Feeding sorghum ergot (Claviceps africana) to sows before farrowing inhibits milk production

Objective To assess the impact of feeding different amounts of sorghum ergot to sows before farrowing. Design Fifty‐one pregnant sows from a continually farrowing piggery were sequentially inducted into the experiment each week in groups of four to seven, as they approached within 14 days of farrowing. Diets containing sorghum ergot sclerotia within the range of 0 (control) up to 1.5% w/w (1.5% ergot provided 7 mg alkaloids/kg, including 6 mg dihydroergosine/kg) were randomly allocated and individually fed to sows. Ergot concentrations were varied with each subsequent group until an acceptable level of tolerance was achieved. Diets with ergot were replaced with control diets after farrowing. Post‐farrowing milk production was assessed by direct palpation and observation of udders, and by piglet responses and growth. Blood samples were taken from sows on three days each week, for prolactin estimation. Results Three sows fed 1.5% ergot for 6 to 10 days preceding farrowing produced no milk, and 87% of their piglets died despite supplementary feeding of natural and artificial colostrums, milk replacer, and attempts to foster them onto normally lactating sows. Ergot inclusions of 0.6% to 1.2% caused lesser problems in milk release and neo‐natal piglet mortality. Of 23 sows fed either 0.3% or 0.6% ergot, lactation of only two first‐litter sows were affected. Ergot caused pronounced reductions in blood prolactin, and first‐litter sows had lower plasma prolactin than multiparous sows, increasing their susceptibility to ergot. Conclusion Sorghum ergot should not exceed 0.3% (1 mg alkaloid/kg) in diets of multiparous sows fed before farrowing, and should be limited to 0.1% for primiparous sows, or avoided completely.     

Early harvest and ensilage of forage sorghum infected with ergot (Claviceps africana) reduces the risk of livestock poisoning

Sorghum ergot produces dihydroergosine (DHES) and related alkaloids, which cause hyperthermia in cattle. Proportions of infected panicles (grain heads), leaves and stems were determined in two forage sorghum crops extensively infected 2 to 4 weeks prior to sampling and the panicles were assayed for DHES. Composite samples from each crop, plus a third grain variety crop, were coarsely chopped and half of each sealed in plastic buckets for 6 weeks to simulate ensilation. The worst-infected panicles contained up to 55 mg DHES/kg, but dilution reduced average concentrations of DHES in crops to approximately 1 mg/kg, a relatively safe level for cattle. Ensilation significantly (P = 0.043) reduced mean DHES concentrations from 0.85 to 0.46 mg/kg.     

Sorghum ergot (Claviceps africana) associated with agalactia and feed refusal in pigs and dairy cattle

OBJECTIVE: To establish the aetiology and define the main clinical features of a syndrome characterised by severe feed refusal, death of piglets and reduced milk production in pigs and dairy cattle. DESIGN: Clinical, pathological, toxicological and epidemiological examination of clinical cases in 10 piggeries and 4 dairies, located between 50 and 150 km south-west of Rockhampton. RESULTS: All cases were associated with the feeding of sorghum grain infected with sorghum ergot (Claviceps africana). There was mild to severe feed refusal when the sorghum was first offered. Sows fed ergot before farrowing had shrunken udders, produced no colostrum, and displayed signs of oestrus. All of their piglets died, apparently from starvation: necropsy of a few piglets showed that they were born alive and walked, but had ingested no milk. Sows fed the grain after farrowing had severe reductions in milk production despite aggressive sucking by piglets, leading to very poor growth of piglets. There were no signs of infectious disease. Ergot in sorghum samples ranged from 1 to 31% ergot sclerotes by weight. Total alkaloid concentrations in mixed feeds ranged from 5 to 40 mg/kg, with dihydroergosine accounting for approximately 90%. At the same time, in the same districts, there were reports of feed refusal and reduced milk production from 4 dairy farms. Grain samples from these farms contained up to 17% C africana ergot sclerotia. CONCLUSION: Agalactia and feed refusal are classical signs of poisoning by rye ergot (C purpurea), but this is the first time that sorghum ergot has been associated with a similar syndrome.     

Effect of feeding dried distillers' grains with solubles on milk yield and milk composition of cows in mid‐lactation and digestibility in sheep

We evaluated the effect of three sources of dried distillers' grains with solubles (DDGS) in diets of mid‐lactating dairy cows on milk production and milk composition and on digestibility in sheep. DDGS from wheat, corn and barley (DDGS₁), wheat and corn (DDGS₂) and wheat (DDGS₃) were studied and compared with a rapeseed meal (RSM). RSM and DDGS were characterized through in situ crude protein (CP) degradability. Nutrient digestibility was determined in sheep. Twenty‐four multiparous cows were used in a 4 × 4 Latin square design with 28‐day periods. Treatments included total mixed rations containing as primary protein sources RSM (control), DDGS₁ (D1), DDGS₂ (D2) or DDGS₃ (D3). RSM contained less rapidly degradable CP (fraction a), more potentially degradable CP (fraction b) and more rumen undegradable CP (UDP) than the three DDGS. In vivo digestibility of RSM organic matter was similar to DDGS. Calculated net energy for lactation (NE_L) was lower for RSM (7.4 MJ/kg DM) than for DDGS, which averaged 7.7 MJ/kg DM. Cows' dry matter intake did not differ between diets (21.7 kg/day). Cows fed D1 yielded more milk than those fed D3 (31.7 vs. 30.4 kg/day); no differences were found between control and DDGS diets (31.3 vs. 31.1 kg/day). Energy‐corrected milk was similar among diets (31.2 kg/day). Diets affected neither milk fat concentration (4.0%) nor milk fat yield (1.24 kg/day). Milk protein yield of control (1.12 kg/day) was significantly higher than D3 (1.06 kg/day) but not different form D1 and D2 (1.08 kg/day each). Feeding DDGS significantly increased milk lactose concentration (4.91%) in relation to control (4.81%). DDGS can be a suitable feed in relation to RSM and can be fed up to 4 kg dry matter per day in rations of dairy cows in mid‐lactation. However, high variation of protein and energy values of DDGS should be considered when included in diets of dairy cows.     

Effect of intracerebroventricular injections of prolactin‐releasing peptide on prolactin release and stress‐related responses in steers

Some evidence suggests that there might be a species difference in the effect of intracerebroventricularly administered (ICV) prolactin‐releasing peptide (PrRP) between rodents and sheep. We compared the levels of cortisol (CORT) and prolactin (PRL), rectal temperature (RT) and behavioral responses to ICV bovine PrRP (bPrRP) in steers. ICV bPrRP (0.2, 2 and 20 nmol/200 µL) tended to evoke a dose‐related increase in CORT concentrations and 0.2 nmol of bPrRP induced transient increase in PRL concentrations. A significant time–treatment interaction was observed for the percent change of CORT (P < 0.05) and PRL (P < 0.05) from pre‐injection value. The time–treatment interaction for changes in RT was not significant (P = 0.50). There tended to be a difference among the four treatments in terms of maximum change in RT from the pre‐injection value between 0 and 90 min (P < 0.1). Stress‐related behavioral signs were not observed in the present experiment. These findings indicate that ICV bPrRP increased CORT and PRL levels, suggesting that central PrRP might participate in controlling the hypothalamo‐pituitary‐adrenal axis and PRL release in cattle, unlike sheep. In contrast, central PrRP is unlikely to be involved in controlling the behavior of this species because ICV bPrRP did not induce marked changes in their behavior.     

Effect of fructose consumption during lactation on sow and litter performance and sow plasma constituents

The effects of dietary consumption of high-fructose corn syrup (HFCS) and dextrose during a 28-d lactation on sow and litter performance and sow plasma constituents were examined in 45 multiparous and 36 primiparous crossbred sows. Isocaloric and isonitrogenous corn-soybean meal diets were formulated to contain either 20% fructose or 20% glucose. Diets were fed on a metabolic BW basis from d 0 to d 28 of lactation. Litter and pig weights on d 28 were not affected (P greater than .05) by treatment. Litter size was greater (P less than .10) at weaning for primiparous sows fed HFCS, but multiparous sows weaned heavier (P less than .05) pigs. Sow weight change during lactation was not influenced by diet, but primiparous sows lost more (P less than .05) weight during lactation and had longer intervals to estrus than multiparous sows did. Milk yields on d 17 and 21 of lactation were not different (P greater than .05) for sows fed HFCS vs dextrose, but sows fed HFCS tended to have greater (P = .05) percentage of milk fat. Preprandial concentrations of fructose in plasma were low in sows fed HFCS and nondetectable in those fed dextrose but were elevated (P less than .05) after consumption of HFCS. Conversely, similar (P greater than .05) concentrations of glucose in plasma preprandially were followed by greater (P less than .05) postprandial glucose concentrations in sows fed dextrose. Although postprandial concentrations of insulin were not affected (P greater than .05) by diet, sows fed dextrose had greater (P less than .05) preprandial insulin concentrations in plasma. Concentrations of nonesterified fatty acids and growth hormone in plasma and response to a glucose challenge were not affected (P greater than .05) by feeding HFCS. However, concentrations of insulin in plasma following glucose infusion were less (P less than .05) during the glucose challenge period on d 25 than on d 13 of lactation.     

母猪妊娠期背膘厚度对仔猪均匀度及繁殖性能的影响

为研究母猪不同阶段的背膘厚度与仔猪均匀度及部分繁殖性能之间的关系,试验采用二次项回归拟合的方法,对9458头纯种长白母猪和13317头纯种大白母猪的分娩、背膘厚度进行分析。结果表明:母猪背膘厚度处于合理的范围有利于提高其产仔性能和窝产仔均匀度,母猪过肥和过瘦均不利母猪繁殖效率的提高。该场的长白母猪配种当天、妊娠30日龄、妊娠80日龄和妊娠105日龄背膘厚度分别为14.0~18.0mm、15.0~20.0mm、16.0~20.0mm、17.0~20.0mm更有利于仔猪均匀度及母猪繁殖性能的提高;该场的大白母猪配种当天、妊娠30日龄、妊娠80日龄和妊娠105日龄背膘厚度分别为13.0~16.0mm、14.0~17.0mm、15.0~18.0mm、15.0~19.0mm更有利于仔猪均匀度及母猪繁殖性能的提高。妊娠期间的背膘厚度对仔猪均匀度及繁殖性能有一定影响,但母猪产仔性能最好的背膘状态并不是产仔均匀度最佳值。     

Effect of protein and energy intake by primiparous sows during lactation on sow and litter performance and sow serum thyroxine and urea concentrations

The effects of protein and energy intakes by primiparous sows during a 28-d lactation on thyroxine (T4) and urea concentrations in blood serum of sows, and sow and litter performance were examined in two experiments. Dietary treatments were protein intakes of 380 (LP) and 760 (HP) g of crude protein X sow-1 X d-1 and energy intakes of 8 (LE) and 16 (HE) Mcal of metabolizable energy (ME) X sow-1 X d-1 in a 2 X 2 factorial arrangement. In Exp. 1 (34 sows), neither protein nor energy intake affected serum T4 concentrations. In both experiments, serum urea concentrations during lactation were influenced by both protein (P less than .001) and energy (P less than .001) intakes. In Exp. 2 (221 sows), sows fed LP or LE lost more weight (P less than .001) during lactation than sows fed either HP or HE. Backfat loss was greater (P less than .001) in sows fed diets of LE than HE, whereas sows fed HP lost more backfat (P = .016) than sows fed LP. Pig weights on d 28 were influenced by both protein (P less than .001) and energy (P = .038), with sows that were provided high intakes of either protein or energy having heavier pigs. Litter weight at weaning was heavier (P less than .005) for sows consuming HP. Sows fed LP had larger litters at d 14 (P = .051) and 28 (P = .046) than sows fed HP. Sow energy intake had no effect on litter size or weight. Percentages of sows in estrus by 7, 14 and 35 d postweaning were higher (P less than .004, P less than .030 and P less than .060, respectively) for sows fed HP than LP, whereas sow energy intakes had no effect on the interval from weaning to first estrus.     

Effects of extracerebral dopamine on salsolinol‐ or thyrotropin‐releasing hormone‐induced prolactin (PRL) secretion in goats

The aim of the present study was to clarify the effect of extracerebral dopamine (DA) on salsolinol (SAL)‐induced prolactin (PRL) secretion in goats. An intravenous injection of SAL or thyrotropin‐releasing hormone (TRH) was given to female goats before and after treatment with an extracerebral DA receptor antagonist, domperidone (DOM), and the PRL‐releasing response to SAL was compared with that to TRH. DOM alone increased plasma PRL concentrations and the PRL‐releasing response to DOM alone was greater than that to either SAL alone or TRH alone. The PRL‐releasing response to DOM plus SAL was similar to that to DOM alone, and no additive effect of DOM and SAL on the secretion of PRL was observed. In contrast, the PRL‐releasing response to DOM plus TRH was greater than that to either TRH alone or DOM alone and DOM synergistically increased TRH‐induced PRL secretion. The present results demonstrate that the mechanism involved in PRL secretion by SAL differs from that by TRH, and suggest that the extracerebral DA might be associated in part with the modulation of SAL‐induced PRL secretion in goats.     

Effects of hypothalamic dopamine (DA) on salsolinol (SAL)‐induced prolactin (PRL) secretion in male goats

The aim of the present study was to clarify the effects of hypothalamic dopamine (DA) on salsolinol (SAL)‐induced prolactin (PRL) release in goats. The PRL‐releasing response to an intravenous (i.v.) injection of SAL was examined after treatment with augmentation of central DA using carbidopa (carbi) and L‐dopa in male goats under 8‐h (8 h light, 16 h dark) or 16‐h (16 h light, 8 h dark) photoperiod conditions. The carbi and L‐dopa treatments reduced basal PRL concentrations in the 16‐h photoperiod group (P < 0.05), while a reduction was not observed in the 8‐h photoperiod group. The mean basal plasma PRL concentration in the control group for the 8‐h photoperiod was lower than that for the 16‐h photoperiod (P < 0.05). SAL significantly stimulated the release of PRL promptly after the injection in both the 8‐ and 16‐h photoperiod groups (P < 0.05). PRL‐releasing responses for the 16‐h photoperiod were greater than those for the 8‐h photoperiod (P < 0.05). The carbi and L‐dopa treatments blunted SAL‐induced PRL release in both the 8‐ and 16‐h photoperiods (P < 0.05). These results indicate that hypothalamic DA blunts the SAL‐induced release of PRL in male goats, regardless of the photoperiod, which suggests that both SAL and DA are involved in regulating the secretion of PRL in goats.     

Effect of different feeding regimes on pre‐weaning growth rumen fermentation and its influence on post‐weaning performance of lambs

Influence of pre‐weaning live weight on post‐weaning growth performance was assessed on thirty‐nine 15‐day‐old Indian native lambs, randomly fed in three equal groups until 180 days of age. During pre‐weaning phase lambs were maintained under feeding regimen of grazing (C‐0; Control), grazing and ad lib creep mixture supplementation (C‐AL) or grazing, with ad lib creep mixture and milk replacer supplementation (C‐ALMR). Lambs were allowed to suckle respective dam in morning and evening till 90 days of age, and fed ad lib green leaves of Ailanthus excelsa after grazing. After weaning all lambs were maintained on grazing and ad lib finisher concentrates supplementation. Pre‐weaning performance of lambs in terms of weaning weight (17.2 kg), average daily gain (ADG; 154 g) and feed conversion ratio 3.73 was higher (p < 0.01) in C‐ALMR lambs but total gain and ADG were similar among three groups during post‐weaning phase. However, improved pre‐weaning plane of nutrition and growth rate increased (p < 0.01) finishing weight (FW) of lambs in C‐AL, 33 kg and C‐ALMR, 32 kg. Dry matter intake was significantly (p < 0.01) higher in C‐AL and C‐ALMR lambs due to combined effect of feeding. Rumen pH was lowest (p = 0.049) in C‐AL lambs. Rumen ciliate protozoa population (10⁴/ml) decreased in C‐ALMR lambs (4.3) but increased in C‐AL lambs (50.0) more so in C‐0 Lambs (19.8). Concentrate feeding of C‐AL lamb improved nutrient digestibility. Lambs of C‐0 group consumed more DM during post‐weaning phase that improved growth performance, while nutrient digestibility was not affected by pre‐weaning nutrition. Thus, pre‐weaning nutrition has significant influence on FW, however influence of milk replacer feeding on lamb growth need further studies.     

The effect of photoperiod and melatonin on plasma prolactin concentrations in female guanaco (Lama guanicoe) in captivity

The present study examined the effects of different photoperiods and melatonin treatment on plasma prolactin concentrations in guanacos, a South American camelid, in captivity. Fourteen adult female guanacos, not gestating or lactating and isolated from males, were studied. The control group was exposed to natural daylight, during short days (N = 7, 10L:14D) and long days (N = 7, 16L:8D). The treatment group (N = 7, 10L:14D) received melatonin implants every 23 days for 6 weeks during long days. Blood samples were taken at intervals of 1 week for 3 weeks, starting the third week of treatment. Prolactin concentrations were measured using competitive ELISA. Plasma concentrations of prolactin in non-lactating female guanacos have seasonal changes, with a higher concentration (p < .001) in short days (3.50 ± 2.24 ng/ml) than long days (1.10 ± 0.91 ng/ml). Melatonin treatment significantly decreases (p < .05) plasma concentrations of prolactin on the 21st day after the treatment. These findings are the first report of an endogenous circannual rhythm of plasma prolactin concentration and the action of melatonin treatment on prolactin secretion in this wild camelid.     

Effect of placenta feeding to sows on plasma biochemical composition and growth of their piglets

The objective of the present study was to investigate the effects on the plasma biochemical composition and growth of piglets of placenta‐fed sows. The experimental animals were a total of 21 sows (L × LW) of third parity, and each sow was suckled by 11 ± 1 piglets. Sows fed without placenta were considered as the control (C), treatment 1 (T1) were placenta‐fed from days 1–7 after farrowing and treatment 2 (T2) were placenta‐fed from day 7 before farrowing to day 7 after farrowing. Glucose of piglets was lower (P < 0.05) in T2 than C and T1 on day 10. Total cholesterol of piglets was higher (P < 0.05) in T2 than C on day 4. Fe of piglets was higher (P < 0.05) in T2 than C on days 4, 20 and 30. Unsaturated iron‐binding capacity was lower (P < 0.05) in T2 than C on days 4 and 30. Immunoglobulin G of piglets was higher (P < 0.05) in T1 and T2 than C on days 4 and 10. Daily gain of piglets was higher (P < 0.05) in T1 than C and T2 on day 4 when daily gain was calculated. Total daily gain increased (P < 0.05) by prolongation of placenta feeding period. The results indicate that feeding placenta to sows may improve the plasma biochemical composition and growth of their piglets.     

Evaluation of high nutrient diets and additional dextrose on reproductive performance and litter performance of heat‐stressed lactating sows

This study investigated the litter performance of lactating sows fed nutrient‐dense diets with or without dextrose at farrowing to weaning, during the summer with an average room temperature of 28.4°C. A total of 60 (13 first parity, 13 second parity, 19 third parity, and 15 forth parity) cross‐bred sows were assigned to three treatments. The three treatments were: standard diet (ST), high nutrient diet (HN; ST + 3% higher energy and 18.0% protein), and high nutrient diet plus dextrose (HND; 3% higher energy, 18.0% protein, and 5% dextrose). BW loss was reduced in the HND sows compared with the ST sows during lactation. The HN and HND sows had a higher piglet and litter weight at weaning. Also, the HND sows had the highest post‐prandial insulin levels at weaning and the shortest weaning‐to‐service interval (WSI). Serum LH was higher in the HND sows than the ST sows. The milk fat level was higher in the HND sows compared with the ST sows, but similar to the HN sows. In conclusion, these results suggest that it is possible to increase the blood insulin response by supplementing dextrose to a high nutrient diet, thus, improving WSI interval and litter growth during heat stress.     

Effects of L‐citrulline supplementation on heat stress physiology,lactation performance and subsequent reproductive performance of sows in summer

Lactating sows are susceptible to heat stress (HS). Part of the thermoregulatory response to HS is to increase peripheral blood flow, which is mediated in part by the vasodilator, nitric oxide (NO). Therefore, the aim of this experiment was to determine the effect of supplementation of L‐citrulline, a NO precursor, on symptoms of HS, lactation performance and subsequent reproductive performance of sows in summer. A total of 221 summer farrowing mixed parity sows were fed either a control diet or supplemented with 1% L‐citrulline upon entry to the farrowing house (6 ± 1.8 days for mean ± standard deviation [SD] before farrowing) until weaning (26 ± 1.5 days). The average daily minimum and maximum temperature in the farrowing house was 21.0 ± 1.88 and 29.2 ± 3.82°C (mean ± SD). Rectal temperature, respiration rate, and plasma and urinary nitrite and nitrate (NOx) of sows were measured on the 19th day post‐farrowing. Supplemental L‐citrulline in the diet did not affect the number of piglets born alive, feed intake of sows, body weight or backfat thickness of sows at weaning, or litter weight gain. L‐citrulline tended to reduce piglet pre‐weaning mortality rate from 18.6% to 15.6% (p = 0.058). L‐citrulline reduced the respiration rate of sows compared to the control diet at 17:00 hr (Time × Diet, p < 0.001); however, rectal temperature was not affected. L‐citrulline tended to increase urinary NOx concentrations (127 vs. 224 µM, p = 0.057) but not plasma NOx concentrations. L‐citrulline did not affect farrowing rate or number of piglets born alive in the subsequent parity. In conclusion, L‐citrulline supplementation reduced respiration rate of lactating sows and reduced piglet pre‐weaning mortality rate in summer. Whether the effects were due to a NO‐dependent mechanism requires further validation.     

Effects of addition of Aspergillus oryzae culture and 2‐hydroxyl‐4‐(methylthio) butanoic acid on milk performance and rumen fermentation of dairy cows

To investigate effects of Aspergillus oryzae culture (AOC) and 2‐hydroxy‐4‐(methylthio) butanoic acid (HMB) on milk performance and rumen fermentation of dairy cows. Sixty‐four multiparous Chinese Holstein cows were randomly allocated into four experimental diets: (i) Control diet; (ii) AOC diet: 5 g AOC/day per head; (iii) HMB diet: 25 g HMB/day; and (iv) AH diet: 5 g AOC plus 25 g HMB/day. Added HMB tended to increase the yield of milk protein (P = 0.06) and 3.5% fat‐corrected milk (P = 0.08) and milk fat content (P = 0.09). Milk fat yield (P = 0.03) and the contents of milk protein (P = 0.05) were increased by adding HMB. The cows fed on AOC diet had a tendency for higher body weight (BW) gain (P = 0.08). Addition of AOC, HMB and AH increased content of microbial protein (MCP) and total volatile fatty acids (VFA) (P < 0.01) in rumen fluid. Populations of rumen fungi, Fibrobacter succinogenes and Ruminococcus flavefaciens relative to total bacterial 16S rDNA (P ≤ 0.03) and activity of carboxymethylcellulase (CMCase) (P < 0.01) were increased with added AOC or HMB. It is inferred that added AOC or HMB can increase the contents of MCP and total VFA potentially by stimulating rumen microbe populations and CMCase activity.     

Effect of dosage and application mode of l‐carnitine on plasma lipid and egg‐yolk cholesterol of turkeys,hatchability of eggs and post‐hatch growth of their offsprings

The effect of dosage and application mode of l ‐carnitine on plasma lipid and egg‐yolk cholesterol of breeder turkeys, hatchability of eggs and post‐hatch growth response was investigated using 180 breeder hens. The hens were assigned to six dietary treatments in a 2 × 3 factorial arrangements of two application modes of l ‐carnitine (diet and drinking water) supplemented at 0, 50 and 100 ppm (mg/kg or mg/l) levels, respectively. Each treatment was replicated five times with six hens per replicate. Dietary inclusion of 50 ppm l ‐carnitine showed the lowest (p < 0.01) plasma total cholesterol (TC) and low‐density lipoprotein concentration (LDL). Breeder hens offered 50 ppm l ‐carnitine with no regard to application mode recorded the highest (p < 0.01) plasma high‐density lipoprotein (HDL). Hens offered 50 and 100 ppm l ‐carnitine irrespective of application mode also showed reduced (p < 0.01) egg‐yolk TC concentration at 32 weeks of age. Dietary supplementation of 50 ppm l ‐carnitine for breeder turkeys recorded the lowest (p < 0.01) egg‐yolk triglyceride (TG) at 40 weeks of age. Hens offered 50 ppm l ‐carnitine irrespective of application mode recorded the highest (p < 0.05) hen‐day egg production. Incidence of dead‐in‐shell also reduced (p < 0.05) with increasing dosage of l ‐carnitine. Dietary supplementation of 50 ppm and oral application in drinking water of 100 ppm l ‐carnitine for breeder turkeys resulted in highest (p < 0.05) egg fertility. Offsprings from breeder hens fed diets supplemented with l ‐carnitine recorded no post‐hatch mortality. Highest (p < 0.05) post‐hatch final live weight and weight gain was obtained with poults obtained from hens fed diet supplemented with 50 ppm l ‐carnitine. In conclusion, dietary supplementation of 50 ppm l ‐carnitine for turkey hens showed improved serum lipid profile, egg fertility, reduced dead‐in‐shell, egg‐yolk cholesterol and resulted in improved post‐hatch growth performance.     

Effects of dietary star anise (Illicium verum Hook f) supplementation during gestation and lactation on the performance of lactating multiparous sows and nursing piglets

Thirty‐two sows were allocated to four treatments to evaluate the effect of dietary star anise (SA) supplementation during gestation and lactation on the lactational performance of sows. At 85 days of gestation, sows were randomly allotted to one of two diets supplemented with 0.5% SA or basal diet. After farrowing, sows were further allotted to one of two lactation diets supplemented with 0.5% SA or basal diet. On a weekly basis, body weight (BW) of sows and piglets was measured. Blood and milk samples were obtained from the sows and piglets. Number of days from weaning to estrus, milk yield and feed intake were also recorded. Weight gain of piglets from sows fed the SA‐supplemented diet during lactation was greater between days 7 and 14, days 14 and 21 and the overall experimental period compared with control groups. Supplementation of SA during lactation improved weaning weight of piglets, milk yield and average daily feed intake (ADFI) of sows. The SA diet increased concentrations of insulin‐like growth factor‐1 (IGF‐1) in ordinary milk and prolactin (PRL) in serum of sows. In conclusion, this study has indicated the beneficial effects of dietary SA addition in improving the lactation performance of sows.     

Effects of temperature and temperature‐humidity index on the reproductive performance of sows during summer months under a temperate climate

Heat stress is known to influence sow reproduction, but it is unknown to which extent under temperate climates. Therefore, the impact of temperature and temperature‐humidity index (THI) on the reproductive performance of sows during summer months from 2009 to 2011 were studied. Reproductive parameters of 22 264 inseminations and 21 610 resulting farrowings of 22 German commercial farms were analyzed. Climatic records were available from the nearest weather station. Effects of temperature and THI at different periods of the reproductive cycle were estimated from May to September where temperatures were expected to influence climatic conditions indoors. High temperatures and THI values 5 days pre‐ and 14 days post‐breeding reduced litter size by 0.01 to 0.03 piglets (P < 0.05). Prior to farrowing, the number of liveborn piglets was reduced (P < 0.05) and of stillborns increased with rising climatic variables (P < 0.001). On the day of farrowing, reduced numbers of weaned piglets were observed when temperature and THI values were elevated (P < 0.05), but pre‐weaning mortality was not influenced (P > 0.05). In conclusion, even under temperate conditions adverse effects of climatic variables on the reproductive performance of sows are present. Thereby, the number of liveborn piglets can be considered as the most sensitive parameter to heat stress. Considering the impact of climate change and predicted heat waves, strategies to mitigate the impact of heat stress are necessary.