Jun Bao

Effects of prior cold stimulation on inflammatory and immune regulation in ileum of cold-stressed broilers

ABSTRACT Acclimation can alleviate the negative impacts of adverse environmental factors on an organism. To investigate the effects of prior cold stimulation on inflammatory and immune regulation in ileum of cold‐stressed broilers, 360 1‐d‐old chicks (Arbor Acres) were divided into 3 groups (G1, G2, G3) and raised at normal (thermal comfort) temperatures during 1 to 7 d. From 8 d, G1 (control) continued to be raised at normal temperatures, whereas G2 and G3 (treatments) were cold‐stimulated at 3°C and 12°C, respectively, below the temperature of G1, but not below 17°C (reached at 32 d in G2 and 14 d in G3). At 42 d, all the groups were subjected to a 24‐h acute cold stress of 7°C, designated as S1, S2, and S3. Ileum tissues and serum of the birds were collected at 42 d and 43 d to detect the levels of pro‐inflammatory and immune‐related factors as well as morphology changes. At 42 d, ileum of G1 and G2 had intact morphological structure and clear outline, with no differences in levels of iNOS, NF‐&kgr;B, COX‐2, PTGEs, TNF‐&agr;, IFN‐&ggr;, or IL‐4 (P > 0.05). G3 ileum suffered inflammatory injuries, with levels of iNOS, COX‐2, PTGEs, TNF‐&agr;, and IL‐4 being higher than those of G1 (P < 0.05). At 43 d, compared with G1, S1 had severely damaged ileum, increased levels of iNOS, NF‐&kgr;B, COX‐2, PTGEs, TNF‐&agr;, and IL‐4 (P < 0.05), but decreased level of IFN‐&ggr; (P < 0.05). The morphological structure of S2 was intact, and there were no differences between G2 and S2 in levels of NF‐&kgr;B, PTGEs, TNF‐&agr;, IFN‐&ggr;, or IL‐4 (P > 0.05). Compared with S1, S2 had decreased levels of iNOS, NF‐&kgr;B, COX‐2, PTGEs, TNF‐&agr;, and IL‐4 (P < 0.05), but increased level of IFN‐&ggr; (P < 0.05). There were no differences between G1 and S2 in levels of NF‐&kgr;B, PTGEs, TNF‐&agr;, IFN‐&ggr;, or IL‐4 (P > 0.05). The results demonstrate that a 3°C‐lower‐than‐normal temperature stimulation of the broilers from 8 to 42 d led to cold acclimation. This prior cold acclimation effectively alleviated elevation of pro‐inflammatory cytokines and Th1/Th2 imbalance of the birds induced by subsequent cold stress.

The relationship of PLR to stereotypic behaviors and neurotransmitters in sows

ABSTRACT This study aimed to validate the relationship between pupillary light reflex (PLR) and stereotypic behaviors or serum neurotransmitters in confined sows. Eight long PLR latency (LL) sows (reaction time ≥10 seconds) and 8 short PLR latency (SL) sows (time of PLR <10 seconds) were selected from 334 sows, and their stereotypic behaviors and neurotransmitters (dopamine [DA] and 5‐hydroxytryptamine [5‐HT]) in blood serum were measured. The results showed that both LL and SL sows showed no significant differences in lying, standing, and rooting behaviors (P > 0.05). Sitting in LL sows was significantly higher (P ≤ 0.05), and grooming was lower in frequency (P < 0.05) than SL sows. For mouth‐related behaviors, no difference was found for bar‐biting between the 2 sow groups (P > 0.05), but trough‐biting and sham‐chewing in LL sows were higher than for SL sows (P ≤ 0.05). However, DA and 5‐HT levels were higher in LL sows than SL sows (P = 0.05 and P = 0.02, respectively). The results also indicated that bar‐biting was negatively correlated with 5‐HT levels (r = 0.542; P < 0.01) and sham‐chewing was positively correlated with 5‐HT levels (r = 0.582; P < 0.01), whereas trough‐biting behavior was positively correlated to DA levels (r = 0.499; P = 0.01). The results of this study suggest that sows PLR is related to serum neurotransmitters and stereotypic behaviors and that the prolonged latency of PLR might have potential to be indicator of chronic stress or depression.

Effects of Feeding Corn-lablab Bean Mixture Silages on Nutrient Apparent Digestibility and Performance of Dairy Cows

This study estimated the fermentation characteristics and nutrient value of corn-lablab bean mixture silages relative to corn silages. The effects of feeding corn-lablab bean mixture silages on nutrient apparent digestibility and milk production of dairy cows in northern China were also investigated. Three ruminally cannulated Holstein cows were used to determine the ruminal digestion kinetics and ruminal nutrient degradability of corn silage and corn-lablab bean mixture silages. Sixty lactating Holstein cows were randomly divided into two groups of 30 cows each. Two diets were formulated with a 59:41 forage: concentrate ratio. Corn silage and corn-lablab bean mixture silages constituted 39.3% of the forage in each diet, with Chinese wildrye hay constituting the remaining 60.7%. Corn-lablab bean mixture silages had higher lactic acid, acetic acid, dry matter (DM), crude protein (CP), ash, Ca, ether extract concentrations and ruminal nutrient degradability than monoculture corn silage (p<0.05). Neutral detergent fiber (NDF) and acid detergent fiber (ADF) concentrations of corn-lablab bean mixture silages were lower than those of corn silage (p<0.05). The digestibility of DM, CP, NDF, and ADF for cows fed corn-lablab bean mixture silages was higher than for those fed corn silage (p<0.05). Feeding corn-lablab bean mixture silages increased milk yield and milk protein of dairy cows when compared with feeding corn silage (p<0.05). The economic benefit for cow fed corn-lablab bean mixture silages was 8.43 yuan/day/cow higher than that for that fed corn silage. In conclusion, corn-lablab bean mixture improved the fermentation characteristics and nutrient value of silage compared with monoculture corn. In this study, feeding corn-lablab bean mixture silages increased milk yield, milk protein and nutrient apparent digestibility of dairy cows compared with corn silage in northern China.

Positive or negative emotion induced by feeding success or failure can affect behaviors, heart rate and immunity of suckling calves

This study investigated behavioral and physiological responses of suckling calves to either positive or negative situations. Twelve healthy female suckling Holstein calves at approximately 30u202fdays of age were randomly selected and allocated to two groups: a) a positive situation (POS) group that received a feed reward and b) a negative situation (NEG) group that experienced food frustration. Behavior, heart rate (HR), and immune parameters were measured during the emotion-inducing periods and analyzed via ANOVA. The results indicated that the POS calves showed significantly increased locomotive play but decreased self-grooming, head shaking, and tongue-rolling behaviors as compared to the NEG counterparts (pu202f<u202f.05). The NEG calves had the highest HR (pu202f<u202f.01) after negative emotion induction. Salivary cortisol (S-CORT) level significantly increased following both positive and negative emotional induction (pu202f<u202f.05). In humoral immunity, serum concentrations of IgA were not significantly affected by either the positive or negative situation (pu202f>u202f.05), but the salivary SIgA level of the POS calves was higher than that of the NEG group (pu202f<u202f.01). Serum IL-2 and IL-3 levels in the POS calves were significantly higher than those of the NEG group (pu202f<u202f.01). However, the serum TNF-α level in the POS group was significantly lower than in the NEG group (pu202f<u202f.05). The results suggest that hunger satiation or food frustration may induce different behavioral and physiological responses in suckling calves, presenting an interesting set of reactions appropriate in response to the emotional situations elicited by this short-term stimulus.

Behavior and physiology of two different sow breeds in a farrowing environment during late 35-day lactation

To improve the overall welfare levels of sows and to reduce stress levels at late 35-day lactation, we selected targeted behavioral indicators that might be associated with stress. Therefore, we monitored and evaluated the adaptive capability of two different breeds of sows to the farrowing environment. In this study, Damin sows (Large White × Min pig sows, n = 20) and Large White sows (n = 20) were farrowed in individual pens. Saliva was collected and tested for cortisol density at –15 min, and then at +15, 30, 60, 90, 120, 180 and 240 min after an adrenocorticotropic hormone (ACTH) stimulation test conducted at 20, 27 and 34 d post-partum. The postures, including ventral and lateral recumbency to other postures, defecating, urinating, sham-chewing and bar-biting behavior, were observed by video from 07:00 to 09:00 and from 13:00 to 15:00 on the 7th day of each week from the 3rd to the 5th week post-parturition. In addition, the concentrations of salivary interleukin (IL)-6, tumor necrosis factor (TNF)-α and secretory immunoglobulin (SIgA) were assayed after the observed behaviors. The results showed no significant difference between Damin sows and Large White sows in terms of behaviors at the 3rd week. Additionally, there were no significant differences between Damin and Large White sows in terms of the behaviors of ventral recumbency and bar-biting with the exception of lateral recumbency to other postures, sham-chewing, defecation and urination in the fifth week. Meanwhlie, there was significant difference between two breeds in term of ventral recumbency at the 4th week. The result of the ACTH test showed a significant difference between the Damin and Large White sows by the 27th and 34th days postpartum (P<0.01). In addition, the serological concentrations of IL-6 and TNF-α were not significantly different between the two breeds at the 3rd week postpartum. However, these indicators were significantly different at the 5th week postpartum (P = 0.000, and P = 0.003, respectively). The SIgA concentrations in saliva were significantly different between breeds at the 3rd week postpartum (P<0.01). In conclusion, both breeds of sows maybe in a state of stress after the 4th week postpartum. However, the Damin sows may be better than the Large White sows in terms of adapting to this farrowing environment.

Pre-cold acclimation improves the immune function of trachea and resistance to cold stress in broilers: SU et al.

Acclimation can alleviate the damage caused by adverse environmental factors. To investigate the effects of cold stimulation on immunity in tracheal of broilers, 360 one‐day‐old chicks were raised at normal temperatures during 1–7 days. From 8 day, G1 (control) continued to be raised at normal temperatures, whereas G2 and G3 (treatment groups) were cold‐stimulated at 3°C and 12°C below the temperature of G1, respectively. At 42 day, all the groups were subjected to a 24‐hr acute cold stress, designated as S1, S2, and S3. Tracheal tissues were collected to detect gene levels of immunoglobulins, antimicrobial peptides, Hsps, and cytokines, and oxidative stress‐related indicators at 14 day, 42 day, and 43 day, and protein levels of Hsps and proinflammatory cytokines as well as morphology changes at 42 day and 43 day. The results showed that, compared with 42G1, tracheal structure of 42G2 was basically intact, and gene levels of immunoglobulins and antimicrobial peptides increased (pu2009<u20090.05), whereas tracheal structure of 42G3 was destroyed, with decreased levels of immunoglobulins ( pu2009<u20090.05), and increased levels of Hsps and proinflammatory cytokines ( pu2009<u20090.05). At 43 day, tracheal damage was visible and gene levels of immunoglobulins and antimicrobial peptides decreased in S1 ( pu2009<u20090.05). Tracheal structure was relatively intact and gene levels of antimicrobial peptides increased in S2 ( pu2009<u20090.05). Compared with S1 and S3, immune‐related gene levels in S2 were higher, and Hsps and proinflammatory cytokines levels were lower. The results demonstrate that cold stimulation of lower 3°C from 8 to 42 day led to cold acclimation, which improved immunity of tracheal mucosa and resistance to cold stress in broilers.

Maternal Behavior, Posture Change, and Production Performance of Lactating Sows Housed in an Enriched Environment

ABSTRACT This study aimed to evaluate whether adding straw to a loose-farrowing house promotes maternal functions and production. Forty-eight sows (Landrace× Large White) were housed in either a farrowing pen without straw (C, n = 24) or with straw (S, n = 24). Behaviors were observed using video recordings and were statistically analyzed. Lateral recumbency was higher and standing was lower in S compared with C (p = .034 and p = .020, respectively), and lateral recumbency to other postures, ventral to lateral recumbency and standing to lying were markedly lower in S than C (p = .014, p = .025 and p = .023, respectively) on Day 1 postpartum. However, except piglet losses during the first three days postpartum (p = .032), piglet weight on Day 21 (p = .037), and piglet weaning weight (p = .020), other production performances were not significantly different between the two groups during the whole experimental period (p ˃.05). The results suggest the enrichment of a farrowing pen with straw has important beneficial effects on sow and piglet welfare and improves piglet survival rates.

The protective role of selenium against cadmium-induced hepatotoxicity in laying hens: Expression of Hsps and inflammation-related genes and modulation of elements homeostasis

The purpose of this study was to examine the potential role of high selenium (Se) diets in alleviating chronic cadmium (Cd) hepatic toxicity in laying hens. In the present study, 128 healthy 31-week-old laying hens were fed a diet supplemented with Se (Na2SeO3, 2u202fmg/kg), Cd (CdCl2, 150u202fmg/kg), or both Se and Cd (150u202fmg/kg of CdCl2 and 2u202fmg/kg of Na2SeO3) for 90 days. The expression levels of heat shock proteins (Hsps, including Hsp60, Hsp70 and Hsp90) and inflammation-related factors, including nuclear factor-kappa B p50 (NF-κB), cyclooxygenase-2 (COX-2), prostaglandin E synthases (PTGES), interleukin 1-beta (IL-1β), and tumor necrosis factor-α (TNF-α) were investigated. The concentrations of 28 elements were also determined. The results indicated that Cd treatment significantly increased the mRNA and protein expression levels of Hsps and significantly improved the expression of inflammation-related genes. Moreover, Cd addition to the diets resulted in disturbances in the systemic balance of 13 elements, leading to decrease in the concentrations of Cr, Mn, Sr, Ba, and Hg and increase in Li, B, Ca, Ti, Fe, Cu, Mo, and Cd concentrations. Treatment with Se significantly alleviated Cd-induced hepatic toxicity, as evidenced by a reduction in Hsp60, Hsp70, Hsp90, NF-κB, COX-2, PTGES, TNF-α, and IL-1β expression. Additionally, Se and Cd co-treatment alleviated the changes in Li, B, Ca, Fe, Ti, Cu, Mo, Cd, Cr, Se, Sr, Ba, and Hg concentrations, which was in contrast to that upon Cd induction. The study indicated that Se could help against the negative effects of Cd and may be related to the alleviation of Cd-induced Hsps stress and the inflammatory responses along with modulating the element homeostasis.

Effects of confinement duration and parity on stereotypic behavioral and physiological responses of pregnant sows

The aim of this study was to evaluate the effects of space restriction stress on the stereotypic behavioral and physiological responses of different parity sows, and it is necessary to understand such effects due to space restriction to improve the welfare of the sows in confined conditions. We selected fifty pregnant sows (Large White) at primiparity and first to fifth parity in a confined farm with the same body condition and due date (3±1.5days). Behavioral observations and physiological analysis were carried out during spatial confinement throughout pregnancy. The results showed that there were no significant changes in vacuum-chewing, bar-biting, trough-biting and the concentrations of serum IL-6 in primiparous sows during the initial confinement (0-8days). With the increase of the confinement duration, the serum cortisol, IgA, IL-6 concentrations and the vacuum-chewing frequency of sows in all groups increased significantly, and the serum concentrations of C-reactive protein and Pig-MAP increased significantly except for the sows in the first and second parity groups. The serum cortisol, IgA, IL-6 concentrations and the vacuum-chewing frequency of older sows were significantly higher than those of the young sows throughout the entire restricted feeding period, but the serum C-reactive protein concentrations of primiparous gilts was significantly higher than those of the other groups. The serum cortisol, IgA, IL-6 concentrations and bar-biting and trough-biting frequencies of all parity sows decreased significantly after entering the delivery bed. In conclusion, long-lasting and recurrent environmental constraints can significantly increase the frequency of stereotypical behavior and serious psychological and physical stress, seriously damaging sow welfare.

Gene Expression Profiling of Broiler Liver under Cold Stress by High-Throughput Sequencing Technology

Cold stress is a major environmental factor restricting the sustainable development of animal husbandry. To gain insight into the gene-regulation processes in broilers under cold stress, gene expression profiling was conducted using high-throughput Solexa sequencing of broiler liver tissue under cold stress conditions and control conditions. According to Solexa sequencing, we identified 255 genes whose expression levels differed between the treatment and control group. Under cold stress, 135 genes were up-regulated and 120 genes were down-regulated genes compared with levels in the control group. Moreover, 469 genes were expressed only in the control group, and 172 genes were expressed only in the treatment group. These data were confirmed by real-time quantitative PCR. Gene Ontology enrichment analysis showed that the differentially expressed genes (DEGs) were mainly enriched in material metabolism and immune functions. KEGG enrichment analysis showed that DEGs were enriched in pyruvate metabolism, glycolysis/gluconeogenesis, fatty acid metabolism, insulin signaling pathway and others. In conclusion, these results may serve as an important reference for broiler breeding and provide new clues for the elucidation of molecular mechanisms of cold stress.