A comparison of Echium, fish, palm, soya, and linseed oil supplementation on pork quality.

OBJECTIVE: Long chain n-3 polyunsaturated fatty acids (PUFA) exert positive effects on human health. The long chain n-3 PUFA of pork can be increased by adding fish oil to the diet. Due to the cost and availability of fish oil an alternative source must be found. METHODS: This study evaluated the effect of five dietary oils on meat quality, fatty acid composition and lipid stability. The five diets contained 1% palm oil (Control), 1% soya oil, 1% linseed oil, 1% fish oil, and 1% Echium oil, respectively. The trial consisted of 60 gilts, randomly allocated to five groups. RESULTS: All color parameters, extractable fat content, fat free dry matter, and moisture content of the m. longissimus muscle were unaffected by dietary treatment. Consumers and a trained sensory panel could not detect a difference between the control samples and the Echium oil sample during sensory analysis. Samples containing higher levels of PUFA (soya, linseed, fish, and Echium oil) had higher levels of primary and secondary lipid oxidation products after refrigerated and frozen storage. However, these values were still well below the threshold value where off flavors can be detected. The Echium oil treatment had significantly higher levels of long chain PUFA than the linseed oil treatment, but it was still significantly lower than that of the fish oil treatment. CONCLUSION: Echium oil supplementation did not increase the levels of n-3 to the same extent as fish oil did. The result did however suggest that Echium oil can be used in pig diets to improve muscle long chain n-3 fatty acid content without any adverse effects on meat quality when compared to linseed, soya, and palm oil.

Responses in apparent total digestibility, rate of passage, growth performance and physicochemical properties of the digesta of Windsnyer pigs fed on increasing levels of potato hash silage.

OBJECTIVE: The study was conducted to determine the apparent total tract digestibility, the rate of digesta passage, growth performance and physicochemical properties of the digesta of Windsnyer pigs fed on increasing levels of potato hash silage. METHODS: Diets were formulated to contain 0, 80, 160, 240, 320 and 400 g potato hash silage /kg of diet. Pigs were randomly assigned to six diets according to a completely randomized design. Six pigs were allocated to each dietary treatment. All diets were blended with chromic oxide (Cr2O3) to calculate apparent total tract digestibility and rate of passage. Pigs were fed diets containing different levels of potato hash silage for 5 d, following 7 d of adaptation. Thereafter, pigs were subjected to a 35-day growth performance experiment. Thirty-six pigs were slaughtered and eviscerated to determine digesta characteristics and gut compartment weights. RESULTS: There was a positive correlation (P < 0.05) between MRT and each of DMD, OMD and CPD. There was a quadratic increase (P <0.05) in digestibility of organic matter, crude protein, fibre and feed intake as dietary levels of potato hash silage increased. Average daily gain and gain to feed ratio decreased linearly (P < 0.05) in pigs as levels of potato hash silage increased. The swelling capacity (SWC) of the digesta from ileum decreased linearly (P <0.05) as dietary levels of potato hash silage increased. The SWC of the digesta from the caecum increased linearly (P <0.05) as dietary levels of potato hash silage increased. The water holding capacity (WHC) of the stomach digesta decreased linearly (P <0.05) as dietary levels of potato hash silage increased. The WHC of the digesta from the ileum and caecum displayed negative quadratic responses (P <0.05) as dietary levels of potato hash silage increased. The WHC of digesta from the proximal colon showed a linear decline (P <0.05) as dietary levels of potato hash silage increased. The WHC of digesta from the distal colon increased linearly (P <0.05) as dietary levels of potato hash silage increased. CONCLUSION: The results indicated that Windsnyer pigs can effectively utilize potato hash silage in diets until the 240 g/kg inclusion level beyond which total tract digestibility and feed intake are compromised.

Interaction effects of pen environment and sex on behavior, skin lesions and physiology of Windsnyer pigs.

OBJECTIVE: The study was carried to determine the interaction effects of pen enrichment and sex on behavioral activities, skin lesions and physiology of Windsnyer pigs. METHODS: Forty-eight growing Windsnyer pigs of both sex, with an average initial body weight of 21.6 (±9.01) kg were used. Four pigs were randomly assigned to either enriched or barren pens at a stocking density of 0.35 m2/pig. Enriched pens contained 2 L bottles filled with stones and suspended at head level on ropes stretching across the pens. In addition, two plastic balls (90 mm in diameter) and 500 mL bottles (235 mm long) were placed on the floor of each enriched pen. RESULTS: Pigs in barren environments had higher heart rates (p<0.001) than those in enriched pens. There was an interaction of pen environment and sex on rectal temperature (p<0.001). Females in enriched pens had higher rectal temperatures (p<0.05) than females in barren pens. There was no interaction of pen environment and sex on time spent eating and drinking (p>0.05). Time spent bullying was influenced (p<0.05) by pen environment and sex. Female pigs in barren environment spent more time on bullying than females in enriched pens. There was an interaction of pen environment and sex on time spent lying down and walking (p<0.05). Female pigs in enriched pens spent more time lying down than females in barren pens. Males in barren pens spent more time walking than males in enriched pens while no effect of pen environment was observed in females. There was an interaction of pen environment and sex on the number of skin lesions in the head, neck and shoulder region and other parts of the body (p<0.05). CONCLUSION: It was concluded that pen enrichment reduced the number of skin lesions and anti-social behaviors, especially for female pigs. There is a need, therefore of housing indigenous pigs under confinement.

Effects of environmental enrichment on behaviour, physiology and performance of pigs - A review.

This paper aims to critically analyse and synthesise existing knowledge concerning the use of environmental enrichment and its effect on behavior, physiology and performance of pigs housed in intensive production systems. The objective is also to provide clarity as to what constitutes successful enrichment and recommend when and how enrichment should be used. Environmental enrichment is usually understood as an attempt to improve animal welfare and to a lesser extent, performance. Common enrichment objects used are straw bedding, suspended ropes and wood shavings, toys, rubber tubings, colored plastic keys, table tennis balls, chains and strings. These substrates need to be chewable, deformable, destructible and ingestible. For enrichment to be successful four goals are essential. Firstly, enrichment should increase the number and range of normal behaviors; secondly, it should prevent the phenomenon of anomalous behaviors or reduce their frequency; thirdly, it should increase positive use of the environment such as space and fourthly it should increase the ability of the animals to deal with behavioral and physiological challenges. The performance, behavior and physiology of pigs in enriched environments is similar or in some cases slightly better when compared with barren environments. In studies where there was no improvement, it should be borne in mind that enriching the environment may not always be practical and yield positive results due to factors such as type of enrichment substrates, duration of provision and type of enrichment used. The review also identifies possible areas that still need further research, especially in understanding the role of enrichment, novelty, breed differences and other enrichment alternatives.

Virulence profiles of enterotoxigenic, shiga toxin and enteroaggregative Escherichia coli in South African pigs.

Enterotoxigenic Escherichia coli (ETEC) and shiga toxin E. coli (STEC) are important causes of colibacillosis in piglets. Recently, enteroaggregative E. coli heat-stable enterotoxin 1 (EAST-1) has been implicated in pig diarrhoea. This study investigated the prevalence of enterotoxin [heat-labile toxins (LT), heat-stable toxin a (STa), heat-stable toxin b (STb)], shiga toxins (Stx1, Stx2, Stx2e), enteroaggregative heat-stable E. coli (EAST-1), associated fimbriae (F4, F5, F6, F41, F18ab, F18ac) and non-fimbrial adhesins [adhesin involved in diffuse adherence 1 (AIDA-1), attaching and effacing factor, porcine attaching- and effacing-associated factor] in South African pigs. A total of 263 E. coli strains were isolated from Landrace (n = 24), Large White (n = 126), Duroc (n = 28) and indigenous (n = 85) breeds of piglets aged between 9 and 136 days. PCR was used in the analysis. Virulent genes were detected in 40.3% of the isolates, of which 18.6, 0.4 and 17.5% were classified as ETEC, STEC and enteroaggregative E. coli (EAEC), respectively. Individual genes were found in the following proportions: STb (19.01%), LT (0.4%), STa (3.4%), St2xe (1.1%) and EAST-1 (20.2%) toxins. None of the tested fimbriae were detected in ETEC and STEC isolates. About one third of the ETEC and STEC isolates was tested negative for both fimbrial and non-fimbrial adhesins. Twenty-five pathotypes from ETEC-, EAEC- and STEC-positive strains were identified. Pathotypes EAST-1 (30.2%), STb (13.2%) and STb/AIDA-1 (10.4%) were most prevalent. The study provided insight on possible causes of colibacillosis in South African pigs.

Estimating pasture intake and nutrient digestibility of growing pigs fed a concentrate-forage diet by n-alkane and acid-insoluble ash markers.

A study was carried out to determine voluntary forage intake and nutrient digestibility in growing pigs fed a mixed forage and concentrate diet. Twenty-five 8-week-old Large White × Landrace crossbred male pigs (27 ± 3.8 kg) were blocked by weight into five groups, and each was randomly allocated to four indoor treatments (A, B, C, and D), which received 100, 90, 80, and 70 % of ad lib concentrated intake and an outdoor treatment (E) that received 80 % of ad lib concentrate. Indoor treatments were either fed the concentrate only (A) or also received freshly cut Kikuyu grass (Pennissetum clandestinum) ad libitum (B, C, and D), while pigs on treatment E were reared outdoors in Kikuyu grass paddocks. There was a significant correlation between the amount of concentrate offered and its intake (P < 0.01). The intake of Kikuyu was similar among treatments (P > 0.05). Mean acid-insoluble ash digestibility estimates of organic and dry matter were superior to C(32) estimates (P < 0.05). Kikuyu intake was higher (P < 0.05) than the estimated intake by 0.076 ± 0.03 kg. It was concluded that Kikuyu intake was not affected by the reduction of the concentrate allowance, and this should be taken into consideration when feeding pigs on pasture.