Difficulties and Countermeasures in Harmless Treatment of Infected Pig Carcasses

This paper introduced the difficulties in the handling of infected pig carcasses,such as difficulty in finding,difficulty in collection and transportation,difficulty in facility construction,and difficulty in monitoring and supervision,etc.The reasons for these difficulties are shortcomings in the top-level design of the policy to the specific measures at the grassroots level.In view of these shortcomings,the author came up with some pertinent recommendations,including improving relevant regulations and policy measures,establishing a sound system and network for the collection,transportation and processing of infected pig carcasses,reinforcing punishment and strengthening linkage and cooperation between departments.

Evaluation of Nutritional Value and Safety of Black Soldier Flies Fed on Dead Pig Meat and Bone Meal

[Objectives]This study was conducted to evaluate the nutritional value and safety of black soldier flies fed with dead pig meat and bone meal(DPMBM)and to explore the resource utilization of DPMBM.[Methods]The general nutrient composition,amino acids,fatty acids and mineral elements of black soldier fly meal(BSLM)were detected and analyzed.[Results]The results showed that the contents of moisture,crude protein,crude fat and ash in BSLM were 3.42%,42.31%,34.04%and 5.40%,respectively.The contents of total amino acids(TAA),essential amino acids(∑EAA)and non-essential amino acids(∑NEAA)and umami amino acids(∑DAA),the EAA/TAA value and the EAA/NEAA value were 37.93%,13.08%,24.85%,13.43%,34.47%,52.61%,respectively.A total of eight kinds of saturated fatty acids and seven kinds of unsaturated fatty acids were detected,accounting for 63.65%and 32.67%of the total fatty acids.Among the major mineral elements,the content of Ca was the highest,followed by K,Mg and Na.Among the trace mineral elements,the content of Mn was the highest,followed by Fe,Zn,Cu,Ni,Cr,Cd,As,Pb,Se,Sn,Ti,Sb and Hg.The contents of heavy metal mineral elements in BSLM were far lower than the limits specified in Hygienical Standard for Feeds.[Conclusions]In conclusion,BSLM has high nutritional value and good safety of heavy metals,and thus great potential for development and utilization as a high quality dietary protein,fat and mineral elements source.

Studies on Reducing Nitrogen Excretion: Ⅰ. Net Energy Requirement of Finishing Pigs Maximizing Performance and Carcass Quality Fed Low Crude Protein Diets Supplemented with Crystalline Amino Acids

Two experiments were conducted to in- vestigate the effects of net energy （NE） level on the performance and carcass traits of finishing pigs fed low crude protein （CP） diets supplemented with crystalline amino acids （CAA）. A total of 216 （Exp. 1） and 360 （Exp. 2 ） barrows （ Yorkshire × Landrace× Duroc ） were allotted to one of six treatments （n =6）. The experimental diets were based on corn and soybean meal, and consisted of a high-CP diet that contained approximately 16% CP and 2.50 Mcal/kg of NE as well as five low-CP diets in which the CP level of the diet was reduced by approximately four percentage units but was supplemented with crystalline lysine, methionine, threonine, and tryptophan. The low CP diets provided 2.64, 2.58, 2.50, 2.42, or 2.36 Mcal/kg in Exp. 1 as well as 2.45, 2.40, 2.35, 2.30, or 2.25 Mcai/kg in Exp.2. In Exp. 1, a linear （P=0.03） increase in weight gain was observed with decreasing NE level while the ratio of gain to feed was unaffect- ed （P 〉 0.05） by NE level. There was a linear in-crease （P = 0.01 ） in the percentage of fat-free lean and a linear decrease （ P = 0.03 ） in the percentage of total fat with decreasing NE levels. In Exp. 2, a sig- nificant quadratic （ P = 0.03 ） effect of NE level was observed for weight gain. The ratio of gain to feed demonstrated a significant （P 〈0.01 ） quadratic effect with pigs fed 2.35 and 2.40 Mcal/kg of NE, Pigs fed the diet containing 2.40 Mcal/kg of NE had the lowest percentage of total fat （36. 95% ） and the highest percentage of fat-free lean （49.36%）. The overall results of these experiments indicate that feed- ing either a surplus or a deficiency of NE is detrimen- tal to both pig performance and carcass composition when low CP diets supplemented with CAA are fed. Our results indicate that when the CP content of the diet is reduced by four percentage units and the diet is properly supplemented with CAA, maximum per- formance and carcass quality will be obtained if the diet provides approximately 2.42 Mcal/kg of NE.

Effects of Dietary Net Energy Density and Standardized Ileal Digestible Lysine: Net Energy Ratio on the Performance and Carcass Characteristic of Growing-Finishing Pigs Fed Low Crude Protein Supplemented with Crystalline Amino Acids Diets

Two 3×3 factorial design trials with 1 080 of Yorkshire×Landrace×Duroc barrows were conducted to investigate the effects of dietary net energy （NE） density and standardized ileal digestible （SID） lysine：NE ratio on the performance of growing- finishing pigs and carcass characteristic of finishing pigs fed low crude protein （CP） supplemented with crystalline amino acids （CAA） diets. Low CP corn-soybean meal basal diets （14% for Exp. 1 and 11% for Exp. 2） supplemented with crystalline lysine, methionine, threonine, and tryptophan were formulated. Nine treatments with increasing NE density and SID lysine：NE ratio were used in each trial （Exp. 1： 9.66, 9.87, and 10.08 MJ kg-1 NE, 0.89, 0.96, and 1.03 g MJ-1 SID lysine： NE; Exp. 2： 9.83, 10.04, and 10.25 MJ kg-1 NE, 0.69, 0.76, and 0.83 g MJ-1 SID lysine：NE）. In Exp. 1, we observed that the average daily gain （ADG） for barrows that received the diet containing 9.87 MJ kg-1 NE was significantly higher than that of barrows fed a 9.66 MJ kg-1 NE diet （P0.05）, but no difference was observed when compared with barrows that received a diet containing 10.08 MJ kg-1 NE （P0.05）. The ADG was affected both linearly （P0.05） and quadratically （P0.05） as the SID lysine：NE ratio increased. The NE density or SID lysine：NE ratio and their interaction had no effect on the average daily feed intake （ADFI） and serum urea nitrogen （SUN） （P0.05）. The feed to gain ratio （F：G） decreased （linearly, P0.05; quadratically, P0.05） as the NE density or SID lysine：NE ratio increased, but no interaction of NE density and SID lysine： NE ratio on the F：G. In Exp. 2, the dietary NE density both linearly （P0.05） and quadratically （P0.05） affected the ADG and F：G. Barrows that received a diet containing 10.04 MJ kg-1 NE had a greater ADG （P0.05） than barrows that received a 9.83 MJ kg-1 diet, but there was no difference （P0.05） as compared with barrows that received a diet containing 10.25 MJ kg-1 NE. F：G was significantly higher （P0.05） for barrows that received a 9.83 MJ kg-1 diet when compared with barrows that received the other two diets. The ADG was significantly decreased （P0.05） for pigs that received a diet containing 0.69 g MJ-1 SID lysine：NE ratio when compared with pigs fed a diet containing 0.76 or 0.83 g MJ-1 SID lysine：NE ratio. The NE density or SID lysine：NE ratio and their interaction had no effect on the average daily feed intake, SUN, and carcass characteristic for finishing barrows （P0.05）. The overall results of the two experiments indicated that barrows that received the diet with the dietary CP level reduced 4 percentage units compared the NRC （1998） recommendations. Maximized the best performance with NE density and SID lysine：NE ratio were 9.87 MJ kg-1, 1.03 g MJ-1 NE for 20-50 kg pigs, and 10.04 MJ kg-1, 0.76 g MJ-1 NE for 60-100 kg pigs, respectively.

Imprinting Analysis of RTL1 and DIO3 Genes and Their Association with Carcass Traits in Pigs (Sus scrofa)

Imprinted genes play significant roles in the regulation of fetal growth, development, function of the placenta and postnatal behavior in mammals, but little is known in pigs. In order to investigate the imprinting status of porcine retro-transposon like 1 （RTL1） and type 3 iodothyronine deiodinase （DIO3） genes, DNA or RNA samples of the parents and F1 animals, generated with reciprocal crosses between Large White and Meishan breeds, were isolated, and analyzed by reverse transcription polymerase chain reaction restriction fragment length polymorphism （RT-PCR-RFLP）. The results demonstrated that the RTL1 gene was paternally expressed in 10 tissues, such as the skeletal muscle, heart, spleen, liver, kidney, lung, stomach, fat, small intestine and brain, and D103 gene exhibited paternal expression in the skeletal muscle, heart, spleen, lung, stomach, and brain, in 2-month-old pigs. The association of RTL1 and DI03 with carcass traits was further analyzed in the F2 population of Large White×Meishan pigs. The statistical results showed that the R TL1 A1101G polymorphism （EU781029） was significantly associated with lean meat percentage （LMP） and fat meat percentage （FMP） （P〈0.05）, while the D103 A744C polymorphism （AY533208） was not significantly associated with any carcass traits. These results indicate that the imprinting status of RTL1 and DIO3 is well kept across the mammalian species, and porcine RTL1 may have important roles in muscle growth and fat deposition.

Effects of Low Protein Diets Supplemented with Ami-no Acids on Production Performance,Carcass Qual-ity and Input-output Ratio of Pigs

[ Objectives ] To study the effects of low-protein diets supplemented with amino acids on the production performance, carcass quality and input-output ratio of fattening pigs and growing-finishing pigs. [ Methods] Two studies were conducted on fattening pigs and growing pigs respectively. Pigs in two experimental groupswere fed with low-protein diets supplemented with amino acids and normal diets respectively, and the initial weight, final weight, feed consumption and car- cass index of the tested pigs were measured. [ Results] The average final weight of fattening pigs in test group was 2.4 kg lower than that in control group, while the difference was not significant （P 〉 0.05 ）. The average daily gain of fattening pigs in test group was 60 g lower than that in control group, indicating that low protein diets had a tendency to decrease the growth rate （P 〉 0.05 ）, and reduction of daily weight gain in low protein diet pigs reached 7.6%. The development of pigs in low protein diet group was poor, however, the difference was not significant. Carcass backfat thickness in low-protein diet group was slightly higher than that in control group, the difference was significant （ P 〈 0.05 ）. There was no significant difference in input-output ratio between low-protein diet group and control group. Finalweight of growing-finishing pigs in low-protein diet group was 3.22 % lower than that in control group, the average daily weight gainwas 6.91% lower than that in control group, feed intake in test group was 5.48% lower than that in control group, and difference between the two treatments was significant （P 〈 0.05 ）. Feed meat ratio in low-protein diet group improved, however, the difference was not significant（P 〉0.05）. [ Conclusions] Production performance of the pigs would be decreasedand the input-output ratio could not be improvedwhen the adding contents of crude protein in diets was reduced 3% -4%. Therefore, it is recommended that the crude protein level should be enough when pigs were fed with low-protein diets.

Supplementation of different fat sources affects growth performance and carcass composition of finishing pigs

Background: There are various fat sources with different energy values and fatty acid compositions that may affect growth performance and carcass composition of grow-finishing pigs. A higher net energy was recently reported in choice white grease compared with soybean oil. Therefore, two experiments were conducted to determine whether practical responses confirm that difference between choice white grease and soybean oil, and to extend the observations to other fat sources.Results: In Exp. 1, pigs fed fats had lower(P < 0.05) average daily feed intake in phase II and overall period,greater(P < 0.05) gain:feed in phase I, phase II, and overall period than pigs fed the control diet. Pigs fed fats tended(P = 0.057) to have thicker backfat depth at the last rib than those fed control. Pigs fed 6% fats had greater(P < 0.01) gain:feed in phase II and overall period than pigs fed 3% fats. During phase I, pigs fed choice white grease grew faster(P < 0.05) than pigs fed soybean oil. In Exp. 2, pigs fed dietary fats(soybean oil, choice white grease, animal-vegetable blend, palm oil, or tallow) had greater(P < 0.01) gain:feed in each phase and overall period, greater(P < 0.01) average daily gain in phase I, but lower(P < 0.01) average daily feed intake in phase II an overall than pigs fed the control diets. The choice white grease also increased(P < 0.05) average daily gain during phase I compared with soybean oil. Pigs fed palm oil had thicker(P < 0.05) backfat depth at the 10 thrib than those fed soybean oil, animal-vegetable blend, or tallow.Conclusions: Inclusion of 6% dietary fat improved feed efficiency of finishing pigs, while different fats produced different practical results that may be consistent with their different energy values. Results from the early stage indicate that dietary fats with relatively more saturated fatty acids may provide greater energy than those with relatively more unsaturated fatty acids for growing pigs.

Effects of the standardized ileal digestible lysine to metabolizable energy ratio on performance and carcass characteristics of growing-finishing pigs

A total of 2,121 growing-finishing pigs （Duroc × Landrace ×Large White） were utilized in six experiments conducted to determine the effects of different ratios of standardized ileal digestible lysine （SID-Lys） to metabolizable energy （ME） on the performance and carcass characteristics of growing-finishing pigs. Exps. 1 （30 to 50 kg）, 2 （52 to 70 kg） and 3 （81 to 104 kg） were conducted to find an optimum ME level and then this level was used in Exps. 4 （29 to 47 kg）, 5 （54 to 76 kg） and 6 （84 to 109 kg） to test the response of pigs to different ratios of SID-Lys：ME. In Exps.1 to 3, four treatments were used consisting of diets with a formulated ME content of 3.1, 3.2, 3.3 or 3.4 in Exps. I and 2 while Exp. 3 used 3.05, 3.1 S, 3.25 or 3.35 Mcal/kg. A constant SID-Lys：ME ratio of 2.6, 2.3 or 2.0 g/Mcal was used in Exps. 1, 2 and 3, respectively. Weight gain was significantly increased with increasing energy level in Exp.1 while weight gain was unaltered in Exps. 2 and 3. For all three experiments, feed intake was decreased （P 〈 0.05） and feed efficiency was improved （P 〈 0.05） with increasing energy level. Tenth rib back fat thickness linearly increased （P 〈 0.05） with increasing energy level, in Exps. 4 to 6, five treatments were used consisting of diets with a SID-Lys：ME ratio of 2.4, 2.6, 2.8, 3.0 or 3.2 in Exp. 1, 2.1, 2.3, 2.5, 2.7, 2.9 or 3.2 in Exp. 2 and 1.8, 2.0, 2.2, 2.4, or 2.6 in Exp. 3. A constant ME level 3.2, 3.2 and 3.05 Mcal/kg was used in Exps. 1, 2 and 3, respectively （selected based on the results of weight gain）. For all three experiments, weight gain increased （P 〈 0.05） and feed efficiency improved linearly （P 〈 0.05） as the SID-Lys：ME ratio increased. Tenth rib back fat thickness linearly decreased （P 〈 0.0,5） as the SID-Lys：ME ratio increased. Based on a straight broken-line model, the estimated SID-Lys：ME ratio to maximize weight gain was 3.0, 2.43 and 2.2 for 29 to 47, 54 to76 and 84 to 109 kg of pigs, respectively.

Effect of N-methyl-aspartate and Betaine on Growth Perfor-mance and Correlation Between Growth Hormone,Growth Performance and Carcass Composition in Finishing Pigs

Ninety finishing pigs were selected to study the effect of N-methyl-aspartate and betaine on the internal growth hormone level in the serum and the correlation between the growth hormone level, growth performance and carcass characteristic of finishing pig. The study showed that the two matters could improve pig growth and carcass composition significantly. The correlation analyses indicated that the growth hormone and IGF-I have a positive correlation with the growth rate. Carcass lean ratio, longissimus dorsi area, serum free fatty acid and lipase activity have a negative correlation with the feed conversion ratio, carcass fat ratio and urine nitrogen. But the growth hormone is more effective than IGF-I (P<0.01). The results implicated that both the two matters may act through growth hormone axis (growth hormone - IGF-I) to manipulate pig growth.

Effects of liquid feeding of corn condensed distiller's solubles and whole stillage on growth performance, carcass characteristics, and sensory traits of pigs

Background： The immense growth in global bioethanol production has greatly increased the supply of by-products such as whole stillage and condensed distiller＇s solubles, which could be potentially used for animal feeding. The objective of this study was to investigate effects of liquid feeding high levels of corn condensed distiller＇s solubles（CCDS） and whole stillage（CWS） on growth performance, carcass characteristics, belly firmness and meat sensory traits of pigs.Methods： A total of 256 pigs were blocked by sex and initial BW（13.5 ± 2.5 kg）, and pens of pigs（8 pigs/pen） were randomly allocated to 1 of 4 dietary treatments（8 pens/treatment）： 1） corn-soybean meal based diet as control, 2） 25%CWS ＋ 5% CCDS, 3） 19.5% CWS ＋ 10.5% CCDS, and 4） 19.5, 26, and 32.5% CWS ＋ 10.5, 14, and 17.5% CCDS in phases 1（28 d）, 2（38 d）, and 3（60 d）, respectively. Inclusion levels of CCDS and CWS for Treatments 1, 2, and 3 were fixed during all the three phases of the experiment. Inclusion levels of CWS and CCDS were on 88% dry matter basis. The liquid feeding system delivered feed from the mixing tank to feed troughs by high-pressure air, had sensors inside feed troughs, and recorded daily feed intake on the basis of a reference feed intake curve. The pigs were fed 5 to 10 times per day with increasing frequency during the experiment.Results： Control pigs had greater（P 0.10） dressing percentage, loin muscle depth, and lean percentage were observed among the four treatments. Inclusion of CWS and CCDS reduced（P 0.10） the overall like,flavor, tenderness and juiciness of loin chops when compared with the control group.Conclusion： In conclusion, our results indicate that including 30–50% of a mixture of whole stillage and condensed distiller＇s solubles in the growing-finishing diets may reduce growth performance, carcass weight and belly firmness, but does not affect pork sensory traits.

Effect of Graded Levels of Wheat Distillers Grains with Solubles on Nutrient Digestibility,Performance and Carcass Traits of Growing-Finishing Pigs Fed Diets Based on Wheat and Field Peas

This trial was conducted to determine the effects of graded levels of wheat distillers dried grains with solubles （DDGS） on nutrient digestibility, performance and carcass characteristics of pigs （21.8 to 112.3 kg） fed diets based on wheat and field peas. Forty crossbred pigs were assigned on the basis of sex and weight to one of five dietary treatments in a 5 x 2 （treatment x sex） factorial arrangement. The experimental diets were based on wheat and field peas and were formulated to contain 0, 4.86%, 9.71%, 14.57% or 19.42% wheat DDGS during the growing period and 0, 4.01%, 8.05%, 12.10% and 16.14% wheat DDGS during the finishing period. At the highest levels, ~vheat DDGS supplied 100% of the supplementary protein. The digestibility coefficient for gross energy showed a tendency towards a linear decline （P 〈 0.08 ） as the level of wheat DDGS in the diet increased while digestibility coefficients for dry matter and crude protein were unaffected （P 〉 0. 05 ） by inclusion level of wheat DDGS. During the growing period （21.8 to 60.8 kg）, weight gain of pigs fed wheat DDGS declined （P〈0.01） linearly. The impairment in growth appeared to be associated with a decrease in feed in- take which also declined linearly （P 〈 0.01 ） with increasing inclusion level of wheat DDGS. Feed conversion was unaffected by level of wheat DDGS. During the finishing period （60.8 to 112.3 kg）, and over the entire experimental period （21.8 to 112.3 kg ）, weight gain and feed conversion declined linearly as the dietary inclusion level of wheat DDGS increased. Carcass traits were generally unaffected by the inclusion of wheat DDGS with the exception of a trend towards a linear （P = 0.10） reduction in lean yield and a linear increase （ P = 0.09） in loin fat as the level of wheat DDGS in the diet increased. Overall, these results suggest that wheat DDGS are inferior to field peas as a supplementary protein source for use in swine rations.

宣和猪生长与胴体性状的典型相关分析

为了揭示宣和猪生长与胴体性状的内在关系,选择了122头体重30 kg左右的宣和仔猪,在相同饲养管理条件下育肥,测定其生长性能,在体重达100 kg左右时进行屠宰测定,并对7个生长性状和6个胴体性状进行Pearson相关与典型相关分析。结果表明:大多数生长性状之间的Pearson相关均达到显著水平(P<0.05或P<0.01),其中,料重比与平均日增重的相关系数最高(r=-0.5851,P<0.01);胴体瘦肉率与眼肌面积、后腿比例均呈极显著正相关(P<0.01);平均日增重、体长与胴体直长,胸围、活体背膘厚与平均背膘厚,宰前活重与屠宰率呈显著正相关(P<0.05或P<0.01),但料重比与平均背膘厚、胴体直长,体长、体高与胴体瘦肉率,胸围、活体背膘厚与后腿比例显著负相关(P<0.05或P<0.01)。生长与胴体性状的第1、第2对典型相关系数分别为0.6777(P<0.001)和0.4797(P<0.001),共解释总相关信息的79.79%;两类性状之间的典型相关主要是由料重比与屠宰率、平均背膘厚的相关所引起的。综上,在宣和猪育种实践中,选择料重比有助于提高宣和猪的生长速率,同时也可能会降低屠宰率和增加平均背膘厚。

性别对五莲黑猪胴体性能及肉品质的影响比较

选择体重100 kg左右的五莲黑猪20头屠宰(10头阉割公猪,10头母猪),研究不同性别试验猪的胴体性能和肉品质。结果表明,性别对试验猪的胴体性能、背最长肌脂肪酸含量影响不显著,对肉的L值和剪切力及蛋氨酸、亮氨酸、酪氨酸、赖氨酸、鲜味氨基酸含量、鲜味氨基酸占总氨基酸比例影响显著。其中,与阉公猪组相比,母猪组肉的L值极显著提高9.97%(P<0.01),剪切力极显著降低31.05%(P<0.01),蛋氨酸和酪氨酸分别提高61.29%(P<0.05)、18.95%(P<0.01);亮氨酸、赖氨酸、鲜味氨基酸含量、鲜味氨基酸占总氨基酸比例阉公猪组分别比母猪组显著提高11.88%(P<0.05)、80.73%(P<0.05)、11.16%(P<0.05)、7.38%(P<0.05)。说明性别对五莲黑猪肉的部分氨基酸含量影响显著,对猪肉的品质有一定影响。

日粮中添加月桂酸对肥育猪胴体品质和肉品质的影响

试验旨在探究日粮中添加月桂酸对肥育猪胴体性状和肉品质的影响。选取体重为73.74±2.48 kg的杜×长×大三元杂交猪144头,公母各半,根据初始体重按照随机区组原则分为4个处理,每个处理6个重复,每个重复6头猪。对照组(0.00%月桂酸组)饲喂玉米-豆粕型基础日粮,试验组分别饲喂在基础日粮中添加0.25%、0.50%、1.00%月桂酸的试验日粮,月桂酸和豆油进行等能值替换,保证各组日粮总能相等,试验期为34 d。试验结束时,每个处理选取体重接近同性别平均体重的8头阉公猪屠宰,采集组织样品并测定胴体性状和肉品质。结果表明:随着日粮月桂酸水平的升高,肥育猪的末重(P<0.01)、平均日增重(ADG)和血清瘦素浓度(P=0.04)线性增加,甘油三酯(TG)水平呈二次升高的趋势(P=0.09),高密度脂蛋白胆固醇(HDL-C)水平呈线性升高的趋势(P=0.08);日粮中月桂酸水平的提高显著改变了肥育猪背最长肌中的脂肪酸组成(P<0.05);肥育猪的活体重、热胴体重、胴体长和腰荐结合处背膘厚也随日粮中月桂酸水平的提高呈线性增加(P<0.01),同样地,背最长肌pH24 h线性升高(P=0.02),L*24 h则线性降低(P=0.01)。总之,日粮中添加月桂酸提高了肥育猪的生长性能,显著改变了肌肉的脂肪酸组成,具有改善肥育猪胴体性状、肉品质以及调节脂质代谢和改善肉风味的潜在作用。

苜蓿多糖对育肥猪生长性能、胴体性状及肉品质的影响

文章旨在研究苜蓿多糖(Alfalfa Polysaccharides,APS)对育肥猪生长性能、胴体性状及肉品质的影响。试验将120只初始体重为(65.47±2.90)kg且健康状况良好的杜长大育肥猪随机分为4组,每组3个重复,每个重复10头。对照组育肥猪参考《猪饲养标准》(NY/T65-2004),饲喂玉米-豆粕型基础日粮,其余3组育肥猪分别在基础日粮中添加1000、2000、3000mg/kg苜蓿多糖。预饲期3d,试验期60d。结果显示:(1)随着苜蓿多糖添加水平的提高,育肥猪末重、平均日增重先上升后下降,料重比先下降后上升。与对照组相比,基础日粮添加2000、3000mg/kg苜蓿多糖能显著提高育肥猪的末重、平均日增重(P <0.05),且显著降低育肥猪的料重比(P <0.05)。(2)与对照组相比,基础日粮添加2000、3000mg/kg苜蓿多糖能显著提高育肥猪的宰前活重、胴体重量(P <0.05)。与对照组相比,基础日粮添加1000、2000、3000mg/kg苜蓿多糖能显著降低育肥猪的背膘厚度(P <0.05)。(3)试验组各项肉品质指标差异不显著(P> 0.05)。结论 :苜蓿多糖可提高育肥猪的生长性能和胴体性状,但对肉品质无显著影响,在本试验条件下,苜蓿多糖的适宜添加量为2000mg/kg。

北京黑猪GREB1L和MIB1基因多态性与肋骨数及胴体性状的关联分析

旨在开展GREB 1L和MIB 1基因多态性与肋骨数和胴体性状(胴体长、胴体直长、胴体斜长及胴体重)关联分析,筛选关键功能位点。本研究选取屠宰日龄为215天的317头健康北京黑猪,并提取耳组织DNA,对GREB 1L和MIB 1基因进行引物设计、并利用聚合酶链式反应(PCR)技术和Sanger测序技术等对SNPs进行基因分型,计算变异位点基因型频率以及等位基因频率分布,并与肋骨数和胴体性状进行关联分析。试验共筛选到6个SNPs,包括GREB 1L基因的3个同义突变、MIB 1基因的2个同义突变和1个内含子区的可变剪切突变。将6个SNPs分别对肋骨数和胴体性状使用Duncan’s多重检验统计分析发现,GREB 1L基因上的3个同义突变6:106574972 G>A、6:106648540 C>T、6:106648558 A>G与性状关联均不显著(P>0.05);MIB 1基因上的1个同义突变6:106936590 C>T与胴体长显著相关(P<0.05);而内含子15~16的6:107016475 A>G可变剪切突变与肋骨数显著相关(P<0.05);第三个同义突变6:107028660 G>A与肋骨数和胴体性状均无显著差异(P>0.05)。结果显示,显著的2个位点可作为北京黑猪肋骨数及胴体长变异的候选基因功能位点。

Effects of the Sheep Polyclonal Antibodies Against the Porcine Adipocyte Plasma Membrane Proteins on Porcine Carcass Composition and Meat Quality

To detect the effects of the polyclonal antibodies raised in sheep against porcine adipocyte plasma membranes on the porcine carcass composition and meat quality, 30 pigs assigned into 6 treatment groups were given intraperitoneal injections of sheep antipig adipocyte plasma membrane immunoglobulin （ASIg） or sheep nonimmune serum immunoglobulin （NSIg）. At the end of the experiment, the pigs were slaughtered at 90 kg body weight, and carcasses and meat quality were evaluated. The results showed that when pigs intraperitoneally immunized with 20 or 30 mg ASIg at 15 kg body weight, 20 mg purified ASIg twice at 15 and 60 kg body weight, or 20 mg purified ASIg at 60 kg body weight, respectively, their lean meat percentage, fat meat percentage, backfat thickness, loin eye area leaf fat weight, caul fat weight, heart weight, liver weight, and kidney weight were significantly affected. However, the kidney weight, lurrg weight, dressing percentage, and spleen weight did not remarkably change. Our results indicated that pigs intraperitoneally immunized with 20 or 30 mg ASIg at 15 kg body weight, and 20 mg ASIg twice at 15 and 60 kg body weight, have significantly different drip loss rate, cooked meat ratio, tenderness, storage loss rate, muscle fiber diameter, moisture content, dry matter content, crude protein content, and crude fat content from the control group that received 20 mg NSIg at 15 kg body weight. However, meat pH, meat color value, meat marbling score, inosinate, and myohemoglobin were not significantly affected. Our results indicated ASIg could not significantly affect the content of most muscular amino acids and intramuscular fatty acids.

Genome-Wide Association Study for Certain Carcass Traits and Organ Weights in a Large White×Minzhu Intercross Porcine Population

Porcine carcass traits and organ weights have important economic roles in the swine industry. A total of 576 animals from a Large White×Minzhu intercross population were genotyped using the Illumina PorcineSNP60K Beadchip and were phenotyped for 10 traits, speciifcally, backfat thickness （6-7 libs）, carcass length, carcass weight, foot weight, head weight, heart weight, leaf fat weight, liver weight, lung weight and slaughter body weight. The genome-wide association study （GWAS） was assessed by Genome Wide Rapid Association using the mixed model and regression-genomic control approach. A total of 31 single nucleotide polymorphisms （SNPs） （with the most signiifcant SNP being MARC0033464, P value=6.80×10-13） were located in a 9.76-Mb （31.24-41.00 Mb） region on SSC7 and were found to be signiifcantly associated with one or more carcass traits and organ weights. High percentage of phenotypic variance explanation was observed for each trait ranging from 31.21 to 67.42%. Linkage analysis revealed one haplotype block of 495 kb, in which the most signiifcant SNP being MARC0033464 was contained, on SSC7 at complete linkage disequilibrium. Annotation of the pig reference genome suggested 6 genes （GRM4, HMGA1, NUDT3, RPS10, SPDEF and PACSIN1） in this candidate linkage disequilibrium （LD） interval. Functional analysis indicated that the HMGA1 gene presents the prime biological candidate for carcass traits and organ weights in pig, with potential application in breeding programs.