Effects of improved amino acid balance diet on lysine mammary utilization, whole body protein turnover and muscle protein breakdown on lactating sows

Background The study objective was to test the hypothesis that low crude protein(CP)diet with crystalline amino acids(CAA)supplementation improves Lys utilization efficiency for milk production and reduces protein turnover and muscle protein breakdown.Eighteen lactating multiparous Yorkshire sows were allotted to 1 of 2 isocaloric diets(10.80 MJ/kg net energy):control(CON;19.24%CP)and reduced CP with“optimal”AA profile(OPT;14.00%CP).Sow body weight and backfat were recorded on d 1 and 21 of lactation and piglets were weighed on d 1,14,18,and 21 of lactation.Between d 14 and 18,a subset of 9 sows(CON=4,OPT=5)was infused with a mixed solution of 3-[methyl-2H3]histidine(bolus injection)and[13C]bicarbonate(priming dose)first,then a constant 2-h[13C]bicarbonate infusion followed by a 6-h primed constant[1-13C]lysine infusion.Serial blood and milk sampling were performed to determine plasma and milk Lys enrichment,Lys oxidation rate,whole body protein turnover,and muscle protein breakdown.Results Over the 21-d lactation period,compared to CON,sows fed OPT had greater litter growth rate(P<0.05).Compared to CON,sows fed OPT had greater efficiency of Lys(P<0.05),Lys mammary flux(P<0.01)and whole-body protein turnover efficiency(P<0.05).Compared to CON,sows fed OPT tended to have lower whole body protein breakdown rate(P=0.069).Muscle protein breakdown rate did not differ between OPT and CON(P=0.197).Conclusion Feeding an improved AA balance diet increased efficiency of Lys and reduced whole-body protein turnover and protein breakdown.These results imply that the lower maternal N retention observed in lactating sows fed improved AA balance diets in previous studies may be a result of greater partitioning of AA towards milk rather than greater body protein breakdown.

Dietary arginine supplementation in multiparous sows during lactation improves the weight gain of suckling piglets

This study investigated the effects of dietary arginine （Arg） supplementation, just during lactation, on sow and litter per- formance, plasma concentrations of metabolites and hormones, and milk yield and composition in multiparous sows. Thirty-one sows were randomly assigned to 3 dietary treatments supplemented with 0.0 （control, n=10）, 0.5% （n=10）, or 1.0% （n=11） L-Arg-HCI, respectively. Experimental diets were provided to the sows from d 3 to 21 of lactation. Plasma and milk samples were collected at d 14 and 21 of lactation. The average daily gain （ADG） of piglets from sows fed diets supplemented with 0.5 or 1.0% L-Arg-HCI at d 3 to 14 of lactation, were higher than that of controls （P〈0.05）. Maternal supplementation with 1.0% L-Arg-HCI also increased ADG of piglets between d 3 and 21 of lactation than that of the controls （P〈0.05）. There was no significant effect of supplementation on average daily feed intake （ADFI）, body weight loss, and backfat thickness loss of lactating sows. Supplementation with 0.5 or 1.0% L-Arg-HCI had a trend towards increasing milk yields and milk fat contents （0.05〈P〈0.10）; milk protein and lactose were unchanged. Supplementation with 1.0% L-Arg- HCI increased plasma concentrations of prolactin and insulin in sows at d 14 and 21 of lactation, and plasma concentrations of non-esterified fatty acid （NEFA）, insulin-like growth factor-1 （IGF-1）, and nitric oxide （NO） in sows at d 21 of lactation, when compared to the controls （P〈0.05）. Supplementation with 1.0% L-Arg-HCI increased IGF-1 and spermine in milk at d 14 of lactation, relative to the controls （P〈0.05）. Plasma Arg concentrations at d 14 and 21 of lactation, as well as plasma NO level and milk IGF-1 at d 21 of lactation, were increased, while plasma urea nitrogen （PUN） concentration at d 14 and 21 of lactation was decreased, by supplementation with 0.5 or 1.0% L-Arg-HCI when compared to the controls （P〈0.05）. Collectively, dietary supplementation of multiparous sows with Arg, just during lactation, is beneficial for enhancing litter weight gain but the complete mechanism remains to be determined and may involve in the maternal endocrine changes and milk polyamines contents.

Reduced protein diet with near ideal amino acid profile improves energy efficiency and mitigate heat production associated with lactation in sows

Background:The study objective was to test the hypothesis that 1)lowering dietary crude protein(CP)increases dietary energetic efficiency and reduces metabolic heat associated with lactation,and 2)excessive dietary leucine(Leu)supplementation in a low CP diet decreases dietary energetic efficiency and increases metabolic heat associated with lactation.Methods:Fifty-four lactating multiparous Yorkshire sows were allotted to 1 of 3 isocaloric diets(10.80 MJ/kg net energy):1)control(CON;18.75%CP),2)reduced CP with a near ideal or optimal AA profile(OPT;13.75%CP)and 3)diet OPT with excessive Leu(OPTLEU;14.25%CP).Sow body weight and backfat were recorded on day 1 and 21 of lactation and piglets were weighed on day 1,4,8,14,18,and 21 of lactation.Energy balance was measured on sows during early(day 4 to 8)and peak(day 14 to18)lactation,and milk was sampled on day 8 and 18.Results:Over 21-day lactation,sows fed OPT lost body weight and body lipid(P<0.05).In peak lactation,sows fed OPT had higher milk energy output(P<0.05)than CON.Sows fed OPTLEU tended(P=0.07)to have less milk energy output than OPT and did not differ from CON.Maternal energy retention was lower(P<0.05)in OPT and OPTLEU compared to CON sows,and did not differ between OPTLEU and OPT sows.Sows fed OPT had higher(P<0.05)apparent energy efficiency for milk production compared to CON.Heat production associated with lactation was lower(P<0.05)or tended to be lower(P=0.082),respectively,in OPT and OPTLEU compared to CON sows.Conclusion:The OPT diet,in peak lactation,improved dietary energy utilization for lactation due to less urinary energy and metabolic heat loss,and triggered dietary energy deposition into milk at the expense of maternal lipid mobilization.Leucine supplementation above requirement may reduce dietary energy utilization for lactation by decreasing the energy partitioning towards milk,partially explaining the effectiveness of OPT diet over CON diets.

The effect of the ratio of standardized ileal digestible lysine to metabolizable energy on growth performance,blood metabolites and hormones of lactating sows

A total of 335 lactating sows （Landrace x Large White） were used in two experiments to determine the optimum ratio of standardized ileal digestible lysine （SID-Lys） to metabolizable energy （ME） for mixed parity sows during lactation. In Exp. 1, 185 sows （weighing an average of 256.2 ± 6.5 kg and having an average parity of 3.4 ± 0.3） were allocated to one of six experimental diets in a completely randomized block design within parity groups （1, 2, and 3＋）. The experimental diets were formulated to contain 3.06, 3.16, 3.20, 3.25, 3.30 or 3.40 Mcal/kg of ME and each diet was fed to the sows throughout a 28 day lactation. All diets provided a similar SID-lysine level （0.86%）. As a result, the diets provided a SID-Lys：ME ratio of 2.81, 2.72, 2.69, 2.65, 2.61 or 2.53 g/Mcal ME. Sow feed intake was significantly （P 〈 0.01） affected by the energy content of the diet as well as by sow parity. Using regression analysis, feed intake was shown to be maximized at 3.25, 3.21, 3.21 and 3.21 Mcal/kg of ME for parity 1, 2, 3＋ sows and the entire cohort of sows respectively （quadratic; P 〈 0.01）. In addition, the result of feed intake can be expressed as 2.65, 2.69, 2.69 and 2.68 g/Mcal based on analysis of SID-Lys：ME ratio. Litter weight gain was affected by dietary treatment for parity 3＋ sows and the entire cohort （P 〈 0.01）. Based on regression analysis, litter weight gain was maximized at 3.25 and 3.24 Mcal/kg of ME for parity 3＋ （quadratic; P 〈 0.01） and the entire cohort （quadratic; P 〈 0.01）. Similarly, the result of litter weight gain could be expressed as 2.65 and 2.66 g/Mcal of SID- Lys：ME ratio. Therefore, 3.25 Mcal/kg of ME was selected for Exp. 2 in which 150 sows （weighing 254.6 ± 7.3 kg and having an average parity of 3.4 ± 0.4） were allocated to one of five treatments in a completely randomized block design within parity （1, 2, and 3＋）. The experimental diets were formulated to contain 2.1, 2.4, 2.7, 3.0 or 3.3 g/Mcal of SID-Lys：ME ratio with all diets providing 3.25 Mcal/kg of ME. The diets were fed to the sows throughout a 28 day lactation. Sow body weight loss was affected by dietary treatment （parity 3＋ sows, P = 0.02; entire cohort, P 〈 0.01） and by sow parity （P 〈 0.01）. Litter weight at weaning and litter weight gain were affected by dietary treatment for parity 1, 2, 3＋ sows and the entire cohort （P 〈 0.01） as well as by sow parity （P 〈 0.01）. Plasma urea nitrogen （P 〈 0.01）, creatinine （P 〈 0.01） and non-esterifide fatty acids （P = 0.04） were decreased as the SID-Lys：ME ratio of the diet increased. Insulin-like growth factor-1 （P = 0.02）, estradiol （P 〈 0.01） and luteinizing hormone （P = 0.02） were increased as the SID-Lys：ME ratio in diet increased. Based on a broken-line model, the estimated SID-Lys： ME ratio to maximize litter weight gain was estimated to be 3.05 g/Mcal.

Effect of dietary near ideal amino acid profile on heat production of lactating sows exposed to thermal neutral and heat stress conditions

Background:Reduced protein diet manifested potential to mitigate heat production based on the concept of ideal amino acid profile.The hypothesis of this study was that lactating sows fed a low crude protein(LCP)diet with supplemental amino acid produce less heat compared to those fed a high crude protein(HCP)diet under both thermal neutral(TN)and heat stress(HS)conditions.Methods:Thirty-two lactating sows were allotted to HCP(193 g CP/kg)and LCP(140 g CP/kg)diets under thermal neutral(TN,21±1.5°C)or cycling heat stress(HS,32±1.5°C daytime and 24±1.5°C nighttime)conditions.Diets contained 0.90%SID lysine and 10.8 MJ/kg net energy.Positive pressure indirect calorimeters were used to measure gas exchange in individual sows with litters,and individual piglets on days 4,8,14 and 18.Sow and litter weights were recorded on days 1,10 and 21.Results:Sow total heat production(THP)was calculated by subtracting litter THP from sow+litter THP based on BW0.75.Sow BW and body protein(BP)loss was greater for LCP diet compared to HCP diet in peak lactation(P<0.05 and P<0.01,respectively)and throughout the entire lactation period(P<0.05 and P=0.056,respectively)under HS conditions.Heat-stressed sows fed HCP diet had higher(P<0.05)rectal temperature at 13:00(P<0.05)and 19:00(P<0.01),and higher respiration rate at 07:00(P<0.05),13:00(P<0.05)and 19:00(P<0.05)compared to TN sows fed HCP diet.In sows fed LCP diet,those under HS tended to have higher(P=0.098)rectal temperature at 13:00 and had higher(P<0.05)respiration rate at 07:00,13:00 and 19:00 compared to TN sows.The relationship between daily THP and days in lactation of sows fed LCP diet was quadratic(P<0.05),with an ascending trend until day 14 and a descending trend from days 14 to 18.Sows fed LCP diet had lower daily THP at day 18(P<0.001)compared to those fed the HCP diet under HS conditions.Conclusion:Reduction in THP in sows fed LCP diet was largely associated with THP on day 18 of lactation under HS conditions.Feeding LCP diets alleviated the increased body temperature in sows under HS conditions throughout lactation,which was accompanied by a reduction in respiration rate.Total heat production is associated with days in lactation,in particular under HS conditions with THP appearing to peak between days 14 and 18.

Effects of Gamma-Aminobutyric Acid on Performance of Lactating Sows during Heat Weather

[ Objective] To study the effects of gamma-aminobutyric acid （GABA） on performance of lactating sows during heat stress. [ Metbod] A total of 14 sows at the same parity and with close expected date of childbirth and similar body we：,ght were randomly divided into control group and experimental group. They were fed a common basal diet and a GABA （300 mg/kg） supplementary diet, respectively. The trial lasted for 21 d. [ Result ] The daily feed intake, lactation yield and average daily gain of piglets in the experimental group were increased by 9.4%, 28.5% and 10.7%, respectively. The backfat of lactating sows was decreased less, and the same with the weaning-oestrus interval. The survival ratio of piglets was increased by 4.5%. Compared with the control group, the content of lactose and fat increased significantly, but other components almost did not change. [Conclusien] Supplementing GABA in diet can improve the performance of lactating sows and promote the growth of piglets effectively.

Optimizing dietary lipid use to improve essential fatty acid status and reproductive performance of the modern lactating sow:a review

Dietary lipid supplementation benefits the prolific and high-producing modern lactating sow. A comprehensive review of recent studies showed that lipid supplementation increases average daily energy intake, which is partitioned for lactation as indicated by greater milk fat output and improved litter growth rate. Recent compelling findings showed that addition of particular lipids during lactation improved the subsequent reproductive outcome of sows. Such benefits were related to the level of dietary essential fatty acids（EFA, linoleic acid, C18：2n-6; and α-linolenic acid, C18：3n-3） during lactation. Lactation diets without supplemental EFA resulted in a pronounced negative balance（intake minus milk output） of linoleic（-25.49 g/d） and α-linolenic acid（-2.75 g/d）; which compromised sow fertility（farrowing rate 〈 75 % and culling rates 〉 25 % of weaned sows）. This phenomenon seems to be increasingly important with advancing sow age because of a progressive reduction of body EFA pool over successive lactations. The net effect of supplemental EFA during lactation was to create a positive EFA balance, which improved the subsequent reproduction of sows. Adequate linoleic acid intake improved the proportion of sows that farrowed in the subsequent cycle（Farrowing rate（%） = [（-1.5 × 10^-3× linoleic acid intake（g/d）^2） ＋（0.53 × linoleic acid intake（g/d）） ＋（45.2）]; quadratic P = 0.002, R^2= 0.997, RMSE = 0.031）. In addition, increasing linoleic acid intake increased the number of pigs born in the subsequent cycle（total pigs born（n） = [（9.4 × 10^-5× linoleic acid intake（g/d）^2） ＋（0.04 × linoleic acid intake（g/d）） ＋（10.94）]; quadratic P = 0.002, R^2= 0.997, RMSE = 0.031）. Supplemental α-linolenic acid resulted in a rapid return to estrus（sows bred： sows weaned = 94.2 %; wean-to-estrus interval = 4.0 d） and achieved a high retention of pregnancy（sows pregnant： sows bred = 98 %）. Collectively, we conclude that a minimum dietary intake of10 g/d of α-linolenic acid, simultaneous with a minimum of 125 g/d of linoleic acid should be provided to ≥ 95 % of the sows; thereby, achieving a maximum sow reproductive efficiency through multiple mechanisms that include rapid return to estrus, high maintenance of pregnancy and large subsequent litter size in mature sows, that appear to be susceptible to EFA deficiency.

Transfer of β-hydroxy-β-methylbutyrate from sows to their offspring and its impact on muscle fiber type transformation and performance in pigs

Background： Previous studies suggested that supplementation of lactating sows with β-hydroxy-β-methylbutyrate（HMB） could improve the performance of weaning pigs, but there were little information in the muscle fiber type transformation of the offspring and the subsequent performance in pigs from weaning through finishing in response to maternal HMB consumption. The purpose of this study was to determine the effect of supplementing lactating sows with HMB on skeletal muscle fiber type transformation and growth of the offspring during d 28 and180 after birth. A total of 20 sows according to their body weight were divided into the control（CON, n = 10） or HMB groups（HMB, n = 10）. Sows in the HMB group were supplemented with β-hydroxy-β-methylbutyrate calcium（HMB-Ca） 2 g/kg feed during d 1 to 27 of lactation. After weaning, 48 mixed sex piglets were blocked by sow treatment and fed standard diets for post-weaning, growing, finishing periods. Growth performance was recorded during d 28 to 180 after birth. Pigs were slaughtered on d 28（n = 6/treatment） and 180（n = 6/treatment） postnatal and the longissimus dorsi（LD） was collected, respectively.Results： The HMB-fed sows during lactation showed increased HMB concentration（P ＆lt; 0.05） in milk and LD of weaning piglets（P ＆lt; 0.05）. In addition, offsprings in HMB group had a higher finishing BW and lean percentage than did pigs in CON group（P ＆lt; 0.05）, meanwhile, compared with pigs from sows fed the CON diet, pigs from sows fed HMB diet showed higher type Ⅱ muscle fiber cross-sectional area（CSA）, elevated myosin heavy chain（MyHC） Ⅱb and Sox6 mRNA, and fast-MyHC protein levels in LD（P ＆lt; 0.05）.Conclusions： HMB supplemented to sow diets throughout lactation increases the levels of HMB in maternal milk and skeletal muscle of pigs during d 28 after birth and promotes subsequent performance of pigs between d 28 and 180 of age by enhancing glycolytic muscle fiber transformation.

Increased maternal consumption of methionine as its hydroxyl analog promoted neonatal intestinal growth without compromising maternal energy homeostasis

Background： To determine responses of neonatal intestine to maternal increased consumption of DL-methionine（DLM） or DL-2-hydroxy-4-methylthiobutanoic acid（HMTBA）, eighteen primiparous sows（Landrace × Yorkshire） were allocated based on body weight and backfat thickness to the control, DLM and HMTBA groups（n = 6）, with the nutritional treatments introduced from postpartum d0 to d14.Results： The DLM-fed sows showed negative energy balance manifested by lost bodyweight, lower plasma glucose, subdued tricarboxylic acid cycle, and increased plasma lipid metabolites levels. Both villus height and ratio of villus height to crypt depth averaged across the small intestine of piglets were higher in the DLM and HMTBA groups than in the control group. Piglet jejunal oxidized glutathione concentration and ratio of oxidized to reduced glutathione were lower in the HMTBA group than in the DLM and control groups. However, piglet jejunal aminopeptidase A, carnitine transporter 2 and IGF-II precursor m RNA abundances were higher in the DLM group than in the HMTBA and control groups.Conclusion： Increasing maternal consumption of methionine as DLM and HMTBA promoted neonatal intestinal growth by increasing morphological development or up-regulating expression of genes responsible for nutrient metabolism. And increasing maternal consumption of HMTBA promoted neonatal intestinal antioxidant capacity without compromising maternal energy homeostasis during early lactation.

Development of the precision feeding system for sows via a rule-based expert system

To precisely meet the nutritional requirements of sows during the stages of pregnancy and lactation,a precision feeding system was developed by using the intelligent sow feeder combined with a rule-based expert system and the Internet of Things(IoTs).The model of uncertain knowledge representation was established for inference by using the certainty factor.The daily feeding amount of each sow was calculated by the expert system.An improved pattern matching algorithm Reused Degree Model-RETE(RDM-RETE)was proposed for the decision of daily feeding amount,which sped up inference by optimizing the RETE network topology.A prediction model of daily feeding amount was established by a rule-based expert system and the precision feeding was achieved by an accurate control technology of variable volume.The experimental results demonstrated that the HASH-RDM-RETE algorithm could effectively reduce the network complexity and improve the inference efficiency.The feeding amount decided by the expert system was a logarithmic model,which was consistent with the feeding law of lactating sows.The inferential feeding amount was adopted as the predicted feed intake and the coefficient of correlation between predicted feed intake and actual feed intake was greater than or equal to 0.99.Each sow was fed at different feeding intervals and different feed amounts for each meal in a day.The feed intake was 26.84% higher than that of artificial feeding during lactation days(p<0.05).The piglets weaned per sow per year(PSY)can be increased by 1.51 compared with that of relatively high levels in domestic pig farms.This system is stable in feeding and lowers the breeding cost that can be applied in precision feeding in swine production.

Assessment of the environmental comfort of lactating sows via improved analytic hierarchy process and fuzzy comprehensive evaluation

Since there are many interacting influence factors of the comfortable degree of lactating sows,a method that combines improved analytic hierarchy process(IAHP)and fuzzy comprehensive evaluation(FCE)was introduced to conduct a quantitative evaluation of the comfortable degree.Besides,an evaluation index system was established,and the weights of different indicators were determined by using IAHP method,including temperature,relative humidity,concentrations of carbon dioxide(CO_(2)),ammonia(NH_(3)),hydrogen sulfide(H_(2)S),and air speed.The construction method of fuzzy membership function and the calculation method of the parameters were proposed following the principle that the summation of membership degrees is equal to 1.Three basic types of membership functions(MFs),i.e.,ridgemf,gaussmf,and trimf were used to build an evaluation model which fitted IAHP-FCE well.The proposed method was verified and applied based on the environmental data in different seasons obtained from a pig farm in Zhenjiang City,Jiangsu Province,China.It is demonstrated that the proposed IAHP-FCE model with various types of MFs has drawn a unique and consistent conclusion.Moreover,the IAHP-FCE model has a higher correlation coefficient of 0.874 compared with the single-factor evaluation(SFE)model.The IAHP-FCE model could be served as a beneficial strategy for the precise regulation and early warning of environmental conditions to improve sow welfare.