哺乳仔猪的管理

1加强母猪饲养管理,增加泌乳量仔猪初生重既影响成活率,又影响断奶重及断奶后仔猪的生长发育。因此,提高仔猪初生重具有重要的意义。加强妊娠母猪后期管理,是提高母猪泌乳量和获得适宜初生重仔猪的关键。如在分娩前10d至哺乳期,给母猪饲料中添加油脂可提高仔猪初生重,也可促进母猪在断奶后尽早发情。     

L-肉碱对母猪代谢和生产性能的影响

近年来,L-肉碱(L-carnitine,CN)作为饲料添加剂在畜禽饲粮中应用越来越多,文章综述了饲粮添加CN对母猪繁殖性能影响的研究。有关妊娠母猪饲粮添加CN对窝产仔数影响的研究结果间存在较大差异,有研究认为能提高窝产活仔数,而另一些研究则认为不能。但研究一致表明,在含低水平天然肉碱的妊娠母猪饲粮中添加CN能提高仔猪个体及窝初生重并促进哺乳仔猪的生长。CN促进宫内发育的生化机制尚未完全阐明。但有证据显示,它能影响胰岛素样生长因子轴,从而促进较大胎盘的形成,进而提高宫体内部营养和刺激胎儿体内葡萄糖氧化,这些机制可部分解释为仔猪初生重的提高。CN对哺乳仔猪的生长刺激效应,可能是因CN补充改善母猪所产仔猪的吸吮行为造成,这种吸吮行为的改善可提高母猪产奶量。总之,近期众多研究表明,饲粮补充CN能提高母猪繁殖性能,妊娠母猪内源肉碱合成量不能满足其代谢需要。     

哺乳母猪泌乳力的影响因素及提高措施

1提高母猪泌乳力的意义1.1提高仔猪断奶窝重母猪的泌乳力是哺乳母猪生产性能的直接体现,母猪泌乳量的多少,直接影响哺乳仔猪的生长发育,进而影响仔猪的断奶窝重。而仔猪的断奶窝重是一个非常重要的选种指标,它与猪的产仔数、初生重、哺育率、哺乳期增重和断奶个体重等主要繁殖性状均呈正相关。因此,提高母猪的泌乳力,可以提高仔猪的断奶窝重。     

提高仔猪断奶窝重的措施

仔猪断奶窝重直接影响猪其后的生长发育，因此提高仔猪断奶窝重是养猪生产中的一个重要环节。仔猪的断奶窝重与母猪泌乳力、窝产仔数、初生窝重、开食早晚、饲料质量、仔猪成活率和哺乳期仔猪的生长速度等因素有关。因此，提高仔猪断奶窝重，必须做到以下几点。     

提高仔猪断奶体重的管理措施

仔猪断奶体重严重影响着育成猪及肥育猪的生长发育。实践证明,仔猪断奶重差1千克,出栏时间将相差7~10天。因此,要最大限度提高仔猪断奶体重,需要从提高仔猪初生重,提高母猪泌乳量,提高仔猪采食量等环节抓起,确保断奶仔猪体重大且能健康生长发育。1科学饲养妊娠母猪,提高子猪初生重     

丁酸盐对母猪繁殖性能和哺乳仔猪生长性能的影响

在母猪妊娠后期和哺乳期日粮中添加丁酸钾和微囊包膜丁酸钠,分别研究其对母猪繁殖性能和哺乳仔猪生长性能的影响。结果发现：添加0．15％丁酸钾和0．15％微囊包膜丁酸钠组的仔猪初生窝重、初生均重、活仔均重以及母猪的产仔数和产健仔数要比对照组差;在哺乳仔猪生长性能方面,添加0．15％丁酸钾,有提高哺乳仔猪日增重、断奶重和存活率的趋势,对母猪断奶后7d发情率也有改善的趋势。可能由于丁酸盐的添加量或添加时间不够,不足以改善母猪繁殖性能;但可以改善母猪体况,让仔猪获取健康奶水,促进哺乳仔猪生长;同时,利于母猪再次发情配种,缩短发情间隔。     

提高仔猪断奶窝重的综合措施（上）

断奶窝重是评定母猪繁殖性能的一项综合指标,其大小可间接反映其他相关性状的优劣。断奶窝重与产活仔数、初生窝重、泌乳力、断奶仔猪数、哺乳期仔猪的生长速度存在强相关,因此,应采取选择优良品种、加强母猪及仔猪饲养管理、搞好疫病防治、科学断奶等综合措施才能达到预期效果。     

母猪哺乳期：初乳与常乳质量

猪场的收益主要由母猪和仔猪生产成绩决定。母猪的生产成绩通过窝产仔数、初生窝重、断奶仔数、断奶窝重和每年分娩窝数来体现。一方面,仔猪断奶成绩受母猪泌乳量的影响,乳汁的质量决定了断奶重、断奶存活率;另一方面,仔猪断奶后生长速度决定了上市时间或配种体重。母猪泌乳期间,20%~30%的仔猪死亡与营养缺乏有关,在死亡仔猪中20%~50%是由母猪压死引起（Fahmy和Benard,1971）,而压死的部分仔猪也是由营养不良引起活力低下所致。     

牲命1号:母猪不发情、无乳的救星

<正>母猪在生产过程中,受母猪生产繁殖应激的影响,经常出现不发情、假发情,产仔数少、胎儿大小不均匀,初生重小,哺乳母猪泌乳不足,仔猪黄白痢发生率高,成活率低,仔猪断奶重小,母猪产前产后出现肢势、步态异常,甚至出现产前产后瘫痪等问题。母猪生产繁殖应激及其综合征是长期困扰养猪业     

L-肉碱对母猪泌乳量及乳汁成分的影响

近年来的研究证实,对母猪补充L-肉碱能促进哺乳期仔猪的生长,但其作用机理尚不明确。本文结合近年来国内外的研究报道,从L-肉碱能促进母猪泌乳及其对乳汁成分影响方面分析,以阐明给母猪补充L-肉碱促进哺乳期仔猪生长的作用机理。     

Effects of L-carnitine and niacin supplied by drinking water on fattening performance, carcass quality and plasma L-carnitine concentration of broiler chicks.

The present study was initiated to determine whether dietary supplemental L-carnitine and niacin affect growth performance, carcass yield, abdominal fat and plasma L-carnitine concentration of broiler chicks. One-day-old broiler chicks (COB500) were used in the experiment. A two by two factorial arrangement was employed with two levels (0 and 50 mg/l) of supplemental L-carnitine and two levels (0 or 50 mg/l) of supplemental niacin in drinking water as main effects. Body weight gain was significantly improved by L-carnitine, or L-carnitine + niacin supplementation during the first 3 weeks. However, supplemental L-carnitine and niacin did not change body weight gain during the last 3 weeks of the experimental period. Supplemental L-carnitine significantly improved feed intake during the first 3 weeks. Supplemental L-carnitine or niacin did not influence carcass weight, carcass yield and abdominal fat weight. L-carnitine content in the plasma was significantly higher in the groups receiving supplemental L-carnitine and L-carnitine + niacin. It is concluded that dietary supplemental L-carnitine or L-carnitine + niacin could have positive effects on body weight gain and feed intake during the early stages of growing. However, supplemental L-carnitine or L-carnitine + niacin were not of benefit regarding the complete growth period.     

Effects of dietary supplemental L-carnitine and ascorbic acid on performance, carcass composition and plasma L-carnitine concentration of broiler chicks reared under different temperature.

The present study was initiated to determine whether dietary supplemental L-carnitine and ascorbic acid affect growth performance, carcass yield and composition, abdominal fat and plasma L-carnitine concentration of broiler chicks reared under normal and high temperature. During the experiment, two temperature regimes were employed in two experimental rooms, which were identical but different in environmental temperature. The regimes were thermoneutral (20-22 degrees C for 24 h) or recycling hot (34-36 degrees C for 8 h and 20-22 degrees C for 16 h). One-day-old broiler chicks (ROSS) were used in the experiment. A 2 x 2 x 2 factorial arrangement was employed with two levels (0 and 50 mg/kg) of supplemental L-carnitine and two levels (0 or 500 mg/kg) of supplemental ascorbic acid in drinking water under thermoneutral or high temperature regimes. Body weight gain was affected by high temperature. However, body weight gain was significantly improved in animals receiving supplemental L-carnitine, ascorbic acid or L-carnitine + ascorbic acid compared to animals receiving unsupplemented diet under high temperature. On the other hand, supplemental L-carnitine or L-carnitine + ascorbic acid reduced body weight gain under thermoneutral condition. Supplemental ascorbic acid significantly improved feed conversion efficiency, the improvement was relatively greater under high temperature. The L-carnitine content in the plasma was higher in the groups receiving supplemental L-carnitine and ascorbic acid under high temperature, while broilers fed supplemental L-carnitine and ascorbic acid had a decreased level of plasma L-carnitine concentration under normal temperature. It is concluded that dietary supplemental L-carnitine or L-carnitine + ascorbic acid may have positive effects on body weight gain, carcass weight under high temperature conditions.     

The effects of dietary L-carnitine supplementation on the performance, organ weights and circulating hormone and metabolite concentrations of broiler chickens reared under a normal or low temperature schedule.

1. The present study examined the effects of the addition of 100 mg/kg L-carnitine to the basal starter (containing 17.8 mg/kg L-carnitine) and finisher (containing 22.9 mg/kg L-carnitine) diets on performance, organ weights and plasma hormone and metabolite concentrations of male and female broiler chickens. The broiler chickens were reared either in a room with a normal temperature (NT) program or with a low temperature (LT) program (rapid decrease from 28 degrees C to 20 degrees C at 14 d of age). 2. Broiler chickens reared under the LT schedule consumed more food and attained a greater body weight at 42 d of age than their counterparts reared under NT schedule, without any difference in food efficiency or abdominal fat content. Dietary L-carnitine supplementation had no significant effects on any of these production parameters, except for a reduction in the abdominal fat content of female NT chickens. However, the LT schedule and dietary L-carnitine supplementation greatly increased absolute and proportional heart weights. The elevated heart weights were not due to right ventricle hypertrophy. 3. Both the LT program and L-carnitine supplementation increased circulating plasma triiodothyronine concentrations. There were also some transient effects of both experimental variables on plasma growth hormone, glucose and triglyceride concentrations. 4. L-carnitine did not improve broiler performance. However, this result does not mean that L-carnitine supplementation cannot have beneficial effects in other circumstances. In view of the elevated proportional heart weights, it can also be argued that L-carnitine is a potential agent for reducing the incidence of metabolic diseases in broiler chickens.     

Effect of dietary L-carnitine supplementation on growth performance of piglets from control sows or sows treated with L-carnitine during pregnancy and lactation

Previous studies showed that supplementation of sows' diets with L-carnitine increases body weights of their piglets at birth. This study was performed to investigate whether piglets of sows treated with L-carnitine differ in their growth potential from that of piglets of untreated control sows after weaning. It was also investigated whether supplementation of piglets' diets with L-carnitine improves their growth after weaning. In two trials, piglets of the first litters of primiparous sows (trial 1) and the second litters of the same sows (trial 2) were divided into four groups: group 1, piglets of control sows, fed a control diet; group 2, piglets of control sows fed a diet supplemented with 30 mg L-carnitine/kg; group 3, piglets of L-carnitine-treated sows, fed a control diet; group 4, piglets of L-carnitine-treated sows fed a diet supplemented with 30 mg L-carnitine/kg. Mean initial body weights of the piglets of the four groups were identical. They were 8.5 kg in trial 1 and 12.5 kg in trial 2. Diets were fed ad libitum over a period of 35 days. Piglets from sows treated with L-carnitine did not differ in body weight gains, feed intake and gain : feed ratio from those of control sows. In trial 1, piglets supplemented with L-carnitine had higher body weight gains (p < 0.005) and showed a tendency towards a higher gain : feed ratio (p = 0.09) than piglets fed the control diets. In trial 2, no significant difference in these parameters emerged between piglets fed the diet supplemented with L-carnitine and those fed the control diet. In conclusion, this study shows that dietary L-carnitine treatment of sows does not improve the growth potential of their piglets after weaning under the conditions of equal initial body weights. The study also shows that L-carnitine supplementation of their diets improves the growth performance in light piglets of primiparous sows.     

Dietary L-carnitine increases plasma insulin-like growth factor-I concentration in chicks fed a diet with adequate dietary protein level

1. The effect of L-carnitine supplemented into experimental diets with varying dietary protein concentrations (50, 200 and 400 g/kg) on body weight gain and plasma insulin-like growth factor-I (IGF-I) concentration in chicks was examined. 2. Dietary L-carnitine supplementation provided 0, 200, 500 and 1000 mg/kg. Chicks were given the diet ad libitum for 10 d. 3. When L-carnitine was provided as 500 or 1000 mg/kg, body weight gain was significantly improved in birds receiving the 200 and 400 g protein/kg diets. 4. There was an interaction between dietary L-carnitine and protein content on plasma IGF-I concentration. L-carnitine supplementation had little influence on plasma IGF-I concentrations in birds receiving the low protein (50 g/kg) diet. When dietary L-carnitine concentrations were increased from 0 to 1000 mg/kg in the adequate protein (200 g/kg) diet, plasma IGF-I concentrations were also increased. However, when dietary L-carnitine content was more than 500 mg/kg in the 400 g/kg protein group, plasma IGF-I concentration decreased with increasing dietary L-carnitine content. 5. Body weight change correlated significantly with the alteration in plasma IGF-I concentrations in chicks given diets with adequate dietary protein. 6. In conclusion, the improvement in body weight gain caused by dietary L-carnitine supplementation was achieved when chicks were given their dietary protein requirement, which may be partially explained by an increase in plasma IGF-I concentration.     

Effects of supplemental L-carnitine in drinking water on performance and egg quality of laying hens exposed to a high ambient temperature

The present study was conducted to investigate effects of L-carnitine supplied with drinking water on performance and egg quality of laying hens under high environmental temperature. In the study, 47-week-old laying hens (Brown hisex) were divided into two groups (control and treatment) and fed with a standard layer diet. Treatment group was received 50 p.p.m L-carnitine with drinking water for an 8-week period. Throughout the study, 8 h hot (35-37 degrees C) and 16 h thermoneutral (20-22 degrees C) environmental temperature regime was employed daily. The results showed that L-carnitine supplementation affected some egg quality characteristics of layers under high environmental temperature. Relative albumen weight and height were increased (p < 0.05) by supplemental L-carnitine. Live weight gain, feed intake, egg mass, egg weight, yolk weight, shell weight, yolk index, egg-shape index, yolk colour score and shell thickness were not affected (p < 0.05) by L-carnitine. It is concluded that L-carnitine supplementation in laying hens could have potential to improve albumen quality under high environmental temperature.     

L-肉碱在水产养殖中的应用

L-肉碱是一种具有多种生理功能的新型添加剂。在水产饲料中添加适量L-肉碱不但可以提高饲料利用效率、降低饵料系数、加快水产动物的生长,还能节约蛋白质日粮,改善肉质。     

Effects of L-carnitine administration on growth performance, carcass traits, blood serum parameters and abdominal fatty acid composition of ducks.

Effects of L-carnitine administration via drinking water on growth performance, carcass traits, blood serum parameters and abdominal fatty acid composition of ducks was examined. One hundred day-old Turkish native duck chicks were divided into two groups, each with five replicates and given the same diets with 0 and 200 mg/l carnitine chlorhydrate via drinking water. The study lasted 8 weeks, with the first 4 weeks as a starter and the last 4 weeks as grower period. At the end of the study five ducks were randomly selected from each subgroup for slaughter. Growth performance parameters of ducks were not affected significantly by L-carnitine administration. Live weight, daily weight gain, cumulative feed consumption and average feed conversion efficiency were found to be 1490 and 1621 g, 26.0 and 28.1 g, 5386 and 5662 g, 3.75 and 3.54 kg/kg in the control and in the carnitine groups respectively. L-carnitine administration did not effect carcass traits and serum cholesterol, total lipid, triglyceride and glucose levels. Total saturated fatty acid content of abdominal fat significantly decreased, mono- and polyunsaturated fatty acid content were not affected by L-carnitine administration. In conclusion, L-carnitine administration by drinking water did not affect growth performance, carcass traits and blood parameters in ducks.     

Effects of increasing dietary L-carnitine on growth performance of weanling pigs

Four experiments were conducted to evaluate the effects of supplementing graded levels (0 to 100 ppm) of L-carnitine to the diet of weanling pigs on growth performance during a 34- to 38-d experimental period. A fifth experiment was conducted to determine the effects of addition of L-carnitine to diets with or without added soybean oil (SBO) on growth performance. In Exp. 1, 128 pigs (initial BW = 5.5 kg) were allotted to four dietary treatments (six pens per treatment of four to six pigs per pen). Dietary treatments were a control diet containing no added L-carnitine and the control diet with 25, 50, or 100 ppm of added L-carnitine. In Exp. 2, 3, and 4, pigs (4.8 to 5.6 kg of BW) were allotted to five dietary treatments consisting of either a control diet containing no added L-carnitine or the control diet with 25, 50, 75, or 100 ppm of added L-carnitine. All diets in Exp. 1 to 4 contained added soybean oil (4 to 6%). There were seven pens per treatment (four to five pigs per pen) in Exp. 2, whereas Exp. 3 and 4 had five and six pens/treatment (eight pigs per pen), respectively. In general, dietary carnitine additions had only minor effects on growth performance during Phases 1 and 3; however, dietary L-carnitine increased (linear [Exp. 1], quadratic [Exp. 2 to 4], P < 0.03) ADG and gain:feed (G:F) during Phase 2. The improvements in growth performance during Phase 2 were of great enough magnitude that carnitine addition tended to increase ADG (linear, P < 0.10) and improve G:F (quadratic, P < 0.02) for the entire 38-d period. In Exp. 5, 216 weanling pigs (5.8 kg of BW) were allotted (12 pens/treatment of four to five pigs per pen) to four dietary treatments. The four dietary treatments were arranged in a 2 x 2 factorial with main effects of added SBO (0 or 5%) and added L-carnitine (0 or 50 ppm). Pigs fed SBO tended (P < 0.07) to grow more slowly and consumed less feed compared with those not fed SBO, but G:F was improved (P < 0.02). The addition of L-carnitine did not affect (P > 0.10) ADG or ADFI; however, it improved (P < 0.03) G:F. Also, the increase in G:F associated with L-carnitine tended to be more pronounced for pigs fed SBO than those not fed SBO (carnitine x SBO, P < 0.10). These results suggest that the addition of 50 to 100 ppm of added L-carnitine to the diet improved growth performance of weanling pigs. In addition, supplemental L-carnitine tended to be more effective when SBO was provided in the diet.     

Effect of dietary L-carnitine on growth performance and body composition in nursery and growing-finishing pigs.

Two experiments were conducted to determine the effect of dietary L-carnitine on growth performance and carcass composition of nursery and growing-finishing pigs. In Exp. 1,216 weanling pigs (initially 4.9 kg and 19 to 23 d of age) were used in a 35-d growth trial. Pigs were blocked by weight in a randomized complete block design (six pigs per pen and six pens per treatment). Four barrows and four gilts were used to determine initial carcass composition. L-Carnitine replaced ground corn in the control diets to provide 250, 500, 750, 1,000, or 1,250 ppm. On d 35, three barrows and three gilts per treatment (one pig/block) were killed to provide carcass compositions. L-Carnitine had no effect (P > 0.10) on growth, percentages of carcass CP and lipid, or daily protein accretion. However, daily lipid accretion tended to decrease and then return to values similar to those for control pigs (quadratic P < 0.10) with increasing dietary L-carnitine. In Exp. 2, 96 crossbred pigs (initially 34.0 kg BW) were used to investigate the effect of increasing dietary L-carnitine in growing-finishing pigs. Pigs (48 barrows and 48 gilts) were blocked by weight and sex in a randomized complete block design (two pigs/pen and eight pens/treatment). Dietary L-carnitine replaced cornstarch in the control diet to provide 25, 50, 75, 100, and 125 ppm in grower (34 to 56.7 kg; 1.0% lysine) and finisher (56.7 to 103 kg; 0.80% lysine) diets. At 103 kg, one pig/pen was slaughtered, and standard carcass measurements were obtained. Dietary L-carnitine did not influence growth performance (P > 0.10). However, increasing dietary carnitine decreased average and tenth-rib back-fat (quadratic, P < 0.10 and 0.05), and increased percentage lean and daily CP accretion rate (quadratic, P < 0.05). Break point analysis projected the optimal dosage to be between 49 and 64 ppm of L-carnitine for these carcass traits. It is concluded that dietary carnitine fed during the nursery or growing-finishing phase had no effect on growth performance; however, feeding 49 to 64 ppm of L-carnitine during the growing-finishing phase increased CP accretion and decreased tenth-rib backfat.