ASSESSING GASTRIC ULCERATION IN FATTENING PIGS HOUSED WITHOUT OR WITH STRAW AND ADDITIONAL SPACE – A MACROSCOPIC AND MICROSCOPIC STUDY ON A CONVENTIONAL AUSTRIAN FARM

Abstract

Gastric ulcerations in finishing pigs can cause growth restriction, sudden death and contamination of the carcass by invading microorganisms. The aim of the study was to compare macroscopic and histological findings of the stomach mucosa in fattening pigs kept at 1m²/pig and provided with long straw (10 groups, 113 pigs) with a control group kept at 0.7m²/pig without straw (11 groups, 120 pigs). At slaughter, the gastric health of pigs was assessed by macroscopic and histological scoring of 233 stomachs ranging from 0 (no alteration of mucosa) to 3 (ulceration). Gastric scores were correlated with organ alterations, carcass lesions and blood parameters. Based onto histological findings after gold standard sensitivity and specificity of macroscopic findings for ulceration (score 3) were 53 % and 98 %, respectively. While the extent of mucosal alterations can be assessed by macroscopic scoring easily at slaughter, histological examination reveals the depth of alterations. Median group prevalences of gastric ulcerations diagnosed by macroscopic examination were 5 % in the control group (range 0–40 %) and 18 % in the straw group (range 0–50 %), with no significant difference between both groups. Macroscopic scores were significantly higher in the straw group. Prevalence of ear-tip lesions was positively correlated with gastric health (p < 0.05). Analysis of particle size distribution in feed revealed, that more than 50 % of the feed consist of particles with less than 0.5 mm in diameter. The fine-ground diet in this herd was therefore identified as an important risk factor for the development of gastric ulceration on this farm. As a conclusion, the known risk factor of a high proportion of small particles in diet was not compensated by possible positive effects of straw and more space, and should be eliminated with high priority. Key words: ear tip lesions; histology; mucosa alterations; stomach; straw; swine OCENJEVANJE GASTRIČNIH ULKUSOV PRI PRAŠIČIH PITANCIH, NASTANJENIH Z NASTILJEM ALI BREZ NASTILJA IN DODATNEGA PROSTORA – MAKROSKOPSKA IN MIKROSKOPSKA ŠTUDIJA NA KONVENCIONALNIH AVSTRIJSKIH KMETIJAH Gastrične ulceracije pri prašičih pitancih v zaključni fazi lahko povzročijo omejevanje rasti, nenadno smrt in kontaminacijo trupa z invazivnimi mikroorganizmi. Cilj raziskave je bil primerjava makroskopskih in histoloških ugotovitev v sluznici želodca pri pitovnih prašičih, ki so nastanjeni na 1m²/prašiča in imajo nastilj sestavljen iz dolge slame (10 skupin, 113 prašičev) v primerjavi s kontrolno skupino, ki je bila nastanjena na 0,7 m²/prašiča in z nastiljem brez slame (11 skupin, 120 prašičev). Pri zakolu je bilo želodčno zdravje prašičev ocenjeno z makroskopskim in histološkim točkovanjem, opravljenem na 233 želodcih, z ocenami, ki se gibljejo od 0 (brez spremembe sluznice) do 3 (ulceracija). Rezultate opazovanj sluznice želodcev smo nato povezali s spremembami organa, poškodbami trupa in krvnimi parametri. Medtem ko se obseg sprememb sluznice lahko oceni z makroskopskim merjenjem pri zakolu, histološki pregled razkrije globino sprememb. Mediana prevalenca želodčnih ulkusov, diagnosticiranih z makroskopskim pregledom, je bila 5 % v kontrolni skupini (razpon od 0 do 40 %) in 18 % v skupini z nastiljem iz slame (razpon od 0 do 50 %), pri čemer ni bilo opaziti značilne razlike med skupinama. Makroskopski rezultati so bili precej višji v skupini z nastiljem iz slame. Razširjenost poškodb ušes je bila pozitivno povezana z zdravjem želodca (p <0,05). Analiza porazdelitve velikosti delcev v krmi je pokazala, da več kot 50 % krme sestavljajo delci s premerom manj kot 0,5 mm. Prehrana z drobno zmleto krmo je bila v čredi opredeljena kot pomemben dejavnik tveganja za razvoj razjed želodca. Znani faktor tveganja z velikim deležem majhnih delcev v prehrani ni bil kompenziran z morebitnimi pozitivnimi učinki slame in več prostora, zato ga je treba iz reje čim prej odpraviti. Ključne besede: poškodbe na vrhu ušesa; histologija; spremembe želodčne sluznice; želodec; slama; prašiči