABSORB group began to increase between 3 and 6 months along with the vessel growth (relative area change: +107.8±25.7% vs. +0.14±7.95%).

CONCLUSIONS

In the growing porcine model, ABSORB was associated with greater extent of recoil 1 month after implantation compared with ICROS but demonstrated substantial adaptability to vessel growth in late phase.

Nutrient digestibility, organ morphometry and performance in vaccinated or non-vaccinated Lawsonia intracellularis infected piglets

Background

Lawsonia intracellularis is one of the world’s most important infectious diseases in pork production with regard to economic losses. So far, studies are missing that describe the effects of a natural infection of piglets on the digestibility of nutrients, possible effects on performance and the morphometrics of the intestine depending on whether piglets are vaccinated, clinically healthy or clinically affected with regard to Lawsonia intracellularis induced diarrhoea.

Results

Digestibility studies were performed on a total of 27 eight-week-old piglets with naturally occurring Lawsonia intracellularis infection in a trial with three repetitions. Nine out of 27 animals were vaccinated as suckling pigs with a commercial Lawsonia intracellularis vaccine (vac; Enterisol®Ileitis). Half of the remaining 18 animals were without clinical signs of infection (non-vac/cs-), half showed moderate clinical signs of Lawsonia intracellularis induced diarrhoea (non-vac/cs+). All three groups were fed one identical complete diet ad libitum. Faecal shedding of Lawsonia intracellularis was found in all groups (25 out of 27 animals). Numerically, the mean excretion in the group non-vac/cs + (7.69 ± 1.65 log₁₀ copies/ g faeces) was higher in comparison to the group non-vac/cs- (5.83 ± 2.35 log₁₀ copies/ g faeces) and vaccinated animals (vac: 6.00 ± 2.89log₁₀ copies/ g faeces). The average daily weight gain (ADG; Ø 8.66 day period) differed significantly (vac: 894^a ± 73.3, non-vac/cs-: 857^ab ± 86.3, non-vac/cs+: 785^b ± 137 g/day). The apparent total tract digestibility (ATTD) of nitrogen was significantly lower in clinically affected animals (vac: 83.0^a ± 1.72, non-vac/cs-: 83.9^a ± 2.03, non-vac/cs+: 80.7^b ± 2.57).The total length of the small intestine in clinically affected animals increased significantly (vac: 15.9^ab ± 1.57, non-vac/cs-: 14.6^b ± 1.12, non-vac/cs+: 16.2^a ± 1.37 m). The relative body weight depending on the length of the small intestine was lower for clinically affected animals (vac: 1.72^a ± 0.21, non-vac/cs-: 1.83^a ± 0.17, non-vac/cs+: 1.56^b ± 0.12 kg/m).

Conclusion

These studies show that clinically moderate L. intracellularis infections lead to significantly lower ADGs in comparison to vaccinated animals. The disease is also found in altered intestinal morphometry and reduced total N digestibility if clinical signs occur.

Selection for growth rate and body size have altered the expression profiles of somatotropic axis genes in chickens

The growth hormone / insulin-like growth factor-1 (GH/IGF-1) pathway of the somatotropic axis is the major controller for growth rate and body size in vertebrates, but the effect of selection on the expression of GH/IGF-1 somatotropic axis genes and their association with body size and growth performance in farm animals is not fully understood. We analyzed a time series of expression profiles of GH/IGF-1 somatotropic axis genes in two chicken breeds, the Daweishan mini chickens and Wuding chickens, and the commercial Avian broilers hybrid exhibiting markedly different body sizes and growth rates. We found that growth rate and feed conversion efficiency in Daweishan mini chickens were significantly lower than those in Wuding chickens and Avian broilers. The Wuding and Daweishan mini chickens showed higher levels of plasma GH, pituitary GH mRNA but lower levels of hepatic growth hormone receptor (GHR) mRNA than in Avian broilers. Daweishan mini chickens showed significantly lower levels of plasma IGF-1, thigh muscle and hepatic IGF-1 mRNA than did Avian broilers and Wuding chickens. These results suggest that the GH part of the somatotropic axis is the main regulator of growth rate, while IGF-1 may regulate both growth rate and body weight. Selection for growth performance and body size have altered the expression profiles of somatotropic axis genes in a breed-, age-, and tissue-specific manner, and manner, and alteration of regulatory mechanisms of these genes might play an important role in the developmental characteristics of chickens.