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1.
在提供充分营养水平的条件下 ,通过饲养试验和屠宰试验测定华南地区杜× (大×长 )生长肥育猪在 2 0～ 10 0kg的生产性能、胴体品质和无脂瘦肉生长速度。结果 :①公、母猪平均日增重、日采食量和饲料转化率分别为 0 .74kg/d、1.88kg/d和 2 .5 6。② 10 0kg体重时的热胴体重、最后肋背脂厚度、第 10肋背脂厚度、第 10肋眼肌面积、屠宰率和瘦肉率分别为 73.2kg、1.83cm、2 .13cm、4 1.4 0cm2 、74 .0 5 %、6 0 .39% ;③胴体无脂瘦肉生长速度为 2 88g/d。 相似文献
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杜×长×大生长育肥猪体蛋白沉积模型及氨基酸需要量预测的研究 总被引：1，自引：0，他引：1
为了验证NRC(1998)生长模型的参数对中国杜×长×大生长育肥猪的适用性并确定其氨基酸需要量,试验选用体重约20kg的杜×长×大公猪和母猪各27头,通过饲养试验和屠宰试验测定了20～35、35～50、50～80、80～100kg阶段猪的生长性能、无脂瘦肉生长指数,并预测其氨基酸需要量。试验结果表明:试验猪的全期日增重、日采食量、料重比分别为782、2147g/d和2.739;试验猪全期胴体无脂瘦肉生长指数为312.1g/d;体蛋白沉积动态模型为公猪Y(g/d)=74.588 1.5375BW-0.0104BW2(R2=0.9085);母猪Y(g/d)=77.753 1.4617BW-0.0119BW2(R2=0.8375);真可消化赖氨酸需要模型为公猪Y(mg/d)=8951 184.5BW-1.25BW2 36BW0.75;母猪Y(mg/d)=9330 175.4BW-1.43BW2 36BW0.75。 相似文献
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华南地区杜×(大×长)生长肥育猪的生产性能、瘦肉生长速度和营养需要量预测的研究 总被引：5，自引：0，他引：5
为验证NRC(1998)猪营养需要模型 ,进而建立我国生长肥育猪营养需要模型 ,本试验选用华南地区杜× (大×长 )生长肥育猪 ,测定其在20～100kg 的生产性能、无脂瘦肉生长速度 ,并预测其营养需要量。结果表明 :①猪平均日增重、日采食量和料重比分别为737g/d、1883g/d和2.56:1。②采用剥离胴体瘦肉实测的胴体无脂瘦肉生长速度为288g/d ,采用胴体指标估测的值为285g/d和292g/d。③用实测的无脂瘦肉生长速度建立了赖氨酸需要量的数学模型 :真可消化赖氨酸需要量 (mg/d )=7652.7059 +115.36W +1.1718W 2-0.01882W3+36W0.75。 相似文献
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长×荣杂交猪体蛋白沉白觉积模型及氨基酸需要量的预测 总被引：2，自引：0，他引：2
以长×荣二元杂交猪为研究对象,通过饲养试验和屠宰试验,测定了试验猪20～35、35～50、50～80、80～100 kg阶段的生产性能和胴体无脂瘦肉生长指数(胴体无脂瘦肉沉积速度).试验结果表明试验猪全期日增重平均为762 g,平均日采食量2 153 g,饲料报酬(F/G)2.787,各生产性能公母间差异不显著(P > 0.05);日增重与体重的回归方程为ADG(g/d)=293.03+15.1BW-0.1 034BW2(R2= 0.9988);试验猪全期胴体无脂瘦肉生长指数为227 g/d;体蛋白沉积模型Y(g/d)=72.211-1.5275BW+0.0648BW2-0.0005BW3(R2= 0.955) ;真可消化赖氨酸需要模型Y(mg/d)= 8 665.41-183.3BW+7.7788BW2-0.0612BW3+36BW0.75,据此模型推算出20～50、50～80、80～100 kg阶段真可消化赖氨酸需要量分别为9.67、13.63和11.61 g/d,总赖氨酸需要量为11.12、15.76和13.42 g/d,真可消化赖氨酸按占风干日粮的百分比表示为0.61 %、0.56 %和0.41 %,总赖氨酸需要量按占风干日粮的百分比表示为0.70 %、0.64 %和0.47 %,其他必需氨基酸需要量按NRC(1998)推荐的理想蛋白模式及各种表示方法的转换系数进行计算. 相似文献
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为了验证NRC(1998)生长模型对我国长×荣二元杂交仔猪的适用性并确定其氨基酸需要量,试验选用体重约10kg的长×荣公猪和母猪各15头,通过饲养试验和屠宰试验测定其生产性能、胴体无脂瘦肉生长指数及胴体成分,结合杨飞云等(2002)20～100kg长×荣生长肥育猪的试验结果,建立日增重与体重、胴体无脂瘦肉生长指数与体重、体蛋白沉积速度与体重之间的回归方程。根据胴体无脂瘦肉生长指数与体重的回归方程以及无脂瘦肉的蛋白质沉积系数和蛋白质沉积的赖氨酸需要系数,建立长×荣杂交猪赖氨酸需要量的数学模型,利用此数学模型预测10～20kg长×荣杂交猪的氨基酸需要量,并用全胴体法进行验证。试验结果显示:①根据NRC(1998)生长模型,用胴体分离法建立10～100kg长×荣杂交猪赖氨酸需要量的数学模型为:真可消化赖氨酸需要量(mg/d)=-0.0515BW3+5.5412BW2-16.904BW+5189.6+36BW0.75,据此模型计算10～20kg长×荣杂交猪的真可消化赖氨酸需要量为6.28g/d,总赖氨酸需要量为7.26g/d;按占风干日粮百分比表示的真可消化赖氨酸需要量为0.69%,总赖氨酸需要量为0.80%。其它必需氨基酸的需要量按NRC(1998)推荐的理想蛋白氨基酸模式中各种氨基酸与赖氨酸的比例计算;②用全胴体法测得10～20kg长×荣杂交猪的赖氨酸沉积速度为5.32g/d,? 相似文献
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三种营养需要模式对生长肥育猪生产性能、胴体品质和瘦肉生长的影响 总被引：5，自引：0，他引：5
试验选用体重约20.4kg的三元杂交[杜×(大×长)]猪96头 ,分为3个处理 ,每个处理4个重复 ,分别饲喂3种营养需要模式的饲粮 ,生长期猪体重为20～50kg,肥育期为50～92kg,研究3种营养需要模式对生长肥育猪生产性能、胴体品质和胴体瘦肉生长的影响。结果表明 ,采用建议的营养需要模式配制的饲粮饲养生长肥育猪 ,获得的生产性能、胴体品质、胴体瘦肉增重和无脂瘦肉增重以及胴体瘦肉成分与采用NRC(1998)营养需要模式配制的饲粮相近 ,而且20～90kg 期间无脂瘦肉增重已达到NRC(1998)认为的具有中-高瘦肉生长速度。采用中国(1987)营养需要模式配制的饲粮饲养生长肥育猪 ,其生产性能、胴体瘦肉增重和无脂瘦肉增重都极显著低于上述两种营养需要模式的饲粮 ,综合胴体品质也较差。从本试验结果看来 ,建议的营养需要模式可满足杜×(大×长)生长肥育猪的需要 相似文献
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为了研究性别对长白×荣昌(以下简称长×荣)仔猪赖氨酸需要量的影响,试验选用体重约10kg的长×荣杂交猪30头(公母各半),通过饲养试验和屠宰试验测定其生产性能和胴体无脂瘦肉生长指数,结合杨飞云等(2002)20～100kg长×荣生长肥育猪的试验结果,建立胴体无脂瘦肉生长指数与体重的回归方程。根据该方程及无脂瘦肉的蛋白质沉积系数和蛋白质沉积的赖氨酸需要系数,建立不同性别长×荣杂交猪的赖氨酸需要量模型,利用此模型预测10～20kg不同性别长×荣杂交猪的赖氨酸需要量。试验结果显示:根据NRC(1998)生长模型的参数,用胴体分离法建立10～100kg长×荣杂交猪的赖氨酸需要量模型为:公猪真可消化赖氨酸需要量(mg/d)=-0.0531BW3+5.7592BW2-22.522BW+5255.6+36BW0.75,母猪真可消化赖氨酸需要量(mg/d)=-0.0499BW3+5.3233BW2-11.286BW+5123.5+36BW0.75;据此模型计算10～20kg长×荣公猪和母猪的真可消化赖氨酸需要量分别为6.308g/d、6.258g/d,总赖氨酸需要量为7.264g/d、7.197g/d;按占风干日粮百分比表示,公猪和母猪的真可消化赖氨酸需要量分别为0.689%、0.693%,总赖氨酸需要量分别为0.793%、0.797%;用NRC(1998)生长模型胴体分离法估测的10～20kg不同性别长×荣杂交猪的赖氨酸需要量相近,说明性别对长×荣仔猪赖氨酸需要量的影响很小。 相似文献
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试验选用1003头公猪和母猪(PIC猪327×1050,初始体重113.5磅),旨在研究饲粮中不同氨基酸平衡水平对生长-育肥猪生长性能和胴体品质的影响。其中饲粮中涉及到的平衡氨基酸组成依照理想氨基酸模式,至少考虑4种必需氨基酸:赖氨酸,苏氨酸,蛋氨酸和色氨酸,其他氨基酸添加水平不低于其推荐水平。试验期为88天,共2个阶段,分别为生长阶段0-28天,育成阶段28-88天。试验分为3个处理,每个处理13个重复(7个重复母猪,6个重复公猪),每个重复27头。处理1饲粮中平衡氨基酸组成满足NRC(1998)推荐水平,处理2饲粮中平衡氨基酸组成满足赢创德固赛公司推荐水平,处理2饲粮中平衡氨基酸组成高于赢创德固赛公司推荐水10%(增加氨基酸营养密度)。结果显示,性别和处理饲粮对生长-育肥猪生长性能和胴体品质不存在交互作用(P>0.30)。生长阶段,提高饲粮氨基酸营养密度可显著提高生长猪平均日增重和料重比(线性分析,P<0.03);其中母猪平均日采食量(P<0.001)和料重比(P<0.001)显著低于公猪。育肥阶段,各个处理组在平均日增重、平均日采食量和料重比方面无显著影响(P>0.62),但母猪平均日增重、平均日采食量显著低于公猪(P<0.001)。整个试验阶段,饲粮中增加氨基酸营养密度可显著改善料重比(线性分析,P<0.04),提高平均日增重趋势(线性分析,P<0.06)。屠宰性能方面,屠宰率、背膘厚、腰肌厚、瘦肉率以及收入/支出比无显著差异。结果表明,对于生长-育肥猪来说,生长阶段饲粮中氨基酸营养密度(特别是赖氨酸水平)高于NRC(1998)推荐值,可有效改善生长猪的生长性能,但对育肥阶段效果不明显。 相似文献
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Live animal and carcass data were collected from market barrows and gilts (n = 120) slaughtered at a regional commercial slaughter facility to develop and test prediction equations to estimate carcass composition from live animal and carcass ultrasonic measurements. Data from 60 animals were used to develop these equations. Best results were obtained in predicting weight and percentage of boneless cuts (ham, loin, and shoulder) and less accuracy was obtained for predicting weight and ratio of trimmed, bone-in cuts. Independent variables analyzed for the live models were live weight, sex, ultrasonic fat at first rib, last rib, and last lumbar vertebra, and muscle depth at last rib. Independent variables for the carcass models included hot carcass weight, sex of carcass, and carcass ultrasonic measurements for fat at the first rib, last rib, last lumbar vertebra, and muscle depth at last rib. Equations were tested against an independent set of experimental animals (n = 60). Equations for predicting weight of lean cuts, boneless lean cuts, fat-standardized lean, and percentage of fat-standardized lean were most accurate from both live animal and carcass measurements with R2 values between .75 and .88. The results from this study, under commercial conditions, suggest that although live animal or carcass weight and sex were the greatest contributors to variation in carcass composition, ultrasonography can be a noninvasive means of differentiating value, especially for fat-standardized lean and weight of boneless cuts. 相似文献
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Crossbred pigs (n = 200) from Duroc sires mated to Landrace x Large White dams, with a mean BW of 107.0 +/- 2.4 kg and intended for highquality dry-cured hams (Teruel ham) from Spain, were used to investigate the effects of sex (barrows and gilts) and slaughter weight (SW; 120, 125, 130, 135, and 140 kg of BW) on growth performance and carcass characteristics. For productive performance, there were 5 treatments based on 5 SW; each treatment was replicated 4 times and the replicate was a pen made up of 5 barrows and 5 gilts allotted together. For carcass traits, there were 10 treatments based on 2 sexes and 5 SW; each treatment was replicated 20 times and the replicate was a carcass. Barrows had fatter carcasses (P < 0.001) and wider hams (P < 0.01) but a lower yield of trimmed shoulder (P < 0.05), loin (P < 0.001), and ham (P < 0.001) than gilts. Also, castrates tended to show a greater proportion of final suitable carcasses for Teruel ham (P < 0.10) than females because more barrows than gilts fulfilled the minimum requirement of carcass weight and fat thickness in the gluteus medius (GM) muscle (P < 0.01). An increase in SW tended to decrease ADG and G:F (P < 0.10). In addition, dressing percentage, fat, and dimensions of carcass and ham increased as SW increased (P < 0.001). Although the weight of trimmed primal cuts (shoulder, loin, and ham) increased with SW, the yield of trimmed loin or ham decreased (P < 0.01). The proportion of final suitable carcasses for Teruel ham improved as SW increased up to 130 kg of BW but not thereafter (P < 0.001) because of an increase in percentage carcasses that fulfilled the minimum carcass and ham weight (P < 0.001) and fat in GM (P < 0.05). We can conclude that barrows were better than gilts when intended for Teruel ham. Furthermore, an increase in SW up to 130 kg in pigs impaired growth performance but improved some aspects of carcass quality that are required by the Teruel ham industry. 相似文献
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Cline TR Cromwell GL Crenshaw TD Ewan RC Hamilton CR Lewis AJ Mahan DC Southern LL 《Journal of animal science》2000,78(4):987-992
A cooperative research study involving 635 gilts was conducted at eight research stations to further estimate the lysine requirement of finishing gilts. Dietary crude protein levels of the five dietary treatments ranged from 16.0 to 24.4% with calculated lysine levels of .80, .95, 1.10, 1.25, or 1.40%. Each station contributed a minimum of two replicate pens of pigs per treatment. Average initial and final weights were 53.6 and 116.4 kg, respectively. At the end of the experimental period, pigs were killed and hot carcass weight, 10th-rib fat depth, and longissimus muscle area were measured. Carcass fat-free lean percentage and fat-free lean gain were estimated from these data. Daily lysine intakes averaged 21.8, 25.9, 30.5, 34.3, and 37.8 g/d for the five treatment groups, respectively. Increasing the dietary lysine from .80 to .95% numerically increased weight gain and gain:feed, but these increases were not maintained at higher levels of dietary lysine. Overall, rate and efficiency of gain decreased (cubic, P < .01) with increasing dietary lysine. Carcasses were leaner at the two higher levels of dietary lysine as evidenced by reduced 10th rib backfat (linear, P < .01), increased longissimus area (quadratic, P < .04), and increased percentage of estimated fat-free lean (linear, P < .01). Carcass fat-free lean gain was not influenced by dietary lysine except for a small numerical improvement (P < .11) at the .95% level of dietary lysine that paralleled the improvement in body weight gain. The results indicate that the dietary lysine requirement of finishing gilts with a mean carcass fat-free lean growth rate of 306 g/d from 54 to 116 kg body weight is probably no higher than .80% of the diet to achieve maximum rate and efficiency of body weight gain and carcass lean growth rate. The results also indicate that higher dietary lysine levels may increase carcass leanness in finishing gilts, possibly due to reduced intake of NE. Whether this response is due to the effects of lysine alone, protein (i.e., other amino acids), or soybean meal is unknown. 相似文献
14.
This study was conducted to model the growth of carcass, viscera, and empty body components and component composition of pigs. Quantitative tissue and chemical composition of 319 swine, representative of barrows and gilts from five commercial genetic populations, was determined at eight stages of growth between 25 and 152 kg. After whole body grinding and carcass dissection, proximate analyses were performed to calculate concentrations of protein, lipid, moisture, and ash of carcass, viscera, empty body, carcass lean, and carcass fat. Linear and nonlinear equations were developed to investigate the growth patterns of each component. Nonlinear growth functions accounted for the greatest amount of variation in empty body protein, lipid, moisture, and ash mass. Differences (P < .05) existed between barrows and gilts for nearly all components investigated. Carcass lean and fat tissues significantly increased in lipid percentage and decreased in moisture percentage as live weight increased. There were significant changes in the ratio and composition of the tissues of barrows and gilts during growth. Nonlinear models fitted the data better than allometric equations for nearly all of the components investigated. 相似文献
15.
Wiseman TG Mahan DC Peters JC Fastinger ND Ching S Kim YY 《Journal of animal science》2007,85(7):1825-1835
Barrows and gilts of 2 genetic lines with differing lean gain potentials (high-lean = 375 g of fat-free lean/d; low-lean = 280 g of fat-free lean/d) were used to determine tissue and organ weights and compositions from 20 to 125 kg of BW. The experiment was a 2 (genetic line) x 2 (sex) x 5 (BW) factorial arrangement of treatments in a completely randomized design conducted with 2 groups of pigs in 6 replicates (n = 120 pigs). Six pigs from each sex and genetic line were slaughtered at 20 kg of BW and at 25 kg of BW intervals to 125 kg of BW. At slaughter, the internal tissues and organs were weighed. Loin and ham muscles were dissected from the carcass and trimmed of skin and external fat, and the ham was deboned. Residuals from the loin and ham were combined with the remaining carcass. Body components were ground, and their compositions were determined. The results demonstrated that tissue weights increased (P < 0.01) as BW increased. Loin and ham muscle weights increased but at a greater rate in the high-lean line and in gilts resulting in genetic line x BW and sex x BW interactions (P < 0.01). Liver and heart expressed on a BW or a percentage of empty BW basis increased at a greater rate in the high-lean line resulting in a genetic line x BW interaction (P < 0.01). Liver and intestinal tract weights were heavier in barrows than in gilts, significant only at 45 (P < 0.05), 75 (P < 0.01), and 100 (P < 0.05) kg of BW. Loin and ham muscles from the high-lean genetic line and gilts had greater (P < 0.01) water, protein, and ash contents compared with the low-lean genetic line and barrows resulting in genetic line x BW and sex x BW interactions (P < 0.01). The remaining carcass (minus loin and ham muscles) had greater (P < 0.01) amounts of water and protein, and less (P < 0.01) fat in the high-lean genetic line and gilts. The high-lean genetic line and gilts had more total body water, protein, and ash, but less body fat, with these differences diverging as BW increased, resulting in a genetic line x BW interaction (P < 0.01). The results indicated that liver and heart weights were greater in high-lean pigs, reflecting the greater amino acid metabolism, whereas the liver and intestinal tract weights were greater in barrow than gilts, reflecting their greater feed intakes and metabolism of total nutrients consumed. 相似文献
16.
Two experiments were conducted to determine the effect of substituting a more available dietary carbohydrate (CHO) for portions of corn or fat in the diet on growth performance, carcass traits, meat quality, and serum or plasma metabolites in growing-finishing pigs. A three-phase feeding program was used with corn-soybean meal diets formulated to provide 105% of the Lys requirement for barrows or gilts gaining 325 g of lean daily in Exp. 1 or gilts gaining 350 g of lean daily in Exp. 2. Diets were isoenergetic within experiments. All other nutrients met or exceeded suggested requirements. In Exp. 1, pigs were allotted to three dietary treatments (0, 7.5, or 15.0% sucrose), with three replications of barrows and three replications of gilts, and with three or four pigs per replicate pen; average initial and final BW were 25.2 and 106.7 kg. In Exp. 2, gilts were allotted to two dietary treatments (waxy [high amylopectin] or nonwaxy [75% amylopectin and 25% amylose] corn as the grain source), with five replications of four gilts per replicate pen; average initial and final BW were 37.7 and 100.0 kg. In Exp. 1, ADG and gain:feed ratio increased linearly (P < 0.02) as dietary sucrose increased. Minolta color scores, a* and b*, and drip loss (P < 0.06) also increased linearly with added sucrose. In Exp. 2, ADG, carcass weight and length, and the Minolta a* value were greater for pigs fed waxy corn (P < 0.08) than for those fed nonwaxy corn. Feed intake, longissimus muscle area, 10th-rib and average backfat thickness, dressing percentage, fat-free lean, percentage of lean and muscling, lean gain per day, total fat, percentage fat, lean:fat ratio, serum or plasma metabolites (Exp. 1: serum urea N; Exp. 2: serum urea N, and plasma nonesterified fatty acids, triacylglycerols, total and high-density lipoprotein cholesterol, insulin, and total protein), pH of the longissimus muscle, and subjective muscle scores (color, firmness-wetness, and marbling) were not affected by diet in either experiment. In summary, increasing availability of dietary CHO in growing-finishing pig diets improved growth performance, but it did not affect carcass traits. 相似文献
17.
Effect of dietary lysine level and environmental temperature during the finishing phase on the intramuscular fat content of pork 总被引：8，自引：0，他引：8
This study was designed to investigate the effects of dietary lysine level on the intramuscular fat content of the longissimus in finishing pigs reared at two environmental temperatures. Seventy-two hybrid gilts were individually penned and given ad libitum access to either a diet formulated to meet their lysine requirement (6.4 g/kg lysine) or a lysine-deficient diet (4.8 g/kg). Pigs were held at one of two environmental temperatures (thermoneutral [18 degrees C] or hot [32 degrees C]). The study was carried out between approximately 90 and 126 kg live weight; pigs in the thermoneutral and hot environments were on test for 5 and 7 wk, respectively. There were no interactions between dietary lysine level and environmental temperature. Dietary lysine content did not influence feed intake or average daily gain; however, pigs on the lysine-deficient diet had a poorer gain:feed ratio than those fed to requirement (P < .01). High environmental temperature decreased feed intake (P < .001) and average daily gain (P < .01) but improved gain:feed ratio (P < .01). Backfat at the 10th rib was increased and loin eye area and estimated percentage lean in the carcass were decreased for pigs on the lysine-deficient diet. The higher environmental temperature resulted in an increase in carcass length but had no effect on other carcass measurements or intramuscular fat. Feeding the lysine-deficient diet resulted in an increase of .55 percentage unit in longissimus intramuscular fat content (P < .01); however, there was no difference in subjective marbling scores between the diets. Warner-Bratzler shear force values were not affected by dietary lysine level or environmental temperature. Results from this study suggest that feeding of lysine-deficient diets at the end of the finishing period can increase intramuscular fat deposition under thermoneutral and hot conditions. 相似文献
18.
Benz JM Tokach MD Dritz SS Nelssen JL DeRouchey JM Sulabo RC Goodband RD 《Journal of animal science》2011,89(2):404-413
A total of 144 barrows and gilts (initial BW = 44 kg) were used in an 82-d experiment to evaluate the effects of dietary fat source and duration of feeding fat on growth performance, carcass characteristics, and carcass fat quality. Dietary treatments were a corn-soybean meal control diet with no added fat and a 2 × 4 factorial arrangement of treatments with 5% choice white grease (CWG) or soybean oil (SBO) fed from d 0 to 26, 54, 68, or 82. At the conclusion of the study (d 82), pigs were slaughtered, carcass characteristics were measured, and backfat and jowl fat samples were collected. Fatty acid analysis was performed, and iodine value (IV) was calculated for all backfat and jowl fat samples. Pigs fed SBO tended to have increased (P = 0.07) ADG compared with pigs fed CWG. For pigs fed SBO, increasing feeding duration increased (quadratic, P < 0.01) ADG and G:F. For pigs fed CWG, increasing feeding duration improved (quadratic, P < 0.01) G:F. For pigs fed SBO or CWG, increasing feeding duration increased carcass yield (quadratic, P < 0.04) and HCW (quadratic, P < 0.02). Dietary fat source and feeding duration did not affect backfat depth, loin depth, or lean percentage. As expected, barrows had greater ADG and ADFI (P < 0.01) and poorer G:F (P = 0.03) than gilts. Barrows also had greater last-rib (P = 0.04) and 10th-rib backfat (P < 0.01) and reduced loin depth and lean percentage (P < 0.01) compared with gilts. Increasing feeding duration of CWG or SBO increased (P < 0.10) C18:2n-6, PUFA, PUFA:SFA ratio, and IV in jowl fat and backfat. Pigs fed SBO had greater (P < 0.01) C18:2n-6, PUFA, PUFA:SFA ratio, and IV but decreased (P < 0.01) C18:1 cis-9, C16:0, SFA, and MUFA concentrations compared with pigs fed CWG in jowl fat and backfat. Barrows had decreased (P = 0.03) IV in jowl fat and backfat compared with gilts. In summary, adding SBO or CWG increased the amount of unsaturated fat deposited. Increasing feeding duration of dietary fat increases the amount of unsaturated fatty acids, which leads to softer carcass fat. 相似文献
19.
Practical means for estimating pork carcass composition 总被引：1，自引：0，他引：1
M W Orcutt J C Forrest M D Judge A P Schinckel C H Kuei 《Journal of animal science》1990,68(12):3987-3997
Three hundred sixty-one market-weight barrow and gilt carcasses were physically dissected into bone, skin, fat and muscle. A three-variable multiple linear regression equation containing the same independent variables (warm carcass weight, 10th rib loin muscle area and 10th rib fat depth) used (U.S.) to determine pork carcass lean weight was found to be the most practical means for predicting weight of muscle standardized to 10% fat. Multiple linear regression equations containing more than three independent variables produced only slight improvements in R2 values; however, the standard deviation about the regression line was not greatly improved by the addition of more independent variables to this three-independent-variable regression model. A single multiple linear regression equation using the three independent variables above may not be adequate to describe variation over the entire live-weight range for all hogs marketed in the U.S. For most accurate muscle weight prediction, different equations should be used for weight subclasses with one equation for carcasses under 100 kg and another for those heavier than 100 kg. A single prediction equation for muscle weight was adequate for carcasses of both barrows and gilts. 相似文献
20.
Brumm MC 《Journal of animal science》2004,82(8):2460-2466
Two experiments were conducted to determine the variation in response to space allocation between barrows and gilts and to examine an alternative allocation regimen for barrows and gilts. Experimental space allocations in both experiments were achieved by varying the number of pigs per pen in a fully slatted facility. In Exp. 1, barrows were given 0.58 and 0.65 m2/pig (nine and eight pigs per pen, respectively) and gilts were given 0.65 and 0.74 m2/pig (eight and seven pigs per pen, respectively). In addition, barrows at 0.58 m2/pig were fed diets formulated for barrows or diets formulated for gilts. Barrows grew 4.8% slower (P = 0.031) and ate 3.1% less feed daily (P = 0.062) at 0.58 vs. 0.65 m2/pig from 22 to 115 kg BW, with no difference in feed conversion, daily lean gain, carcass lean percent, or variation in weight within the pen at time of first pig removal to slaughter. There was no improvement in daily gain, feed intake, feed efficiency, lean gain, or carcass lean percent when gilts were given 0.74 vs. 0.65 m2/pig from 22 to 115 kg BW. There was no difference in performance between the population that consisted of barrows and gilts at 0.65 m2/pig vs. the population of barrows at 0.58 m2/pig and gilts at 0.74 m2/pig. There was no difference in performance by barrows at 0.58 m2/pig when fed either barrow or gilt diets, except for a slight increase (P = 0.078) in within-pen weight variation when the first pig was removed for slaughter for the barrows fed gilt diets. In Exp. 2, barrows and gilts were given 0.58 m2/pig or 0.74 m2/pig (18 vs. 14 pigs per pen) from weaning (mean age 17 d) to slaughter on d 168 postweaning. There were no interactions between space allocation and gender. Daily gain and feed intake were decreased by 2.8% (P = 0.037) and 2.9% (P = 0.084), respectively, with no effect on feed conversion or standardized fat-free lean daily gain for the 0.58 vs. the 0.74 m2/pig treatment, whereas total live weight gain per pen was increased 20.8% (P < 0.001). Results of Exp. 1 suggest that space allocation can be used to achieve similar growth rates between barrows and gilts, and results of Exp. 2 suggest that the response to space allocation is similar for barrows and gilts. The difference in magnitude of response to space allocation between experiments may be due in part to when the social group was formed, with a smaller difference in performance in Exp. 2 associated with a stable social group from weaning to slaughter. 相似文献