Impacts of a modified farrowing pen design on sow and litter performances and air quality during two seasons

The impacts of using a modified farrowing pen (MOD) on the performance of sows and their litters and on ambient air quality over a hot and a cool season were evaluated. Primiparous Yorkshire × Landrace sows farrowed either during the months of February and March (thermoneutralily, TN) or June and July (heat-stress, HS). Temperatures within each season were controlled to 21 and 29 °C, respectively, for TN and HS. Animals from each group were assigned to a standard farrowing crate (STD; TN, n = 17; HS, n = 16) or a MOD pen (TN, n = 19; HS, n = 19). The MOD pen consisted of a STD crate with a 1.5 × 1.6-m comfort zone in the back, equipped with rubber floor mats, a feeder and a nipple waterer. Litter size was standardized to 10 or 11. No creep feed was provided and piglets were weighed weekly. Sows were weighed on days 2 and 22. Feed intake of sows was monitored daily, a milk sample was obtained on day 21 for compositional analyses and jugular blood samples were collected on days 2 and 21 to measure prolactin, IGF-I and urea. Sows consumed less feed (3.4 vs. 4.7 ± 0.1 kg/day, P < 0.001) in a hot than in a cool season and, at 29 °C, sows in MOD pens consumed more feed (3.9 vs. 3.0 ± 0.2 kg/day, P < 0.01) than sows in STD pens. Sow lactation weight loss was greater (− 26.4 vs. − 19.1 ± 1.9 kg, P < 0.05) for sows in STD than MOD pens in a hot season. The reduction in prolactin concentrations from days 2 to 22 of lactation tended to be greater (P = 0.08) in a hot season for sows in STD pens. Concentrations of urea and IGF-I increased as lactation advanced (P < 0.01) and IGF-I was lower for HS compared to TN sows on both days (P < 0.01), whereas urea was greater for HS sows on day 2 only (P < 0.01). Milk DM was less in a hot than in a cool season (P < 0.01). Average piglet weight gain was reduced in a hot compared to a cool season during the second week of lactation (P < 0.05) and this reduction was less in MOD than STD pens during the third week of lactation (P < 0.01). During a hot season, even though not significant, average weight gain of piglets from days 2 to 21 of lactation was reduced by 6.0% in MOD pens compared to 9.7% in STD pens.     

Gut growth and glucose tolerance in newborn pigs subjected to prenatal protein restriction and postnatal Glucagon-like Peptides

Fetal protein restriction is potentially associated with organ dysfunctions after birth (e.g. impaired gut growth, glucose tolerance and pancreatic β-cell function). Just after birth, gut growth and maturation is stimulated by enteral food intake, and inhibited by total parenteral nutrition (TPN), in part mediated via differential release of insulino- and intestino-tropic hormones like the Glucagon-Like Peptides 1 and 2 (GLP-1, GLP-2). We hypothesized that short-term co-infusion of GLP-1 and GLP-2 would stimulate pancreatic and intestinal growth in newborn TPN-fed pigs subjected to prenatal protein restriction. Two sows were fed a protein-restricted diet (PR: 8% crude protein during last 50% of gestation) while a third sow was fed a control diet (C: 15% crude protein). PR pigs were killed either at birth (n = 7) or after 3 days TPN with (n = 6) or without (n = 4) intravenous infusion of a mixture of synthetic human GLP-1_7–37 and GLP-2_1–33 (each 50 μg/kg/d). At birth, PR piglets did not show reduced body weight, relative to controls (1.45 vs. 1.50 kg), but significantly reduced weight of the small intestine (18.0 ± 0.6 vs. 21.9 ± 0.5 g/kg, P < 0.001) and a marginally reduced pancreas weight (0.85 ± 0.02 vs. 0.93 ± 0.04 g/kg, P = 0.10). Co-infusion GLP-1 and GLP-2 into PR pigs resulted in increased basal glucose levels (5.3 vs. 4.0 mM), and glucose-stimulated insulin release, but did not have any significant effect on body weight, or weight of internal organs (heart, lungs, spleen, kidneys, adrenals, stomach, colon, liver, intestine, pancreas). We conclude that short-term (3 days) infusion of native GLP-1 and GLP-2 does not stimulate gut growth or glucose tolerance in TPN-fed piglets born from protein-restricted mothers. Moderate maternal protein restriction does however cause significant reduction in intestinal growth in newborn piglets which may decrease the neonatal digestive capacity.     

Effect of floor cooling on performance of lactating sows during summer

Forty Landrace × Large White lactating sows were used to evaluate the effects of cooling of the floor when maintained under high temperature conditions during summer on their productive and reproductive performance. The sows were allocated in a completely randomized design with two treatments with 20 replicates according to parity number and body weight, with each animal being considered an experimental unit. The treatments consisted of cooling of the floor under the sow with water circulation at about 17 °C and no cooling. The resulting temperatures of the floor were 27.6 and 35.8 °C for the cooled and the control treatments, respectively. The sows from both treatments were exposed to average maximum and minimum environmental temperatures of 26.9 and 20.8 °C, respectively. Sows maintained on a cooled floor had a higher feed intake (6.47 vs. 5.61 kg/day; P < 0.01). Despite this higher intake, sows maintained on a cooled floor had higher body weight and body protein losses during the lactation period (P < 0.01) in connection with a higher milk yield and subsequent growth of the litter (2280 vs. 1798 g/day; P < 0.01). There was an effect of treatment on rectal temperature, surface temperatures and respiratory rate (P < 0.01) with lower values in sows submitted to floor cooling. It is concluded that floor cooling under the lactating sow improves its productive and reproductive performance, as well as the performance of its litter.     

Effects of pre- and postnatal exposure to garlic and aniseed flavour on pre- and postweaning feed intake in pigs

The low nutrient intake shortly after weaning is a major cause of post-weaning problems. Feed intake after weaning is strongly related to feed intake during lactation. Feed intake during lactation, however, varies considerably between litters. We hypothesised that prenatal and postnatal exposure to certain flavours would increase the intake of feed containing the same flavours pre- and postweaning. Multiparous sows did (n = 17) or did not (n = 14) receive 50 g garlic granulate/powder and 25 g aniseed as daily additive to their diet during the last month of gestation and during lactation. From day 14 of lactation, litters were submitted to intermittent suckling: 12 h separation form the sow each day. During lactation, all litters had 40 g garlic and 20 g aniseed per kg added to their creep feed. After weaning, half of the litters had no additive in their diet. Piglets were weaned at 4 weeks (13 litters) or at 6 weeks (18 litters). At 6 weeks of lactation, litters of which the dam received the flavour in her diet, had a higher feed intake (309 ± 43 vs 233 ± 35 g/p/d) than litters of dams without the flavour, although the difference was not significant. Sow diet had no effect on postweaning feed intake, but postweaning piglet diet did. Late (week 6) weaned litters receiving the flavoured feed had a higher feed intake from 3 to 10 days after weaning (833 ± 38 vs 687 ± 58 g/p/d). Weight gain during the first 10 days after weaning was not affected by sow or pig diets. Feed intake and weight gain shortly after weaning were strongly related to feed intake during lactation (overall R = 0.64, P < 0.05 and R = 0.77, P < 0.05). We conclude that early experience with flavours increases later acceptance and improves adaptation to post weaning conditions.     

The perinatal development of the gastrointestinal tract in piglets can be modified by supplementation of sow diet with bioactive substances

Dietary bioactive substances involving taurine, l-carnitine, polyunsaturated fatty acids, flavonoids and antioxidants were shown to control the perinatal development in mammals. A blend of bioactive substances was used to supplement the diet of sows according to the optimal needs of their offspring. Our study aimed to examine the development of gastrointestinal tract in their offspring as compared to the offspring from control sows fed with standard diet. The supplemented diet was given from the gestation day 80 until the end of lactation period. One piglet from each litter was sacrificed on postnatal days 1 (i.e., unsuckling neonates), 2, 4, 7, 14, and 28 for tissue sampling. At birth, the stomach relative weight was larger in the supplemented group, and the small intestine relative weight was smaller as compared to control. These differences disappeared within 1–4 postnatal days. The stomach weight was larger at postnatal day 28 in the supplemented group as compared to control. Gastric protein content and the proteolytic activity in the offspring of the supplemented sows showed after birth a tendency to increase as compared to control, though the differences disappeared after the fourth postnatal day. In conclusion, the supplementation of sow diet with dietary bioactive substances affected primarily the prenatal development of the stomach and small intestine in their offspring.     

妊娠后期母猪和仔猪补饲外源精胺对初生和28日龄仔猪肠道形态结构及二糖酶活性的影响

本文通过研究妊娠后期母猪和仔猪补饲外源精胺对初生和28日龄仔猪肠道形态结构和二糖酶活性的影响,初步探讨干预“仔猪早期断奶综合征”的技术措施.试验第1阶段,选择6头体重和膘情相近、胎次为3、已怀孕91 d的健康“长×大”母猪,随机分为Ⅰ、Ⅱ和Ⅲ3个组,每个组设2个重复,每个重复1头母猪.Ⅰ、Ⅱ和Ⅲ组妊娠母猪饲粮中外源精胺的添加量为0、1.5和3.0 mg/kg,饲喂至分娩结束;第2阶段,分娩后母猪采食同一种不含外源精胺的饲粮,Ⅰ、Ⅱ和Ⅲ组哺乳仔猪于7日龄起相应补饲外源精胺添加量为0、3.0和6.0 mg/kg的哺乳仔猪饲粮至28日龄.在仔猪初生和28日龄时,分别从每窝仔猪中选1头接近平均体重的健康仔猪进行屠宰,用于胃肠发育指标的测定.结果表明:与未添加外源精胺相比,妊娠母猪饲粮添加3.0 mg/kg外源精胺显著提高了初生仔猪十二指肠和回肠的柱状细胞数量、十二指肠和空肠的杯状细胞数量(P＜0.05),显著增加了空肠隐窝深度(P＜0.05),显著提高了麦芽糖酶和蔗糖酶比活力(P＜0.05);哺乳仔猪饲粮添加6.0 mg/kg外源精胺显著增加了28日龄仔猪空肠黏膜重(P＜0.05),显著提高了十二指肠和空肠的麦芽糖酶和蔗糖酶比活力(P＜0.05),极显著增加了空肠柱状细胞和杯状细胞数量(P＜0.01),极显著增加了十二指肠和空肠隐窝深度(P＜0.01).因此,在妊娠后期母猪和哺乳仔猪饲粮中添加外源精胺有利于初生和28日龄仔猪肠道形态结构的改善和二糖酶活性的提高.     

太湖猪高产综合技术研究试验

本文系对103头360窝太湖猪的繁殖性能进行系统研究。结果是60头母猪在6个繁殖周期中共繁殖360窝,平均繁殖周期158.33天,年产仔2.31胎。窝产仔16.35头,活仔15.10头,35日龄断奶育成14.44头,窝重83.48公斤。每头母猪年产仔37.69头,年产活仔34.81头,年提供断奶仔猪33.29头。其中窝产仔达到18头以上,出现1胎或连续4胎高产的母猪69头,占试验母猪群66.99％。     

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.     

Dietary nucleotide supplementation reduces occurrence of diarrhoea in early weaned pigs

In the weaning period, transition from sow's milk to the post-weaning diet causes the withdrawal of important nutrients as milk nucleotides, which are known to be determinant for the development of the gastrointestinal tract and immune function. The objective of these investigations was to study the effect of including these nucleotides in solid diets for piglets. Nucleotide composition of sow's milk was analyzed using 5 sows at 21 days of lactation. The average free nucleotide concentration was 102.8 ± 9.16 μmol/100 mL. Two experiments were performed to assess the effect of a product based on this composition (Nucleoforce Piglets®) on digestive adaptation and incidence of diarrhoea of nursery piglets. In Exp. 1, three groups of 6 piglets were weaned at 21 days of age and fed with a diet supplemented with 0 (control), 1000 or 2000 ppm of nucleotides, and a fourth group of 6 piglets was maintained in lactation. Seven days after weaning, piglets were euthanized and samples of jejunal mucosa were processed for histological measurements. Villus height decreased from 448 μm in un-weaned pigs to 275 μm in the control group 7 days after weaning. Although there were no differences in feed intake among groups, the reduction in villous height was less pronounced (P < 0.001) in nucleotide supplemented groups showing a villous height of 351 and 378 μm with the doses of 1000 or 2000 ppm respectively. In Exp. 2, 384 early weaned pigs were fed during 14 days with a diet supplemented with 0 (control), 750 and 1000 ppm of nucleotides. ADG and ADFI were not modified by the treatment, but nucleotide supplementation reduced the number of pigs treated with antibiotic as a result of diarrhoea (15.63% vs 3.13% and 1.56%; for control, 750 and 1000 ppm; P < 0.001). These results suggest that dietary supplementation with nucleotides from yeast might help to prevent post-weaning diarrhoea in piglets.     

发酵中药渣对妊娠母猪繁殖性能、血浆生化参数和抗氧化指标的影响

本试验旨在研究发酵中药渣对妊娠母猪繁殖性能的影响,并通过测定血浆生化参数和抗氧化指标探讨其作用机制。试验选用3~5胎次、体况和预产期相近的长白×大白二元母猪75头,随机分为3组,每组25头,对照组饲喂基础饲粮,中药渣组和发酵中药渣组分别在基础饲粮中添加1.5 kg/t的中药渣和发酵中药渣。试验周期为整个妊娠期,统计返情、空怀和流产的母猪数,窝产仔数、产活仔数以及仔猪初生窝重和初生个体重。分别于母猪妊娠第45天、第75天和第114天(分娩当天),每组随机选取8头母猪,耳缘静脉采血,分离血浆,测定生化参数和抗氧化指标。结果表明:饲粮添加中药渣或发酵中药渣对母猪的繁殖性能无显著影响(P0.05)。与对照组相比,妊娠第114天时,发酵中药渣组的血浆总蛋白(TP)含量显著升高(P0.05),中药渣组和发酵中药渣组的血浆高密度脂蛋白-胆固醇(HDL-C)和低密度脂蛋白-胆固醇(LDL-C)含量显著升高(P0.05);妊娠第45天时,中药渣组和发酵中药渣组的血浆过氧化氢酶(CAT)活性显著升高(P0.05),同时血浆碱性磷酸酶(ALP)活性显著降低(P0.05)。综上所述,饲粮添加1.5 kg/t发酵中药渣不影响妊娠母猪的繁殖性能,但可在一定程度上改善机体代谢,增强抗氧化功能。     

母猪饲粮添加β-羟基-β-甲基丁酸对母猪繁殖性能及仔猪生长性能和免疫功能的影响

本试验旨在研究母猪饲粮添加β-羟基-β-甲基丁酸(HMB)对母猪繁殖性能及仔猪生长性能和免疫功能的影响。选取20头3～6胎次、妊娠74 d的"长×大"母猪,随机分成2组,每组10个重复,每个重复1头母猪,对照组饲喂基础饲粮,试验组在对照组基础饲粮中添加2 000 mg/kg HMB。试验从母猪妊娠第74天开始,至仔猪21日龄断奶结束。结果表明:与对照组相比,试验组仔猪初生个体重显著提高14.1%(P<0.05),仔猪7、21日龄窝重分别显著提高16.6%、11.7%(P<0.05),仔猪初生至7日龄、初生至21日龄窝增重分别显著提高28.3%和12.5%(P<0.05);与对照组相比,试验组母猪在妊娠第98天和分娩当天血清免疫球蛋白G(IgG)含量分别提高35.3%(P<0.01)、13.0%(P>0.05),免疫球蛋白M(IgM)含量分别提高34.7%(P<0.05)、12.6%(P>0.05);与对照组相比,试验组母猪初乳中IgG含量显著提高19.0%(P<0.05),分娩后第14天常乳中IgM含量显著提高21.4%(P<0.05);与对照组相比,试验组仔猪7日龄血浆IgG、IgM含量分别显著提高11.4%和40.1%(P<0.05)。上述结果提示,母猪妊娠后期及哺乳期饲粮中连续添加2 000 mg/kg HMB,可显著提高仔猪初生重和哺乳期增重,改善母猪及仔猪免疫功能。     

ACCURACY AND PRECISION OF DUAL-ENERGY X-RAY ABSORPTIOMETRY FOR EX VIVO DETERMINATION OF MINERAL CONTENT IN TURKEY POULT BONES

The right humerus was removed from 30 20-week-old male turkey poults for humerus strength analysis using dual-energy x-ray absorptiometry and humerus-breaking strength. Specimens were cleaned and dried before scanning. To determine the most precise and accurate protocol of bone densitometry analysis for avian long bones, we scanned each specimen using five different techniques, all aimed to simulate soft-tissue thickness. Correlation coefficients and linear regression equations between 1) bone mineral content and humerus ash, and 2) bone mineral density and humerus-breaking strength were estimated with each technique and compared. The coefficient of variation values for precision ranged from 0.40% to 1.69% for bone mineral content and from 0% to 4.19% for bone mineral density. The accuracy was determined by comparing the bone mineral content of each humerus with the corresponding ash weight; the correlation coefficients between the two parameters were highly significant (range 0.949-0.963; P < or = 0.01). Significant correlations were also observed between humerus-breaking strength and bone density measurements (range 0.762-0.785; P < or = 0.01). Linear regression coefficients relating both parameters considered were also highly significant. We concluded that dual-energy x-ray absorptiometry is an accurate and precise method with which to determine ex vivo bone mineral content and strength in turkey bones. Further investigations are requested for field applications of this method to study factors affecting bone physiology and strength.     

Mammary development and milk production in the sow: Effects of udder massage, genotype and feeding in late gestation

The primary aim of the study was to investigate whether post-ejection udder massage 1–2 weeks pp (post partum) had an effect on the amount of mammary tissue and milk production in the domestic sow.

The nursing behaviour of 35 primiparous LYL or YLY sows and their litters was followed on days 7 and 14 pp. The milk production was measured by the weigh–suckle–weigh method of the whole litter on days 11 and 18 pp. After weaning on day 28 pp, the sows were slaughtered and the mammary tissue excised and weighed.

No significant correlations were found between the duration of post-ejection udder massage and the subsequent milk production. LYL sows had more mammary tissue (P < 0.05) and their piglets spent more time performing post-ejection udder massage compared to the YLY sows (P < 0.01). Individual variation was found in the proportion of time that the sows were lying on either their right or left side. The weight of the mammary tissue from the left side was positively affected by the amount of udder massage (pre- and post-ejection massage) that the sows had received while lying on the right side relative to the amount that she had received while lying on the left side on day 7 pp (P < 0.01).

In conclusion, the intensity of udder massage influenced the amount of mammary tissue at slaughter. The genotype of the sow affected the expression of nursing behaviour and milk production. No connection was found between post-ejection udder massage and the measures of milk production 1–2 weeks pp. Finally, feeding during the last half of gestation affected the nursing behaviour.     

Experimental study on the effect of in-feed administration of a clinoptilolite-rich tuff on certain biochemical and hematological parameters of growing and fattening pigs

Twenty twin-bearing Shropshire ewes were either maintained on an adequate (H) or 60% restricted feeding level (L) during the last 6 weeks of gestation. The ewes were sired by a ram selected for either high daily growth (Growth, G) or increased cross-sectional area of m. Longissimus dorsi (LD) combined with minimal fat thickness above LD (Meat, M). The male offspring (n = 23) from these ewes were studied with regard to production, fibre type, bone parameters and meat quality traits. Maternal nutrient restriction during late gestation caused a reduced birth weight of the offspring, a low growth rate from birth to weaning, yet compensatory growth after weaning. No relation was found between maternal nutrient restriction during late gestation and meat quality in terms of proteolytic potential, myofibrillar fragmentation index or shear force measured in meat from 5 month old lambs. The data do not support the hypothesis of a long-term programming effect of maternal nutrient restriction during late gestation on meat tenderness. However, a long-term effect of maternal nutrient restriction was found for bone growth. Femur weight was significantly reduced in L-lambs and cortical bone density and mean relative wall thickness were significantly increased by maternal nutrient restriction during late gestation, suggesting that only some of the bone parameters evaluated express compensatory growth. The effects of maternal nutrition in late gestation on bone parameters have implications for the robustness of breeding stock.     

Morphological changes of the cartilage and bone in newborn piglets evoked by experimentally induced glucocorticoid excess during pregnancy

The study examined articular and growth plate cartilages as well as bone tissues in the offspring of sows treated with glucocorticoid during the last 45 days of pregnancy (dexamethasone at the dose of 0.03 mg/kg body weight intramuscularly, every second day). The offspring were tested at the birth and basal morphology for both articular and growth plate cartilages, and the histomorphometry of trabeculae of the epiphysis and metaphysis of femur and tibia were established. The concentration of selected cytokines and the activity of bone alkaline phosphatase were determined in blood serum. Maternal dexamethasone (DEX) administration reduced the thickness of proliferative, resting and hypertrophic zones of growth plate of femur and tibia of male piglets when compared with the control. DEX significantly reduced the thickness of the resting zone in both bones. It also elongated proliferative and hypertrophic zones of the growth plate in the femur as well as the hypertrophic zone in the tibia of female piglets when compared with the control group. Moreover, DEX decreased the articular cartilage thickness of the tibia in female piglets and enhanced the articular cartilage thickness of the femur in male piglets. Articular cartilage was highly cellular, and chondrocytes were separated by thin septa of matrix. An analysis of the trabecular bone architecture in male piglets showed a loss of the trabecular bone by thinning and DEX‐related increase in trabecular porosity. Moreover, the cortical bone looked similar to the trabeculae because of trabecularization of the cortex. There was a DEX that reduced serum osteocalcin and BAP concentrations in both female and male newborn piglets, whereas the serum IL‐1 and Il‐6 was reduced only in male piglets. The obtained results demonstrated that DEX administration to sows during the last 45 days of pregnancy might cause the growth to slow and eventually to stop, especially in male piglets. It might lead to an alteration within the cartilage during its normal function, and with the time, arthritic changes can follow.     

Investigations on potential dietetic effects of lactulose in pigs

Effects of lactulose (lac) as feed additive on chyme and feces quality in pigs (reared piglets: n = 10; fattening pigs: n = 20) were tested. Furthermore, fattening pigs were experimentally infected with Salmonella Derby (orally 2.6 × 10⁸ cfu/pig, single dose infection on 1 day) to examine potential prophylactical effects. Pigs were fed a conventional diet ad libitum (in the control group without lac, in the experimental group including lac: 28.6/26.9 g lac/kg dry matter). In piglets and fattening pigs lac intake did not alter fecal dry matter (DM) content or feces pH. Contrary to findings in human beings only small amounts of lac reached the hindgut, although higher lac concentrations were measured in ileal chyme (in piglets: 10–40 g, in fattening pigs 40–70 g lac/kg DM of chyme). Lac ingestion led neither to increased concentrations of lactic acid or volatile fatty acids (vfa) nor to reduced pH data in chyme of small intestine, but in cecum and colon contents higher vfa concentrations (significant effects in piglets) were measured. Furthermore, lac ingestion resulted in reduced ammonia levels in small and large intestine contents. But no protective effects of lac ingestion were recognized when fattening pigs were infected orally with Salmonella Derby. Due to the fact that only parts of lac reach the hindgut there are doubts, whether lac can lead to comparable dietetic effects in pigs as known from human beings (laxation, forced elimination of bacteria a.s.o.). The obtained results in pigs underline the necessity of experimental studies in the target species before substances are used and recommended for dietetic purposes in feeding of pigs.     

Evaluation of smallholder pig production systems in North Vietnam: Pig production management and pig performances

This study investigated the productive adaptability of pig breeds under different smallholder production conditions in Vietnam, comparing an indigenous with a Vietnamese improved breed. Fieldwork was conducted in four villages with different remoteness in North Vietnam from 2001 to 2002, in 64 households keeping the improved Mong Cai or indigenous Ban as sow breeds and progeny for fattening. Four visits per farm yielded 234 structured interviews. Reproductive performances were derived from 135 litters. Individual weights of pigs (n = 755) were obtained. Data were analysed by regression, linear and generalised linear, especially loglinear models.

Two distinct pig production systems were identified, that differed in remoteness, market access, resource availability, distribution of pig breeds and pig production intensity. Higher performances of 1.4 and 1.5 litters year^− 1, 8.4 and 8.4 piglets weaned litter^− 1, 66.6 and 93.0 kg piglets weaned sow^− 1 year^− 1, and 136 and 177 g day^− 1 ADG were found in two villages near town with semi-intensive production conditions and a high rate of improved Mong Cai sows and MC and LW × MC offspring in the observed population. Lower performances of 1.1 and 1.1 litters year^− 1, 4.6 and 5.5 piglets weaned litter^− 1, 20.5 and 30.9 kg piglets weaned sow^− 1 year^− 1, and 66 and 85 g day^− 1 ADG were observed in parallel to higher incidences of indigenous Ban pigs away from town under extensive conditions. Total live weight offtake per household per year was higher near town and in one village distant to town. MC and LW × MC remained even under demand-driven conditions below the performance potential reported for improved genotypes. Under resource-driven conditions with a saving-oriented production pattern, the higher-yielding but more demanding Mong Cai might not be an efficient production alternative as a further performance reduction can be assumed. A considerable live weight output was observed under resource-driven conditions and with a higher percentage of crossbred LW × Ban offspring in the population, possibly representing a promising production alternative. Factors influencing the performance expression of pigs, and the suitability of different methods for the assessment of performance parameters on-farm are discussed.     

Bone development of suckling piglets after prenatal,neonatal or perinatal treatment with dexamethasone

In mammals, the release from growth‐inhibiting conditions results in catch‐up growth. To investigate animal evidence for whether prenatal dexamethasone (DEX) treatment leads to the development of growth restriction especially reduced mineralization of skeleton, and release from it leads to the phenomenon of catch‐up, piglets were prenatally exposed to DEX (3.0 mg/sow per day^?2) during the last 24 days of prenatal life and tested further in two different ways: discontinued at birth and continued administration of DEX (0.5 mg/kg day^?2) to piglets through 30 days of neonatal life. Using dual energy X‐ray absorptiometry methods, bone mineral density (BMD) and bone mineral content (BMC) were measured. The three‐point bending test was applied to determine the mechanical properties of the bones. Furthermore, geometric properties of the bones were assessed. Serum concentration of osteocalcin (OC) was determined. Histomorphological analysis of the ribs was also performed. The consequences of neonate DEX treatment and in utero DEX exposure were reflected in a dramatic decrease of BMD, BMC and blood serum OC concentration and geometric parameters of piglets’ bones. Prenatal action of DEX during the last 24 days of pregnancy resulted in continued neonatal modification of bone tissues, thus diminishing bone quality, and negatively influenced structural development and mechanical properties, finally increasing the risk of fractures of ribs and limb bones. Prenatal DEX treatment limited to the last 24 days of foetal life did not reduce the term birth weight and the growth of suckling piglets followed up to 30 days of neonatal life, and catch‐up in bone mineralization did not occur.     

Effects of Dextrose Plus Lactose in the Sows Diet on Subsequent Reproductive Performance and within Litter Birth Weight Variation

Effects of dextrose plus lactose in sow’s feed were tested on subsequent reproductive performance and within litter birth weight variation. During the last week of gestation and lactation, sows were either fed a commercial lactation diet (Control: C), or an isocaloric diet containing 25 g/kg dextrose plus 25 g/kg lactose (Treatment: T). In the subsequent weaning‐to‐oestrus interval (WEI), all sows received the same amount of a commercial feed, but T sows were supplemented with 150 g dextrose plus 150 g lactose per day. Weight and backfat changes were recorded as well as litter characteristics during the treatment period and the subsequent parity. No significant effect of treatment was found on the subsequent reproductive performance, including the number of piglets born, although the number of live born piglets was 0.51 larger (p = 0.31) and weight of the live born piglets was 84 g higher in the T sows (p = 0.07) than in the C sows. When sows were categorized in sows with 12 or less and more than 12 total born piglets in the previous litter, treatment of sows with dextrose plus lactose resulted for the group with 12 or less piglets in a strong increase in subsequent total born piglets (13.97), whereas in the untreated sows the subsequent litter size was 11.89. In the group with more than 12 total born piglets, no effect of treatment was found (interaction between previous litter size and treatment p = 0.03). The within litter variation in birth weight in the subsequent litter was numerically lower in the T sows. We concluded that the use of dextrose and lactose during lactation and WEI seems to enhance litter size in sows with low previous litter size and seems to have the potential to reduce the within litter variation in birth weight.     

Effects of additional zinc and phytase on zinc availability in piglets and chicks fed diets containing different amounts of phytates

Two maize based diets containing 2.3 g phytic P and 38 mg Zn/kg (P+) or 1.3 g phytic P and 25 mg Zn/kg (P−) were formulated. A third diet (P+/Phytase) was P+ supplemented with 3-phytase (500 FTU/kg). Each of these three basal diets, supplemented or not with 15 mg Zn/kg, was given during 20 days to weaned piglets and to 1-day-old chicks. Chicks fed the P− diets were removed from the data set because of an abnormally low feed intake.

In piglets, added Zn increased bone (P < 0.05) and plasma Zn (P < 0.01) irrespective of the basal diet (basal diet × Zn, P > 0.05). Supplementing P+ with phytase was more efficient in improving these indicators of Zn status than replacing P+ by P−. In chicks, supplemental Zn improved Zn status in a higher extent when added to P+ than to P+/Phytase (basal diet × Zn, P < 0.05). Phytase increased Zn status in a lesser extent than 15 ppm supplemental Zn. More Zn was soluble in gizzard than in stomach which corresponded to the differences in pH (4.2 vs 5.0). Phytase increased soluble Zn in stomach (P < 0.05) but not in gizzard. These results suggest a higher availability of Zn in chicks than in piglets in the absence of phytase. This may explain the higher efficacy of phytase for improved Zn availability in piglets than in chicks.