Evaluation of environmental and management-related risk factors associated with chronic mastitis in sows

Investigating risk factors behind piglet facial and sow teat lesions through a literature review and a survey on teeth reduction

Introduction

Piglet facial and sow teat lesions are the main reported reasons why pig producers routinely practice teeth resection. This is a painful procedure performed on piglets, where their needle teeth are clipped or ground to resect the pointed tip. The practice raises welfare concerns. In contrast to other procedures, such as tail docking, we know little about the risk factors for these two types of lesions.

Methods

We employed two methods to answer these questions: (1) reviewing the literature to identify potential risk factors, and (2) surveying pig production stakeholders worldwide to identify the occurrence of these lesions and the strategies used in practice that enable pig producers to manage or prevent these lesions while avoiding teeth resection. For the literature review, we used Google Scholar to include peer-reviewed publications and gray literature. We distributed the survey using convenience sampling and documented information on the current situation regarding teeth resection, including the methods, frequencies, and reasons for resecting piglets' teeth, the occurrence of piglet facial and sow teat lesions, and measures used to prevent and control these lesions.

Results

The literature review identified six major risk factors for both lesions, including the presence or absence of teeth resection, housing system, litter size, piglet management, environmental enrichment, milk production and other piglet management practices. However, most studies focused on the effects of the first two factors with very few studies investigating the other risk factors. There were 75 responses to the survey from 17 countries. The survey showed that half of the respondents practiced teeth resection with many recognizing that facial and teat lesions are the main reasons behind this practice. However, many producers used other interventions rather than teeth resection to prevent these lesions. These interventions focused on improving milk production of the sow, managing large litters, and providing environmental enrichment.

Discussion

More research is needed to validate these interventions and more science-based advice is needed to bridge the gap between research and practice to help more producers further understand the cause of piglet facial and sow teat lesions to transition toward the cessation of routine teeth resection.

Influence of mastitis metritis agalactia (MMA) on bone and fat metabolism

Mastitis metritis agalactia (MMA) is a common disease in post-partum sows and has a negative effect on sows' longevity as well as on sows' and piglets' health. MMA leads to an inflammatory state. The aim was to investigate the impact of MMA on bone and fat metabolism. The hypothesis was that it is possible to predict MMA by measuring ketone bodies and bone markers. Blood samples from 175 sows were taken within 72 hr after farrowing. Serum was analysed for 25-hydroxyvitamin D (25-(OH)-D), serum crosslaps (CTX-I), osteocalcin (OC), alkaline phosphatase (ALP), calcium (Ca), magnesium (Mg), phosphorus (P), parathyroid hormone (PTH), triglycerides (TG), beta-hydroxybutyric acid (BHB), tumour necrosis factor-alpha (TNF-α) and haptoglobin. Spontaneous urine was collected, and pH value was measured in addition to Ca and P. A proximate analysis of the sows' diets was performed. Age, litter size, body condition score (BCS) and clinical signs of MMA were recorded for each sow. A multivariable logistic regression was undertaken with disease status (MMA or healthy) as the dependent variable. Significance was accepted at p < .05. MMA sows had a poorer BCS (p < .001) in relation to healthy sows. Age and number of piglets did not differ. MMA sows showed increased serum CTX-I (p = .004) and decreased serum OC (p < .001). Concentrations of P (p = .007), activity of ALP (p = .002) and BHB (p = .019) as well as TNF-α (p < .001) and haptoglobin (p = .048) concentrations were increased in MMA sows. No difference in urinary pH value between MMA and healthy sows was found. Our results are in accordance with the known fact that sows are in an extreme catabolic state peripartum. Bone metabolism in MMA sows is much more negatively affected than in healthy sows post-partum, due to inflammatory processes shown by higher concentrations of pro-inflammatory cytokines.

Prevalence and Clinical Signs of Postpartum Dysgalactia Syndrome at The First Day after Farrowing in Farmed Sows in The Republic of Macedonia

The objective of the present study was to determine the prevalence of postpartum dysgalactia syndrome (PDS) and associated clinical signs in farmed sows in the Republic of Macedonia (RM) in the first 12-24 h postpartum. A total of 202 sows of different parity and different genetic lines from 5 pig farms in RM were included in the study. The sows and their litters were clinically examined 12-24 hours after farrowing. Postpartum dysgalactia syndrome was detected in 23.3% of all clinically examined sows, while prevalence between farms ranged from 14.8% to 38.1%. Altered piglet’s behavior was the most frequent clinical pattern observed in 68.1% of the PDS–affected (PDSA) sows. Regarding the clinical signs in PDSA sows detected among farms, significant differences were observed in the altered piglet’s behavior (p<0.05) and hypogalactia (p<0.05). Endometritis was more often detected in older sows (90%) compared to endometritis in younger animals (44.4%). In addition, fever was also more frequently diagnosed in higher parity (≥3 parity) sows (55.0%) in contrast to other PDSA sows (22.2%). This study has demonstrated the presence of PDS in farmed sows in RM. High frequency of altered piglet’s behavior found in this study could be an useful indicator for early detection of lactation problems in sows. Frequent pathological vaginal discharge in older sows indicates that endometritis plays an important role in the clinical manifestation of PDS. Further investigations should be conducted in order to identify specific risk factors associated with clinical PDS in farmed sows in RM.

Facial lesions in piglets with intact or grinded teeth

BACKGROUND

Piglets are born with eight sharp teeth that during nursing can cause facial lesions on littermates and teat lesions on the sow. Teeth grinding in piglets is therefore often practiced to reduce these lesions. The aim of this study was to assess the consequences of grinding piglet teeth in regard to the occurrence of lesions.In this study the piglets' teeth were grinded in 28 litters, and in 36 litters the piglets' teeth were kept intact. Twice, one time during the first week and one time during the second week after birth facial lesions of the piglets were scored and the teats of the sows were examined for lesions. The facial lesion score accounted for the amount and severity of lesions. The individual observations on piglets in the litter were synthesized in a litter facial lesion score.

FINDINGS

69.8% and 43.5% of the piglets had facial lesions in week 1 and week 2 respectively. The effect of treatment was not significant on litter facial lesion score. The litter facial lesion score was higher in week 1 than in week 2 (p < 0.001) and higher in large litters (p = 0.003) than in small litters. Mortality between week 1 and week 2 was higher in litters with intact teeth (p = 0.02). Sow teat lesions only occurred if litters had intact teeth.

CONCLUSIONS

According to our results teeth grinding is only justifiable in large litters.

Mastitis: comparative etiology and epidemiology

Mastitis is broadly defined as the inflammation of the mammary gland; however, the concept of mastitis is customized to address its social and clinical impact in the case of humans and the health, welfare, and economic consequences for other mammals. There are many microbial, host, and environmental factors that influence the development of mastitis. Some are common to all mammals as well as inherent to each species. Together these factors influence the most prevalent etiological agents for each species and might determine the possibility of interspecies transmission with its consequences to public health. The present review will summarize and compare reports on mastitis etiology and its epidemiology in humans and food animal species.

Risk factors associated with postpartum dysgalactia syndrome in sows

The aim of this study was to investigate management and strategy-related risk factors for the occurrence of postpartum dysgalactia syndrome (PDS) in commercial pig herds. A questionnaire was sent to 250 pig herdsmen. Of the responding herdsmen (n=110), 37 reported occurrences of PDS, whereas 73 reported no cases of PDS. Data were then analysed using logistic regression. After univariate analysis, eight variables associated with PDS (P<0.2) were retained and these were used to construct a multivariable logistic regression model. Four significant risk factors were found: (1) moving pregnant sows to the farrowing unit 4 days or less before expected farrowing (Odds Ratio [OR] 6.272); (2) farrowing induction (OR 4.804); (3) feeding sows ad libitum during lactation (OR 3.149) and (4) frequent farrowing supervision (OR 0.085). This study has demonstrated that a considerable number of modern pig herds still suffer from problems with PDS, and that control measures should include optimising management and feeding practices.