Effect of postweaning feed intake on performance, intestinal morphology, and the probability of diarrhoea in piglets.

Changes in gastrointestinal architecture, high incidence of diarrhoea, and low feed intake (FI) are commonly observed around weaning of pigs, but the relationship between postweaning FI and diarrhoea is unclear. This study aimed to determine the effect of low or high FI during the first days after weaning on growth performance, diarrhoea probability, intestinal permeability, and morphology in pigs until postweaning day (PWD) 28. A total of 120 pigs (7.20 ± 0.26 kg) weaned at 28 days of age (PWD 0) were randomly allocated to five diets and housed individually until PWD 28. Two diets differed in CP and three diets differed in threonine and tryptophan levels. At PWD 4, pigs with the 25% lowest accumulated FI (LOW; n = 30) and 25% highest accumulated FI (HIGH; n = 30) were selected for the study. Faecal consistency was evaluated daily using a 4-scale visual scoring system. Blood was collected at PWD 4, 14, 21 and 28, and small intestinal and colonic tissue was obtained at slaughter on PWD 28. Until PWD 4, LOW pigs consumed approximately 20% (35.7 ± 5.9 g/day) of the FI of HIGH pigs (181 ± 5.75 g/day; P < 0.05) and their average daily gain (ADG) was -103 ± 15.1 g/day. At PWD 28, average daily feed intake, ADG, and feed conversion ratio were still negatively affected by the FI level (P < 0.05) and pigs in the LOW group were on average 4.4 kg lighter than HIGH pigs. Pigs in the HIGH group showed a 55% higher probability of diarrhoea compared with LOW pigs during PWD 0-28. The number of antibiotic treatment days against diarrhoea was 2.38 days higher for HIGH compared with LOW pigs (P = 0.04). The intestinal permeability markers diamine oxidase and D-lactate in plasma were unaffected by the level of FI (P > 0.10). The systemic inflammatory markers haptoglobin and C-reactive protein were higher for HIGH pigs at PWD 4 (P = 0.005), but not affected in the following periods (P > 0.10). Pigs in the HIGH group had an increased area of acidic mucin-producing cells in the small intestine compared with LOW pigs (P < 0.05), but other intestinal morphology measurements at PWD 28 were unaffected by the level of FI. In conclusion, high FI just after weaning was associated with higher growth performance but also higher probability of diarrhoea and more frequent use of antibiotics until PWD 28.

A static model to analyze carbon and nitrogen partitioning in the mammary gland of lactating sows.

Quantitative estimates of mammary nutrient inputs, outputs and metabolism in sows are scarce, despite being critical elements to identify parameters controlling milk synthesis central for the feeding of lactating sows. The objective of this study was to quantify the mammary gland input and output of nutrients as well as the intramammary partitioning of carbon and nitrogen with the purpose to identify mechanisms controlling mammary nutrient inputs, metabolism and milk production in lactating sows. A data set was assembled by integration of results from four studies. The data set included data on litter performance, mammary arterial-venous concentration differences (AV-difference) of energy metabolites and amino acids, and the contents of lactose, fat and amino acids in milk. Milk yield was estimated based on average litter size and litter gain, and mammary plasma flow (MPF) was estimated using the sum of phenylalanine and tyrosine as internal flow markers. The yield and composition of milk were used to estimate mammary nutrient output in milk, and MPF and AV-difference were used to estimate net mammary input of carbon and nitrogen and output of CO2. Carbon and nitrogen used for the synthesis of lactose, fat and protein in milk and CO2-yielding processes were represented in a static nutrient partitioning model. The origin of mammary CO2 output was calculated using theoretical estimates of carbon released in processes supporting mammary synthesis of de novo fat, protein and lactose in milk, mammary tissue protein turnover and transport of glucose and amino acids. Results indicated that total input of carbon from glucose and lactate was partitioned into lactose (36%), fat (31%) and CO2-yielding processes (34%). Theoretical CO2 estimates indicated that de novo fat synthesis, milk protein synthesis and mammary tissue protein turnover were the main processes related to mammary CO2 production. More than 90% of mammary gland amino acid input was used for milk protein. The quadratic relationship between AV-difference and mammary input of essential amino acids indicated that both changes in AV-difference and MPF contributed to the regulation of mammary input of essential amino acids. The impact of the arterial supply of amino acids on mammary input may be greater for the branched-chain amino acids, arginine and phenylalanine than for other essential amino acids. In conclusion, relationships between input and output parameters indicate that AV-difference and MPF regulate mammary nutrient input to match the supply and demand of nutrients for the mammary gland.

Transcriptional profiling of swine mammary gland during the transition from colostrogenesis to lactogenesis using RNA sequencing.

BACKGROUND: Colostrum and milk are essential sources of antibodies and nutrients for the neonate, playing a key role in their survival and growth. Slight abnormalities in the timing of colostrogenesis/lactogenesis potentially threaten piglet survival. To further delineate the genes and transcription regulators implicated in the control of the transition from colostrogenesis to lactogenesis, we applied RNA-seq analysis of swine mammary gland tissue from late-gestation to farrowing. Three 2nd parity sows were used for mammary tissue biopsies on days 14, 10, 6 and 2 before (-) parturition and on day 1 after (+) parturition. A total of 15 mRNA libraries were sequenced on a HiSeq2500 (Illumina Inc.). The Dynamic Impact Approach and the Ingenuity Pathway Analysis were used for pathway analysis and gene network analysis, respectively. RESULTS: A large number of differentially expressed genes were detected very close to parturition (-2d) and at farrowing (+ 1d). The results reflect the extraordinary metabolic changes in the swine mammary gland once it enters into the crucial phases of lactogenesis and underscore a strong transcriptional component in the control of colostrogenesis. There was marked upregulation of genes involved in synthesis of colostrum and main milk components (i.e. proteins, fat, lactose and antimicrobial factors) with a pivotal role of CSN1S2, LALBA, WAP, SAA2, and BTN1A1. The sustained activation of transcription regulators such as SREBP1 and XBP1 suggested they help coordinate these adaptations. CONCLUSIONS: Overall, the precise timing for the transition from colostrogenesis to lactogenesis in swine mammary gland remains uncharacterized. However, our transcriptomic data support the hypothesis that the transition occurs before parturition. This is likely attributable to upregulation of a wide array of genes including those involved in 'Protein and Carbohydrate Metabolism', 'Immune System', 'Lipid Metabolism', 'PPAR signaling pathway' and 'Prolactin signaling pathway' along with the activation of transcription regulators controlling lipid synthesis and endoplasmic reticulum biogenesis and stress response.

Mammary nutrient uptake in multiparous sows fed supplementary arginine during gestation and lactation.

Arginine is the precursor for the synthesis of nitric oxide and may increase mammary plasma flow (MPF), which may in turn increase mammary nutrient uptake. Quantifying mammary nutrient uptake improves our understanding of mammary nutrient metabolism and may potentially allow identification of limiting nutrients for colostrum and milk production. Thus, the objectives of the present study were 1) to study the impact of 25 g/d of crystalline Arg (ARG) on MPF and uptake of nutrients by the mammary glands compared with an isonitrogenous supply of Ala (51 g/d; control [CON]) fed to a total of 8 sows from d 30 of gestation until weaning on d 28 of lactation and 2) to quantify mammary nutrient uptake in late gestation and in early and at peak lactation. Sows were surgically fitted with indwelling catheters on d 76 ± 2 SEM of gestation. -amino hippuric acid (AH) was infused (3.0 mmol/h) in the infusion catheter inserted in the mammary vein, initiated 1 h before the first blood sample at -10, -3, 3, and 17 d in milk (DIM). Blood samples were simultaneously drawn from catheters inserted in the femoral artery and the mammary vein, and the samples were collected in hourly intervals from 0.5 h before to 6.5 h after feeding. Sow milk production was assessed at 3 and 17 DIM. Arterial plasma concentrations of Arg and Ala were increased in ARG and CON sows, respectively ( < 0.01), whereas we did not succeed in detecting a greater MPF in ARG sows ( = 0.30). Arterial-venous differences ( = 0.03) and net mammary flux ( = 0.01) of Ala were increased in CON sows, while the net flux of most other metabolites ( > 0.05) was unaffected by treatment. The mammary extraction of all essential AA was below 13% in late gestation. The average mammary extraction of essential AA at peak lactation was greatest for Leu (51%), while the preprandial extraction was greatest for Lys (57%). The mammary carbon balance (input-output) was negative (-39 ± 12 mol C/d) in early lactation but almost balanced at peak lactation (-13 ± 14 mol C/d), suggesting that mammary fat depots contributed to milk synthesis. In conclusion, we failed to observe an increased MPF and mammary uptake of AA and energy metabolites in ARG-supplemented sows. The mammary extraction rate of essential AA indicated that AA were not limiting for the mammary glands in late gestation, while Lys and Leu appeared to be the 2 most limiting essential AA for milk production at peak lactation.

Impact of fat source and dietary fibers on feed intake, plasma metabolites, litter gain and the yield and composition of milk in sows.

Sow lactation diets often include fat sources without considering the impact on digestion, metabolism and performance. Fiber ingredients may reduce feed intake and are often completely excluded from lactation diets, although locally available ingredients may be cost-efficient alternatives to partly replace cereals in lactation diets. Thus, a standard lactation diet low in dietary fiber, and two high-fiber diets based on sugar beet pulp (SBP) or alfalfa meal (ALF) were formulated. The SBP diet was high in soluble non-starch polysaccharides (NSP), whereas ALF being high in insoluble NSP. Each diet was divided in three portions and combined with 3% soybean oil (SOYO), palm fatty acid distillate (PFAD), or glycerol trioctanoate (C8TG) as the dietary fat source. Equal amounts of metabolizable energy were fed to 36 second parity sows from day 105 of gestation and throughout lactation to study the impact on feed intake, plasma metabolites, milk production and litter performance. Backfat thickness and BW of sows were recorded on days 3, 17 and 28 of lactation; blood was sampled on days 3 and 17; milk samples were obtained on days 3, 10, 17 and 24 of lactation; and piglets were weighed on days 2, 7, 14, 21 and 28 of lactation. Litter gain and milk yield during late lactation were greater in sows fed C8TG or SOYO than in sows fed PFAD (P=0.05), whereas loss of BW (P=0.60) and backfat (P=0.70) was unaffected by fat source. Milk protein on days 3 and 10 of lactation were lower in C8TG and SOYO sows, than in PFAD sows (P<0.05). The lowest concentration of plasma lactate on day 3 (P<0.05) and plasma acetate on day 17 (P<0.05) was observed in C8TG sows. Milk yield was unaffected by fiber treatment (P=0.43), whereas milk protein concentration was lowest in ALF sows (P<0.05). Feed intake tended to be lower (P=0.09), and litter gain during the 3rd week of lactation was decreased (P<0.05) in SBP sows. In conclusion, performance was enhanced in SOYO and C8TG compared with PFAD sows, possibly associated with reduced energy intake in PFAD-fed sows. Furthermore, the SBP diet seemed to impair feed intake and litter gain at peak lactation, suggesting that effects of the dietary fiber fraction on energy intake determines the potential inclusion level of fiber-rich ingredients.

Impact of improving dietary amino acid balance for lactating sows on efficiency of dietary amino acid utilization and transcript abundance of genes encoding lysine transporters in mammary tissue.

Lactating multiparous Yorkshire sows ( = 64) were used in 2 experiments to test the hypothesis that reducing dietary CP intake and improving AA balance through crystalline AA (CAA) supplementation improves apparent dietary AA utilization efficiency for milk production and increases transcript abundance of genes encoding Lys transporter proteins in mammary tissue. In Exp. 1, 40 sows were assigned to 1 of 4 diets: 1) high CP (HCP; 16.0% CP, as-fed basis; analyzed concentration), 2) medium-high CP (MHCP; 15.7% CP), 3) medium-low CP (MLCP; 14.3% CP), and 4) low CP (LCP; 13.2% CP). The HCP diet was formulated using soybean meal and corn as the only Lys sources. The reduced-CP diets contained CAA to meet estimated requirements for essential AA that became progressively limiting with reduction in CP concentration, that is, Lys, Ile, Met + Cys, Thr, Trp, and Val. Dietary standardized ileal digestible (SID) Lys concentration was 80% of the estimated requirement. In Exp. 2, 24 sows were assigned to the HCP or LCP diets. In Exp. 1, blood samples were postprandially collected 15 h on d 3, 7, 14, and 18 of lactation and utilization efficiency of dietary AA for milk production was calculated during early (d 3 to 7) and peak (d 14 to 18) lactation. Efficiency values were estimated from daily SID AA intakes and milk AA yield, with corrections for maternal AA requirement for maintenance and AA contribution from body protein losses. In Exp. 2, mammary tissue was biopsied on d 4 and 14 of lactation to determine the mRNA abundance of genes encoding Lys transporter proteins. In peak lactation, Lys, Thr, Trp, and Val utilization efficiency increased with decreasing dietary CP (linear for Trp and Val, < 0.05; in sows fed the MHCP diet vs. sows fed the HCP diet for Lys and Thr, < 0.05). Total essential and nonessential 15-h postprandial serum AA concentrations increased with decreasing dietary CP (linear, = 0.09 and < 0.05, respectively), suggesting increased maternal body protein mobilization. Transcript abundance of several genes involved in Lys transport in mammary tissue did not differ between sows fed the LCP and HCP diets. Feeding lactating sows low-CP diets supplemented with CAA increases the efficiency of utilizing dietary Lys, Thr, Trp, and Val for milk protein production but is unrelated to abundance in mRNA of genes encoding Lys transport proteins in the mammary gland. Dietary Lys utilization for milk protein production in lactating sows appears to be optimized when crystalline Lys is included at a minimum of 0.10% in a diet containing 15.70% CP.

Technical note: Measurement of mammary plasma flow in sows by downstream dilution of mammary vein infused -aminohippuric acid.

The objectives of the present study were to design a method to estimate mammary plasma flow (MPF) in lactating sows using downstream dilution of -aminohippuric acid (AH) and to compare these estimates with MPF estimates based on specific AA as internal markers (MPF-AA). A permanent indwelling catheter was surgically implanted in the femoral artery, and another 2 were inserted in the right cranial mammary vein of 8 second- and third-parity sows on d 76 ± 2 SEM of gestation. On the 3rd and 17th days in milk, arterial and venous blood samples were drawn in hourly intervals from 0.5 h before until 6.5 h after feeding. The MPF in the right cranial mammary vein was measured by downstream dilution of infused AH (3.0 mmol/h). Total MPF-AH was calculated assuming that the measured flow constituted the flow from 5 out of 14 suckled glands on the basis of the anatomical structure of the mammary vascular system. Total MPF-AA was estimated on the basis of the output of the specific AA marker in milk and the arteriovenous differences of the marker as free AA in plasma, assuming a direct transfer of AA from plasma to milk protein. Total MPF-AH was 6,860 L/d in early lactation and increased to 8,953 L/d at peak lactation ( = 0.003). In early lactation, MPF-AA estimates were greater or tended to be greater (132% to 175%; < 0.10) than MPF-AH estimates for all internal markers, except Met (119%). Moreover, MPF-AH was correlated with MPF-AA only for MET as an internal marker ( = 0.74; = 0.03) in early lactation. In contrast, MPF-AH and MPF-AA estimates did not differ and were well correlated at peak lactation with the strongest correlation observed when Met ( = 0.84; = 0.009) and Phe + Tyr ( = 0.82; = 0.01) were used as the internal AA markers. Litter gain increased from d 3 to 17 of lactation (2.13 vs. 3.46 g/d; = 0.001) and was correlated with MPF-AH during lactation ( = 0.74; < 0.001), whereas no correlation between litter gain and MPF-AA was observed ( > 0.10). These results suggest that downstream dilution of infused AH and the AA methods are applicable methods to estimate MPF at peak lactation. The reason for the observed discrepancy in early lactation between MPF- AH and MPF-AA is not obvious but might be related to the rapid metabolic changes observed in early lactation. In conclusion, MPF measured by downstream dilution of mammary infused AH was higher at peak compared to early lactation, which the internal AA marker approach failed to show.

Impact of feeding reduced crude protein diets to lactating sows on nitrogen utilization.

Forty lactating multiparous Yorkshire sows were used to test the hypothesis that reducing dietary CP and supplementing with crystalline amino acids (CAA) increases dietary N utilization for milk production during early and peak lactation. Sows were assigned to 1 of 4 diets: 1) 16.0% CP (as-fed; analyzed contents; HCP); 2) 15.7% CP (MHCP); 3) 14.3% CP (MLCP); 4) 13.2% CP (LCP); diet HCP was formulated using soybean meal and corn as the only Lys sources. The reduced CP diets contained CAA to meet requirements of the limiting AA. Sow and piglet BW were measured on d 1, 3, 7, 14, 18, and 21 of lactation. Nitrogen retention was measured on sows between d 3 and 7 (early) and d 14 and 18 (peak) of lactation. Milk true protein output was calculated from estimated milk yield and analyzed true protein concentration. Sow BW change (overall mean: -4.2 ± 3.37 kg over the 21-d lactation period) and average daily DM intake (overall mean: 4.05 ± 0.18 and 6.12 ± 0.20 kg/d, early and peak lactation, respectively) did not differ between diets. Nitrogen intake decreased as dietary CP concentration decreased (114.3, 106.0, 107.4, and 99.0 ± 5.29 g/d and 169.5, 168.3, 161.2, and 145.1 ± 5.29 g/d for HCP, MHCP, MLCP, and LCP in early and peak lactation, respectively; L: < 0.05). Sow loin eye area loss tended to increase as dietary CP concentration decreased (Linear (): = 0.082). Litter growth rate (LGR) over the 21-d lactation period tended to increase with decreasing dietary CP concentration (L: = 0.084). In early lactation, N retention (N intake- fecal and urinary N) and milk true protein and casein output were not affected by dietary treatment. In early lactation, as dietary CP decreased, N retained as percentage of N intake tended to increase (L: = 0.093) and estimated efficiency of using retained N for milk N output was not influenced by dietary CP concentration. In peak lactation, N retention (122.5, 123.8, 121.2, and 109.0 ± 4.88 g/d for HCP, MHCP, MLCP, and LCP, respectively) decreased (L: < 0.05), N retained as percentage of N absorbed (N intake - fecal N) increased (L: < 0.05), milk casein yield increased ( = 0.051), and estimated efficiency of using retained N for milk N output (44.5, 51.0, 54.9, and 62.9 ± 5.9% for HCP, MHCP, MLCP, and LCP, respectively) increased (L: < 0.05). Feeding lactating diets reduced in CP from 16.0% to 14.3% with CAA inclusion as partial replacement for limiting AA improved N retention and N utilization efficiency for milk protein production in peak lactation, while these effects were less pronounced in early lactation.

Impact of sow and litter characteristics on colostrum yield, time for onset of lactation, and milk yield of sows.

The aim of the present study was to estimate the concurrent impact of sow and litter characteristics on sow productivity. Sow productivity was defined as colostrum yield (CY), onset of lactation (the time point when milk secretion increased steeply, approximately 31 h postpartum), transition milk yield (MY; 36-60 h postpartum), and the mean MY in wk 1 to 4 of lactation. Therefore, the study investigated how factors related with sow nutrition, litter characteristics, farrowing characteristics, and composition of mammary secreta affected sow productivity. Data obtained from 5 previous sow experiments were used. The variables describing sow productivity were all defined as dependent variables and Pearson coefficient of correlation was used to examine relations among dependent variables. The results showed that CY was positively correlated with transition MY and MY in wk 1 and 2 of lactation (P < 0.05), and time for onset of lactation was positively correlated with transition MY (P < 0.05) but negatively correlated with MY in wk 1, 2, and 4 of lactation (P < 0.05). Multivariate regression analyses with a backward elimination approach were performed for each dependent variable to investigate relations with characteristics of sow nutrition, litter size, farrowing, and composition of mammary secreta (independent variables). Litter size was positively related with both CY and MY in wk 1 to 4 (P < 0.001). Milk protein concentration was negatively correlated with MY in all 4 wk (P < 0.01), which indicated that high yielding sows were unable to maintain milk protein synthesis during lactation. Additionally, mean intake of ME prepartum ( < 0.05) was included in the regression model for transition MY and the BW of the sow on d 3 was included in the regression model for MY in wk 1 ( P< 0.05). Except litter equlization, none of the observed independent variables were related with time for onset of lactation. In conclusion, when maximizing sow productivity in the future, it may be rewarding to pay attention to sow productivity in the colostrum period and around time for onset of lactation, and special attention should be given to dietary supplies of protein and essential AA.

Intrauterine growth restricted piglets defined by their head shape ingest insufficient amounts of colostrum.

The increasing litter sizes of modern pig breeds have led to a significant number of piglets that are born undersized ("small" piglets) and some have been exposed to different degrees of intrauterine growth restriction (IUGR). The aim of this study was to investigate the physiology and capability to ingest colostrum of these small piglets, suffering from various degrees of IUGR, to see if their IUGR score could be a useful tool for easy identification of piglets in need of intervention in the colostrum period. Piglets were classified at birth based on head morphology. Piglets were classified either "normal," "mildly IUGR" (m-IUGR), or "severe IUGR" (s-IUGR), based on head morphology. Blood samples were collected at birth and at 24 h, and colostrum intake during two 12-h periods and blood metabolites at 0 and 24 h were measured. At 24 h, piglets weighing <900 g at birth and the median piglet in birth order were sacrificed, and organ weights and hepatic glycogen were measured. Overall, there was an influence of the piglets' classification on most characteristics, with normal piglets having a greater colostrum intake between 0 and 12 h (P < 0.001) and between 12 and 24 h (P < 0.05), and higher birth weight, crown rump length, body mass index, and ponderal index (P < 0.001), and a tendency toward a higher vitality score (P < 0.069) than s-IUGR piglets. There was a time × IUGR interaction, with plasma glucose levels being lowered (P < 0.001) and lactate levels elevated (P < 0.001) in s-IUGR piglets at 24 h compared with normal and m-IUGR piglets. Some differences were found in electrolytes; sodium plasma concentrations were greatest for normal piglets (P < 0.05) and highest at 0 h (P < 0.05). At 24 h of age, s-IUGR piglets had a higher heart (P < 0.001) and brain percentage (P < 0.001), and a lower liver percentage (P < 0.001) relative to body weight, compared with normal piglets. In addition, s-IUGR piglets had less hepatic glycogen than m-IUGR piglets and normal piglets. The present study showed that the physiology of piglets in the colostrum period was affected by IUGR status at birth and their intermediary metabolism was altered due to different colostrum intakes. Furthermore, it was demonstrated that the head shape of newborn piglets is a good selection criteria for identifying piglets that need oral supplementation during the neonatal stage.

Isoleucine requirement of pigs weighing 8 to 18 kg fed blood cell-free diets.

The aim of the present study was to determine the minimum requirement of Ile in young pigs, enabling feeding of balanced low-CP diets. Most previous studies have used experimental diets that included blood cells, which are particularly high in Leu and known to antagonize the use of Ile. One week after weaning at d 28, 100 crossbred female pigs weighing 7.9 ± 0.7 kg were allocated to 1 of 5 dietary treatments. Diets were formulated to contain 1.15 g standardized ileal digestible (SID) Lys/MJ NE and were free of blood cells. The SID Ile was 0.42, 0.47, 0.53, 0.58, and 0.62 relative to Lys. The other indispensable AA were supplied according to requirements. Representative samples from the 5 diets were analyzed in 4 replicates at 3 different laboratories. The pigs were fed ad libitum and individually housed in 7 identical rooms during a 21-d period. At d 0, 7, 14, and 21, the pigs were weighed, and feed intake was determined. At d 15, blood samples were collected from the jugular vein to determine the plasma urea and free AA content. There were differences among the 3 laboratories in the analyzed content of several AA, and also Ile and Lys showed a large variation within the diets, which may cause variation in published requirement estimates. The concentration of Ile in plasma increased linearly (P < 0.01), and Lys in plasma decreased linearly (P = 0.02) with increasing SID Ile:Lys. A tendency for a linear decrease in plasma concentration was found for Thr (P = 0.10). Both ADFI and ADG were reduced when Ile was supplied above the Ile requirement estimate. Quadratic regression curves on ADFI, ADG, and G:F all showed the maximum at 0.52 SID Ile:Lys. Modeling with 2-sloped quadratic broken-line curves showed the maximum at 0.50, 0.53, and 0.54 SID Ile:Lys for ADFI, ADG, and G:F, respectively. In conclusion, the average estimation of requirement in this dose-response study using blood cell-free diets was 0.52 SID Ile:Lys during a 21-d experimental period from 8 kg BW.

Colostrum and milk production of sows is affected by dietary conjugated linoleic acid.

The present experiment was conducted to investigate dietary effects of conjugated linoleic acid (CLA) on sow traits related to piglet survival and growth performance. A total of 23 gestating sows were fed either a standard lactation diet (control diet [CON]) or the CON supplemented with 1.3% CLA (cis-9, trans-11 and trans-10, cis-12) from day 108 of gestation until weaning (4 wk after parturition) to evaluate whether dietary CLA affects the yield and composition of colostrum, time for initiation of milk production, and sow milk yield. Sows fed CLA tended to produce more colostral fat (6.3 vs. 5.2%, respectively; P = 0.10) than CON sows whereas contents of lactose, protein, and dry matter were similar in the two groups. Sows fed CLA tended to produce less colostrum than CON sows (409 vs. 463 g/piglet, respectively; P = 0.07) as predicted by the piglet rate of gain from 0 to 24 h (58 vs. 97 g/piglet, respectively; P = 0.07). The piglet mortality during the first week of lactation tended to be higher for sows fed CLA than for CON sows (6.8 vs. 2.3%, respectively; P = 0.10), and the number of piglets that died or were moved to others sows to ensure survival during the first week was more than double in the CLA group (17.6 vs. 7.8%, respectively; P = 0.04). Copious milk production was initiated 33 h (CLA) and 34 h (CON) after parturition and was not affected by dietary treatments (P = 0.41). Sow milk yield was improved by the CLA treatment from days 7 to 14 of lactation (P = 0.03). Weight at birth (1.40 kg for both groups; P = 0.98) and at weaning [8.2 kg (CLA) and 8.0 kg (CON); P = 0.52] was not statistically different. In conclusion, colostrum yield was inhibited but milk yield was stimulated by dietary inclusion of cis-9, trans-11 and trans-10, cis-12 CLA and indicates that sow productivity may be improved by using different fatty acids for transition and lactating sows.