种猪场后备母猪的选留与饲养管理

后备母猪的选留与管理是种猪场持续再生产的关键。每年必须选留和培育出占种猪群25％～30％的后备母猪,来替代年老体弱、繁殖性能低下的种母猪。培育后备母猪的任务就是获得体格健壮、发育良好、具有品种典型特征和高度种用价值的种猪:1 后备母猪的选留1.1 出生时后备母猪的选留(主要是窝选)1.1.1 父母的生产成绩优良,同窝产仔数在7头以上。     

高档肉牛育肥期饲养管理技术

高档肉牛生产作为一项综合配套生产技术,在各级政府的重视支持下,日益发展壮大,已成为畜牧业新的经济增长点。但随着其不断发展,各地都以不同的方式方法进行培育发展。本文就固原地区高档肉牛育肥期饲养管理技术进行简单论述,旨在给广大养殖户提供技术指导。     

后备母猪选留及饲养管理要点

养猪场(户)每年必须要更新种猪,比如长大二元母猪年更新率大约为30%～33%。种猪的更新率及更新质量关系到养猪场(户)的经济效益。但许多养殖户在进行引种选留时存在着一些误区,往往导致     

如何提高母猪的繁殖力

根据市场和实际生产需要，经济和饲养条件差的农村可选择长本、大本等二元母猪生产商品肉猪；销往大中城市或供港猪，宜选择大长、长大等外二元母猪生产优质(DLY)肉猪。选择的后备母猪，体型上应符合品种特征，发育良好，背部平直或微倾。腹部比较大而松弛，腹部过度收缩的母猪繁殖力较差。奶头排列整齐均匀，一般在6对以上，奶头饱满不能有瞎头、副乳头等。外阴部大小适中、下垂。     

商品肉鸡育肥期的饲养

商品肉鸡的育肥期为28～56日龄。此期间饲养管理的总原则是采取有效措施,加快生长速度．提高商品合格率。     

后备母猪选留及饲养管理要点

<正>饲养母猪是为了获得数量多、质量好的健康仔猪。而完善的后备母猪饲养管理,可最大地发挥母猪的生产性能,提高母猪的繁殖力,并给生产带来巨大的经济效益。本文就后备母猪的选留和饲养管     

肉牛直线育肥技术育肥期饲养管理

直线育肥也叫持续强度育肥,就是犊牛断奶后不吊架子,直接转入生长肥育阶段。采用舍饲与全价日粮饲喂的方法,使犊牛一直保持很高的日增重量,直到达到屠宰体重时为止。一般12~15个月时,体重可达500 kg 以上,日增重量可达0.8 kg 以上,平均每千克增重消耗精饲料2 kg。     

后备母猪选留及饲养管理要点

养猪场(户)每年必须要更新种猪，如长大二元母猪年更新率约30％～33％。种猪的年更新率及更新质量关系到养猪场(户)的经济效益。但许多客户在引种时存在一些误区，往往导致引种失败，造成经济损失。笔者在规模化猪场工作多年，现将对后备母猪选留及饲养管理等环节的体会总结如下。     

肉驴育肥期的饲养管理技术要点

随着社会的发展和人民生活水平的提高,自我保健意识不断增强,人们越来越意识到食品与人类健康的密切关系,人们在选择畜禽产品时,尤其青睐那些高蛋白、低脂肪和具有保健功效的绿色无公害食品.在我国传统的畜禽产品中,驴肉是最符合上诉标准.为此,肉驴饲养前景广阔,肉驴的科学饲养技术推广和提高也成为老百姓迫切需求的.     

母猪产房期的饲养管理

现代化、规模化养猪场的生产工艺普遍分为四个工段：配种妊娠工段、分娩哺乳工段、保育工段和育成工段。本文主要阐述分娩哺乳工段即产房期的饲养管理。本段上接配种妊娠工段,是上一个工段工作成绩的收获阶段。下连保育工段。是断奶仔猪即保育工段的开始。如何做好产房期的饲养管理就显得尤为重要。本文着眼从产前准备。母猪分娩。产后护理三方面予以阐述。     

Further assessment of the dietary lysine requirement of finishing gilts

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.     

后备母猪的引进与管理

对于一个需要进行连续繁殖生产的猪场来说,引进后备母猪是一项必不可少的工作。本人曾在《当代畜禽养殖业》2003年第11期上发表了“引进种猪的方法”一文,主要对引进种猪的注意事项进行了简单总结。根据目前刚刚开始从事养猪业的个体饲养场(户)比较多(猪价低谷时投资)的特点,以     

The effects of recombinant porcine somatotropin on reproductive function in gilts treated during the finishing phase.

The objective of this study was to determine the effects of recombinant porcine somatotropin (rpST) treatment during the finishing phase on subsequent reproductive function in crossbred gilts. Forty gilts weighing 50 kg and housed in a swine finishing facility were randomly assigned to control or rpST treatment. Four control and four rpST-treated gilts were allotted per pen. Twenty rpST-treated gilts received 6 mg of rpST.gilt-1.d-1 in 1 ml of buffered carrier and 20 control gilts received 1 ml of buffered carrier.gilt-1.d-1. Injections were administered daily at 1400 in the extensor muscle of the neck. All gilts received an 18% CP diet containing 1.2% lysine. Treatment was terminated when the average weight in each pen reached 110 kg. Gilts treated with rpST gained more weight (P less than .05) than control gilts (59.8 +/- 1.0 vs 53.5 +/- 1.0 kg). Age at puberty was not different (rpST, 182.2 +/- 3.3; control 181.4 +/- 3.1 d). Prior treatment with rpST did not significantly affect length of estrus (rpST, 1.9 +/- .1; control, 1.8 +/- .1 d) or estrous cycle length (rpST, 20.6 +/- .4; control, 20.4 +/- .4 d). Ovulation rates at second estrus were similar for rpST gilts (15.1 +/- .5) and control gilts (14.4 +/- .5). More embryos (P = .10) were recovered on d 9 to 12 of gestation from rpST-treated gilts than from control gilts (13.1 +/- .9 vs 10.7 +/- .9).(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of infusion of urea into the vena cava on feed intake of finishing gilts

Three experiments were conducted to evaluate the relationship between feed intake and plasma urea concentration. In Exp. 1, six gilts (BW 53 kg) with catheters in their venae cavae were used in a 5x5+1 Latin square design to determine the amount of infused urea needed to mimic the plasma urea concentration of pigs fed a 25% CP diet. Five gilts were fed a 16% CP corn-soybean meal diet and were infused continuously with either saline or one of four doses of urea (6, 12, 18, and 24 g/d) during each of five periods (12 h/period). Between periods, infusions were stopped for 36 h. The sixth pig was fed a 25% CP diet and infused with saline during each of the experimental periods. Venous blood samples were obtained at 1-h intervals starting 1 h before infusion. As expected, plasma urea concentration increased with increasing amount of urea infused. A daily infusion of 24 g of urea resulted in a plasma urea concentration similar to that of the pig fed the 25% CP diet with saline infusion. In Exp. 2, 12 gilts (BW 60 kg) were used in a crossover design. Pigs received a 16% CP diet and a different treatment (saline or 24 or 30 g/d of urea) in each of three infusion periods. Each infusion period lasted 2 wk. Infusions were stopped for 2 d between periods. Blood samples were obtained before infusion and daily after infusions started. Feeders were weighed daily to determine ADFI. Experiment 3 was similar to Exp. 2, except that only two treatments (saline and 30 g/d of urea) were used. Data from Exp. 2 and 3 were combined for statistical analysis. Plasma urea concentration increased linearly (P<.001) with increasing amount of urea infused. Overall, there was a trend (P<.10) for urea infusion to decrease ADFI, and pigs infused with 30 g/d consumed less (P<.05) feed than pigs infused with saline. Therefore, plasma urea concentration may play a role in regulating feed intake in gilts consuming excess protein.     

The effect of excess protein on growth performance and protein metabolism of finishing barrows and gilts

Two experiments were conducted to evaluate the effect of excess protein on growth performance, carcass characteristics, organ weights, plasma urea concentration, and liver arginase activity of finishing barrows and gilts. In Exp. 1, 35 barrows and 35 gilts with an initial BW of 51 kg were used. Five pigs of each sex were slaughtered at the start of the study to determine initial body composition. The remaining 60 pigs were allotted to a randomized complete block (RCB) experiment with a 2x5 factorial arrangement of treatments (two sexes x five protein levels: 13, 16, 19, 22, and 25% CP). The experiment continued until the average BW was 115 kg, at which time three blocks of pigs (30 total) were selected randomly and slaughtered. Feed intake decreased with increasing protein concentration (linear, P<.05), and the reduction was greater in gilts than in barrows (P<.05). There was a trend toward a linear negative effect of dietary protein on ADG (P<.10) and also a quadratic effect of protein on protein accretion (P<.10). Fat accretion decreased linearly as protein level increased (P<.05). Increased protein concentrations increased liver, kidney, and pancreas weights (linear, P<.05). Plasma urea concentration increased with each protein concentration, with the exception of the 25 vs. 22% CP treatment in gilts. In Exp. 2, 18 barrows and 18 gilts (BW 63 kg) were allotted to an RCB design consisting of a 2x2 factorial arrangement of treatments with two sexes and two dietary protein concentrations (16 and 25% CP). The experiment was terminated when the average BW of pigs reached 105 kg. Average daily feed intake was greater (P<.10) in barrows than in gilts. Average daily gain was reduced by 18% in gilts when dietary protein was increased from 16 to 25% but was only reduced 3% in barrows (sex x protein, P<.10). Barrows had lighter livers (P<.005), greater arginase activities (P<.05), and greater plasma urea concentrations (P<.005) than did gilts. Increasing dietary protein concentration from 16 to 25% increased liver weight, arginase activity, and plasma urea concentration (P<.005). These data suggest that gilts are more sensitive than barrows to excessive intakes of protein. The more negative effects in gilts may be related to liver metabolic capacity and activity of urea cycle enzymes.     

外购后备母猪的选择与饲养管理

当前,各地出台优惠政策扶持生猪饲养场和猪标准化饲养小区建设,从布局到硬件设施十分完备,但个别饲养场由于在选择后备母猪和后备母猪饲养管理出现问题,造成严重经济损失。针对这一问题,笔者总结提出以下解决方法。     

Determining an optimum lysine:calorie ratio for barrows and gilts in a commercial finishing facility

Our objective was to determine an optimum Lys:calorie ratio (g of total dietary Lys/Mcal of ME) for 35- to 120-kg barrows and gilts (Pig Improvement Company, L337 x C22) in a commercial finishing environment. Seven (3 barrow and 4 gilt) trials were conducted using randomized complete block designs (42 pens per trial, a total of 7,801 pigs). Six treatments with increasing Lys:calorie ratio were used in each study. Diets were corn-soybean meal-based with 6% choice white grease. Lysine:calorie ratios were attained by adjusting the amount of corn and soybean meal. No crystalline Lys was used. In barrow trial 1 (43 to 70 kg), increasing the Lys:calorie ratio (2.21, 2.55, 2.89, 3.23, 3.57, and 3.91) increased (quadratic, P < 0.01) ADG, G:F, income over feed costs (IOMFC), and feed cost per kilogram of gain, and decreased (linear, P < 0.01) backfat. In barrow trial 2 (69 to 93 kg), increasing the Lys:calorie ratio (1.53, 1.78, 2.03, 2.28, 2.53, and 2.78) improved (linear, P < 0.01) ADG, G:F, and IOMFC, and decreased (quadratic, P < 0.01) backfat. In barrow trial 3 (102 to 120 kg), increasing the Lys:calorie ratio (1.40, 1.60, 1.80, 2.00, 2.20, and 2.40) increased (linear, P < 0.03) ADG and G:F, and numerically improved (linear, P = 0.12) IOMFC. In gilt trials 1 (35 to 60 kg), 2 (60 to 85 kg), and 3 (78 to 103 kg), increasing the Lys:calorie ratio (2.55, 2.89, 3.23, 3.57, 3.91, and 4.25; 1.96, 2.24, 2.52, 2.80, 3.08, and 3.36; and 1.53, 1.78, 2.03, 2.28, 2.53, and 2.78, respectively) improved (quadratic, P < 0.04) ADG, G:F, IOMFC, and feed cost per kilogram of gain, and decreased (linear, P < 0.01) backfat. In gilt trial 4 (100 to 120 kg), increasing the Lys:calorie ratio (1.40, 1.60, 1.80, 2.00, 2.20, and 2.40) improved (linear, P < 0.02) ADG, G:F, LM depth, IOMFC, and (quadratic, P < 0.06) feed cost per kilogram of gain. These studies suggest that feed cost per kilogram of gain decreases, and reductions in biological performance and IOMFC are rather modest when feeding marginally Lys-deficient diets early (35 to 70 kg) in the grower-finishing period compared with the more severe penalties in growth and economic performance of feeding marginally deficient diets in the late finishing period (70 kg to slaughter). The equations (Lys:calorie ratio = -0.0133 x BW, kg, + 3.6944 and = -0.0164 x BW, kg, + 4.004, for barrows and gilts, respectively) best describe our interpretation of the Lys:calorie ratio that met biological requirements and optimized IOMFC on these pigs (PIC, L337 x C22; 35 to 120 kg) in this commercial finishing environment.     

Reduced intake of dietary lysine promotes accumulation of intramuscular fat in the Longissimus dorsi muscles of finishing gilts

The present study was conducted to elucidate the effect of dietary lysine levels on the intramuscular fat (IMF) content in the Longissimus dorsi (L. dorsi) muscles of finishing gilts. Eleven gilts in total from two litters of pigs aged 110 days were used. The average initial bodyweight of the pigs was 61.7 kg. Six pigs were assigned to the low lysine (LL) diet group (lysine content: 0.43 or 0.40%) and five pigs were assigned to the control group (lysine content: 0.65 or 0.68%). The diets were iso‐energetic and iso‐protein, and contained all essential amino acids (apart from lysine) in the recommended amounts. The pigs were fed these diets until their live weights reached 110 kg. Live weight gain and feed efficiency tended to be lower in the LL group (P = 0.118 and P = 0.052, respectively). Pigs from the LL group took 5 days longer to reach 110 kg (P < 0.01). The IMF content in the L. dorsi of the LL group was twice as high as that of the control group (6.7 vs 3.5%; P < 0.01). The percentage of oleic acid in the L. dorsi of the LL group tended to be higher than that of the control group (P = 0.052), whereas the percentage of linoleic acid and the total percentage of polyunsaturated fatty acids in the L. dorsi were lower (P < 0.05) in the LL group. Free L‐carnitine content in the L. dorsi was lower (P < 0.05) in the LL group. The average abundance of peroxisome proliferator‐activated receptor gamma mRNA in the L. dorsi of the LL group was threefold higher than that of the control group. The leptin mRNA abundance in the L. dorsi of the LL group was 3.3‐fold higher than that of the control group (P < 0.01). These results suggest that a higher activity of adipogenesis may have been involved in the promoted accumulation of IMF in the L. dorsi muscles of pigs, induced by a dietary LL level.     

Effects of increasing dietary standardized ileal digestible lysine for gilts grown in a commercial finishing environment

Three experiments were conducted to determine the effects of increasing dietary standardized ileal digestible (SID) Lys on growing and finishing gilts. Diets in all 3 experiments were corn-soybean meal-based and contained 0.15% l-Lys?HCl and 3% added fat from choice white grease. Desired SID Lys concentrations were achieved by altering levels of corn and soybean meal in the diet. Each experiment consisted of 6 treatments with 7 pens per treatment and approximately 27 gilts (PIC 337 × 1050) per pen. In Exp. 1, 1,085 gilts (initially 38.2 kg) were fed diets formulated to contain SID Lys concentrations of 0.7, 0.8, 0.9, 1.0, 1.1, or 1.2% for 28 d, which were analyzed to be total Lys concentrations of 0.78, 0.86, 0.99, 1.06, 1.14, and 1.24%, respectively. As SID Lys increased, ADG and G:F improved (quadratic, P < 0.003) with optimal performance reached at the SID Lys level of 1.1% or SID Lys:ME ratio of 3.16 g/Mcal. Broken-line analysis indicated breakpoints of 1.03 and 1.05% SID Lys for ADG and G:F, respectively. Gilts in this trial required approximately 21.8 g of SID Lys intake per kilogram of BW gain from 38 to 65 kg. In Exp. 2, 1,092 (initially 55.2 kg) gilts were fed diets formulated to contain SID Lys concentrations of 0.66, 0.74, 0.82, 0.90, 0.98, or 1.06% for 28 d, which were analyzed to be total Lys concentrations of 0.75, 0.73, 0.84, 0.90, 0.95, and 0.97%, respectively. Both ADG (quadratic, P = 0.12) and G:F improved (linear, P < 0.001) as SID Lys increased, with broken-line analysis of ADG indicating a requirement estimate of 0.90%, which corresponds to a SID Lys:ME ratio of 2.58 g/Mcal. Gilts in this trial required approximately 19.6 g of SID Lys per kilogram of BW gain from 55 to 80 kg. In Exp. 3, 1,080 gilts (initially 84.1 kg) were fed diets formulated to contain SID Lys concentrations of 0.54, 0.61, 0.68, 0.75, 0.82, or 0.89% for 29 d, which were analyzed to be total Lys concentrations of 0.62, 0.92, 0.79, 0.99, 0.93, and 1.07%, respectively. As the SID Lys concentration increased, ADG and G:F improved (linear, P < 0.001), and performance responses were maximized at the greatest SID Lys level of 0.89% or SID Lys:ME ratio of 2.55 g/Mcal of ME. Gilts in this trial required 23.0 g of SID Lys per kg of BW gain from 85 to 110 kg. The ideal SID Lys:ME ratio was based on the requirement determined by broken-line analysis in Exp. 1, 2, and 3, with the greatest level being tested in Exp. 3. This equation, SID Lys:ME ratio = -0.011 × BW, kg + 3.617, estimates the optimal SID Lys:ME ratios for growth of gilts (PIC 337 × 1050) in this commercial finishing environment. These studies showed growth performance advantages to increasing SID Lys for growing and finishing gilts over previously reported optimal levels, particularly in the later finishing stages.