Influence of increased feeding frequency on behavior and integument lesions in growing-finishing restricted-fed pigs

This study evaluated how feeding frequency affects behavior and the occurrence of skin lesions in growing-finishing pigs. One hundred eighty pigs (27 to 112 kg of BW) were reared in one environmentally controlled room (20 pens; 9 pigs/pen). Pigs in 10 pens were fed 3 times daily (reference group), whereas the others were fed 9 times daily (experimental group). Both groups received the same total amount of liquid feed. Rations were adjusted to the mean pen weights. Behavioral observations (scan sampling, as well as continuous focal pig observations) were made in wk 4, 10, and 14 of the growing-finishing period. After each observation, skin lesions were assessed individually for each pig. Pigs fed 9 times daily tended to lie laterally for less time (P = 0.083) and tended to be active (P = 0.054) during the day, especially in growing-finishing wk 4 (P = 0.007). With continuously observed focal pigs, no differences in time allocations for feeding were found between groups. During feeding in growing-finishing wk 4, focal pigs belonging to the experimental group displayed more aggressive actions (P = 0.019), tended to perform aggressive actions for a longer time (P = 0.076), and tended to be belly-nosed for a longer time (P = 0.083) compared with the reference group. In addition, in growing-finishing wk 14, pigs in the experimental group had greater scores for skin lesions (head, P = 0.001; belly, P < 0.001; caudal part, P < 0.001) and tended to be belly-nosed for a longer time (P = 0.084). In the case of pigs restricted-fed liquid feed, a greater frequency of feeding per day appears to be a condition that results in greater competitive feeding than with a lower feeding frequency.     

Effects of amperozide and azaperone on aggression and productivity of growing-finishing pigs

Levels of aggression, activity and performance were determined in 270 pigs (initial wt 29.8 kg) injected with amperozide (1.0 mg/kg i.m.), azaperone (2.2 mg/kg i.m.) or saline (.1 ml/kg i.m.) immediately prior to mixing. Pigs had ad libitum access to feed in pens of 15, and six pens were allotted to each treatment. Each pen was video-taped for 48 h after injection. Aggression was determined by continuous observation and summarized for each 2-h period. Injuries on the ears and shoulders of each pig were scored prior to injection and 1, 2, 3 and 7 d after treatment. Eating, drinking and lying were determined by scan sampling at 2-min intervals and summarized for each 2-h period. Weight gain, feed consumption and efficiency were determined for periods ending on d 3, 7, 14, 28, 42, 56, 70 and 84. Both drugs reduced total fighting from 309.8 min for saline to 190.7 and 189.6 min for amperozide- and azaperone-treated pens, respectively (P less than .01). Treatment differences in aggression and lying were evident during the initial 6 h only. Amperozide resulted in fewer fights involving two pigs (197.3/pen) than did azaperone (260.2/pen) or saline (298.3/pen) (P less than .05). Injuries to the ears (P less than .01) and total injuries (P less than .05) were less severe in amperozide-treated pigs than in pigs on the other treatments.(ABSTRACT TRUNCATED AT 250 WORDS)     

饲粮能量浓度对肥育猪行为特点的影响

采用单因子试验设计,研究不同能量浓度对肥育猪非采食期间行为的影响。选取81头年龄、体重相近的杜长大三元杂种猪,采用随机区组设计,共3个处理组,每处理组3栏,每栏9头猪,分别饲喂能蛋比相同的3种不同消化能浓度的饲粮(能蛋比均为79 MJ/kg),低能饲粮消化能10.87 MJ/kg;中能饲粮消化能12.54 MJ/kg;高能饲粮消化能14.21 MJ/kg。试验结果表明,饲喂高能饲粮的生长肥育猪行为规癖发生频率最低,趴卧时间最多(P<0.05)。     

猪咬尾的发生原因分析

猪咬尾在全世界的规模化养猪场中普遍发生。本文对猪咬尾的相关因素(包括遗传、环境、营养和管理等方面)进行了重点分析。总而言之,环境因素与猪咬尾的相关性大于其他因素。必须首先从改善环境入手,减少咬尾的发生;其次,提供稳定的全价饲粮,减少咬尾的加重。     

Tail biting in pigs

Extract

Sir:- Referring to a letter (N.Z. vet. J. (1983) 31: 105–6) by C. Larsen on tail biting, I would like to add some theories about the causes of tail biting under the conditions of intensive pig-rearing     

Use of a box to prevent agonistic behavior after regrouping in isolated and non-isolated pigs

The effects of a box in the pen on the agonistic behavior of pigs after regrouping was determined in 24 pigs from five litters that were kept in three pens after weaning. For the experiment, the pigs were allocated to six pens with four animals each and kept with their peers for 2 weeks. The lightest pig from each pen was removed and isolated for 2 weeks, and then regrouped with its original peers. At the time of regrouping, half of the pens were equipped with the box. The number and duration of agonistic behavior events were particularly large and long in the pen without a box on the first day after regrouping, and for the isolated pig on the first day (all P  < 0.05). The number of times the box was accessed was large for the isolated pig on the first day after regrouping ( P  < 0.01). The number of agonistic behavior events and the times the box was accessed was correlated on the first day after regrouping ( r _s = 0.79, P  < 0.01). The number of agonistic behavior events on the first day after regrouping was greater in the pens without a box than in the pens with a box ( P  < 0.01). It was suggested that the box had the effect of reducing agonistic behavior after regrouping.     

Effects of farrowing system on behavior and growth performance of growing-finishing pigs

A study was conducted to compare growth performance and behaviors of group-farrowed pigs with those of confinement-farrowed pigs. A total of 216 pigs (8 wk of age) were used, with an equal number of group-farrowed or confinement-farrowed pigs from 1 farrowing batch. Group-farrowed pigs were farrowed in bedded, individual pens and mingled into a group of 8 litters at 12 (±1.3) d of age. Pigs were weaned at 33 (±1.3) d and remained in the farrowing room until 8 wk of age. Confinement-farrowed pigs were farrowed in farrowing crates. At weaning (32 ± 2.0 d of age), confinement-farrowed pigs were mixed and moved to pens of 9 pigs in a confinement nursery and remained there until 8 wk of age. At 8 wk of age, pigs from the 2 housing systems were allocated to 24 pens of 9 pigs in a confinement growing-finishing barn, with 12 pens from each of the housing systems. Within farrowing system, pigs from different groups or pens were mixed upon entering the growing-finishing barn. Individual BW was recorded at allotment (wk 0) to the growing-finishing barn and every 2 wk thereafter for 14 wk. Feed intake and G:F were monitored on a pen basis every 2 wk between wk 0 and 14 of the study period. Behaviors of pigs were video recorded in 6 pens of each housing treatment for 24 h on the day of mixing (d 0), d 7, and d 14 after mixing in the finisher barn. The video recordings were scanned at 5-min intervals to calculate behavioral time budgets for lying, standing, eating, drinking, and belly nosing. Data were analyzed using the Proc Mixed model of SAS with repeated measures. Compared with confinement-farrowed pigs, group-farrowed pigs spent more time lying (85.7 vs. 82.7%; SE = 0.75; P < 0.001) and belly nosing (0.05 vs. 0.02%; P < 0.05) and less time standing (5.8 vs. 7.5%; SE = 0.49; P < 0.01) and eating (7.3 vs. 9.3%; SE = 0.40; P < 0.001). The difference in behavioral time budgets was associated with differences in performance of pigs from the 2 housing systems. Group-farrowed pigs exhibited greater ADG (866 vs. 814 g; SE = 10.3; P < 0.01) for the initial 2 wk after mixing, less ADFI (2,004 vs. 2,188 g; SE = 42.5; P < 0.05), and improved G:F (0.431 vs. 0.393; SE = 0.0078; P < 0.01) for the entire 14-wk study period compared with confinement-farrowed pigs. These results suggest that group-farrowed pigs were more efficient than confinement-farrowed pigs in utilizing dietary energy for BW gain by lying more and standing and eating less during the growing and finishing period.     

Effects of feeding systems on social and feeding behavior and performance of finishing pigs

Two experiments were conducted to study the effects of feeding systems on feeding behavior, aggression, social ranks and average daily gain (ADG) of pigs. In Exp. 1, feed was delivered during the day from 1100 to 1400 and at night from 2300 to 0200. One pen containing 10 barrows and 10 gilts was used. Correlation coefficients were calculated between pairs of traits. In Exp. 2, four feeding systems were tested using similar group composition as in Exp. 1. Two feeding systems were ad libitum, offering either dry or wet feed; the other two used time-restricted feeding from 0900 to 1100 and from 1600 to 1800, but with water supplied either ad libitum or time-restricted. Analyses of variance were used to test feeding system effects; correlation coefficients were calculated for pairs of traits. Results of Exp. 1 indicated that pigs displayed predominantly daytime activities. Frequency of aggressive acts were correlated significantly with feeding frequency (r = .48), time to first feeding (r = -.50) and ADG (r = .56). In Exp. 2, pigs on time-restricted feeding with ad libitum water had significantly depressed ADG and reduced feed intake. A possible association between time-restricted feeding and water intake is postulated. Feeding behavior, aggression and social rank were associated with ADG in time-restricted systems but not in ad libitum systems. There was a tendency in time-restricted-fed pigs for the more aggressive pigs to perform more feeding activities, to rank higher in the social order, and to gain faster.     

甘露聚糖酶对大猪生产性能的影响

为探讨甘露聚糖酶在常规饲养水平下 ,对大猪生产性能及其经济效益的影响 ,试验选用中猪阶段结束后杜×长×大三元杂大猪 72头 ,依据体重、性别比例相近的原则 ,进行分组处理 ;各组基础日粮相同 ,营养水平一致 ,A组饲喂基础日粮 +0 .1 %复合酶A(不含甘露聚糖酶 ) ,B组饲喂基础日粮 +0 .1 %复合酶B(含 1 0 0 0U/g甘露聚糖酶 )、C组饲喂基础日粮 +0 .1 %复合酶C(含2 0 0 0U/g甘露聚糖酶 )。试验期从 2 0 0 2年 9月 30日至 2 0 0 2年 1 0月 30日 ,共 30d。试验结果表明 :试验期日增重A组为 739g、B组为 785g、C组为 835g ,B、C组日增重比对照组分别提高 6 .2 2、1 2 .99;料肉比A、B、C组分别为 3.5 4、3.2 9、3.0 2 ,B、C组比对照组分别降低 7.1、1 4 .7% ;综合经济效益每千克增重饲料成本B组、C组分别为 5 .4 9、5 .0 4元 ,对照组为 5 .91元 ,B、C组经济效益分别提高 7.1、1 4 .7%。     

二氢吡啶对猪生长发育和肉质性能影响的研究

二氢吡啶 (Diludin)的化学名称为 2、6 -二甲基 - 3、5 -二乙酯基 - 1、4 -二氢吡啶 ,具有抗氧化、提高畜禽生产性能等多种作用 ,是一种良好的饲料添加剂 ,目前已广泛应用到畜禽生产中。我国利用二氢吡啶的研究主要集中在家禽上 ,二氢吡啶对猪生长发育的研究较少 ,对猪肉质影响的报道更少 ,为进一步探讨猪饲料中二氢吡啶的最佳添加浓度和对肉质的影响 ,进行了本次试验。1　材料和方法1 1　二氢吡啶　由北京桑普生物化学技术有限公司提供。1 2　地点和试验期　本研究在江西某猪场进行 ,试验期为 1 0 0d。1 3　试猪及分组　试验选择体重、…     

Lesions of so-called flank biting and necrotic ear syndrome in pigs

Skin lesions were established on the flanks of pigs aged 10 to 12 weeks, in the areas of the ribs, the mid-upper leg, the shoulder and the tuber ischii. Skin lesions on the ear tips, known as porcine necrotic ear syndrome, were detected in weaners throughout the raising period. By the histological examination of 50 samples of skin lesions from the flank, two stages of epidermal and dermal changes were established; the milder stage had epidermal changes with marked acanthosis, rete ridges formed deep in the dermis and mild infiltrates of mononuclear cells in the layers around the capillaries in the dermis; the more severe stage had ulcers, under which there were infiltrates of polymorphonuclear cells. The same histological changes were observed in 23 samples of skin lesions taken from the tips of ears with necrotic ear syndrome. On healthy skin from the flank and ear tip, micrococci were the dominant organism, whereas on skin lesions from both the affected areas staphylococci were dominant. Since the histological lesions on the flanks were identical to those in necrotic ear syndrome, which has been associated with Staphylococcus hyicus infection, the pathogenesis of the lesions on the flanks is probably the same.     

半胱胺对育肥猪生产性能的影响

动物的生长发育受神经内分泌系统的调节，而其中最重要的是由下丘脑-垂体-靶腺构成的神经内分泌生长轴（the somatotropic axis）。生长激素（Growth Hormone，GH）是该调控的核心，它能够促进肌肉组织蛋白质的合成，抑制脂肪组织葡萄糖的摄入和脂肪的合成。生长抑素（Somatostatin，SS）是由神经系统和胃肠道产生的，     

Factors affecting agonistic interactions of pigs after regrouping in pens with a box

To determine the factors affecting agonistic interactions after regrouping, 24 pigs were allocated to six pens that each had a box. Half of the pigs were experienced in using the box. One castrated male and one female pig were transferred from each pen to another pen at random. The number of pigs attacked was particularly large for the pigs that had no experience in using the box and were transferred on the first day ( P <  0.05). The duration of access to the box was markedly longer for the pigs that had experience in using the box and were not transferred on the first day ( P <  0.05). The number and duration of attacks were significantly larger and longer toward unfamiliar individuals than toward familiar ones (both P < 0.01). The number of attacks toward the same sex was significantly larger than toward the opposite sex ( P <  0.01). A negative correlation was found between the number of agonistic interactions on the first day and the range of body weights in the pen mates ( r =  −0.78, P  = 0.07). In conclusion, regrouping with unfamiliar individuals should be avoided, but when unavoidable, the following methods are recommended to reduce agonistic interactions: (1) ensure the intruders are experienced in using a box, (2) move experienced intruders in with residents that have no experience in using a box, (3) mix different sexes, and (4) have wide variations in body weights in a pen.     

植物甾醇对生长猪生产性能和血脂的影响

选取90头体重约40kg的杜枫姜三元杂交猪,随机分成2组,每组3个重复,每重复15头,分别饲喂基础日粮(对照组)和基础日粮+25mg/kg植物甾醇的试验日粮(试验组)。研究植物甾醇对生长猪生产性能和血脂水平的影响。试验60d后,检测生产性能指标和血清血脂指标。结果显示:植物甾醇能显著提高育肥猪饲料转化率(P<0.05),降低血清中低密度脂蛋白和甘油三酯含量(P<0.05);具有降低血清胆固醇、高密度脂蛋白含量的趋势(P>0.05);植物甾醇可能通过抑制低密度脂蛋白的生成来降低血脂。     

光照对猪生产性能及生理节律的影响

光照作为重要环境参数之一,通过影响动物的生理节律调控动物生产。合理的光照环境可以促进猪的生长发育和性腺活动,提高生产性能和繁殖性能,增加猪场经济效益。本文综述了光照强度、光照周期及光照波长等方面对不同生理阶段猪的生产性能或繁殖性能影响的研究进展及光照影响动物生理节律的机制,以期为养猪生产的光照控制提供一定的理论依据和参考数据。