妊娠后期母猪日粮中添加低聚木糖和益生菌对母猪繁殖性能及哺乳仔猪生长性能的影响

试验旨在研究妊娠后期母猪日粮中添加低聚木糖和益生菌对母猪繁殖性能及哺乳仔猪生长性能的影响。试验采用随机区组试验设计,选取妊娠108 d的母猪(体重及预产期相近,长白×大白)48头,随机分为3个处理,每个处理16个重复,每个重复1头母猪。对照组饲喂基础日粮,试验组分别在基础日粮中添加0.05%XOS(试验1组)和0.05%XOS+0.03%益生菌(试验2组),试验期35 d。结果表明:(1)3个处理母猪哺乳期平均日采食量(ADFI)、产仔总数、活产仔数、合格仔数、初生均重和母猪7 d发情率等几方面差异均不显著(P>0.05)。所有胎次母猪的发情间隔、背膘损失和产程差异均不显著(P>0.05)。但3~6胎次母猪试验1组的发情间隔显著低于对照组(P<0.05),试验2组母猪背膘损失极显著低于对照组(P<0.01);(2)从所有胎次母猪和3~6胎母猪所产仔猪来看,3个试验组仔猪的哺乳期ADG差异不显著(P>0.05)。但从3~6胎以外母猪所产仔猪来看,试验2组的哺乳期ADG比对照组高34.36%(P<0.01),试验1组哺乳期ADG比对照组高21.47%(P<0.05)。(3)3个试验组仔猪断奶成活率没有显著差异(P>0.05)。由此可见,在妊娠后期母猪日粮中单独添加低聚木糖或者同时添加低聚木糖和益生菌对母猪产程和发情间隔没有明显的改善作用,同时添加低聚木糖和益生菌极显著降低3~6胎母猪的背膘损失。仔猪断奶成活率与母猪胎次以及低聚木糖和益生菌的添加水平有关。母源性低聚木糖和益生菌对哺乳仔猪生长性能没有明显促进作用。     

Effects of dietary fermentable carbohydrates on energy metabolism in group-housed sows

The effect of dietary nonstarch polysaccharide (NSP) content on the metabolic rate in group-housed sows was studied. Twelve groups of six nonpregnant sows were each fed one of four experimental diets similar in composition except for the starch and NSP content. Exchanging sugar beet pulp silage (SBPS) for tapioca created the difference in starch and NSP ratio in the diet. On a DM basis, diets contained 0, 10, 20, or 30% SBPS. Sows were group-housed and fed at 1.30 times the assumed maintenance energy requirements. Nitrogen and energy balances were measured per group during a 7-d experimental period, which was preceded by a 33-d adaptation period. Both digestibility and metabolizability of energy decreased with increasing dietary SBPS content (P < 0.05). Heat production and energy retention were unaffected by the exchange of starch for NSP (P > 0.1). Based on energy retention data and apparent fecal digestibilities of crude protein, crude fat, starch, and NSP, the estimated net energy value of fermented NSP was 13.4 kJ/g. The present study shows that group-housed sows are capable of using energy from fermented NSP (i.e., NSP from SBPS) as efficiently as energy from digested starch (i.e., starch from tapioca).     

Effects of dietary fermentable carbohydrates on behavior and heat production in group-housed sows

The effects of dietary nonstarch polysaccharides (NSP) on behavior and heat production in group-housed sows were studied. Twelve groups of six nonpregnant sows were fed one of four experimental diets that were similar in composition except for starch and NSP contents. Exchanging sugar beet pulp silage (SBPS) for tapioca created the difference in dietary starch and NSP ratio. On a dry matter (DM) basis, diets contained 0, 10, 20, or 30% SBPS. Sows were group-housed. Intake of fermentable NSP (fNSP) for diets containing 0, 10, 20, or 30% SBPS averaged 7.06, 9.18, 11.61, and 13.73 g x kg(-0.75) d(-1), respectively. Sows were fed, once a day at 0800. Dry matter intake for diets containing 0, 10, 20, or 30% SBPS, averaged 38.05, 38.38, 38.53, and 38.35 g x kg(-075) x d(-1), respectively, and ME intake averaged 523, 518, 514, and 493 kJ x kg(-0.75) x d(-1), respectively. On average, sows spent 177 min/d on physical activity, of which 8.8% was spent on eating. Time spent in physical activity was affected by diet (P = 0.005). Sows fed 0 or 10% SBPS spent more time on physical activity than sows fed 20 or 30% SBPS (P = 0.002). Energy cost of physical activity averaged 464 kJ x kg(-0.75) x d(-1) (standard estimated mean of 31) and was similar for diets (P = 0.679). Total heat production (HP) and activity-related heat production (AHP) were affected by diet (P < 0.05). Sows tended to be quieter when fNSP intake increased (P = 0.063). The effect of fNSP intake on HP and AHP was not constant during the day. During the night period, fNSP intake did not affect HP and AHP (P > 0.10). During the day period, increased fNSP intake decreased HP (P = 0.006) and tended to decrease AHP (P = 0.062). During eating, increased fNSP intake increased HP (P = 0.012) and tended to increase AHP (P = 0.074). Despite similar DMI, sows fed 0 or 10% SBPS spent less time eating than sows fed 20 or 30% SBPS (P = 0.009). Feed consumption rate was higher (P = 0.003) in groups fed 0 or 10% SBPS than in groups fed 20 or 30% SBPS. Feed consumption rate decreased by 0.19 g DM x kg(-0.75). min(-1) (P = 0.003) for each gram of fNSP intake. The energy saving effect of physical activity on the NE value of fNSP from SBPS ranged between 2.3 and 3.7 kJ/g of fNSP intake. In conclusion, intake of fNSP from SBPS affected energy expenditure for physical activity (P = 0.063); however, this effect was not constant during the day.     

Influence of Carnichrome on the energy balance of gestating sows

Twelve multiparous sows with an average initial weight of 182 kg were used in a randomized complete block design to determine the effects of feeding Carnichrome (50 mg of carnitine and 200 microg of chromium picolinate per kilogram of feed, as fed) on energy and nitrogen utilization in early, mid-, and late gestation. All sows were fed a diet with or without Carnichrome for the preceding 28-d lactation, the weaning-to-estrus period, and for the duration of gestation. Daily feeding allowances over pregnancy were based on calculated energy and nutrient requirements to achieve a target sow maternal weight gain of 20 kg and remained constant throughout gestation. Heat production (HP) and its partitioning (activity, thermic effect of feeding short term [TEFst], basal) were determined in early (wk 5 or 6), mid- (wk 9 or 10), and late (wk 14 or 15) pregnancy using indirect calorimetry. Net maternal weight gain and total number of fetuses averaged 21.6 kg and 16.4, respectively. Organic matter and energy digestibility for the Carnichrome diet was greater (P < 0.05), which resulted in greater DE and ME contents (0.6%, P < 0.05) compared with the control diet. The digestibility coefficient of energy in the current experiment for a typical corn and soybean meal diet (92%) was greater than that predicted from DE values of corn and soybean meal in feeding tables (88%). Carnichrome had no effect on total HP, energy retained as protein or lipid, and maternal energy retention in early, mid-, or late gestation. Heat production in late gestation increased linearly (4.0 kJ/[kg BW0.75 x d]) for each additional day from d 90 to 110, despite the reduction of ME intake per unit of BW0.75. Metabolizable energy requirement for maintenance was 405 kJ/(kg BW0.75 x d). On average, activity HP was 116 kJ/(kg BW0.75 x d), which was equivalent to 20% of ME intake; however, this value ranged from 11 to 37% between sows, which corresponds to duration of standing ranging from 210 to 490 min/d. Energy cost of standing activity averaged 0.30 kJ/(kg BW0.75 x min). In conclusion, Carnichrome had no effect on the components of heat production and maternal weight gain during gestation, although it improved energy and organic matter digestibility of the diet.     

Effects of catechins on litter size,reproductive performance and antioxidative status in gestating sows

This study was conducted to investigate the effects of catechins on reproductive performance, antioxidative capacity and immune function of gestating sows. A total of 60 cross-bred(Landrace × Large White) multiparious sows were blocked by body weight, parity and backfact and randomly allocated to 1 of 5 treatments: 0.100,200,300, or 400 mg/kg catechins. Dietary treatments were imposed from mating to d 40 of gestation of sows. At farrowing, litter total born, born alive, dead, and normal-(healthy piglets,0.85 kg) and low-birth weight piglets(0.85 kg) were recorded. Within 3.00 ± 0.50 days after farrowing litter size was standardized to 8,00 ± 1.50 piglets within treatment. The piglets were weighed at birth(d 1) and weaning(d 28). Sows serum samples were obtained from blood samples collected on d 40 of gestation for analyses of glutathione peroxidase(GSH-Px), superoxide dismutase(SOD), catalase(CAT),malondialdehyde(MDA), hydrogen peroxide(H_2 O_2), nitric oxide synthetase(NOS) and nitrogen monoxide(NO). Our results showed that supplementation of catechins at levels of 200 or 300 mg/kg led to improvements in litter born alive(P 0.01) and piglet born healthy(P 0.01) and a decrease in stillborn(P 0.05) at farrowing when compared with the control. In comparison with the control, catechins at any supplemental levels all enhanced the serum SOD(P 0.05) and CAT(P 0.01) activities of sows at farrowing but no obvious differences in the serum GSH-Px and NOS activities were observed in this trial(P 0.05). Sows received 200 mg catechin per kg diets showed a reduction(P 0.05) of the serum MDA level at farrowing compared with all other treatments. Sows received all the levels of catechin showed a reduction(P 0.05) of serum H_2 O_2 level compared with sows received the control diet on both d 40 of gestation and farrowing. Our results demonstrated that the catechins may be a potential antioxidant to increase the reproductive performance and antioxidative capacity of sows when it was added into diets during the early gestation.     

Survey among Belgian pig producers about the introduction of group housing systems for gestating sows

There is a global move from individual to group housing of gestating sows. In the European Union, individual gestating stalls will be banned by 2013. Just like in other industrialized regions, these stalls have been the standard housing system for intensively kept sows from the 1960s onward in the Flemish region of Belgium. Because the socioeconomic consequences for the pig industry may be far-reaching and because farmer attitude may influence the realization of the hoped-for improvement in animal welfare in practice, we conducted a survey from 2003 until 2009 among representative samples of Flemish pig producers every 2 yr. The share of farms with group housing increased from 10.5% in 2003 to 29.8% in 2007, but then dropped to 24.6% in 2009. It appears that after 2005 users of old group housing systems in particular stopped farming. Because sow herd size increased more on farms with vs. without group housing and because the proportion of the herd that was group-housed also tended to increase between 2003 to 2009, the change to group housing took place faster when expressed at the level of the sow (from 9.1% in 2003 to 34.1% in 2009) instead of farm. The percentage of farmers planning to convert to group housing within 2 yr was 4.1% in 2003, and 6 to 7% thereafter. These were typically young farmers (P = 0.006) with a large sow herd (P < 0.001) and with a likely successor (P = 0.03). Free access stalls were the most common group housing system (31% of farms, 37% of sows). Their popularity is expected to increase further at the expense of electronic feeding stations, ad libitum feeding, and stalls/troughs with manual feed delivery. User satisfaction was generally high but depended on whether or not all gestating sows were kept in group (P < 0.001), the provisioning of environmental enrichment (P = 0.057), and the age (P = 0.012) and type (P = 0.016) of system. The main criteria for choosing a certain group housing system were the investment costs and sow health and welfare. The importance of economic reasons (P = 0.007) and type of labor (P = 0.043) decreased with the age of the system. In 2003 and 2005 the main reason for not having converted to group housing was that farmers would stop keeping sows by 2013. In 2007 and 2009 the reasons mainly concerned uncertainty about the future and maximally delaying the conversion. Belgium is one of the European Union countries where the pig industry is expected to undergo drastic changes during the few years remaining before the ban on individual housing.     

Effect of dietary protein content and tryptophan supplementation on dominance aggression, territorial aggression, and hyperactivity in dogs

OBJECTIVE: To evaluate the effect of high- and low-protein diets with or without tryptophan supplementation on behavior of dogs with dominance aggression, territorial aggression, and hyperactivity. DESIGN: Prospective crossover study. ANIMALS: 11 dogs with dominance aggression, 11 dogs with territorial aggression, and 11 dogs with hyperactivity. PROCEDURE: In each group, 4 diets were fed for 1 weeks each in random order with a transition period of not < 3 days between each diet. Two diets had low protein content (approximately 18%), and 2 diets had high protein content (approximately 30%). Two of the diets (1 low-protein and 1 high-protein) were supplemented with tryptophan. Owners scored their dog's behavior daily by use of customized behavioral score sheets. Mean weekly values of 5 behavioral measures and serum concentrations of serotonin and tryptophan were determined at the end of each dietary period. RESULTS: For dominance aggression, behavioral scores were highest in dogs fed unsupplemented high-protein rations. For territorial aggression, [corrected] tryptophan-supplemented low-protein diets were associated with significantly lower behavioral scores than low-protein diets without tryptophan supplements. CONCLUSIONS AND CLINICAL RELEVANCE: For dogs with dominance aggression, the addition of tryptophan to high-protein diets or change to a low-protein diet may reduce aggression. For dogs with territorial aggression, tryptophan supplementation of a low-protein diet may be helpful in reducing aggression.     

Performance of gestating sows in bedded hoop barns and confinement stalls

The effects of gestation housing systems on sow and litter performance were evaluated for 2.5 yr in southwest Iowa. Gestation housing system treatments were as follows: 1) individual gestation stalls in a mechanically ventilated confinement building with a partially slatted floor and a manure flush system and 2) group pens with individual feed stalls in deep-bedded, naturally ventilated hoop barns. In all, 957 litters from 353 sows were evaluated. Number of pigs born alive per litter differed for the 2 housing treatments (P = 0.002). Sows gestated in hoop barns gave birth to more live pigs per litter (10.0 +/- 0.2 pigs) than sows gestated in stalls (9.3 +/- 0.2 pigs). Preweaning mortality was not different for the 2 housing treatments (P = 0.70). Cross-fostering was done to equalize litter size within 24 h of birth, which resulted in an equal number of weaned pigs per sow (P = 0.50) regardless of gestation housing treatment. The weaning-to-breeding interval was different (P = 0.01), with sows kept in stalls (4.3 +/- 0.6 d) returning to estrus sooner than sows gestated in hoop barns (6.0 +/- 0.6 d). These results indicate that gestating sows can be housed as groups in deep-bedded hoop barns equipped with individual feeding stalls and will perform comparably to gestating sows housed in confinement systems with individual gestation stalls.     

Effect of folic acid supplements on homocysteine concentration in plasma of gestating sows.

An experiment comprising 19 German Landrace sows was established to evaluate the effect of folic acid supplements (10 mg/kg concentrate) on homocysteine and folic acid concentration in plasma and serum, respectively, of highly pregnant sows as compared to an unsupplemented control (basal diet contained 0.62 mg folic acid/kg concentrate). Blood samples were taken between day 75 and 110 of gestation for homocysteine analysis and on day 100 of gestation for folic acid determination. Due to the folic acid supplements serum folic acid concentration increased significantly (104 nmol/l in controls and 140 nmol/l in supplemented sows). In contrast, homocysteine concentration in the plasma was not significantly influenced by folic acid supplements (16.6 mumol/l in controls and 15.2 mumol/l in supplemented sows). Further investigations seem to be necessary to clarify the physiology of homocysteine metabolism in swine.     

Effects of tryptophan supplementation on plasma tryptophan and related hormone levels in heifers and dairy cows

This study was conducted to investigate the effects of rumen-protected tryptophan (125 g tryptophan per day) in heifers and dairy cows. Blood samples from dairy cows and heifers were collected for 24h in 3-h intervals on the day before tryptophan supplementation, on day 2, 5 and 7 of tryptophan supplementation, and in heifers additionally on d 14 after tryptophan supplementation was ceased. Plasma tryptophan, melatonin, serotonin, and prolactin concentrations were determined. Tryptophan plasma concentrations on d 5 were augmented at day (11:00 h) and nighttime (02:00 h), (P<0.05) in response to tryptophan supplementation in heifers by 119% and in dairy cows by 47%, respectively, as compared with d 0. Melatonin increased (P<0.05) in response to tryptophan supplementation in heifers, but not in cows. The effect of tryptophan supplementation on plasma tryptophan and melatonin was reversible as demonstrated in heifers on d 14 after cessation of tryptophan supplementation. Serotonin and prolactin in plasma did not respond to tryptophan supplementation. However, milk yield during morning milking increased significantly in tryptophan supplemented cows on d 1, 3 and 4 as compared to the day before tryptophan supplementation. Additional blood samples were taken during afternoon milking in cows at 1-min intervals for the analyses of oxytocin and prolactin on the day before the start and on d 7 of tryptophan supplementation. Milk flow curves were recorded during milking. No effect of tryptophan supplementation on the milking related release of oxytocin and prolactin and on any characteristic of milk flow was observed. In conclusion, tryptophan supplementation caused increased plasma tryptophan in cows and heifers and plasma melatonin in heifers. However, plasma serotonin, prolactin and oxytocin release in cows remained unchanged by tryptophan supplementation. Milk yield at morning milking increased slightly and transiently in response to tryptophan supplementation.     

Long-term effects of corn gluten feed on the reproductive performance and weight of gestating sows

Corn gluten feed (CGF) was evaluated as the primary energy and protein source for gestating sows. Eighty gravid multiparous Yorkshire x Landrace sows were assigned randomly to three treatment groups for the entire three-parity trial. The gestation treatment diets were 1) corn-soybean meal fed at 1.8 kg/d (control), 2) CGF plus soybean meal fed at 2.3 kg/d (CGF-low) and 3) CGF plus soybean meal fed at 2.6 kg/d (CGF-high). The CGF diets contained 92.2% and 93.7% CGF, respectively. Feeding levels of Diets 2 and 3 were based on the assumption that CGF had 80% and 70% of the net energy value of corn, respectively. All sows had ad libitum access to a conventional corn-soybean meal diet during lactation and were fed 3.2 kg/d during breeding. Intakes of gestation treatment diets were increased 25% during winter months. Based on litter size and weight, the performance of sows fed CGF did not differ from that of the sows fed the control diet. Mean number of pigs at birth and 21 d (weaning) for the three parities were: (control) 10.16, 7.65; (CGF-low) 11.30, 8.44; (CGF-high) 10.73, 8.13, respectively. Pigs from CGF-fed sows were smaller at birth (P less than .05), but subsequent pig weights did not differ. Mean pig birth and 21-d weights for the three parities were: (control) 1.44, 5.18; (CGF-low) 1.30, 4.84; (CGF-high) 1.31, 5.01 kg, respectively. CGF-low sows weighed less (P less than .01) at d 109 of gestation than did the control and CGF-high sows, which did not differ in weight.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of alpha-lipoic acid supplementation on antioxidative ability and performance of sows and nursing piglets

The current study was carried out to determine the effects of alpha‐lipoic acid (LA) supplementation during late‐gestation and lactation on antioxidative ability and performance of sows and their nursing piglets. A total of 160 multiparous sows were randomly allocated to four treatments with 40 replicates per treatment according to parity number and backfat (BF) thickness. Sows were fed 1 of 4 diets from day 85 of gestation to day 21 of lactation. Diets were control without LA; 400 ppm LA supplementation; 600 ppm LA supplementation; and 800 ppm LA supplementation. BF thickness of sows was determined on day 85 and 110 of gestation and days 1 and 21 of lactation. Piglet bodyweight was measured at birth, days 7, 14 and 21. Blood samples were obtained from the sows, and average daily feed intake (ADFI) of the sows during lactation was recorded. There were no differences in BF thickness or ADFI among treatment groups. Dietary LA supplementation resulted in a decrease in blood urea nitrogen (p < 0.01) concentration at days 110 of gestation. Dietary 800 ppm LA increased serum glutathione peroxidase (GSH‐Px) activity (p < 0.05) and reduced maleic dialdehyde levels (p < 0.01) of sows compared with the control diet at days 21 of lactation. Alpha‐lipoic acid supplementation increased the birthweight and weaning weight of piglets (p < 0.01) compared with the control group. Weight gains of piglets from sows fed the 800 ppm LA diets were greater (p < 0.01) between days 7 and 14 compared with piglets from control sows. Weight gains of piglets from sows fed the LA‐supplemented diets were greater between days 14 and 21 (p < 0.05) and between days 1 and 21 (p < 0.01) compared with piglets from control‐fed sows. In conclusion, the results indicate that antioxidant LA was effective in enhancing antioxidant enzymes activity and improving the performance of sows and their nursing piglets.     

Effects of tryptophan supplementation on cashmere fiber characteristics, serum tryptophan, and related hormone concentrations in cashmere goats

This study was designed to investigate the effects of tryptophan (Trp) supplementation on cashmere fiber characteristics and on serum Trp, melatonin (MEL), prolactin (PRL), insulin-like growth factor 1 (IGF-1), triiodothyronine (T(3)), and thyroxine (T(4)) concentrations in cashmere goats during the cashmere fast-growth period. Thirty-six Liaoning cashmere wether goats were stratified on the basis of body weight (28 ± 0.8 kg) and assigned randomly to 1 of the following 4 rumen-protected Trp treatments: 0, 2.0, 4.0, and 6.0 g per goat per day. The experimental period lasted 137 d. Blood samples were collected monthly during the daytime (8:00 AM) and at night (8:00 PM). Tryptophan supplementation improved cashmere growth rates, cashmere weight, and body weight (P = 0.001) and increased serum Trp levels, nighttime MEL concentrations, IGF-1, and T(3) and T(4) concentrations (P < 0.05). Across the treatments and sampling months, a highly positive correlation between cashmere growth rate and nighttime serum MEL concentrations was observed (r = 0.879, P = 0.001). A moderately negative correlation between cashmere growth rates and serum PRL concentrations during the day and at night (r(day) = -0.645, P = 0.007; r(night) = -0.583, P = 0.018) was observed. A moderately positive correlation between the cashmere growth rate and the daytime serum IGF-1 concentration (r = 0.536, P = 0.032) was observed, and no correlation was found between the cashmere growth rate and the other serum hormone concentrations. These data indicate that changes in serum concentrations of MEL, IGF-1, and PRL are related to cashmere growth in Liaoning cashmere goats during the cashmere fast-growth period. Under the experimental conditions of the current trial, we suggest that Trp may promote cashmere growth by increasing daytime IGF-1 and nighttime MEL secretion.     

Effect of L-carnitine supplementation on performance parameters in gilts and sows

The effect of L-carnitine supplementation during pregnancy and lactation on performance parameters of sows was studied. The trial comprised a total of 127 sows (40 gilts, 87 mature sows) which were divided into a control and a treatment group. All animals were fed individually and received basic feed mixtures for pregnancy and lactation with low carnitine concentrations (gestation diet: 4.7 mg/kg feed, lactation diet: 12.5 mg/kg feed). The rations of the sows in the treated group were supplemented with 125 mg L -carnitine per head and day during pregnancy and 250 mg L -carnitine per head and day during lactation. The animals of the control group received identical feed mixtures in identical amounts, but without the L -carnitine supplement. L -carnitine supplementation resulted in higher sow liveweight gains between day 1 and day 85 of pregnancy. The number of piglets per litter and the number born alive did not differ between the control sows and those treated with L -carnitine. However, the L -carnitine-supplemented sows produced only half as many non-viable piglets as the control animals. Moreover, litter weight and mean birth weight of piglets from L -carnitine-treated sows were higher than in the control sows. This effect was more marked in gilts (+8% higher litter weight, +9% higher piglet weight) than in sows (+7% and +6%, respectively). Piglets from sows whose ration was supplemented with L -carnitine showed higher liveweight gains during the suckling period (+12% for gilts, +4% for sows), which is why litter weights post weaning were also higher among the sows treated with L -carnitine than in the control sows (+14% for gilts, +10% for sows). Overall, the study shows that dietary supplementation with L -carnitine during pregnancy and lactation improves the reproductive performance of sows.     

添加色氨酸、诱食剂对断奶仔猪生产性能和腹泻的影响

试验研究添加色氨酸和诱食剂对早期断奶仔猪生产性能和腹泻的影响。选择(23±1)日龄断奶的初始体重为(6.0±0.5)kg的48头PIC仔猪,随机分为4组(1个对照组、3个试验组)。对照组饲喂对照饲粮,试验1￣3组分别饲喂添加0.05%的色氨酸饲粮、添加0.02%的香味剂饲粮和添加0.02%的甜味剂饲粮,试验期为28d。结果表明:①在整个试验期内,与对照组相比,添加甜味剂显著提高仔猪的日采食量和日增重(P<0.05),显著降低仔猪的料肉比(P<0.05),使腹泻指数降低74.07%。②与对照组相比,添加色氨酸显著提高仔猪的日采食量和日增重(P<0.05);有降低料肉比的趋势(P>0.05),未降低腹泻指数。③与对照组相比,添加香味剂使采食量、日增重显著降低(P<0.05),料肉比显著增加(P<0.05),腹泻指数降低5.56%。④添加甜味剂与添加色氨酸在提高断奶仔猪采食量上差异不显著(P>0.05),但是添加甜味剂组仔猪的日增重显著高于添加色氨酸组的仔猪(P<0.05),并且前者的料肉比显著低于后者(P<0.05)。添加甜味剂组仔猪的腹泻指数比添加色氨酸组仔猪低75.0%。     

Studies on the tryptophan requirement of lactating sows. Part 2: Estimation of the tryptophan requirement by physiological criteria

Mature sows were fed for a total of 72 lactations with diets which provided an adequate supply of energy and nutrients except for tryptophan (Trp). By supplementing a basal diet [native 1.2 g Trp/kg, equivalent to 0.8 g apparent ileal digestible (AID) Trp or 0.9 g true ileal digestible (TID) Trp] with L-Trp, five further diets (2-6) containing 1.5-4.2 g Trp/kg were formulated. The dietary Trp content had no effect on amino acid contents in milk on days 20 and 21 of lactation, but Trp in blood plasma on day 28 of lactation reflected the alimentary Trp supply with an increase from 2.74 +/- 1.14 mg/l (diet 1) to 23.91 +/- 7.53 mg/l (diet 6; p < 0.001). There were no directional differences between the diets with regard to the other amino acids. Concentrations of urea in milk and blood were higher with diet 1 (211 and 272 mg/l, respectively) than with diets 3-6 (183 and 227 mg/l, respectively). Serotonin levels in the blood serum were lower with diet 1 (304 ng/ml) than the average of diets 4-6 (540 ng/ml). This study confirms previously given recommendations for the Trp content in the diet of lactating sows, estimated by means of performance, of 1.9 g AID Trp (equivalent to 2.0 g TID Trp; approximately 2.6 g gross Trp) per kg diet.     

Influence of dietary L-carnitine and chromium picolinate on blood hormones and metabolites of gestating sows fed one meal per day

Gestating sows (n = 44; parity = 2.0; BW = 208 kg) were used to determine the effects of dietary L-carnitine and Cr picolinate (CrP) on daily blood hormone and metabolite profiles. Diets were formulated as a 2 x 2 factorial with L-carnitine (0 or 50 ppm) and CrP (0 or 200 ppb) and were fed from breeding through gestation, lactation, and 28 d into the subsequent gestation, at which time blood collection occurred. Sows were fed 1 meal per day during gestation (2.04 kg from breeding until d 100 and 2.95 kg from d 100 until farrowing) and ad libitum during lactation. Sows were fitted with indwelling venous catheters, and blood (plasma) was collected at feeding, then once every 15 min for the first 3 h after feeding, and at 6, 9, 15, 20, and 24 h after feeding. Postfeeding and overall insulin and connecting peptide of insulin (c-peptide) was decreased for sows fed diets with CrP or L-carnitine and was greatest for sows fed the control diet; however, sows fed both L-carnitine and CrP had an intermediate response (L-carnitine x CrP, P < 0.01). Postfeeding glucose peak was decreased (P < 0.05) in sows fed diets with L-carnitine, CrP, or both, vs. the control, and mean glucose concentration was decreased (P < 0.01) for sows fed diets with CrP. L-Carnitine decreased (P < 0.04) the NEFA concentration. Sows fed diets with CrP exhibited increased (P < 0.03) postfeeding and overall NEFA and greater (P < 0.02) fasting and overall glycerol. Overall plasma urea N was lowest for sows fed the diet with L-carnitine; however, diets containing CrP had intermediate responses compared with the control (L-carnitine x CrP, P < 0.005). Sows fed diets with L-carnitine had greater (P < 0.008) IGF-I from 3 to 24 h after feeding and tended to exhibit greater (P < 0.06) overall IGFBP-3. Sows fed the diets with CrP had greater (P < 0.05) IGFBP-3 from 2 to 20 h after feeding. No differences were observed for glucagon or triacylglycerol (P > 0.10). The changes in metabolites and metabolic hormones indicate that both L-carnitine and CrP influence energy metabolism of gestating sows; however, their effects on blood hormones and metabolites differ. Thus, the improvement in energy status from adding both L-carnitine and CrP may have an additive effect on reproductive performance of sows.     

Effects of dietary supplementation of l-carnitine on the reproductive performance of sows in production stocks

Investigations by Robinson [Robinson, D.L., 2007. Days to calving in artificially inseminated cattle: comparison of potential traits. Livestock Science 110, 174–180] concluded that the most useful trait for assessing fertility of artificially inseminated (AI) beef cows is AI days to calving (AIDC), a trait that mimics days to calving for naturally mated cows. Various fixed and random effects were fitted to AIDC to determine the best way of modelling lactation status of the cow, the effect of service sire, using smaller contemporary groups and lowering the penalty value for non-calvers. Fitting the time interval between calving and the start of mating either as a 10-level factor or a cubic spline function explained considerably more variation than fitting the standard 2-level factor (wet or dry). Estimated permanent environmental effects of the cow were considerably reduced. This suggests that, if a cow calves late in the season (less than 60 days before she is inseminated), her fertility is reduced. Models should therefore account for this effect. If fitted, service sire explained 1.6% of phenotypic variation, compared to a much larger sire × contemporary group interaction (3% of phenotypic variation). It is therefore important to account for sire × contemporary group interactions. When the fertility of service sires is not being evaluated, service sires could be incorporated into the definition of contemporary groups. Ideally, breeders should be encouraged to formally record contemporary (or mating) groups. Reducing the size of contemporary groups (inferred from the data) by limiting the time interval between first and last inseminations from 120 to 60 days had only a marginal effect as did reducing the penalty for non-calvers from 21 to 10 days.     

Effect of soluble and insoluble fiber on energy digestibility, nitrogen retention, and fiber digestibility of diets fed to gestating sows

Twenty-four sows (12 nulliparous, 12 multiparous) were used to determine soluble fiber (SF) and insoluble fiber (ISF) effects on energy digestibility, N balance, and SF and ISF digestibility. Experimental diets included a corn-soybean meal control (C; 1.20% SF, 9.78% ISF), a 34% oat bran diet high in SF (HS; 3.02% SF, 10.11% ISF), a 12% wheat straw diet high in ISF (HIS; 1.11% SF, 17.86% ISF), and a 16% sugar beet pulp diet (HS + HIS; 2.32% SF, 16.08% ISF). Sows were assigned randomly to diets within parity group and individually fed to meet their energy requirements according to the NRC model assuming 10 pigs per litter and 40 kg of gestation gain. Total feces and urine were collected in 5-d periods at wk 5, 10, and 14 of gestation. There were no interactions between dietary treatments and parity group for any of the response criteria evaluated. Dietary energy digestibility was greatest (P < 0.01) for females fed C (87.9%) and HS (89.3%) diets compared with females fed diets high in ISF (HIS, 82.9; HS + HIS, 86.8%). Energy digestibility was not affected by stage of gestation. Dietary N digestibility was similar between C and HS (86.1 and 86.2%) but greater (P < 0.01) than HIS and HS + HIS (82.8 and 82.8%, respectively). Nitrogen digestibility declined (P < 0.05) as gestation progressed for sows fed HS only. Nitrogen retention as a percentage of N intake was not affected by diet (C, 51.8; HS, 44.0; HIS, 42.0; HS + HIS, 48.6). Soluble fiber digestibility was different (P < 0.01) among experimental diets (C, 85.8; HS, 89.5; HIS, 77.7; HS + HIS, 80.3%). Sows fed HS + HIS (61.8%) and HS (58.4%) had greater (P < 0.05) ISF digestibility than sows fed C (53.5%), whereas sows fed HIS (38.3%) had lower (P < 0.01) ISF digestibility than sows fed the other experimental diets. Greater digestibility of dietary energy (87.1 vs. 86.2%; P < 0.05), N (85.7 vs. 83.2%; P < 0.01), and ISF (54.5 vs. 51.2%; P < 0.06) was observed in multiparous vs. nulliparous sows. In conclusion, increased intake of ISF decreased energy digestibility, whereas increasing SF intake improved energy digestibility. Diet had no effect on N retention. Insoluble fiber digestibility improved when SF intake increased, suggesting that knowledge of specific dietary fiber components is necessary to accurately predict effects of dietary fiber on digestibility. Multiparous sows demonstrated a greater ability to digest fibrous diets than nulliparous sows.     

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.