Review: Improving the performance of neonatal piglets.

Newborn piglets have a high incidence of preweaning mortality that is not only associated with low birth weights but also with the presence of intra-uterine growth-restricted (IUGR) piglets. Such IUGR piglets are commonly seen in litters from hyperprolific sows as a result of insufficient placental transfer of nutrients. Nutritional strategies can be used prior to and during gestation to enhance foetal development and can also be implemented in the transition period to reduce the duration of farrowing and increase colostrum yield. Recent findings showed that the energy status of sows at the onset of farrowing is crucial to diminish stillbirth rate. Newborn piglets often fail to consume enough colostrum to promote thermostability and subsequent growth, and this is particularly problematic in very large litters when there are fewer available teats than the number of suckling piglets. One injection of 75 IU of oxytocin approximately 14 h after farrowing can prolong the colostral phase, hence increasing the supply of immunoglobulins to piglets. Nevertheless, assistance must be provided to piglets after birth in order to increase their chance of survival. Various approaches can be used, such as: (1) optimising the farrowing environment, (2) supervising farrowing and assisting newborn piglets, (3) using cross-fostering techniques, (4) providing nurse sows, and 5) providing artificial milk. Although research advances have been made in developing feeding and management strategies for sows that increase performance of their newborn piglets, much work still remains to be done to ensure that maximal outcomes are achieved.

Heritability of udder morphology and colostrum quality traits in swine.

The heritability of udder quality traits, defined as morphology and colostrum IgG concentration at farrowing, was estimated together with the genetic and phenotypic correlations of these traits with other production and reproduction criteria. Udder morphology traits were recorded in 988 Meidam sows and colostrum samples were collected from 528 sows. Teat length, teat diameter (DIA), interteat distance within the same row (SAMER), and teat distance from the abdominal midline (AML) were recorded to the nearest millimeter. For each sow, a record was also made of udder development score (DEV), the proportion of teats oriented perpendicular to the udder, and the proportion of nonfunctional teats. Colostrum IgG concentration was estimated with a Brix refractometer. Heritability of udder morphology traits varied from high ( = 0.46 for teat length and = 0.56 for DIA) to moderate ( = 0.37 for SAMER, = 0.22 for AML, = 0.25 for DEV, = 0.3 for the proportion of nonfunctional teats, = 0.1 for the proportion of teats oriented perpendicular to the udder, and = 0.35 for colostrum IgG concentration). The SAMER was negatively genetically correlated with the number of stillborns (genetic correlation [] = -0.48) and positively genetically correlated with the number of piglets born alive ( = 0.69), with the opposite for the trait AML ( = -0.40 for number of piglets born alive and = 0.40 for stillborns). The highest genetic correlation with productive traits was estimated between AML and ADG during rearing ( = 0.42), although this had a negative phenotypic correlation (; -0.11). Teat length was also moderately correlated with ADG ( = 0.27). Backfat thickness at 100 kg was positively correlated with DIA and the total number of teats present in both rows ( = 0.28 and = 0.36, respectively) and negatively correlated only with DEV ( = -0.22). The same results were found for the phenotypic correlation between backfat thickness at end of test and the total number of teats present in both rows ( = 0.03). Udder quality traits can be included in the breeding goal and appropriately weighted with other important traits in the breeding objectives to enhance maternal performance.

Udder characteristics of importance for teat use in purebred and crossbred pigs.

Possible side effects of the current sow selection criteria on udder characteristics and their influence on teat use and functionality have not yet been investigated. The first aim of the present study was to investigate differences in udder morphology characteristics (distance between teats in a pair, teat length, and teat diameter) in 2 different pure breeds (Norsvin Duroc [ND; = 12] and Norsvin Landrace [NL; = 12]) and 1 crossbreed (Norsvin Landrace × Yorkshire [NL×Y; = 14]) at 3 different time periods (Days 1, 21, and 35) during lactation. Second, we also investigated the association between udder morphology and teat use on d 1 and if some of these characteristics influence whether teats become nonfunctional (from d 1 to 35) during lactation. During lactation, udder morphology (teat pair distance, teat length, and diameter of functional teats) and teat use (from 6 consecutive nursings: functional teats being used/not being used and which teat row [left or right] was uppermost) were documented. The NL had shorter distance between teat pairs than ND ( = 0.030). Teat pair distance increased with sows' parity ( = 0.010) and was affected by teat position ( < 0.001). The ND had shorter teats than NL and NL×Y ( < 0.001). Teat length and diameter increased with parity ( = 0.027 and = 0.043, respectively) and were affected by teat position ( < 0.001 and < 0.001, respectively). Functional teats were less used on d 1 postpartum (21.4%) than at 2 later time periods (10.4% on Day 21 and 4.7% on Day 35; < 0.001) during lactation. On d 1, the greater the distance between teat pairs in the middle and posterior position, the higher was the proportion of not-used functional teats ( = 0.003), with a larger decline in the lower teat row ( < 0.001), where approximately half of middle and posterior teats were not used. Proportion of not-used functional teats in the lower middle position increased when the teat pair distance exceeded 16 cm, whereas in the lower posterior position, this limit was 14 cm. Furthermore, the proportion of not-used teats on d 1 influenced teats becoming nonfunctional during lactation ( < 0.001). The greater the distance between pairs, the more teats became nonfunctional irrespective of teat position ( < 0.001). The present results suggest that teat pair distance is of importance for teat use in all breeds and should be included in the breeding program to ensure colostrum intake and maintain teat functionality during lactation.

Sources of variation in udder morphology of sows.

This experiment investigated the sources of variation in sow udder morphology. A cross-sectional study of 218 sows (109 Large White × Landrace [LWL] and 109 Meidam [Large White × Meishan {MDM}]) of different parities was conducted using a combination of scores and metric measurements. For each teat, 4 measures were taken: the inter-teat distance within the same row (SAMER), the distance from the base of the teat in the upper row to the abdominal midline (AML), the length of the teat from the tip to the base (LEN), and the diameter at the tip of the teat (DIA). Scores were adopted to define teat orientation (0 = teat not orientated perpendicular to the mammary gland and 1 = teat orientated perpendicular to the mammary gland), teat functionality (1 = milk channel not working, including teats that were blind, inverted, or very damaged; 2 = reduced availability of colostrum; and 3 = perfectly functional), and udder development (1 = not developed to 3 = fully developed). A longitudinal study on a subset of sows ( = 70) investigated how udder morphology changed in consecutive parities. Meidam had shorter teats, which were closer to the abdominal midline than LWL (LEN, < 0.001; AML, < 0.001). In both studies, first and second parity sows had smaller teats (LEN, < 0.001; DIA, < 0.001) than older multiparous sows. Teat position had a significant ( < 0.001) effect on SAMER in both breeds, with less distance between middle teat pairs. The distance from the base of the teats in the upper row to the abdominal midline was shorter in the anterior and posterior teats compared with the middle teat pairs. Teat length was greater in the anterior and middle teats than in the posterior ones, whereas DIA was greater in the middle teats. Teat pair position was associated with teat orientation ( < 0.001) and teat functionality ( < 0.001). Parity was associated with udder development ( < 0.001). Breed, parity, and teat pair position were all significant sources of variation in udder morphology in sows.

Pain alleviation during castration of piglets: a comparative study of different farm options.

Pain alleviation associated with castration of piglets is an important welfare issue. The present study compares the effect of different approaches and products suitable for farmer use, with the aim to alleviate pain due to castration in piglets. A randomized within-litter design, with 28 replicate litters, compared 7 treatments: handling () restraint of the piglet and manipulation of the scrotum, castration without pain relief (), 2 treatments (, ) with different concentrations of tetracaine (2 and 6%) applied topically 10 min before and immediately post-surgery, and 3 treatments with i.m. injection of different nonsteroidal anti-inflammatory drugs () 10 min prior to surgery (-meloxicam, -ketoprofen, -tolfenamic acid). Efficacy of pain relief was assessed during a 300 min period after castration by serum cortisol, behavior (walking, lying, suckling, in the nest, isolated and pain related: tremors, rubbing the rear, hunching, wagging of the tail), facial expression and scrotal skin pressure sensitivity. C pigs had greater serum cortisol concentration than all other groups at 60 min post-surgery ( < 0.001), while H pigs had lower concentrations than pigs given topical anesthesia ( < 0.001) though not injected analgesia. No treatment differences were significant at 180 min, but at 300 min cortisol concentration was greater in T2 and T6 piglets than those given NSAIDs ( = 0.03). These treatment differences were mirrored by the pressure sensitivity of the scrotum; in comparison with C piglets, those given NSAIDs showed a reduced sensitivity ( 0.003) but those given local anesthesia did not ( = 0.15). C pigs showed increased frequency of pain-related behavior in the first 30 min in comparison with all other treatments, more time isolated than H or NSAID treatments, and more time standing inactive than H or K treatments. No behavioral differences were apparent after 60 min. No differences in facial expressions were observed among treatments. In conclusion, on-farm methods for pain relief can provide some, though not complete, pain alleviation in the hours after castration. The use of topical anesthesia gave only minor benefit in comparison to NSAID agents injected prior to castration. Since the main differences in indicators of pain between positive and negative controls were observed within the first h after castration, it is important to select drugs that act quickly after administration to facilitate practical processing schedules on farm.

Evaluation of an on-farm method to assess colostrum IgG content in sows.

The objective of this work was to investigate the evaluation of swine colostrum immunoglobulin G (IgG) concentration using the Brix refractometer. Colostrum samples were collected across all teats, from 124 sows of mixed parities. According to sampling time, three categories were created: samples available from 9 h before the onset of parturition until the first piglet was born were classified as before farrowing; samples collected after the first birth until 4 h later were classified as during farrowing; and finally samples collected from this point until 14 h after parturition, were classified as after farrowing. Samples were drawn and divided into three portions; one was immediately analyzed, a second was refrigerated and the third was frozen at -20°C. Fresh and refrigerated colostrum samples were analyzed at the farm with a Brix refractometer. IgG content of frozen samples was analyzed using a Brix refractometer, with a subset of 42 samples also tested with a commercially available radial immune diffusion (RID) kit. The Brix percentage ranged from 18.3% to 33.2%. Brix percentage repeatability, assessed by the intraclass correlation coefficient (ICC), was very strong (fresh ICC=0.98, refrigerated ICC=0.88 and frozen ICC=0.99). One-way repeated-measures ANOVA showed that storage temperature did not affect BRIX percentage of colostrum IgG (P>0.05). ANOVA results show a significant effect of sampling time on colostrum immunoglobulin concentration, measured with both Brix and RID (Brix: P<0.003; RID: P<0.05). Immunoglobulin G concentration measured by RID ranged from 13.27 to 35.08 mg/ml. Pearson correlation coefficient revealed that Brix percentage was positively correlated (r=0.56, P<0.001) with RID results (regression equation: RID=1.01 (±0.2) Brix -1.94 (±5.66); R 2=0.31). The results of this study indicate that the Brix refractometer provides a simple, fast and inexpensive estimation of colostrum IgG in sows.

Management strategies to improve the performance of low birth weight pigs to weaning and their long-term consequences.

Performance of pigs from birth to slaughter is a result of a complex interaction of factors, with the early stages of a pig's life likely to affect lifetime performance. During the preweaning stage, piglets are reliant on the sow for nutrition, and sibling competition is likely to affect growth, in particular for low birth weight (LBiW) piglets. The objective of the experiment was to determine the effect of litter composition (littermate weight) and milk supplementation during lactation on the performance of LBiW pigs to weaning and the long-term consequences of treatment to slaughter. The experiment was a 2 × 2 factorial with littermate weight (normal or LBiW) and provision of supplementary milk from d 1 to 28 (yes or no) as factors. A total of 265 piglets were selected within 24 h of birth and cross-fostered to create 2 litter types (LOW = LBiW pigs [≤ 1.25 kg] only and MX = both LBiW and normal birth weight pigs [1.6 to 2.0 kg]); half of the litters within a type were supplemented with milk and the other half were not. The behavior of litters given milk was recorded to identify milk consumption patterns. Piglets were weaned at d 28 and kept in their litters until d 70 and then subsequently housed in mixed groups until slaughter. No difference was observed at any stage in the ADG of pigs given access to supplementary milk or not (P > 0.05) nor was there any significant interaction between milk provision and litter composition (P > 0.05). However, LOW litters drank significantly more supplementary milk than MX litters (P < 0.001). There was a significant effect of litter type on ADG from d 14 to 28, with LBiW pigs in LOW litters performing better than those in MX litters (0.252 versus 0.217 kg/d; P < 0.05). At weaning, LBiW piglets in LOW litters weighed over 500 g more than those in MX litters (P < 0.05). In MX litters there was a significant interaction between birth weight and supplementary milk on the CV of BW from d 14 to slaughter (P < 0.05). In conclusion, grouping LBiW piglets with similar sized littermates preweaning can improve preweaning performance by reducing competition from heavier littermates; however, this advantage does not persist after weaning. Although supplementary milk does not improve LBiW pig performance before or after weaning, it affects their drinking behavior and can reduce the variation in the BW of LBiW piglets in mixed litters to slaughter.

Modeling digestibility of dietary phosphorus in growing and finish pigs.

Low P digestibility combined with intensive pig production can lead to water pollution. The aim of this paper was to develop a model able to represent P digestion in pigs across diets and contribute towards the reduction of P excretion. Phosphorus in plant feedstuffs includes some nonphytate P (NPP) that is readily digested but is mostly as organic phytate P (oP) that is indigestible unless it is dephosphorylated. The ability of pigs to dephosphorylate oP using endogenous phytase enzymes is limited and is a function of Ca intake. The effect of Ca (g/kg diet) on the proportion of oP dephosphorylated (kg/kg) in the small intestine (SI) and large intestine (LI) was determined as 0.26 - (0.015 × dietary Ca) and 0.69 - (0.059 × dietary Ca), respectively. The dephosphorylated oP in the LI was assumed to be indigestible and was excreted. Proportion of oP dephosphosphorylation (kg/kg) by microbial and plant phytase activity (FTU) in the stomach was estimated to be 0.56 × [1 - exp(-0.001 × FTU)] and 0.38 × [1 - exp(-0.002 × FTU)], respectively. Phosphorus digestibility (kg/kg) of NPP and dephosphorylated oP in the SI was assumed to be constant at 0.8. The model was used to predict P digestibility in 2 experiments by Stein et al. (2011) and Poulsen et al. (2010) and compare the predictions with experimental outcomes. The model successfully predicted the P digestibility to a range of dietary Ca concentrations and for 2 levels of supplementation with microbial phytase. However, the predictions overestimated P digestion systematically but always within a 10% margin of the observed values. The model could be a useful tool for formulating strategies to improve the efficiency of P digestion and reduce soluble P excretion in pigs.

Effect of reducing dietary mineral content on growth performance, water intake, excreta dry matter content and blood parameters of broilers.

1. The objective of this study was to investigate whether it is possible to reduce phosphorus (P) excretion by feeding a lower level of dietary P than that currently recommended, without compromising welfare, and whether this is sensitive to the level of dietary calcium (Ca). 2. A randomised complete block design was used with a total of 224 1-d-old male chicks of a commercial genotype in two batches. Chicks had a 10-d adaptation period. After this, they were moved to cages and allocated to one of 4 dietary treatments (4 and 3 birds per cage in batch 1 and 2, respectively). A standard level of Ca and P (8.3 and 6.6 g/kg, respectively) was compared with three lower levels of Ca (7.3, 6.3 and 5.3 g/kg) all at the same reduced level of P (5.5 g/kg). Records were made of live weight of birds on an individual basis and feed and water consumption on a cage basis. Every 7 d, the dry matter (DM) content of a sample of mixed excreta from each cage was measured. Birds were slaughtered and samples taken for analysis of plasma mineral content, retention of N, Ca and P and tibia bone strength. 3. The initial reduction in dietary mineral level did not adversely affect performance or bone strength. However, decreasing dietary Ca level below 7.3 g/kg, at constant P, led to reduced feed consumption and bone strength. Dietary treatment had no significant overall effect on water intake, water : feed ratio, excreta DM content, Ca and P retention or metabolisability of DM. There was no significant correlation between mean plasma Ca or P level and DM content of rectal digesta. 4. In conclusion, reducing dietary P from 6.6 to 5.5 g/kg to reduce potential environmental impact of broiler production had an adverse effect on bird welfare when the level of Ca was reduced below 7.3 g/kg, as a result of decreased feed intake in the early growth period and reduced skeletal strength.

Neonatal lamb vigour is improved by feeding docosahexaenoic acid in the form of algal biomass during late gestation.

To determine whether feeding a sustainable, algal source of docosahexaenoic acid (DHA) to sheep during late pregnancy would improve neonatal lamb vigour, 48 English mule ewes, of known conception date, were divided into four treatment groups. For the last 9 weeks of gestation, ewes received one of two dietary supplements: either a DHA-rich algal biomass providing 12 g DHA/ewe per day, or a control supplement based on vegetable oil. The four dietary treatment groups (n = 12) were: control supplement for the duration of the trial (C), DHA supplement from 9 to 6 weeks before parturition (3 week), DHA supplement from 9 to 3 weeks before parturition (6 week) and DHA supplement for the duration of the trial (9 week). Dietary supplements were fed alongside grass silage and commercial concentrate. There was a tendency for gestation length to be extended with increased duration of DHA supplementation (P = 0.08). After parturition, the concentrations of eicosapentaenoic acid (EPA) and DHA in ewe and lamb plasma and colostrum were elevated in line with increased periods of DHA supplementation. Lambs from the 6-week and 9-week groups stood significantly sooner after birth than lambs from the C group (P < 0.05). These data show that neonatal vigour may be improved by the supplementation of maternal diets with DHA-rich algal biomass and that this beneficial effect depends upon the timing and/or duration of DHA allocation.

Efficacy of forearm versus upper arm tourniquet for local anaesthetic surgery of the hand.

A prospective study was undertaken to compare the use of forearm and upper arm tourniquets for local anaesthetic procedures on the hand. One hundred consecutive patients with an upper arm tourniquet were compared with a further consecutive 100 patients in whom a forearm tourniquet was used. The tourniquet time was always less than 20 minutes and the scoring of perceived pain was not significantly different in the two groups. Use of a forearm tourniquet was well tolerated and was not associated with an increase in complications.

Relationships between fatty acid status of sow plasma and that of umbilical cord, plasma and tissues of newborn piglets when sows were fed on diets containing tuna oil or soyabean oil in late pregnancy.

To investigate the relationships between maternal, umbilical cord and piglet fatty acid status, multiparous sows (six per diet) were fed on diets containing supplements (30 g/kg) of either soyabean oil or tuna oil for the last 21 d of pregnancy. The proportions of most fatty acids differed between diets: in particular, the tuna-oil-containing diet supplied more 22:6n-3 and less 18:2n-6 fatty acids than the soyabean-oil-containing diet. Maternal plasma fatty acid concentrations (mg/l) were greater than those in umbilical plasma and 20:4n-6 and 22:6n-3 fatty acids were present in higher proportions (g/100 g fatty acids) in umbilical than maternal plasma. Feeding tuna oil increased the proportionate amounts (g/100 g fatty acids) of total n-3 fatty acids (particularly 22:6n-3) in umbilical cord, plasma and piglet tissues compared with feeding soyabean oil: in contrast, the proportion of 20:4n-6 was decreased by feeding tuna oil. Changes in piglet fatty acid proportions as a result of oil feeding were not influenced by piglet weight. While proportions of the long-chain n-3 and n-6 polyunsaturated fatty acids in piglet liver, spleen and reproductive tract (ovaries plus uterus of the female, testes of the male) correlated well with those of umbilical plasma, those in brain and retina were poorly correlated. Therefore umbilical plasma cannot be used to predict the fatty acid status of piglet brain.

Effect of feeding tuna oil or soyabean oil as supplements to sows in late pregnancy on piglet tissue composition and viability.

To investigate whether long-chain n-3 polyunsaturated fatty acids could cross the porcine placenta in late pregnancy and alter neonatal piglet tissue composition, multiparous sows (seven per diet) were fed on diets containing a supplement (30 g/kg) of either soyabean oil or tuna oil for the last 21 d of pregnancy and the first 7 d of lactation. The proportions of all fatty acids, except 18:1n-7, differed between diets: in particular, the tuna-oil-containing diet supplied more 22:6n-3 and less 18:2n-6 fatty acids than the soyabean-oil-containing diet. The proportions of n-3 fatty acids, particularly 22:6n-3 (g/100 g total fatty acids) in sow plasma, colostrum and milk were increased and the proportion of 18:2n-6 was decreased by feeding tuna oil. Piglet tissue n-3 fatty acid proportions (particularly 22:6n-3), obtained shortly after birth, were increased in piglets born to tuna-oil-fed sows compared with progeny of soyabean-oil-fed sows. The increase in the proportion of n-3 fatty acids (g/100 g total fatty acids) in piglet tissues as a result of tuna-oil feeding, compared with soyabean-oil-feeding, was in the order plasma > liver > erythrocytes > spleen > brain > retina. Piglets born to tuna-oil-fed sows had a lower viability score at birth than the progeny of soyabean-oil-fed sows. The proportions of long-chain n-3 fatty acid in tissues of new-born piglets were increased by feeding tuna oil to the sow in late pregnancy; however no improvements in piglet viability were observed.