Dietary silage supplement modifies fatty acid composition and boar taint in pork fat

In organic pig husbandry, the use of roughage is mandatory as dietary supplement. This study investigated the effects of oat silage on the fatty acid composition, in entire males and gilts, as well as indole and skatole levels in perirenal adipose tissue of entire males. Entire males and gilts (forty-five to forty-eight pigs/sex) were assigned to two dietary roughage feeds (control with straw vs. oat silage). There was no significant effect of silage or sex on total SFA and MUFA in pork fat. However, the oat silage increased the total PUFA n-3 and decreased the PUFA n-6/n-3 ratio. The content of boar taint compounds (skatole and indole) in the entire male pigs did not differ between diets, although human nose scoring rejected in a greater extent more pork fat from entire males supplemented with oat silage, compared with those only supplied with straw. Approximately 50% of the entire males (90 to 97 kg of carcass) had low skatole values (≤0.1 μg/g), that were below the range of boar taint detection, regardless of the feeding regime. This finding indicates that more studies should be performed to avoid the problem of taint detection in entire males under organic production

Feasibility of on/at line methods to determine boar taint and boar taint compounds: An overview

Classification of carcasses at the slaughter line allows an optimisation of its processing and differentiated payment to producers. Boar taint is a quality characteristic that is evaluated in some slaughter plants. This odour and flavour is mostly present in entire males and perceived generally by sensitive consumers as unpleasant. In the present work, the methodologies currently used in slaughter plants for boar taint classification (colorimetric method and sensory quality control-human nose) and the methodologies that have the potential to be implemented on/at the slaughter line (mass spectrometry, Raman and biosensors) have been summarized. Their main characteristics are presented and an analysis of strengths, weaknesses, opportunities and threats (SWOT) has been carried out. From this, we can conclude that, apart from human nose, the technology that arises as very promising and available on the market, and that will probably become a substitute for the colorimetric method, is the tandem between the laser diode thermal desorption ion source and the mass spectrometry (LDTD-MS/MS) with automation of the sampling and sample pre-treatment, because it is able to work at the slaughter line, is fast and robust, and measures both androstenone and skatole.info:eu-repo/semantics/publishedVersio

Can sensory boar taint levels be explained by fatty acid composition and emitted volatile organic compounds in addition to androstenone and skatole content?

peer reviewedThis study aimed at understanding which molecules were responsible for the differences existing in boar taint sensory evaluation. The latter was therefore linked to the results of skatole and androstenone chemical analyses, fatty acid composition and VOC profiles of heated backfat. This study confirmed that some discrepancy exists between chemical analysis and sensory evaluation of tainted backfats. Significant correlations between human nose scores and fatty acid composition were not revealed. Strong correlations between emissions and contents in skatole and androstenone were found. Oxidation products of polyunsaturated fatty acids, with fatty odor descriptors, were found to be more present in the VOC profiles of boar fat considered untainted through the human nose methodology. Weak coefficient of determination for partial least square regression indicates that other factors, yet unknown, are responsible for sensory evaluation outcomes. These findings hence support the idea that high human nose score is mainly due to boar taint compounds rather than general differences in VOC profiles. Keywords: boar taint, androstenone, skatole, human nose, fatty acid, VO

Estratègies prèvies al sacrifici que poden afectar el benestar animal i la qualitat de la carn de porcs de diferent genotip RYRI

The main objective of this thesis was to study (i) the effect of the fasting and lairage on carcass and technological meat quality and (ii) the inclusion of magnesium (MgCO3 and MgSO4) and/or tryptophan during 5 days before slaughtering pigs as a strategy to decrease stress levels and improve meat quality, with two different porcine RYR1 genotypes (NN and nn). An adequate combination of fasting and lairage period is recommended. A supplement of MgCO3 or Trp did not improve meat quality under minimal stressful ante mortem conditions; and MgSO4 had a laxative effect on pigs supplemented with it. When including nn pigs to the herd, it is recommended to consider the supplements’ combination of tryptophan and a source of Mg (avoiding MgSO4) to alleviate the negative effect of the stress and to improve technological meat quality.L’objectiu principal d’aquest treball fou estudiar (i) l’efecte del dejuni i el temps d’espera a l’escorxador i (ii) l’efecte de l’addició de suplements de magnesi (MgCO3 o MgSO4) i/o triptòfan a la dieta durant els 5 dies previs al sacrifici com a estratègia per disminuir els nivells d’estrès i millorar la qualitat de la carn, en dos genotips porcins diferents respecte el gen RYR1 (NN i nn). Es recomana combinar correctament el dejuni i l’espera per millorar el benestar i la qualitat de la carn. El MgCO3 o el Trp no va millorar la qualitat de la carn en condicions de mínim estrès; i el MgSO4 provocà problemes digestius. En el cas d’optar per la utilització de genètiques nn, es recomana considerar la utilització de suplements de L-Trp amb fonts de magnesi (excloent el MgSO4) per pal•liar les conseqüències negatives de l’estrès i millorar la qualitat tecnològica de la carn

Using 19% of alfalfa hay in beef feedlot finishing diets did not modify meat quality but increased feed intake and ADG

To evaluate the effects of including extra alfalfa hay in high concentrate diets fed to beef heifers on intake, average daily gain (ADG), gain to feed ratio (G:F), and carcass and meat quality, we used 24 Simmental heifers (initial BW 235.6 ± 4.19 kg). Heifers were blocked in 4 BW blocks and allotted in groups of 3 in a randomized block design with 2 treatments and 12 heifers per treatment. Treatment diets offered as total mixed ration (TMR) were: a) TMR with 10% barley straw (BS), considered the control diet, and b) TMR with 19% alfalfa hay (AH). The experiment was performed over 4 28-d experimental periods, and we took measurements in the last week of each period. After this period of performance control, heifers were fed the corresponding diet until each BW block reached the target weight of 400 kg on average. Feed intake and ADG were greater for AH than BS (9.5 vs 8.4 kg/d, and 1.45 vs 1.29 kg/d, respectively; P 0.10). Diet did not affect hot carcass weight, dressing percentage, backfat color, pH and meat color, or carcass grade. The sixth rib was dissected to determine the proportion of fat, lean and bone, which were unaffected by diet. Diet did not affect the Longissimus muscle composition in water, protein, collagen, intramuscular fat, and cholesterol. The intramuscular fat proportion of C18:1 n-7 was greater in BS than in AH (P = 0.016), whereas the proportion of C18:3 n-3 tended to be greater in AH than in BS (P = 0.09). When fatty acid concentration was expressed as g per 100 g of Longissimus muscle, these differences disappeared, and only the content of C15:0 tended to be greater (P = 0.08) in BS than in AH. Meat characteristics evaluated by trained panelists did not differ in toughness, chewiness, juiciness, odor, taste and overall acceptability, and there were no differences between diets in Warner-Bratzler shear force values after 3 or 10 d of ageing (P > 0.10). In summary, heifers fed TMR with alfalfa hay at 19% of inclusion showed a greater feed intake and ADG than those fed barley straw at 10% of inclusion, but without affecting G:F ratio. However, this extra alfalfa hay was not sufficient to cause any relevant change in the carcass and meat quality of the heifers fed this diet.info:eu-repo/semantics/acceptedVersio

Dietary silage supplement modifies fatty acid composition and boar taint in pork fat

In organic pig husbandry, the use of roughage is mandatory as dietary supplement. This study investigated the effects of oat silage on the fatty acid composition, in entire males and gilts, as well as indole and skatole levels in perirenal adipose tissue of entire males. Entire males and gilts (forty-five to forty-eight pigs/sex) were assigned to two dietary roughage feeds (control with straw vs. oat silage). There was no significant effect of silage or sex on total SFA and MUFA in pork fat. However, the oat silage increased the total PUFA n-3 and decreased the PUFA n-6/n-3 ratio. The content of boar taint compounds (skatole and indole) in the entire male pigs did not differ between diets, although human nose scoring rejected in a greater extent more pork fat from entire males supplemented with oat silage, compared with those only supplied with straw. Approximately 50% of the entire males (90 to 97 kg of carcass) had low skatole values (≤0.1 μg/g), that were below the range of boar taint detection, regardless of the feeding regime. This finding indicates that more studies should be performed to avoid the problem of taint detection in entire males under organic production.info:eu-repo/semantics/publishedVersio

Effect of magnesium sulphate and L-tryptophan and genotype on the feed intake, behaviour and meat quality of pigs

Sixty-nine entire male pigs with different halothane genotype (homozygous halothane positive – nn –, n=36; and homozygous halothane negative – NN-, n=33) were fed with a supplementation of magnesium sulphate (Mg) and/or L-tryptophan (Trp) in the diet for 5 days before slaughter. Animals were housed individually and were submitted to stressful ante mortem conditions (mixed in the lorry according to treatments and transported 1 hour on rough roads). Individual feed intake was recorded during the 5-d treatment. At the abattoir, pig behaviour was assessed in the raceway to the stunning system and during the stunning period by exposure to CO2. Muscle pH, colour, water holding capacity, texture and cathepsin activities were determined to assess meat quality. The number of pigs with an individual feed intake lower than 2 kg/d was significantly different among diets (P&0.05; Control: 8.7 %; Mg&Trp: 43.5 %; Trp: 17.4 %) and they were considered to have inadequate supplement intake. During the ante mortem period, 15.2 % of pigs included in the experiment died, and this percentage decreased to 8.7 % in those pigs with a feed intake & 2kg/day, all of them from the stress-sensitive pigs (nn). In general, no differences were observed in the behaviour of pigs along the corridor leading to the stunning system and inside the CO2 stunning system. During the stunning procedure, Trp diet showed shorter periods of muscular excitation than control and Mg&Trp diets. The combination of a stressful ante mortem treatment and Mg&Trp supplementation led to carcasses with high incidence of severe skin lesions. Different meat quality results were found when considering all pigs or considering only those with adequate supplement intake. In this later case, Trp increased pH45 (6.15) vs Control diet (5.96) in the Longissimus thoracis (LT) muscle (P&0.05) and pH at 24h (Trp: 5.59 vs C: 5.47) led to a higher incidence of dark, firm and exudative (DFD) traits in SM muscle (P&0.05). Genotype affected negatively all the meat quality traits. Seventy-five percent of LT and 60.0 % of the SM muscles from nn pigs were classified as pale, soft and exudative (PSE), while none of the NN pigs showed these traits (P&0.0001). No significant differences were found between genotypes on the incidence of DFD meat. Due to the negative effects observed in the Mg&Trp group in feed intake and carcass quality, the utilization of a mixture of magnesium sulphate and tryptophan is not recommended

Role of AMPK signalling pathway during compensatory growth in pigs

Background: The molecular basis of compensatory growth in monogastric animals has not yet been fully explored. Herewith, in this study we aim to determine changes in the pig skeletal muscle transcriptome profile during compensatory growth following a feed restriction period. A RNA-Seq experiment was performed with a total of 24 females belonging to a Duroc commercial line. Half of the animals received either a restricted (RE) or ad libitum (AL) diet during the first fattening period (60-125 d of age). After that, all gilts were fed ad libitum for a further ~30 d until the age of ~155 d, when animals were slaughtered and samples of gluteus medius muscle were harvested to perform RNA-Seq analyses and intramuscular fat content determination. Results: During the period following food restriction, RE animals re-fed ad libitum displayed compensatory growth, showed better feed conversion rate and tended to deposit more subcutaneous fat than AL fed animals. Animals were slaughtered in the phase of accelerated growth, when RE animals had not completely compensated the performance of AL group, showing lower live and carcass weights. At intramuscular level, RE gilts showed a higher content of polyunsaturated fatty acids during the compensatory growth phase. The comparison of RE and AL expression profiles allowed the identification of 86 (logFold-Change > 1, p < 0.05) differentially expressed (DE) genes. A functional categorization of these DE genes identified AMPK Signaling as the most significantly enriched canonical pathway. This kinase plays a key role in the maintenance of energy homeostasis as well as in the activation of autophagy. Among the DE genes identified as components of AMPK Signaling pathway, five out of six genes were downregulated in RE pigs. Conclusions: Animals re-fed after a restriction period exhibited a less oxidative metabolic profile and catabolic processes in muscle than animals fed ad libitum. The downregulation of autophagy observed in the skeletal muscle of pigs undergoing compensatory growth may constitute a mechanism to increase muscle mass thus ensuring an accelerated growth rate. These results reveal that the downregulation of AMPK Signaling plays an important role in compensatory growth in pigs

Effect of magnesium sulphate and L-tryptophan and genotype on the feed intake, behaviour and meat quality of pigs

Sixty-nine entire male pigs with different halothane genotype (homozygous halothanepositive – nn-, n=36; and homozygous halothane negative – NN-, n=33) were fed with a supplementation of magnesium sulphate (Mg) and/or L-tryptophan (Trp) in the diet for 5days before slaughter. Animals were housed individually and were submitted to stressful ante mortem conditions (mixed in the lorry according to treatments and transported 1h on rough roads). Individual feed intake was recorded during the 5-day treatment. At the abattoir, pig behaviour was assessed in the raceway to the stunning system and during the stunning period by exposure to CO2. Muscle pH, colour, water holding capacity, texture and cathepsin activities were determined to assess meat quality. The number of pigs with an individual feed intake lower than 2kg/day was significantly different among diets (P 2kg/day, all of them from thestress-sensitive pigs (nn). In general, no differences were observed in the behaviour ofpigs along the corridor leading to the stunning system and inside the CO2 stunningsystem. During the stunning procedure, Trp diet showed shorter periods of muscularexcitation than control and Mg&Trp diets. The combination of a stressful ante mortemtreatment and Mg&Trp supplementation led to carcasses with high incidence of severeskin lesions. Different meat quality results were found when considering all pigs orconsidering only those with adequate supplement intake. In this later case, Trp increased pH45 (6.15) vs Control diet (5.96) in the Longissimus thoracis (LT) muscle (P<0.05) and pH at 24h (Trp: 5.59 vs C: 5.47) led to a higher incidence of dark, firm and dry (DFD) traits in SM muscle (P<0.05). Genotype affected negatively all the meat quality traits. Seventy-five percent of LT and 60.0% of the SM muscles from nn pigs wereclassified as pale, soft and exudative (PSE), while none of the NN pigs showed these traits (P<0.0001). No significant differences were found between genotypes on the incidence of DFD meat. Due to the negative effects observed in the Mg&Trp group in feed intake and carcass quality, the utilization of a mixture of magnesium sulphate and tryptophan is not recommende