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.

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.

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.

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.

巴民和松巴民杂交猪生长性能、胴体和肉质性状的比较研究

本试验旨在通过测定巴克夏公猪与民猪母猪的二元杂交猪(简称巴民猪)和松辽黑猪公猪与巴民母猪的三元杂交猪(简称松巴民猪)的生长性能、胴体和肉质性状,比较分析利用地方品种、地方培育品种和引进品种进行三元杂交的优势和可行性。试验选用出生日龄相近的巴民猪200头,松巴民猪196头,用于生长性能测定;选用100 kg体重的巴民猪50头,松巴民猪45头,屠宰用于测定胴体性状和肉质性状。结果表明,松巴民猪日增重和饲粮转化率显著高于巴民猪(P<0.05),校正至100 kg日龄和校正至100 kg体重背膘厚均显著低于巴民猪(P<0.05);松巴民猪平均背膘厚和肌内脂肪含量显著低于巴民猪(P<0.05),瘦肉率显著高于巴民猪(P<0.05),其他肉质指标差异不显著(P>0.05)。综上所述,松巴民猪生长速度和饲料利用率均高于巴民猪,瘦肉率亦有所提高,肌内脂肪含量虽有所下降,但也达到了4%,保持了民猪的优良肉质特性,因此饲养松巴民三元杂交猪将具有更高的经济效益。

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。

益生菌发酵中草药对育肥猪胴体性状及肉品质的影响

为了探讨益生菌发酵中草药对育肥猪胴体性状和肉品质的影响。试验选择72头体重为(25.00±0.50 kg)的杜×长×大三元杂交猪作为试验研究对象,随机分成4组,每组3个重复,每个重复6头。试验Ⅰ组(对照组)饲喂基础日粮,试验Ⅱ组(基础日粮+1%发酵中草药)、试验Ⅲ组(基础日粮+2%发酵中草药)和试验Ⅳ组(基础日粮+3%发酵中草药)。预试期1周,正试期12周,统计分析各试验组的胴体性状指标和肉品质指标。结果显示:与试验Ⅰ组相比,试验Ⅲ和Ⅳ组显著提高了育肥猪的胴体重、屠宰率和胴体瘦肉率(P<0.05);育肥猪的肌肉嫩度、肌内脂肪和大理石花纹明显改善(P<0.05),同时提高了猪肉中蛋白水平,降低了粗脂肪和挥发性盐基氮含量(P<0.05)。结果表明,益生菌发酵中草药可以提高育肥猪的胴体性状指标及改善猪肉品质,发酵中草药适宜添加量为3%。

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。

猪胴体重在线分级预测线性回归模型研究

[目的]针对国内大多数屠宰企业仍通过人工测量猪胴体背膘厚度,再结合胴体重对其进行分级,存在劳动强度大、作业效率低、人畜交叉污染风险高等问题,本文旨在建立猪胴体重预测模型,以便利用图像处理等技术获取模型中的相关参数,进而获得胴体重。[方法]在14:00—15:00、15:20—16:20、16:30—17:30三个时段内,随机选取按照标准化工艺屠宰后15 min左右、胴体重50~90 kg的猪胴体60头,在完成各试样前腿处横长(L_(f))、1/2处横长(L_( 1/2))、后腿处横长(L_(r))、1/2处背膘厚度(t_(1/2))、胴体直长(L_(t))及胴体重(w)等参数测定的基础上,建立不同的胴体重预测模型并进行优化及准确率验证。[结果]采用横长加权均值(L_(e))代替背膘厚度,与直长建立的胴体重预测模型为w=4.05L_(e)+0.45 L_(t)-116.32,其决定系数由0.48提高到0.96(P=0.01),预测准确率最高达94.16%。[结论]采用横长加权均值减小了误差,建立的猪胴体重预测模型准确性较其他模型高。

饲粮粗纤维水平对猪生长性能、胴体性状及肉品质的影响

【目的】探讨饲粮粗纤维(CF)水平对育肥期马身猪和杜洛克猪×长白猪×大白猪(杜长大猪)生长性能、胴体性状及肉品质的影响,为猪精准营养需要量构建和优质猪肉的生产提供理论依据。【方法】选取体重为(49.67±5.85) kg的健康马身猪和杜长大猪各80头,品种内随机分为4组,每组5个重复,每个重复4头猪,各组猪分别饲喂粗纤维水平为2%、5%、8%和11%的饲粮,分别记为2%CF、5%CF、8%CF、11%CF组。预试期7 d,正试期30 d。试验结束后,每个处理挑选体重接近平均值的3头猪屠宰,测定胴体性状和肉品质指标。【结果】饲粮粗纤维水平显著影响猪的生长性能,其中11%CF组马身猪平均日增重显著低于其他3组(P<0.05),11%CF组杜长大猪料重比显著高于其他3组(P<0.05)。饲粮粗纤维水平对猪的背膘厚、眼肌面积和后腿比例等胴体性状有显著影响,其中2%CF组马身猪背膘厚显著高于其他3组(P<0.05),11%CF组杜长大猪背膘厚显著低于其他3组(P<0.05);随着粗纤维水平的提高,眼肌面积呈逐渐增大趋势,在马身猪和杜长大猪中均表现为11%CF组的眼肌面积极显著高于其他3组(P<0.01),8%CF组显著高于2%CF和5%CF组(P<0.05);5%CF和8%CF组马身猪后腿比例显著高于其他2组(P<0.05)。饲粮粗纤维水平对猪肉品质有显著影响,其中2%和5%CF组马身猪肌内脂肪含量极显著高于其他2组(P<0.01);5%CF组马身猪胱氨酸含量显著高于其他3组(P<0.05),2%CF组蛋氨酸含量显著低于其他3组(P<0.05);8%CF组马身猪棕榈酸、硬脂酸、油酸和亚油酸含量均为最高,而杜长大猪的变化趋势则相反。【结论】马身猪在饲喂8%粗纤维水平饲粮时,饲料转化率升高,背膘厚降低,眼肌面积增大,肉色得到改善;杜长大猪在饲喂5%粗纤维水平饲粮时,日增重增加,饲料转化率提高,眼肌面积增大,胴体性状和肌肉嫩度较好。

青贮果穗玉米对生长育肥猪生长性能和猪肉品质的影响

为研究饲粮中添加青贮果穗玉米对生长育肥猪生长性能、胴体性状及肌肉品质的影响,本试验以192头日龄相近,初始体重为(36.82±1.50) kg的“杜×长×大”商品猪为研究对象,随机分为对照组和试验组(Ⅰ、Ⅱ、Ⅲ),每组4个重复。对照组饲喂基础饲粮,试验组在生长阶段(54 d)分别饲喂含15%、30%和45%青贮果穗玉米的试验饲粮,育肥阶段(62 d)分别饲喂含23%、46%和69%青贮果穗玉米的试验饲粮。结果表明,青贮果穗玉米饲粮对生长育肥猪胴体性状和肌肉品质各项指标无显著影响。对照、试验Ⅲ组全期平均日增重显著低于试验Ⅰ组(P<0.05),其他生长性能指标无显著影响。试验Ⅲ组肌肉亚油酸含量较对照组显著增加36.22%(P<0.05),粗脂肪含量较对照组和试验Ⅰ组显著降低(P<0.05)。综上可知,猪生长、育肥阶段饲粮适宜的青贮果穗玉米含量比例分别为15%~30%和23%~46%,可为其在生长育肥猪上的推广应用提供数据支撑。

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。