Effect of weaning age and postweaning feeding programme on the growth performance of pigs to 10 weeks of age

This study aimed to determine the effects of weaning age and postweaning feeding programme on pig performance and health. In experiment 1, 96 same gender pairs of pigs weaned at 3, 4 and 5 weeks of age were used in a 3 (weaning age)×4 (dietary programme) factorial design experiment. Pigs received different amounts of a phase 1 diet (16.2 MJ/kg digestible energy (DE) and 16.2 g/kg lysine) and phase 2 diet (15.3 MJ/kg DE and 15.0 g/kg lysine): (A) very low (VL, 1 kg phase 1 and 3 kg phase 2 diet per pig); (B) low (L, 2 kg phase 1 and 6 kg phase 2 diet per pig); (C) medium (M, 3 kg phase 1 and 9 kg phase 2 diet per pig) or (D) high (H, 4 kg phase 1 and 12 kg phase 2 diet per pig), followed by a cereal based phase 3 diet (15.0 MJ/kg DE and 13.8 g/kg lysine) to 10 weeks of age. In experiment 2, faecal samples from 60 pigs weaned at 3, 4 and 5 weeks of age were collected at 10 days postweaning and analysed for Escherichia coli and lactic acid bacteria counts. In experiment 1, there were no interaction effects of age×dietary programme on growth performance. Dietary programme did not affect growth performance from weaning to 10 weeks of age. From weaning to 10 weeks of age, increasing weaning age increased average daily gain (ADG; 363, 402, and 476 g for 3, 4 and 5 weeks respectively; s.e. 17.6; P<0.001), average daily feed intake (ADFI; 560, 620, and 680 g; s.e. 26.1; P<0.001), and improved feed conversion ratio (FCR; 1.57, 1.55, and 1.43; s.e. 0.045; P<0.05). However, weaning age had no effect (P>0.05) on pig weight at 10 weeks of age. In experiment 2, 3 week weaned pigs had higher faecal counts of E. coli (P<0.05) than 4 week weaned pigs and higher faecal counts of lactic acid bacteria (P>0.01) than 5 week weaned pigs at 10 days postweaning. In conclusion, feeding higher amounts of phases 1 and 2 diets did not affect performance at any of the weaning ages tested. Increasing weaning age increased growth performance between weaning and 10 weeks of age, but had no effect on the resulting body weight. Pigs weaned at 3 weeks of age had increased counts of selected faecal bacteria compared to those weaned later.     

断奶日龄和断奶后饲喂策略对10周龄仔猪生产性能的影响

1 研究背景断奶这一过程,对于仔猪来说是一个非常大的应激.仔猪断奶后,面临着生理的、环境的、心理和营养性的应激,进而对仔猪肠道结构造成损伤,目前欧盟已经禁止仔猪在21日龄前断奶.断奶后一段时间,常常伴随着低采食量,较差的生产速度,甚至严重的腹泻情况.断奶后前几天低的采食量完全不能满足仔猪营养的需求,一般需到断奶后的2～3周,仔猪采食量才能满足其营养需要,达到断奶前的生长速度.仔猪断奶后的生长速度已被证实具有巨大的提升空间,如何缩短断奶后的生长缺陷已经成为当今仔猪营养领域一个非常重要的研究课题.     

Effect of age, weaning and diet on digestive enzyme levels in the piglet

Thirty-seven pigs were used to evaluate the effects of age and weaning on the level of protease in the gastric mucosa and trypsin, chymotrypsin, amylase and lipase in the pancreas. There was a positive allometry of the pancreas and gastric mucosa associated with age and with weaning to a solid diet. Increases with age in total activity of chymotrypsin, trypsin, amylase and gastric proteases were due to increases in both tissue weight and enzyme activity per gram of tissue. A general depression in pancreatic enzymatic activities, but not in gastric proteolytic activity, was found during the first week following weaning. Forty pigs were used in a second trial to evaluate the effects of age and weaning diet on the same digestive enzymes. Total activity of all enzymes assayed increased with time postweaning. Increases in total activity of lipase and chymotrypsin were due primarily to increased pancreatic weight postweaning. Amylase, trypsin and gastric protease increases were due both to increased tissue weight and increased activity per gram of tissue. There were no effects of diet on the weight of gastric mucosa or the level of activity of the gastric proteases. Pigs fed a diet containing 20% whey had larger pancreases (P less than .10) at slaughter and a greater, but nonsignificant, mean activity per gram of pancreas for all pancreatic enzymes. It appears that the pig has sufficient pancreatic and gastric enzyme activity so that performance should not be limited, with the possible exception of the period shortly after weaning. However diet digestibility and subsequent pig performance may be more directly related to the extent of release of these enzymes into the intestine and the conditions that exist therein.     

Uterus development in swine from birth to 8 months of age

Macroscopic examination was applied to the ovaries and histological tests to the uterus of 108 pigs aged between one and 240 days. The results have shown that the growth of the uterus in swine had not taken place with continuity. Extraordinarily strong thickness growth of the endometrium and myometrium was observed over the first three months of age. Thickness growth of both layers then continued at reduced rate. The uterine glands began to develop from superficial epithelium in the second week of age and reached the basal part of the endometrium in the fourth week. Both the number of uteroglandular sections per visual field and the glandular surface over the whole area of the endometrium, as recorded from cross-section specimens, increased strongly over the first three months of age, followed by less marked change. Continued development and maturation of the elements involved took place between the twelfth and 24th weeks of age, with the uterine glands acquiring capacity of secretion. Stagnation is uterus development and growth was observed at the age of over 180 days. The most favourable date for zootechnical stimulation of puberty was considered to lie in the period between 170 and 200 days of age, whereas biotechnical induction of puberty might give best results when applied at an age between 180 and 200 days.     

不同锌源对断奶仔猪生长性能和消化酶的影响

自发现高锌能促进动物生长以来 ,现已广泛应用在养猪生产中 ,但高锌所带来的负面作用也是不容忽视的 ,长期应用高锌必然造成环境污染和资源的浪费。为此 ,国内外研究人员积极研究开发能替代无机锌的产品 ,以减少饲料中锌的使用量 ,同时又不影响生产效益。本研究以“杜×长×大”商品仔猪为试验对象 ,研究常规氧化锌、蛋氨酸锌和纳米氧化锌对断奶仔猪生长性能的影响。1　材料与方法1 1　试验材料　氧化锌、蛋氨酸锌和纳米氧化锌 ;试验动物为“杜×长×大”三元杂交猪 ;基础日粮参考NRC( 1 998)仔猪营养需要配合而成的粉状配合饲料 ,基础日…     

Effect of starter feeding program on growth performance and gains of body components from weaning to market weight in swine

Three experiments were conducted to test the hypothesis that different starter feeding programs (High, high quality; Low, low quality) will affect growth performance and body composition of pigs from weaning to market weight and that this effect may be influenced by gender (barrows or gilts) and breed (F, Yorkshire-Duroc x Hampshire; P, PIC Camborough 15 x PIC line 405). In Exp. 1, 21 +/- 4-d-weaned F pigs (n = 90) were used in a 2 (High or Low) x 2 (barrows or gilts) factorial design. In Exp. 2, 21 +/- 3-d-weaned pigs (n = 184) were used in a 2 (F or P) x 2 (High or Low) x 2 (barrows or gilts) factorial design. In Exp. 3, 21 F pigs from each gender and feeding program treatment were killed at d 0, 3, 7, 14, 42, 82, or 152 postweaning for evaluating body composition. Two starter feeding programs (High or Low) were applied to pigs for 6 wk postweaning. Pigs from both High and Low treatments were provided the same corn-soybean meal-based diets for the growing and finishing periods. Although the ADG of all pigs receiving the High treatment during the early starter period were higher (P < .01) than those of the Low, the terminal BW of F barrows were similar between High and Low (Exp. 1 and 2) and those of gilts were similar between High and Low (Exp. 2) (P > .80). However, the BW of P pigs receiving the High treatment, regardless of gender, tended to be heavier than those receiving the Low (Exp. 2) and F barrows receiving the High treatment tended to be heavier than those receiving the Low (Exp. 1). For the first 7 d postweaning, the High-fed pigs gained more protein (P < .05) and lost less fat (P < .05) than Low-fed pigs. During the growing-finishing period, the Low-fed pigs exhibited compensatory protein gain and achieved a body protein content similar (P < .60) to High-fed pigs by termination. Protein gains from weaning to termination between High- and Low-fed pigs were not different in Exp. 2 and 3. The protein gain of gilts was higher (P < .05) than that of barrows. Similarly, fat gain within genders was not affected by starter feeding program. Fat gain of gilts, however, was lower (P < .08) than that of barrows in Exp. 3. In conclusion, the nutritional quality of the starter feeding program affected growth performance immediately after weaning but did not affect protein gain over the entire production period.     

Changes in piglet leucocytes, B lymphocytes and plasma cortisol from birth to three weeks after weaning

Piglet leucocytes and plasma cortisol were studied at birth, one, two, five, 10 and 20 days after birth; one, 12 and 21 days after weaning, and in adults. Plasma cortisol concentrations fell rapidly from very high levels at birth to adult values by five days old. These values were then maintained throughout the rest of the study period. The number of neutrophils rose rapidly after birth, declined during late lactation and then rose to adult levels after weaning. The number of lymphocytes rose steadily throughout the study period to reach a peak 12 days after weaning at levels double that of adults. There was no significant variation in the proportion of B lymphocytes between ages, the values fluctuated between 11 and 18 per cent. There was no significant difference in the proportion of B lymphocytes between piglets at birth and adults. However, the number of B lymphocytes was significantly depressed at birth, and elevated during weaning, when compared with adults. The leucocyte results were verified by flow cytometry which provided an objective estimate of values such as the proportion of lymphocytes and B lymphocytes. In addition, this method revealed that in the two days after birth there was a transient decrease in the proportion of B lymphocytes bearing a high density of surface immunoglobulin.     

Effect of split nursing on variation in pig growth from birth to weaning

OBJECTIVE: To determine the effect of split nursing (i.e., removal of the larger pigs in a litter from the dam for a short period within 24 hours after birth to allow the smaller pigs in the litter uninhibited access to the dam) on variation in growth from birth to weaning among pigs. DESIGN: Clinical trial. ANIMALS: 1,193 pigs in 118 litters. PROCEDURE: Litters were randomly assigned to 1 of 3 treatment groups: control group (pigs were not split nursed), group 1 (heaviest 50% of pigs in the litter were removed from the sow for 2 hours), or group 2 (heaviest 50% of pigs were removed from the sow for 2 hours and, after the heaviest pigs were returned to the sow, the lightest 50% of pigs were removed for 2 hours). Birth weights and weaning weights were measured. RESULTS: Significant differences in average daily gain (ADG), weaning weight, or serum IgG concentration among groups were not detected. However, significant linear improvements in the SD and coefficient of variation of the ADG were detected, but only for litters with > or = 9 pigs born alive. Percentages of pigs from split-nursed litters that weighed < 3.6 kg (8 lb) at weaning (1.3 and 1.6% for groups 1 and 2, respectively) were lower than percentage of control pigs that did (3%). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that split nursing will decrease variation in ADG of pigs from birth to weaning but only for pigs from litters with > or = 9 pigs born alive.     

Effect of swine weaning age on body fat and lipogenic activity in liver and adipose tissue

Two experiments were conducted to evaluate the effects of weaning swine at 2 or 5 wk of age on postweaning performance and fat metabolism. In the first experiment, 52 pigs were weaned at 2 or 5 wk of age with body weights determined from birth to 8 wk. The early weaned group was fed a 20% protein corn-soybean meal-oat diet containing 25% dried whey from 2 to 5 wk while both groups were fed a 20% protein cereal grain-based diet from 5 to 8 wk of age. In a second experiment, a total of 90 pigs weaned at similar ages and fed the same diet sequences were killed at weekly intervals from 2 to 8 wk of age to evaluate body fat content and lipogenesis in liver and adipose tissue. Lipogenic capacity was measured by incorporation of acetate-1 14C into the total lipid fraction in liver slices and adipose tissue minces or by monitoring liver ATP citrate lyase activity. The results demonstrate that pigs weaned at 2 wk experience a slower postweaning growth rate with lower empty body weights than those either concurrently nursing the dam or weaned at 5 wk of age. Both groups had similar body weights from 6 to 8 wk of age. The body fat content of nursing pigs increased from 2 to 5 wk of age. Pigs weaned at 2 wk lost approximately 25% of their body fat the first week postweaning while later-weaned pigs did not lose body fat postweaning. Body fat composition of both groups was similar by 8 wk of age. Lipogenic activity was higher in liver than in adipose tissue from 2 to 5 wk of age and remained relatively constant throughout the trial. Adipose tissue lipogenic activity was lower in the nursing pig but increased dramatically at 5 wk in the early-weaned group and 7 wk of age in the late weaned group. These results suggest that weaning age can affect postweaning body fat composition and that adipose contributes a greater lipogenic capacity than liver tissue as the pig matures.     

Immunoglobulins in nasal secretions of dog puppies from birth to six weeks of age

In order to investigate local immune defence mechanisms in the dog, the concentration of immunoglobulins (Ig) G, A and M in nasal secretions (NS) and serum of 42 healthy, neonatal Rottweiler puppies was determined. Ig were measured with a commercially available, dog-specific ELISA during the first six weeks of life. On average, IgG was the predominant Ig isotype during the first three days of life. The IgA:IgG ratio changed between weeks 1 and 3 due to markedly decreasing IgG concentrations. Between the fourth and sixth week, IgG predominated again. During the first week, only 21-39% of puppies had measurable amounts of IgM in NS, in week 2, this percentage increased to 69%. Marked differences between litters and between individual puppies within litters were found. No puppy diseased during the observation period and all developed normally.     

Strongylus edentatus: development and lesions from ten weeks postinfection to patency.

Pony foals inoculated with infective Strongylus edentatus larvae were examined at necropsy from ten to 72 weeks postinfection. At ten weeks postinfection larvae were visible retroperitoneally in the liver and flanks and were recovered from the ligaments of the liver. The fourth molt was detected at 16 weeks postinfection and larvae were also recovered from the wall of the cecum at this time. By 40 weeks adult S. edentatus containing eggs were found in the contents of the cecum and colon. While many larvae migrate to remote parts of the body, it is likely that only those that attain the base of the cecum are successful in establishing in the cecum and colon as adult forms. By 36 weeks postinfection no larvae were found in the liver and up to this time none were found in the peritoneal cavity. Larvae were not recovered from the parenchyma of the lungs. Adhesions and disruption of omental architecture were frequent changes observed throughout infection. Casts of necrotic eosinophils enclosing tracks and larvae were observed beneath the intima of major veins of the cecum and colon. The liver was rough and the capsule thickened at 16 and 20 weeks postinfection and the flanks remained edematous until 36 weeks postinfection.     

Adrenocorticotropic hormone stimulation tests in healthy foals from birth to 12 weeks of age

The purpose of this study was to investigate total baseline plasma cortisol and adrenocorticotropic hormone (ACTH) concentrations, and ACTH-stimulated cortisol concentrations in foals from birth to 12 wk of age. Plasma (baseline) cortisol and ACTH concentrations were measured in 13 healthy foals at birth and at 1, 2, 3, 4, 5, 7, 10, 14, 21, 28, 42, 56, and 84 d of age. Each foal received cosyntropin (0.1 μg/kg) intravenously. Plasma cortisol concentrations were measured before (baseline), and 30, and 60 min after cosyntropin administration at birth and at 3, 5, 7, 10, 14, 21, 28, 42, 56, and 84 d of age. Compared with baseline, cortisol concentration increased significantly 30 min after administration of cosyntropin on all days. Cortisol concentration was highest at birth, measured at 30 and 60 min after cosyntropin administration, compared with all other days. With the exception of birth measurements, cortisol concentration was significantly higher on day 84, measured at 30 and 60 min after cosyntropin administration, when compared with all other days. Baseline plasma ACTH was lowest at birth when compared with concentrations on days 2, 3, 4, 5, 7, 10, 14, 42, 56, and 84. Administration of 0.1 μg/kg of cosyntropin, IV, reliably induces cortisol secretion in healthy foals. Differences in the magnitude of response to cosyntropin are observed depending on the age of the foal. These data should serve as a reference for the ACTH stimulation test in foals and should be useful in subsequent studies to evaluate the hypothalamic-pituitary-adrenal axis in healthy and critically ill foals.     

Mortality in mink kits from birth to weaning

In 1988, a necropsy survey of the pattern and major causes of mortality in mink kits from birth to weaning was undertaken. The overall preweaning mortality rate was 20%. Mortalities occurring within the first three days after birth accounted for 91% of submissions, and 78% of the kits in this age group had no lesions or bacterial isolates. The average weight of kits which died within one day of birth (7.9 g) was significantly lower than the average birthweight of healthy kits (10.7 g). In kits under four days of age and with lesions, the most common diagnoses were dystocia (12%), systemic infection (4%), anasarca (2%), and congenital defects (1%). In unweaned kits four days of age or older, the most common diagnoses were systemic infection (19%), external trauma (6%), dystocia (5%), and cervical adenitis (2%).     

A spline polynomial model to describe serum IGF-I concentration from birth to slaughter in calves: effects of weaning age,pre-weaning concentrate feeding and breed

The statistical analysis of hormones sampled throughout the production cycle is complicated because factors such as age and weight at the measuring date interfere. Spline curves constructed from pieces of low-degree, random-effects polynomials could be used for a more accurate analysis of data. Concentration of insulin-like growth factor-1 (IGF-1), weight gain, and concentrate intake of Parda de Montaña (PM) (n = 27) and Pirenaica calves (n = 14) were modeled with a spline model according to age at weaning, pre-weaning concentrate feeding, and breed. At birth, calves were randomly assigned to early weaning (EW) at 90 d or traditional weaning (TW) at 150 d. During lactation, half of PM calves received concentrates (S), whereas the remainder received no concentrates (NS). After weaning, calves received concentrates on an ad libitum basis until they reached a weight of 450 kg. The spline model had better likelihood than a polynomial of 6 degrees or a split-plot model. Serum IGF-1 concentration was greatly affected by age at weaning and pre-weaning concentrate feeding, but not by breed. In NS calves, IGF-1 concentration was greater in EW than in TW calves from 120 to 300 d, irrespective of breed. During lactation, S calves had greater IGF-1 concentration than NS calves. After weaning, EWNS calves reached the IGF-1 concentration of EWS calves after 4 mo on concentrates, whereas TWNS calves attained IGF-1 concentration of TWS calves after only 2 mo, because of their increased concentrate intake relative to TWS calves. Concentration of IGF-1 was positively correlated with the immediate weight gains and intake, but it was not a good predictor of performance in the long term.     

早期断奶对猪生产性能的影响

通过综述早期断奶对仔猪的消化吸收和免疫抗病,对母猪的发情、受胎、产仔以及繁殖寿命的影响,提示在研究和应用早期断奶技术时,要充分遵循生物学规律,才能取得最大限度的经济效益。     

肠膜蛋白粉对早期断奶仔猪生产性能及消化道发育的影响

豆粕中含有的大豆球蛋白和ｂｅｔａ -ｃｏｎｇｌｙｃｉｎｉｎ等抗原 ,可导致断奶仔猪肠粘膜细胞发生过敏反应 ,进而降低其生产性能 (谯仕彦等 ,1 995,1 996) ,因此人们试图用其他原料替代或降低日粮中的豆粕用量。研究表明 ,日粮中添加乳清粉和血浆蛋白粉能够提高断奶仔猪日采食量和日增重 (管武太 ,1 994) ,但昂贵的价格限制了其广泛的应用。最近试验表明 ,用ＤＰＳ(肠膜蛋白粉 ,其中ＤＰＳ30 、ＤＰＳ50 的粗蛋白质含量分别为 30 %、50 % )全部或部分替代乳清粉或血浆蛋白粉 ,能够在降低饲料成本的同时 ,保持甚至提高断奶仔猪的生产性能。…     

Effect of rearing environment and age on gut development of piglets at weaning

Outdoor reared pigs are reported to be larger at weaning than indoor reared pigs and respond better to the weaning process. This may be due to enhanced gut development associated with increased size. Eighty sows were allocated to either indoor or outdoor farrowing on the basis of size, parity and past performance. Resulting litters were weaned at either 4 or 6 weeks of age. On days 26 and 40 of age, 40 (10/treatment) and 20 piglets (10/treatment still unweaned) were killed to measure intestinal morphology. Data were analysed as a 2 × 2 factorial using the GLM procedures of Minitab 12.2. Pigs reared outdoors were larger than those reared indoors at both weaning ages, pigs weaned at 6 weeks were heavier than those weaned at 4 weeks, 8.4 versus 7.4 kg at 4 weeks and 12.9 versus 10.5 kg at 6 weeks respectively (± 0.25, P ≤ 0.001). There were no differences in small intestine size relative to body weight due to rearing environment and no differences in gut morphology. When corrected for body weight, 6 week pigs had heavier small intestines than 4 week pigs, 0.39 (± 0.010) versus 0.34 (± 0.007) g/cm length, respectively (P ≤ 0.001). Six week unweaned pigs had similar villus heights to 4 week unweaned pigs but wider villi (P < 0.05) and deeper crypts, for example, at the 25% site crypt depths were 236 and 193 μm (± 7.7/5.5) respectively (P < 0.001). Hence increased piglet size due to outdoor rearing did not advance gut maturation whereas increased piglet size due to age did influence maturation of gut structure.     

Intake energy, energy retention and heat production in lambs from birth to 24 weeks of age

Intake energy (IE), metabolizable energy intake (MEI), energy retention (ER) and heat production (HP) were estimated in twelve male and six female suckling lambs from birth to 4 wk of age and in nine of these male lambs after weaning from 9 to 24 wk of age. Intake energy and MEI were estimated from the milk intake and combustible energy of the milk in the suckling lambs and from digestibility trials and energy content of feed and feces in the weaned lambs. Energy retention was estimated from body composition changes and HP was calculated from MEI - ER and from the rate of O2 consumption. The O2 consumption of the ewes was also measured during late pregnancy and during lactation. In the suckling lambs, daily MEI was 277 kcal/kg.75 and ER was 112 kcal/kg.75 and as calculated from O2 consumption was 168 kcal/kg.75. Daily HP as calculated by MEI - ER was 165 kcal/kg.75. Daily maintenance HP was equal to 121 kcal/kg.75 and the efficiency of utilization of energy for ER was 70.7%. In the weaned lambs, HP as measured from O2 consumption was 10% lower than that estimated using MEI and ER. Comparison of 9- to 16-wk-old with 17- to 24-wk-old lambs, showed daily increases in MEI from 212 to 228 kcal/kg.75, in ER from 54 to 95 kcal/kg.75 and in HP from 158 to 194 kcal/kg.75, whereas there was a daily decrease in maintenance HP from 101 to 90 kcal/kg.75. Efficiency of utilization of energy for production was similar in the two postweaning periods (48.8 and 46.5%, respectively). The O2 consumption of the ewes (/kg.75) was increased over that of nonpregnant, nonlactating controls by 30% in late pregnancy, by 62% in the first month of lactation and by 50% in the second month of lactation.