Weaning-to-estrus Interval Research Articles

Factors associated with the productive longevity of sows in commercial breeding herds

Abstract. Maximizing sows' productive longevity (PL) represents a significant challenge faced by the swine industry, as the growing increase in the removal rate of sows, mainly young sows, directly impacts the system's economy. In addition, there are ethical concerns associated with animal welfare issues due to the low PL of sows. The objective of this study was to identify and evaluate the risk factors influencing the removal of sows from commercial swine production systems. The variable of interest was the PL of sows. The PL was modeled using Cox regression analysis to identify the factors that affected this variable. The factor with the greatest contribution to PL was sow type (ST), followed by the return to estrus percentage (REP), herd size (HS), season, lactation duration, weaning–estrus interval (WEI), piglets born alive, mummy percentage, and total piglets born. The removal risk was higher for hyperprolific sows than for normal sows. According to the nonproductive day (NPD) variable (an indicator that considers REP and WEI in its calculation), sows with more than 60 nonproductive days per year are at higher risk of elimination. The risk of removal was higher for sows from large herds than for sows from medium or small herds. The PL of sows within a herd is determined by the type of sow and the sows' association with environmental disturbances, including climatic factors (artificial climate control), management practices (human resources), and economic resources (size and infrastructure).

Managing Reproduction in Hyperprolific Sow Herds.

The rearing of large litters from hyperprolific sows is a characteristic of modern genotypes. However, these sows have body and reproductive characteristics that differentiate them from the genotypes of the past decades, making it necessary to adopt different management strategies. This review describes the main care and challenges associated with the hyperprolificity of sows during the period in which replacement gilts are selected, along with gestation, parturition, lactation, and the weaning-estrus interval. It describes the challenges that these sows' piglets will face during the lactation period and includes some strategies adopted to develop these surplus piglets. In addition, it identifies areas where more research is needed to understand the reproductive management of modern genotypes.

Supplementation with alpha-glycerol monolaurate during late gestation and lactation enhances sow performance, ameliorates milk composition, and improves growth of suckling piglets

BackgroundPhysiological changes during lactation cause oxidative stress in sows, reduce immunity, and hamper the growth capacity of piglets. Alpha-glycerol monolaurate (α-GML) has potential for enhancing the antimicrobial activity of sows and the growth of suckling piglets.MethodsEighty sows were allocated randomly to four groups: basal diet and basal diets supplemented with 500, 1000, or 2000 mg/kg α-GML. The experiment started on d 85 of gestation and lasted until piglets were weaned on d 21 of lactation. The number of live-born piglets was standardized to 12 ± 1 per sow on day of parturition. On d 0 and 21 of lactation, body weight of piglets was measured and milk samples were obtained from sows, and serum samples and feces from piglets were obtained on d 21.ResultsFeed intake, backfat loss, and weaning estrus interval did not differ among the four groups of sows. Maternal α-GML supplementation increased (P < 0.05) the body weight of piglets at weaning and the apparent total tract digestibility of crude fat of sows. The immunoglobulin A and immunoglobulin G levels were greater (P < 0.05) in a quadratic manner in the milk of sows as dietary α-GML increased. Concerning fatty acid profile, C12:0, C15:0, C17:0, C18:2n6c, C18:3n3, C24:0, and C22:6n3 were higher (P < 0.05) in linear and quadratic manners in colostrum of sows-fed α-GML diets compared with the control sows. There was lower (P < 0.05) n-6:n-3 polyunsaturated fatty acid ratio in milk than in the control sows. Maternal α-GML increased the abundance of Firmicutes (P < 0.05) and decreased the abundance of Proteobacteria (P < 0.05) of piglet fecal microbiota.ConclusionsDietary supplementation with α-GML improved milk immunoglobulins and altered fatty acids of sows, thereby improving the health of piglets.

The evaluation of an artificial intelligence system for estrus detection in sows

BackgroundGood estrus detection in sows is essential to predict the best moment of insemination. Nowadays, a technological innovation is available that detects the estrus of the sow via connected sensors and cameras. The collected data are subsequently analyzed by an artificial intelligence (AI) system. This study investigated whether such an AI system could support the farmer in optimizing the moment of insemination and reproductive performance.M&MThree Belgian sow farms (A, B and C) where the AI system was installed, participated in the study. The reproductive cycles (n = 6717) of 1.5 years before and 1.5 years after implementation of the system were included. Parameters included: (1) farrowing rate (FR), (2) percentage of repeat-breeders (RB), (3) farrowing rate after first insemination (FRFI) and (4) number of total born piglets per litter (NTBP). Also, data collected by the system were analyzed to describe the weaning-to-estrus interval (WEI), estrus duration (ED) and the number of inseminations used per estrus. This dataset included 2261 cycles, collected on farms B and C.ResultsIn farm A, all parameters significantly improved namely FR + 4.3%, RB − 3.75%, FRFI + 6.2% and NTBP + 1.06 piglets. In farm B, the NTBP significantly decreased with 0.48 piglets, but in this farm the insemination dose was too low (0.8 × 109 spermatozoa per dose). In farm C, only the NTBP significantly increased with 0.45 piglets after the implementation of the system. The WEI as determined by the system varied between 78 and 90 h, being 10–20 h shorter in comparison with the WEI as determined by the farmer. The ED, determined by the system ranged from 48 to 60 h, and was less variable as compared to the ED as assessed by the farmer. The mean number of inseminations per estrus remained similar over time in farm B whereas it decreased over time from approximately 1.6–1.2 in farm C.ConclusionThe AI system can help farmers to improve the reproductive performance, assess estrus characteristics and reduce the number of inseminations per estrus. Results may vary between farms as many other variables such as farm management, genetics and insemination dose also influence reproductive performance.

Dietary fibre supplemented pre-mating diets do not improve follicle development and litter characteristics in primiparous sows

Piglet birth weight is an important factor for their survival and growth. As the pre-mating diet influences the sow's metabolic state, this may have an impact on follicle development after weaning and subsequent piglet birth weight. We investigated the pre-mating effect of dietary fibre (DF; sugar beet pulp (SBP) and microfibrillated cellulose (MFC)) on metabolic hormones and metabolites (IGF-1, non-esterified fatty acids (NEFA), creatinine, urea and leptin), follicle development, and litter characteristics at subsequent farrowing in 58 hyper-prolific primiparous sows farrowing 16.5 ± 0.4 piglets used in three consecutive batches. We supplemented commercial diets (CON) with SBP and MFC during the last week of lactation and the weaning-to-oestrus interval (WEI). We measured follicle diameters with ultrasound and collected preprandial blood samples at weaning, 3 days after weaning, and at oestrus. A tendency for higher average daily feed intake (ADFI; 5.69 v. 6.61 kg/day, P < 0.07) and significant lower backfat (BF; 1.1 v. 0.2 mm, P < 0.05) loss were observed in SBP sows than in MFC sows during one week before weaning. Total dietary fibre (TDF) intake during the last week of lactation was higher in SBP sows than in CON sows, whereas TDF intake in SBP sows was similar to MFC sows (775.0 vs. 900.6 vs. 840.9 g/day, respectively, for CON, SBP and MFC, P < 0.05). Creatinine concentration at weaning was higher in SBP sows than in MFC sows (162.9 v. 136.6 mmol/L, P < 0.001). Other hormones and reproductive parameters were not affected by pre-mating diets. At subsequent farrowing, there was no difference in litter characteristics (P > 0.05). In our study, the different types of DF fed pre-mating affected feed intake and body protein mobilization during lactation. However, the supplementation of DF before mating did neither improve follicle development nor litter characteristics in the hyper-prolific sows.

Sow-related factors affecting the postweaning feed intake in Landrace × Large White females.

During the weaning-to-estrus interval (WEI), a high feeding level is usually offered to recover losses due to lactational catabolism. However, several factors can affect the appetite, possibly impairing the efficacy of this strategy. This study aimed to investigate the effect of sow-related factors on average daily feed intake (ADFI) during WEI in 142 primiparous and 458 multiparous sows. After weaning, the sows received 4.3 kg/day of feed and the wastage was recorded. The ADFI after weaning was lower in primiparous than multiparous sows, and on estrous day than in 2 and 3 days preceding estrus (P ≤ 0.05). In primiparous sows, lower ADFI was observed if they had higher backfat thickness at 112 days of gestation (BFT ≥ 11.5 mm) or higher reserves at weaning (BFT ≥ 10.5 mm, caliper units ≥ 12 or ≥ 157 kg; P ≤ 0.05). Higher body reserves at the end of gestation (caliper units ≥ 12, BFT ≥ 11.0 mm, or BCS ≥ 3.0) or weaning (caliper units ≥ 13, BFT ≥ 12.5 mm) negatively affected the ADFI in multiparous sows (P < 0.04). Weaned litter size ≤ 11 piglets (P = 0.06) and shorter lactation length (P< 0.01) decreased the ADFI in primiparous sows. Greater loss in caliper units during lactation tended to reduce ADFI in primiparous and multiparous sows (P ≤ 0.07). Multiparous sows with greater losses in BFT and BCS had lower ADFI (P ≤ 0.03). The ADFI during WEI is reduced when sows are in estrus or if they have greater body reserves.

IGF-1 concentrations after weaning in young sows fed different pre-mating diets are positively associated with piglet mean birth weight at subsequent farrowing

Pre-mating diets can influence piglet birth weight and within-litter birth weight variation and thereby piglet survival and development. The major objective of this study was to evaluate the litter characteristics of young sows whose pre-mating diets received different supplementation. The supplements included a top-dressing of 200 g, consisting of either wheat (CON) or wheat plus microfibrillated cellulose, L-carnitine or L-arginine at one of two supplementation levels (low and high) in late lactation and during the weaning-to-oestrus interval (WEI). The second objective was to investigate the role of body condition loss and IGF-1 concentration during the WEI for subsequent litter characteristics. In total, sows after their first (N =41) and second (N =15) lactation were used. One week before weaning, the sows were allocated to the seven treatments based on the number of piglets and BW loss from farrowing until 1 week before weaning. Pre-mating diets did not affect litter characteristics at subsequent farrowing. However, at subsequent farrowing, sows after their first lactation had a lower total number of piglets born per litter (18.3 v. 20.3), higher mean piglet birth weight (1365 v. 1253 g), lower CV of birth weight (20.0 v. 26.1%) and lower percentage of piglets <1000 g (11.5 v. 24.4%) than sows after their second lactation. Litter weight at second parturition was positively related to IGF-1 during the WEI after first lactation (P <0.04). Within parity, piglet mean birth weight was positively related to IGF-1 at oestrus (P <0.02). Surprisingly, within parity, a higher relative loin muscle depth loss during previous lactation was related to lower CV and SD of birth weight (P <0.05, for both). In conclusion, pre-mating diets did not affect litter characteristics at subsequent birth. However, a higher IGF-1 concentration during the WEI was positively associated with subsequent litter weight and piglet mean birth weight. Further studies should elucidate the role of IGF-1 during the WEI for subsequent litter characteristics and dietary interventions to stimulate IGF-1.

Causes of death of sows in three Brazilian pig farms

ABSTRACT: Sow mortality is directly related to financial losses and productive efficiency in pig farms. Despite this, diseases associated with the death of sows are poorly understood. This study aimed to determine the main causes of death of sows in Brazilian pig farms. To perform this research, three Brazilian pig farms were visited, and necropsies were performed on all sows that had died spontaneously or were subjected to euthanasia. Tissue fragments were collected for histopathological and bacteriological examination. In addition, the clinical signs, productive stage, parity, and type of death (spontaneous or euthanasia) were recorded. A total of 138 necropsies were performed, and 132 had a conclusive diagnosis. The most frequent productive stages were gestation and lactation (33.3 and 31.9%, respectively), followed by parturient sows (17.4%), cull sows (9.4%), weaning-to-estrus interval (WEI) (4.3%), and unmated gilts (3.6%). The most affected organ systems were reproductive (28%), digestive (25%), locomotor (22%), cardiovascular (9.1%), and hematopoietic (6.1%). The most frequently diagnosed conditions were uterine prolapse (16/132; 12.1%), gastric ulcer (13/132; 9.8%), suppurative arthritis (11/132; 8.3%), liver lobe torsion (11/132; 8.3%), heart failure (9/132; 6.8%), vaginal or vaginal and rectal prolapse (9/132; 6.8%), and pododermatitis (8/132; 6.1%). Although 58.2% of the deaths were due to one of these seven diseases, there was a great variability in diagnoses.

Equine chorionic gonadotrophin (eCG) after weaning in reproductive performance of sows from distinct parturition order

The weaning to estrus interval (WEI) and litter size are points that influences sow reproductive parameters and consequently the swine production. This study evaluated the effect of equine chorionic gonadotrophin (eCG), applied 5 hours after weaning, in sows of 1st to 5th parturition order (PO1-5) and sows with parturition order equal to or greater than 6 (PO6+) on reproductive parameters. PO1-5 sows (n = 240) were allocated into three groups: control group (n = 80), received 4 ml of saline solution; eCG800 group (n = 80), received 800 UI of eCG; and eCG1000 group (n = 80), received 1000 UI of eCG. PO6+ sows (n = 160) were allocated in control group (n = 80), receiving 5 ml of saline solution, and eCG1000 group (n = 80), that received 1000 IU of eCG. The estrous duration and litter parameters (mean weight, number of piglets per litter, number of live piglets, stillborn and mummified), insemination number and parturition order were evaluated. Chi-square test and analysis of variance with Tukey test were used in MIXED procedure of statistical package SAS (p < 0.05). An increased estrus duration and a mean increase of 1.5 piglets per litter was observed in eCG1000 group of PO1-5 sows, without affecting their mean weight. For PO6+ sows, the eCG1000 group was increased by one piglet per litter without interfering in the mean weight at birth. The economic analysis revealed a revenue of 400% of eCG investment in the PO1-5 sows, and 268% in the PO6+ group. It was concluded that the use of 1000 UI of eCG improves the reproductive parameters of sows of both (PO1-5 and PO6+) parturition orders.

Reproductive attributes of Hampshire, Gunghroo, Large Black and Tenyi Vo (local Naga Pig) under intensive management system in subtropical condition of Nagaland

Different reproductive attributes, viz. age at puberty, age at first mating, age at farrowing, litter size at farrowing, litter size at weaning, gestation period, weaning to estrus interval (WEI) and pre-weaning mortality were comparatively analysed in different breeds under intensive management system. Age at puberty, age at first mating and age at farrowing was significantly lower in Tenyi Vo pig compared to others breeds. Mean age of puberty varied from 185 days to 284 days. Age at first mating was recorded from 226 days in local Naga pig to 323 days in Hampshire. Age at first mating and age at first farrowing was significantly higher in Hampshire and Gunghroo breed as compared to Large Black and Tenyi Vo. Mean litter size at farrowing and weaning varied from 5 to 12 and 5 to 10, respectively. Litter size at farrowing and weaning was significantly higher in Large Black pig as compared to other breeds. Mean gestation period varied from 112 days in Gunghroo to 116 days in Tenyi Vo breed which differ significantly (P&lt;0.05). WEI was significantly higher in Large Black compared to other breeds. Pre-weaning mortality was highest in Tenyi Vo breed (32%) and lowest in Hampshire breed (13%). In the present study, reproductive performance of Large Black, Gunghroo and Hampshire breed was recorded to be superior to Tenyi Vo pig. Also, reproductive performance of Large Black was better than other breeds.

Effects of different amounts and type of diet during weaning-to-estrus interval on reproductive performance of primiparous and multiparous sows

During weaning-to-estrus interval (WEI), the sows are usually fed with high feed level to improve the reproductive performance. However, the WEI has been reduced over the years which may reduce the impact of feed level on performance in the modern genetic lines. The aim of this study was to evaluate the effect of two feeding levels (moderate feeding level (MFL): 2.7 kg/day and high feeding level (HFL): 4.3 kg/day) and two diet types (gestation: 13.67 MJ/kg of metabolizable energy (ME) and 0.62% of standard ileal digestible lysine (SID Lys) and lactation: 14.34 MJ ME/kg and 1.20% of SID Lys) offered during the WEI on reproductive performance. In total, 19.0% of sows were excluded from the analysis due to feed intake below 75% (9.6% and 28.5% in MFL and HFL groups, respectively), remaining 254 primiparous and 806 multiparous sows. Follicular size and change in BW were measured in subsamples of 180 and 227 females, respectively. Data were analyzed considering the sow as the experimental unit. Feeding level, diet type, parity and their interactions were included as fixed effects, whereas the day of weaning was considered as a random effect. The feed intake of MFL and HFL groups averaged 2.5 ± 0.02 and 3.8 ± 0.02 kg/day, respectively. There was an interaction between feeding level and parity for daily feed intake. Within HFL, multiparous sows consumed 181 g/day more than primiparous sows (P < 0.01), but no difference was observed within MFL (P > 0.05). Both primiparous and multiparous sows lost proportionally less weight when fed HFL than MFL gestation diet during WEI. The percentage of weight loss was lower in HFL than in the MFL group in multiparous sows fed the lactation diet. The WEI was not affected by feeding level, diet type or its interaction (P > 0.05), but it was longer in primiparous than in multiparous sows (P = 0.001). There was no effect of feeding level, diet type, parity or their interactions on anestrus and farrowing rates. Multiparous sows showed greater follicular size, and greater numbers of total born and born alive piglets in the subsequent cycle than primiparous sows (P < 0.05). In conclusion, feeding weaned primiparous and multiparous sows with 4.3 kg/day of a gestation (58.78 MJ ME and 26.66 g SID Lys) or a lactation diet (61.66 MJ ME and 51.60 g SID Lys) does not improve follicular size and reproductive performance in the subsequent cycle.

IGF-1 concentration patterns and their relationship with follicle development after weaning in young sows fed different pre-mating diets

Piglet birth weight and within-litter birth weight variation are important for piglet survival and growth. Pre-mating diets may improve IGF-1 and follicle development during the weaning-to-oestrus interval (WEI) and subsequent piglet birth weight. The objective of this study was to modulate IGF-1 concentration during late lactation and the WEI of young sows by using specific pre-mating diets supplemented with microfibrillated cellulose (MF), l-carnitine (LC) or l-arginine (AR). A further objective was to investigate the relationship between IGF-1 and subsequent follicle development and oestrus and ovulation characteristics. In total, 56 first-parity and 20 second-parity sows in three consecutive batches were used for this experiment. Sows received daily either wheat (CON) or wheat plus MF, LC or AR at one of two supplementation levels (low and high) during last week of lactation and WEI. From weaning onwards, follicle and corpus luteum (CL) diameters were repeatedly measured with ultrasound. Blood samples were collected during the WEI for IGF-1 and on day 21 of pregnancy for progesterone analyses, respectively. Insulin-like growth factor-1 concentration, follicle diameter, oestrus and ovulation characteristics and CL diameter were not affected by pre-mating diets. Low IGF-1 class (≤156 ng/ml, N = 22) sows had smaller follicles at weaning (3.5 v. 3.8 mm, P < 0.05) and a longer weaning-to-ovulation interval (147.2 v. 129.8 h, P < 0.05) than high IGF-1 class sows. In first-parity sows, high loin muscle depth (LM) loss sows (≥8%, N = 28) had lower IGF-1 concentrations at weaning (167 v. 214 ng/ml, P < 0.05) compared to low LM loss sows (<8%, N = 28). However, after weaning, IGF-1 concentrations increased and did not differ between high LM loss and low LM loss sows. In conclusion, the different supplemented compounds in pre-mating diets did not improve IGF-1 concentrations around weaning in young sows. Furthermore, high body condition loss caused lower IGF-1 concentrations at weaning, but these levels rapidly recovered after weaning and were related to follicle development and the interval from weaning to ovulation.

Phytogenic actives supplemented in hyperprolific sows: effects on maternal transfer of phytogenic compounds, colostrum and milk features, performance and antioxidant status of sows and their offspring, and piglet intestinal gene expression.

Phytogenic actives (PA) are plant-derived natural bioactive compounds that may promote livestock health and well-being, as well as improve growth performance and production efficiency. The current study aims to evaluate their effects on sows and their offspring. Eighty-one hyperprolific sows (up to parity 7) were assigned to 3 experimental treatments. Control sows were offered a nonsupplemented diet during gestation and lactation, and treated sows were fed the control diet supplemented with 1 g/kg of a blend of PA (BPA) in lactation (L) or during gestation and lactation (GL). An evaluation was made of placental and milk maternal transfer of these BPA and colostrum-milk features, sows and piglets antioxidant status, reproductive performance (litter size), body weight (BW) changes, weaning-estrus interval, and litter performance. Finally, piglet´s jejunum gene expression was measured. The BPA supplementation during gestation (GL) increased the number of piglets born alive (P = 0.020) and reduced (P < 0.05) the newborn piglets BW, while there were no differences among treatments on the suckling (day 20) and weaned (day 7) piglets BW (P > 0.05). Dietary phytogenic volatile compounds reached GL placental fluid, and milk of L and GL sows (P < 0.05). Moreover, colostrum protein in GL and milk fat content in L and GL were increased (P < 0.05). Milk of GL showed inhibitory activity against Bacillus subtilis and Staphylococcus aureus (P < 0.05). Antioxidant status of GL sows showed an enhanced (P < 0.05) of catalase (CAT) and total antioxidant capacity levels at early gestation (day 35), whereas higher levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) enzymes at late gestation (day 110). Likewise, GL newborn piglets showed higher CAT levels, whereas both CAT and SOD levels in suckling piglets, as well as CAT, SOD, and GSH-Px in weaned piglets, were increased in L and GL (P < 0.05). Jejunum messenger ribonucleic acid abundance of suckling piglets in L and GL groups showed overexpression of barrier function MUC2, digestive enzyme IDO, and immune response PPARGC-α, TNF-α, TGF-β1, and IL-10 genes (P < 0.05). In conclusion, dietary BPA supplementation in hyperprolific sows increased the litter size (born alive) and improved the composition and bioactivity of colostrum and milk, besides, modified the antioxidant status of sows and their offspring, as well as the suckling piglets gut health gene expression. Several BPA volatile compounds were prenatal and postnatal maternally transferred (placental fluid and milk).

Metabolomic Profiling Reveals the Difference on Reproductive Performance between High and Low Lactational Weight Loss Sows.

Sows suffering excess weight loss during lactation may delay weaning to estrus interval (WEI) and have a detrimental effect on subsequent reproductive performance, however, the underlying mechanism is not completely clear. Therefore, the goal of this study was to investigate physiological profiles manifested in plasma originating from high (HWL) and low lactational weight loss (LWL) sows. The plasma biochemical parameters, hormones, antioxidant parameters, and milk compositions were assessed. Furthermore, plasma metabolites were analyzed using ultrahigh-performance liquid chromatography/time-of-flight mass spectrometry in positive and negative ion modes. Results showed that HWL sows had a lower feed intake and higher lactational weight loss and prolonged WEI, but had similar litter performance and milk composition compared to LWL sows. These changes were associated with lower plasma insulin-like growth factor 1 and higher fibroblast growth factor 21 levels in the HWL sows. Moreover, HWL led to a severe oxidative stress and metabolic damage, as accompanied by excessive protein breakdown and lipids mobilization at weaning. Metabolomic analysis revealed differences in 46 compounds between HWL and LWL sows, and the identified compounds were enriched in metabolic pathways related to amino acids metabolism, fatty acids oxidation metabolism, bile acids biosynthesis, and nucleoside metabolism. These results provide the evidence for physiological mechanism in sows with excessive lactational weight loss that delayed the WEI. Metabolomic data provides essential information and gives rise to potential targets for the development of nutritional intervention strategies.

Gruel creep feed provided from 3 days of age did not affect the market weight and the sow's catabolic state

The provision of a suitable, high-quality starter diet to piglets has been described as a potential tool to minimize effects on the sow's catabolism during lactation and decrease the lag time between weaning and first feed intake at the nursery stage. This study aimed to determine the effects of gruel creep feed on (1) the piglets' performance from pre-weaning to finishing and (2) the sows' catabolism during lactation and its subsequent reproductive performance. Sixteen hybrid sows were selected according to parity, and were allotted in three treatments: control (CON, n = 5) only maternal milk without creep feed; dry creep feed (DCF, n = 5) maternal milk + dry creep feed; gruel creep feed (GCF, n = 6) maternal milk + gruel creep feed. The treatment was randomly assigned to a litter from day 3 post-farrowing until weaning. The experimental unit pre-weaning was considered the litter. After weaning, the cages with four piglets were considered the experimental units. The sows' catabolism was measured weekly through body weight and backfat losses during the lactation, associated with plasma metabolites parameters. Weaning-to-estrus interval (WEI) and estrus duration were used to measure reproductive performance after weaning. A total of 136 piglets had the body weight (BW) and feed intake measured at birth and on days 7, 14 and 21 (maternity period); 35, 49 and 63 (nursery period) and 104 and 133 (growing and finishing period) to calculate the average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR). On day 14 and 28, six piglets by treatment were randomly euthanized to analyze of intestinal morphometry. Sows had similar (P > 0.05) body weight and backfat loss during the lactation among the treatments. Also, the plasma metabolites were similar, except BHB was higher in GCF sows than in the other groups (P < 0.05). Feed: gain ratio and ADFI at 3–7 d were greater in GCF than in DCF piglets. In the other traits of piglets' performance differences were not observed. The coefficient of variation of birth weight and weaning weight were no statistical differences among treatments. At d133, there was higher variability in weight of GCF animals in comparison with control group, and DCF animals were similar to other treatments (P < 0.05). Besides, at 28 days in the ileum, the lower villus height: crypt depth ratio (VH: CD) was observed (P < 0.05) in GCF in comparison to CON and, low crypt depth (CD) was observed for CON piglets related the other treatments (P < 0.05). In conclusion, creep feed provided to piglets did not influence on the piglets' performance from pre-weaning to finishing and was not able to enhance sows' reproductive performance.

Addition of cactus (Opuntia ficus-indica) to the diet of lactating sows: effect on feed intake and productive behavior according to farrowing number

Metabolic factors that affect sows during lactation, such as blood glucose (BG) increase and insulin resistance, lead to decreased feed intake and negatively affect productive performance of sows. Cactus could be an unconventional strategy for regulating the glycolytic pathway, mitigating resistance to insulin. This research aimed to investigate the effect of cactus [Opuntia ficus-indica (L.) Mill.] addition to the diet of lactating sows on feed intake and productive performance, according to farrowing number (FN). Seventy-two pregnant hybrid sows were analyzed over a 12-month period. Sows entered the maternity ward in groups of six per month; they were divided into two groups: 1) control (CG; n=36), with sows fed conventionally; and, 2) experimental (EG; n=36), where sows were provided with commercial feed plus cactus (1.7±0.6 kg average fresh base day(‑1)). Response variables included blood glucose (BG), daily feed intake (DFI), total feed intake (TFI), loss of body weight (LBW), weaning-estrus interval (WEI), and subsequent litter size (SLS). The lowest (p<0.05) pre-prandial BG levels were for the EG with 55.5±8.5 vs. 70.5±8.4 mg dL(‑1) for the CG. DFI and TFI were higher for EG sows. The greatest LBW was for the CG (12.0%). Sows from the EG showed significantly lower WEI (5.5 days, p<0.05) compared to the CG (6.1 days) and higher SLS, up to 1.8 more piglets (p<0.05). Addition of cactus to the diet of lactating sows reduced BG levels during lactation, which had a positive impact on their productivity, presenting as higher DFI, lower LBW and WEI, and higher SLS.

Effect of optimizing dietary valine-to-lysine ratio in late gestation or lactation on biochemical indices and performance of lactating primiparous sows

A study was conducted to investigate the effect of optimizing valine-to-lysine ratio by dietary supplement with valine (Val) in late gestation (starting on day 85) or lactation on biochemical indices and lactation performance. Sixty pregnant gilts (Yorkshire × Landrace) were randomly allocated to one of four treatments in a 2 × 2 factorial experimental design, where the factors were supplementation with L-Val (optimizing total valine: lysine to 0.87:1) or with L-alanine (Ala, isonitrogenous control) in late gestation and/or lactation. The diets contained 14.02 MJ of ME/kg energy and 203.1 g/kg to 203.3 g/kg crude protein (CP), were fed at 2 kg daily during late gestation and ad libitum during lactation. Feeding the Val-supplemented diet compared with control during late gestation improved the weaning body weight (BW) and of sucking piglets (P < 0.05), and a marked increase in maternal feed intake (P < 0.05); there were no differences in backfat loss, weaning-to-estrus interval (WEI) or biochemical variables. With Val-supplementation of the lactation diet, weaning BW of sucking piglets and BW gain of litters were greater than the controls (P < 0.05). Improvement of milk fat (day 7 to day 14 of lactation), milk protein (day 7 of lactation) and non-fat solids (day 7 to day 14 of lactation) were noted from the sows fed Val-supplemented diet during lactation (P < 0.05). On day 14 of lactation, plasma concentrations of free Val and prolactin in sows and concentrations of some free amino acids (AA) in milk were greater (P < 0.05), and plasma glucose was lower (P < 0.05), in response to Val supplementation during lactation. There was no gestation × lactation Val interaction on the performance of sows and their suckling piglets. Collectively, results indicate the beneficial effects of optimizing the total dietary Val: Lys to 0.87:1 in late gestation and lactation on improving the performance of lactating sows.

Factors affecting estrus and ovulation time in weaned sows with induced ovulation by GnRH administration in different seasons.

Follicle development in post-weaning sows is influenced by various factors. To control ovulation time using hormone, factors that influence ovulation should be investigated. The present study was performed to evaluate the effect of GnRH (buserelin) administration in relation to season and sow parameters on ovulation time in weaned sows. Seventy-seven weaned sows were divided into the following groups: control (hot season, n=21; cool season, n=16) and treatment (hot season, n=22; cool season, n=18). Sows were kept in a close house equipped with an evaporative cooling system. Ovulation time was determined every 6 hr using transrectal ultrasonography. Administration of 10 µg buserelin at 72 hr after weaning affected estrus-to-ovulation interval (EOI) and weaning-to-ovulation interval (WOI) in sows (P<0.05). The percentage of sows that ovulated between 44–56 hr after injection was higher in the cool season than in hot season (P<0.05). Weaning-to-estrus interval (WEI) and injection-to-estrus interval (IEI) were affected by season (P<0.05). Body condition score (BCS) of sows influenced EOI (P<0.01). Sows with low backfat thickness, lactation length <20 days, or litter weight ≥67 kg, had delayed injection-to-ovulation interval (P<0.05). In conclusions, buserelin administration (10 µg, at 72 hr after weaning) advanced ovulation. Hot season prolonged ovulation time. Sows that were weaned with lactation length of at least 20 days, litter weight less than 67 kg, or BCS of at least 3, had better responses to buserelin injection. High backfat reserve after weaning is important for ovulation induction response by buserelin injection.

The effect of feeding different glycerol sources on the performance of lactating sows

Glycerol is a by-product of the biodiesel industry and it might be a good alternative to moderate the energy deficiency of sows during the lactation period. Preliminary experiments were carried out to test the effect of a powder, solid based “food grade” glycerol source with 72.9% glycerol content (Trial 1) and a liquid “feed grade” glycerol source with 86% glycerol content (Trial 2) on the performance of lactating sows and their litters. Trial 1 was conducted with 5 Hungarian Large White×Hungarian Landrace sows/treatment (313±24.9 kg) and Trial 2 with 12–12 DanAvl (323±17.0 kg) sows and their litters/treatment. Neither the solid, powder based glycerol (Trial 1), nor the liquid glycerol source (Trial 2) had significant effect on the feed intake, reduction in live weight and back-fat thickness, and weaning-tooestrus interval (p&gt;0.05) of lactating sows. In Trial 2, on the 14th, 21st and 27th days of lactation the milk samples were collected and it was found that 50 kg/t glycerol decreased the protein content of milk samples (p&lt;0.05). Glycerol supplementation had no effect on dry matter, fat, lactose content of milk samples (p&gt;0.05). In Trial 2, no significant difference was found between control and experimental sow groups in triglyceride concentration of blood samples and in the activity of liver enzymes (ALT, AST, GGT; p&gt;0.05), but the concentration of plasma glucose and cholesterol increased tendentiously (p&lt;0.10).&#x0D; Based on our preliminary results, it can be concluded that additional dose trials are needed to perform in order to study the effect of glycerol supplement on milk production and on metabolic processes of lactating sows.

Arginine improves nutritional quality of sow milk and piglet performance

ABSTRACT The objective of this study was to evaluate the effect of L-arginine supplementation in lactation diets on the productive and reproductive performance of pluriparous sows and their litters. Seventy-six sows of the same genetic line were assigned to four treatments in a completely randomized design with 19 replicates. The experimental unit was the sow and its respective litter. Treatments comprised a control diet (no L-arginine supplementation) and other three diets obtained by top dressing the control diet with 0.5, 1.0, and 1.5% of L-arginine. L-arginine supplementation had no effect on any performance variables, body condition, milk production, or weaning-estrus interval. There was a quadratic effect on percentage of protein and fat in milk as well as on the daily production of these components. Protein and fat percentage declined during lactation. Adding L-arginine to the diet had a quadratic effect on piglet weight at 13 and 21 days, the optimal level of L-arginine supplementation being estimated as 0.64% and 0.71%, respectively. L-arginine supplementation had a quadratic effect on the weight gain of piglets during the first 13 days and on total period of lactation, the optimal level of L-arginine supplementation being estimated as 0.60% and 0.70%, respectively. Supplementing lactation diets with 0.70% of L-arginine, corresponding to 45 g day−1, improves the weight gain of piglets by improving the nutritional quality of sow milk.