Whole body amino acid composition of the growing pig

The protein in the whole bodies of 76 Landrace × Large White entire male and female pigs fed different diets (different combinations of protein and non-protein energy intake) for 0, 4, 6 or 8 weeks from 12 kg liveweight, were analysed for their amino acid composition. The purpose was to see if the composition changed in any systematic way with body protein weight. It was found that there were some effects of dietary treatment and sex on the concentrations of some amino acids, but these effects were exerted through their effects on protein weight. The concentrations, in the protein, of lysine and histidine increased significantly (P <0.01), whereas cystine concentration decreased significantly (P <0.001) with increasing protein weight. These changes were consistent with the assumption that there is a change in the proportion of total body protein as hair protein with increasing body protein weight, since lysine and histidine are present in relatively high proportions in the body (excluding hair) of the pigs, whereas cystine is present in particularly high concentrations in the hair. The concentration of an amino acid in the body of the pig could thus be expressed as a function of body protein weight; this allows for changes in the amino acid concentrations of the body protein as the animal increases in size.     

Tolerance of growing pigs to trypsin and chymotrypsin inhibitors in chickpeas (Cicer arietinum) and pigeonpeas (Cajanus cajan)

The threshold level of growing pigs to trypsin and chymotrypsin inhibitors was investigated by adding graded levels of meals rich in these inhibitors to diets and recording responses. Diets were formulated to contain either 250, 500 or 750 g kg^?1 of Opal chickpea, dehulled Tyson chickpea or dehulled pigeonpea meals and pig response compared to that of pigs given a wheat and soya-bean meal control. Trypsin inhibitor levels (mg g^?1) of the diets were, respectively, control, 0.2; chickpea meal 1, 1.2.32; chickpea meal 2, 1.7–4.7; pigeonpea meal, 1.4–3.6. Chymotrypsin inhibitor levels (mg g^?1) of the diets were, respectively, control, 0.2; chickpea meal 1. 0.9–2.2; chickpea meal 2, 1.6–4.5; pigeonpea meal. 0.8–2.1. The diets were offered ad libitum over the 20–50 kg growth phase. Growth responses of the pigs fed the two chickpea meals were similar to those of the pigs fed the control soya-bean meal diet (P>0.05). In contrast, the addition of pigeonpea meal linearly depressed growth rate (P<0.001), feed intake (P<0.05) and increased the feed conversion ratio (P<0.05), inclusion levels of the chickpea meals had no effect on organ weights, whereas the inclusion of pigeonpea meal significantly affected the weights of the liver and pancreas (P<0.05), indicating the presence of other anti-nutritional factors. The results indicate that the growing pig can tolerate dietary levels of at least 4.7 and 4.5 mg g^?1 of trypsin and chymotrypsin inhibitors, respectively. These threshold levels are unlikely to be exceeded in conventional diets containing the majority of grain legumes. The results also indicate that dehulled pigeonpea meal contains an anti-nutritional factor(s) for growing pigs.     

The influence of fibre level and fat supplementation in expander‐processed diets on grower–finisher pig performance

Seventy‐two entire male pigs (40.4 ± 1.0 kg) were used to study the effects of increasing crude fibre (CF) level in the diet and maintaining the digestible energy (DE) content of the diet by increasing dietary fat inclusion on pig performance and nutrient digestibility in a 3 × 2 factorial experiment. Productive performance and nutrient digestibility were determined in individually fed pigs offered expander‐processed pelleted diets ad libitum containing three levels of CF (50, 60 and 70 g kg^?1) and two levels of fat supplementation (25 and 50 g kg^?1) until slaughter at 100 kg. All diets were expander processed at 105 °C for 5 s at 35 bar pressure having been previously conditioned at 85 °C for 5 s. All diets were formulated to have similar concentrations of digestible energy (13.5 MJ kg^?1) and lysine (10 g kg^?1) and the fat source was a 60:40 blend of tallow and palm oil. The increase in dietary CF level decreased (P < 0.05) the apparent digestibility of crude protein, organic matter (OM) and energy, while the inclusion of 50 g kg^?1 fat decreased (P < 0.01) OM and energy digestibility. The inclusion of 50 g kg^?1 fat in the diet increased (P < 0.01) ether extract digestibility at the 50 and 60 g kg^?1 CF levels; however, fat inclusion had no effect at the 70 g kg^?1 CF level. There was no CF × fat interaction in any growth criteria. The inclusion of 50 g kg^?1 fat in the diet significantly reduced (P < 0.05) feed intake (2.28 versus 2.43 kg day^?1, SEM 0.039), average daily gain (ADG; 0.877 versus 0.927 kg day^?1, SEM 0.017) and DE conversion ratio (36.1 versus 35.0 MJ kg^?1, SEM 0.40). The increase in dietary CF level decreased (linear, P < 0.05) feed intake (2.45 versus 2.32 versus 2.29 kg day^?1, SEM 0.040), ADG (0.940 versus 0.896 versus 0.872 kg day^?1, SEM 0.021) and kill‐out proportion (740 versus 741 versus 730 g kg^?1, SEM 3.6). In conclusion, increasing both the CF level and supplementary fat inclusion rate had a negative effect on pig growth performance and nutrient digestibility. © 2002 Society of Chemical Industry     

Significance of Porcine Fat Quality in Meat Technology: A Review

Pork is the most important meat product globally. The aim of this review was to assess whether fat quality of pork is important in meat processing. Good quality backfat can be defined as firm and white. Problems associated with the use of poor fat quality (soft fat) in meat products were found to be insufficient drying, oily appearance, rancidity development, seperation between muscle, and adipose tissue on cutting. Criteria were set for good quality fat, in terms of physical properties and fatty acid composition. It was proposed that measurement of physical and chemical fat quality properties could serve as a guideline to assess good quality fat. Factors responsible for influencing fat quality were identified as backfat thickness, breed or race, age, slaughter weight, gender, growth promotors, diet, rearing conditions, and environmental temperature. We considered the influence of fat quality on the technological properties of fresh meat, raw fermented and cured sausages, cooked and uncooked cured, whole muscle meat products, and cooked and emulsion-type sausages. We concluded that saturated fats are needed to manufacture good quality products and that better technological properties of fat are thus associated with poorer health properties.     

Effect of surgical castration,immunocastration and chicory-diet on the meat quality and palatability of boars

This study evaluates 1) carcass quality, meat quality and palatability for barrows, immunocastrates and boars and 2) the effect of chicory supplemented feed during 10 days before slaughter on boar meat quality.     

Effect of preslaughter fasting on the characteristics of pig livers

Seventy-seven pigs of about 60 kg liveweight were killed in two experiments, which examined the influence of food deprivation preslaughter on the chemical composition, physical characteristics and eating quality of liver. In the first experiment pigs were fasted for 0, 24 or 48 hr before slaughter. Livers from fasted animals were lighter in weight ( P < 0.001) and contained proportionally slightly more water ( P < 0.001), fat ( P < 0.001) and protein ( P < 0.001) but very much less glycogen ( P < 0.001) and less lactate ( P < 0.001). They had higher pH values ( P < 0.001) both just after slaughter and during storage at 2°C for up to 72 hr. They were darker in colour initially ( P < 0.05) and after chilling for 72 hr ( P < 0.01) partly due to the higher ( P < 0.05) concentrations of haem pigments. The second experiment examined how these differences influenced eating quality. It included a control group killed 2 hr after food withdrawal and groups fasted for 12, 24 and 48 hr. After frying, livers from pigs fasted longer were found to be darker in appearance ( P < 0.001), less tender ( P < 0.001), less juicy ( P < 0.001) and, overall, less acceptable ( P < 0.001). Livers from pigs fasted longer also lost less weight during cooking ( P < 0.05) and were tougher ( P < 0.05) based on instrumental measurements. Livers from half of the pigs in each fasting group were stored at 2°C prior to assessment of eating quality; the remaining livers were frozen at −20°C. Freezing had small deleterious effects on the texture ( P < 0.01) and juiciness ( P < 0.05) of livers but did not influence mean overall acceptability.     

丝兰提取物对猪场环境污染及猪生长性能的影响

综述了丝兰提取物对猪粪尿除臭效果及猪生长性能的影响 ,在饲料中添加丝兰提取物 ,不但有明显促进猪生长、提高饲料转化率的作用 ,而且具有显著抑制猪场臭气的效果     

L-canavanine: A natural feed-intake inhibitor for pigs (isolation,identification and significance)

Abstract : A major feed-intake inhibitor for pigs is present in seeds of Vicia villosa spp dasycarpa Roth cv Namoi. When the seed is fed for 4 days at only 80 g kg^?1 of the diet, it produces a steady diminution in daily feed intake to 25% or less of their pre-treatment consumption (P < 0·001), after the first feeding. The inhibitor has been isolated and identified as L -canavanine. When analytically pure L -canavanine dihydrochloride is supplied at an equivalent dietary concentration (13·0 mmol kg^?1) to that supplied by 80 g kg^?1 of Namoi vetch seed, it successfully mimics the response. The response is only observed after the first meal. A review of published literature showed the diversity of animal species exhibiting a feed-inhibition response to canavanine-containing seeds. These reports suggest that this well-documented arginine analogue will be a useful molecule for the study of post-ingestion feed-intake regulation. An ambient temperature procedure for the large-scale isolation of L -canavanine dihydrochloride is described.     

The composition and consistency of pig backfat as it affects the quality of vacuum-packed rindless bacon rashers

Samples of adipose tissue from unsatisfactory, soft, vacuum-packs of rindless bacon rashers were compared with satisfactory harder samples to determine the factors responsible for the difference in consistency. Lipid from unsatisfactory packs contained significantly higher mean concentrations of unsaturated fatty acids, lower mean concentrations of saturated fatty acids and had a lower mean melting point and mean slip point. Discriminant analysis revealed that the samples were best differentiated according to their proportion of linoleic acid or by the ratio of stearic acid to linoleic acid. Linoleic acid was the best discriminator although stearic acid and palmitic acid were correlated best with the melting point and slip point of the lipid and with the force required to puncture the intact adipose tissue by a probe attached to an Instron materials testing machine. Samples which would give satisfactory firm packs, based on the data from discriminant analysis, required a puncture force greater than 7N. In terms of the spectrum of backfat consistency in British pigs, satisfactory bacon comes from hard backfat whereas the unsatisfactory packs come from backfat of medium consistency.     

高粱原花青素对生长育肥猪抗氧化、免疫以及养分消化率的影响

研究高粱原花青素(sorghum procyanidins,SPC)对生长育肥猪生长性能、养分消化率、消化酶活性、免疫力和抗氧化能力的影响。160头70日龄、平均体重为(31. 28±1. 12) kg的杜×长×大三元杂交猪,按照单因素完全随机设计分为4个组,分别饲喂玉米-豆粕基础日粮,以及基础日粮中添加100、150、200 mg/kg SPC。实验期为14周,生长期和育肥期各7周。在每个实验阶段开始和结束时称重,每天记录采食量,计算各阶段平均日增重(ADG)、平均日采食量(ADFI)和料重比(F/G)。在每个实验阶段的最后3 d,收集粪样测养分消化率。在每个实验阶段结束时,采血测血清抗氧化指数和免疫参数,同时,每个重复随机屠宰2头猪,取胰腺组织,测消化酶活性。结果表明,日粮添加SPC对生长育肥猪的生长性能没有显著的促进作用(P 0. 05)。在生长猪阶段,日粮添加150 mg/kg和200 mg/kg SPC显著降低了消化酶的活性,对养分消化率有降低的趋势。在育肥猪阶段,日粮添加150 mg/kg显著提高了粗蛋白的表观消化率(P 0. 05),200 mg/kg SPC显著地抑制了消化酶的活性(P 0. 05)。与对照组相比,不论是在生长期还是育肥期,添加150 mg/kg或200 mg/kg的SPC均显著地增强了猪血清谷胱甘肽过氧化物酶(GSH-Px)和超氧化物歧化酶(SOD)的活性以及血清总抗氧化能力(T-AOC)(P 0. 05),降低了血清丙二醛(MDA)浓度(P 0. 05),提高了猪血清IgG、IgM和白细胞介素2(IL-2)的浓度(P 0. 05)。总之,SPC有利于提高生长育肥猪抗氧化能力,增强免疫力,但是对于生长育肥猪的生长性能及养分消化率没有显著的促进作用,相反,高浓度的SPC甚至抑制了消化酶的活性,从而影响养分的消化利用。