Chemical composition of yak colostrum and transient milk

The objective of this study was to assess the changes in the chemical composition of yak colostrum and transient milk. Samples were collected from 12 yaks on days 1, 2, 3, 4, 5, 6 and 7 post‐partum (PP). The gross composition, nitrogen fraction distribution, amino acid (AA) profile and fatty acid (FA) profile were analysed. All the components decreased rapidly during the first 3 days except lactose which increased. The ratio of whey protein to casein protein decreased from 46:54 to 17:83 during the first 7 days PP. The content of all the AAs decreased, while the percentages of eight essential AAs in protein of samples increased during the study period. Monounsaturated FAs and polyunsaturated FAs decreased in the first 7 days PP, whereas saturated FAs increased. In conclusion, the changes in chemical composition were remarkable during the first 3 days. The slight variations, happened during the transient period, are not negligible, which also should be taken into account in the development of yak colostrum supplements.     

Heat stress affects fecal microbial and metabolic alterations of primiparous sows during late gestation

Background: Heat stress(HS) jeopardizes intestinal barrier functions and augments intestinal permeability in pigs.However, whether HS-induced maternal microbial and metabolic changes in primiparous sows during late gestation remains elusive. We present here, a study investigating the fecal microbial and metabolic responses in late gestational primiparous sows when exposed to HS.Methods: Twelve first-parity Landrace × Large White F1 sows were randomly assigned into two environmental treatments including the thermoneutral(TN)(18–22 ℃; n = 6) and HS(28–32 ℃; n = 6) conditions. Both treatments were applied from 85 d of gestation to farrowing. The serum and feces samples were collected on d 107 of gestation,for analyses including intestinal integrity biomarkers, high-throughput sequencing metagenomics, short-chain fatty acid(SCFA) profiles and nontargeted metabolomics.Results: Our results show that HS group has higher serum Heat shock protein 70(HSP70), lipopolysaccharide(LPS)and lipopolysaccharide-binding protein(LBP) levels. The gut microbial community can be altered upon HS by usingβ-diversity and taxon-based analysis. In particular, the relative abundance of genera and operational taxonomic units(OTUs) related to Clostridiales and Halomonas are higher in HS group, the relative abundance of genera and OTUs related to Bacteroidales and Streptococcus, however, are lower in HS group. Results of metabolic analysis reveal that HS lowers the concentrations of propionate, butyrate, total SCFA, succinate, fumarate, malate, lactate, aspartate,ethanolamine, β-alanine and niacin, whereas that of fructose and azelaic acid are higher in HS group. These metabolites mainly affect propanoate metabolism, alanine, aspartate and glutamate metabolism, phenylalanine metabolism, β-alanine metabolism, pantothenate and CoA biosynthesis, tricarboxylic acid cycle(TCA) and nicotinate and nicotinamide metabolism. Additionally, correlation analysis between significant microbes and metabolites indicated that the HS-induced microbiota shift is likely the cause of changes of intestinal metabolism.Conclusions: Taken together, we reveal characteristic structural and metabolic changes in maternal gut microbiota as a result of late gestational HS, which could potentially provide the basis for further study on offspring gut microbiota and immune programming.     

五指山猪的泌乳性能及泌乳行为

为了研究五指山小型猪的泌乳性能及泌乳行为,试验测定了8头初产五指山母猪初乳(≤3d)常规成分含量、泌乳行为及第3、13、24和35d的泌乳量。结果表明:①五指山猪初乳(≤3d)中的脂肪、蛋白、乳糖和总固形物的含量分别为(6.64±0.56)%、(15.25±1.27)%、(1.99±0.15)%、(27.46±1.25)%。②随产后日龄的增加,母猪泌乳次数和泌乳持续时间逐渐减少,表现为泌乳次数第35日龄比第3和13日龄均少5.14次/d(P<0.05),且下午(12:00￣20:00)比晚上(20:00￣04:00)多1.46次(P<0.05);泌乳持续时间第24日龄显著短于第3日龄(P<0.05);日龄与日泌乳时段对泌乳次数和泌乳持续时间无显著交互作用(P>0.05)。③母猪分娩后0～35d的全期泌乳量和日平均泌乳量分别为31528.59g和900.82g,且第35日龄泌乳量显著高于第3和第24日龄泌乳量(P<0.05);日龄与日泌乳时段对泌乳量无显著交互作用(P>0.05);35d哺乳期内每窝仔猪每克初生体重日耗乳量0.94g,若以普通肉用型猪每窝每克初生体重日耗乳量0.50￣0.99g为参考值,则说明五指山母猪泌乳量充足。本试验结果表明,五指山母猪分泌的初乳干物质含量高、乳糖含量低,分娩后(35d泌乳期内)泌乳量能充分满足仔猪的维持和生长需要。     

Influence of energy and protein intake during lactation on body composition of primiparous sows

The effects of energy and protein intakes by 32 primiparous sows during a 28-d lactation on sow and litter performance and sow body composition and bone properties were examined. Dietary treatments were energy intakes of 8 (LE) and 16 (HE) Mcal of ME/d and protein intakes of 380 (LP) and 760 (HP) g of CP/d in a 2 x 2 factorial arrangement. Sows fed diets that were inadequate in either energy or protein lost more weight than did sows fed the HE-HP diet, but backfat losses were greater when energy intake was deficient than when protein was deficient. Carcass measurements were influenced in a similar manner, with energy intake affecting (P less than .001) backfat thickness and protein intake affecting (P less than .05) longissimus muscle area. Heart, kidneys and liver of sows fed LP diets weighed less (P less than .01) and contained less water and protein (P less than .05) than those of sows fed HP. Sows fed LE had heart, liver and viscera that weighed less (P less than .05) than those of sows fed HE. There was less fat (P less than .05) in the heart, lung, liver and viscera of sows fed LE than in those of sows fed HE. Carcass components of the supraspinatus muscle and standardized sections through the longissimus muscle and right shoulder weighed less (P less than .05) from sows fed LP rather than HP, and these components contained less water and protein. Sows fed the LE diets had less fat in the loin soft tissue section, right shoulder section and supraspinatus muscle than sows fed HE. Bone composition and strength were not influenced by dietary treatment. The composition of weight lost during lactation was diet-dependent. Sows fed diets that were deficient in protein but adequate in energy lost large amounts of protein from muscles and internal organs. Energy deficiency resulted primarily in fat loss.     

Nutritional plane and selenium supply during gestation affect yield and nutrient composition of colostrum and milk in primiparous ewes

The objectives were to investigate effects of nutritional plane and Se supply during gestation on yield and nutrient composition of colostrum and milk in first parity ewes. Rambouillet ewe lambs (n = 84, age = 240 ± 17 d, BW = 52.1 ± 6.2 kg) were allocated to 6 treatments in a 2 × 3 factorial array. Factors included Se [adequate Se (ASe, 11.5 μg/kg of BW) or high Se (HSe, 77.0 μg/kg of BW)] initiated at breeding, and nutritional plane [60 (RES), 100 (CON), or 140% (HIH) of requirements] initiated at d 40 of gestation. Ewes were fed individually from d 40, and lambs were removed at parturition. Colostrum was milked from all ewes at 3 h postpartum, and one-half of the ewes (n = 42) were transitioned to a common diet meeting lactation requirements and mechanically milked for 20 d. Colostrum yield was greater (P = 0.02) for HSe ewes than ASe, whereas CON had greater (P < 0.05) colostrum yield than RES and HIH. Colostrum Se (%) was greater (P < 0.01) for HSe than ASe. Colostrum from ewes fed HSe had less (P = 0.03) butterfat (%), but greater (P ≤ 0.05) total butterfat, solids-not-fat, lactose, protein, milk urea N, and Se than ASe. Colostrum from HIH ewes had greater (P ≤ 0.02) solids-not-fat (%) than RES, whereas RES had greater (P ≤ 0.04) butterfat (%) than CON and HIH. Colostrum from ewes fed the CON diet had greater (P = 0.01) total butterfat than HIH. Total solids-not-fat, lactose, and protein were greater (P < 0.05) in colostrum from CON than RES and HIH. Ewes fed HSe had greater (P < 0.01) milk yield (g/d and mL/d) than ASe, and CON and HIH had greater (P < 0.01) yield than RES. Milk protein (%) was greater (P ≤ 0.01) in RES compared with CON or HIH. Ewes fed HSe had greater (P < 0.01) milk Se (μg/g and mg/d) than ASe on each sampling day. Milk from CON and HIH ewes had greater (P < 0.01) total solids-not-fat, lactose, protein, and milk urea N than RES. Total Se was greater (P = 0.02) in milk from ewes fed the CON diet compared with RES. Somatic cell count and total somatic cells were greater (P ≤ 0.05) in milk from CON than RES. A cubic effect of day (P ≥ 0.01) was observed for milk yield (g and mL). Butterfat, solids-not-fat, lactose, milk urea N, and Se concentration responded quadratically (P ≤ 0.01) to day. Protein (%), total butterfat, and total Se, and somatic cells (cells/mL and cells/d) decreased linearly (P < 0.01) with day. Results indicate that gestational nutrition affects colostrum and milk yield and nutrient content, even when lactational nutrient requirements are met.     

Effect of transportation and relocation in post-weaning anoestrous primiparous sows

The object of this investigation was to study the clinical and endocrine responses to transportation and relocation in 8 post-weaning anoestrous sows. They had been anoestrous for at least 24 days after weaning before transportation/relocation was performed. Laparoscopy, performed at the beginning of the experiment, revealed that the ovaries contained many follicles (less than or equal to 6 mm in diameter), but no corpora lutea. Blood samples, taken before and after transportation/relocation, showed that LH activity was low at the beginning of the experiment and increased after transportation/relocation in the majority of the sows. Peripheral plasma concentrations of of oestradiol-17 beta increased 1-4 days after transportation/relocation in 6 out of 8 sows which was followed by oestrus and ovulation. Progesterone concentrations were also below the practical detection limit until the end of oestrus. This study has demonstrated that a change in environment by transportation and relocation can induce oestrus by increasing the LH activity in post-weaning anoestrous sows.     

Altrenogest and fat for summer breeding of primiparous sows

Delaying the onset of estrus after weaning and adding fat to the postweaning diet were studied for their effects on estrus and fertility in 232 crossbred primiparous sows on a commercial swine farm. Sows were assigned randomly to the following treatments after weaning in June, July, August, or September, 1983: 1) altrenogest (20 mg/d) was fed for 7 d after weaning (n = 76), 2) altrenogest was fed for 7 d plus .53 kg dried animal and vegetable fat product (.45 kg actual fat/d) for 14 d after weaning (n = 78), or 3) no treatment (controls, n = 78). While a similar proportion of sows came into heat after weaning (lactation length = 4 wk), sows fed altrenogest (14.4 +/- .2 d) returned to estrus about 9 d later (P less than .01) than controls (5.6 +/- .2 d). Serum progesterone concentration was assayed in blood samples collected from a subgroup (74%) of the cows not observed in estrus by 3 wk after weaning to determine possible causes of anestrus. If serum progesterone (greater than 5 ng/ml) was elevated, we assumed that sows had ovulated without expressing estrus (behavioral anestrus) or ovulated with undetected estrus (less overt estrus or error in estrous detection), whereas low progesterone (less than or equal to 5 ng/ml) indicated that sows were anovulatory. About 53% of the sows not observed in estrus across all treatments had luteal function, probably resulting from post-weaning ovulation. Incidence of anovulation without estrus was 47%. Farrowing rate was higher (P less than .05) for sows fed only altrenogest (64%) compared with controls (46%), but similar to fat supplemented, altrenogest-treated sows (52%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Antioxidant defence of colostrum and milk in consecutive lactations in sows

Background

Parturition is supposed to be related to oxidative stress, not only for the mother, but also for the newborn. Moreover, it is not clear whether consecutive pregnancies, parturitions, and lactations are similar to each other in regards to intensity of metabolic processes or differ from each other. The aim of the study was to compare dynamic changes of antioxidative parameters in colostrum and milk of sows taken during 72 h postpartum from animals in consecutive lactations. Activities of glutathione peroxidase (GSH-Px), glutathione transferase (GSH-Tr), and superoxide dismutase (SOD), and amount of vitamin A and C were measured. Healthy pregnant animals were divided into 4 groups according to the assessed lactation: A -1^st lactation (n = 10), B - 2^nd and 3^rd lactation (n = 7), C - 4^th and 5^th lactation (n = 11), D - 6^th - 8^th lactation (n = 8). The colostrum was sampled immediately after parturition and after 6, 12, 18 and 36 h while the milk was assessed at 72 h after parturition. Spectrophotometric methods were used for measurements.

Results

The activity of antioxidative enzymes and the concentration of vitamin A increased with time postpartum. The concentration of vitamin C was the highest between the 18th and 36th h postpartum.

Conclusions

Dynamic changes in the values of antioxidant parameters measured during the study showed that sows milk provides the highest concentration of antioxidants in the 2^nd and 3^rd and 4^th and 5^th lactation giving the best defence against reactive oxygen species to newborns and mammary glands.     

Plasma prolactin concentrations in mares and their neonates after oxytocin induction of parturition

Studies were undertaken to investigate the effects of oxytocin induction on prolactin release in term (Group II) and preterm (Group III) mares and to compare these effects to spontaneously foaling mares (Group I). Since physiological concentrations of prolactin in blood have not been measured in the neonatal foal, experiments were designed to monitor prolactin in the cord artery and jugular blood of the foals from all groups of mares. Although prolactin levels varied in term mares (Group I and II) during the last 11 days of pregnancy, an increase was observed between Day -6 and Day 0 (2.7 and 11.9 ng/ml respectively; P less than 0.1). The average concentration of prolactin over the last 4 days (Days -3 to 0) had increased by 40% when compared to the average concentration on Days -6, -5, and -4. These findings indicate a rising trend which appears to occur concomitantly with changes in concentrations of 2 mammary components tested, sodium and potassium. Prolactin concentrations did not significantly increase in term mares after oxytocin treatment or in spontaneously foaling mares. However, the preterm induced mares had higher prolactin concentrations during the first stage of labor (19.3 +/- 7.2 ng/ml) than prior to treatment with oxytocin (4.7 +/- 2.0 ng/ml; P less than 0.01). Levels of prolactin in all groups significantly declined by 20-min post-placental expulsion. For the first 30 min after birth, prolactin concentrations in foals from oxytocin-induced mares appeared to be 2-fold higher than those from spontaneously foaling mares. Thereafter, prolactin values declined to baseline values by 48 hrs. When comparing cord arterial plasma with cord venous plasma in each group, prolactin concentrations were similar. However, the average prolactin levels in both the cord artery and vein appeared higher (ave: 1.1 ng/ml) in Group II and III than in Group I (less than 0.5 ng/ml). From these results, the authors suggest that 1) prolactin may have a role in regulating mammary secretory products in mares just prior to parturition; 2) oxytocin may increase prolactin secretion in preterm induced mares; 3) oxytocin induction may have a short term effect to increase circulatory prolactin concentrations in neonates in utero regardless whether their dams were treated preterm or term.     

Relationship between body fat and postweaning interval to estrus in primiparous sows

Twenty-two primiparous Yorkshire sows were used to determine whether a minimal threshold of body fat exists below which the return to estrus is delayed. A second objective was to examine the relationship between body fat and interval from weaning to estrus in restricted-fed sows. During lactation (28 d), sows received 7, 9, 11 or 13 Mcal of ME daily to produce a range of sow body fatness at weaning. Intake of all dietary essentials except ME was similar for all sows. Litter size was adjusted to 10 pigs for all sows by d 3 postpartum. Each day from weaning to estrus, sows received 110 kcal ME per kg metabolic body weight plus 1,359 kcal ME per sow. Body fat was estimated at weaning and at first postweaning estrus by deuterium oxide dilution. Last rib backfat depth was determined ultrasonically 24 h postpartum and at weaning. Irrespective of dietary ME intake, percentage body fat at weaning (R2 = .24; P less than .05) and first postweaning estrus (R2 = .03; P greater than .50) accounted for only a small portion of variation in interval from weaning to estrus. Likewise, loss of backfat depth during lactation was not an accurate predictor of interval from weaning to estrus (R2 = .24; P less than .05). The low coefficients of determination (less than .25) suggest that body fat is a minor controller of postweaning interval to estrus. In contrast, dietary ME intake during lactation accounted for the largest portion of the variation (R2; = .48; P less than .01) in postweaning interval to estrus. We conclude that timing of postweaning estrus in primiparous sows is not dependent on a minimal threshold of body fat. Furthermore, effects of lactational ME intake on the postweaning interval to estrus are more pronounced than the effects of body fat.     

Traits affecting postweaning weight gain and feed intake of primiparous sows

Seventy-six primiparous Duroc and Landrace sows from two genetic lines with or without selection for improved sow productivity were used to identify sow traits that affect postweaning gain (positive or negative) and feed intake. Sows lost weight (P less than .01) and consumed less feed (P less than .01) during wk 1 postweaning (37 d) compared with wk 2, 3, and 4. Sows gained more weight during wk 2 and 3 (P less than .01) than during wk 4. Weekly feed consumption was similar during wk 2 and 4 and highest during wk 3 (P less than .05). Sow weight gain postweaning was predicted by sow weaning weight (P less than .01) and adjusted 21-d litter weight (P less than .05) during wk 1, wk 1 to 2, and wk 1 to 4 feeding periods. Feed consumption was best predicted by adjusted litter weaning weight (P less than .01), sow weaning weight (P less than .01), average backfat at farrowing (P less than .01), average backfat change (P less than .05), and adjusted 21-d litter weight (P less than .05). Feed intake was positively correlated (P less than .01; r = .77) and sow weight at breeding, farrowing, and weaning was negatively correlated (P less than .05; r = -.23, -.21, and -.26, respectively) with sow weight gain. Average backfat at weaning was negatively correlated (P less than .05) with gain and feed intake during each period. Adjusted 21-d litter weight and adjusted litter weaning weight were positively correlated with postweaning feed intake (P less than .05; r = .22 and .23, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of litter size on metabolic status and reproductive axis in primiparous sows

This study on primiparous sows was designed to 1) determine the impact of nursing a large litter on LH secretion and follicular development, and 2) investigate the metabolic adaptations by which milk yield increases with litter size. At farrowing, crossbred, primiparous sows were assigned to 1 of 3 experimental groups differing in litter size and feed allowance. Sows with 13 or 14 piglets (13AL, n = 7) were fed ad libitum. Sows with 7 piglets were fed ad libitum (7AL, n = 6) or were feed-restricted (7R, n = 8). The restriction was based on the estimated energy deficiency for the 13AL sows. On d 9 +/- 1 of lactation, a jugular catheter was surgically implanted. Serial blood samplings and glucose tolerance tests were performed in mid- and late lactation. Sows were slaughtered 3 d after weaning, and ovarian characteristics were recorded. During lactation, the 7AL sows lost no or little body reserves, and their estimated energy balance was near zero. The 13AL and 7R sows exhibited similar negative energy balances and similar losses of backfat and estimated lipid content. Litter growth rate was greater (P < 0.05) in the 13AL than in the 7AL and 7R groups. After weaning, the volume of the largest 14 follicles was smaller (P < 0.05) in sows nursing 13 or 14 piglets than in sows with 7 piglets. Plasma concentrations of LH and LH pulse frequency did not differ between groups (P > 0.1). The longer glucose half-life on d 16 than on d 27 of lactation (22.5 vs. 18.8 min; P < 0.05) indicated a lower glucose tolerance in mid- than in late lactation. The area under the insulin curve was greater in the 7AL than in the 13AL sows (P = 0.08) and intermediate in the 7R group, with no differences in glucose profiles. This led to the suggestion that the 7AL sows were more resistant to insulin than the 13AL sows. In all groups of sows, follicular development after weaning was correlated with LH secretion in midlactation. Active follicular development was associated with prolonged secretion of insulin in response to glucose challenge. Our results show that besides litter size, a sow's metabolic status in lactation influences follicular maturation after weaning and also indicate that the metabolic adaptations by which primiparous sows nursing large litters increase litter growth rate and body reserve mobilization do not involve an accentuated peripheral insulin resistance.     

Effects of dietary horse beans (Vicia faba) on colostrum and milk composition and milk yield in sows

In an experiment sows received 0, 17 and 34% horse beans in the diet. Horse beans replaced the protein mixture (soybean meal, fishmeal, and meat and bone meal) by one half or in full.The composition of colostrum was altered by the dietary horse beans. An increase in dietary horse beans significantly reduced dry matter contents (P ≤ 0.05) and protein contents (P ≤ 0.001). As to the various protein fractions, total whey protein and albumin showed the greatest decline (P ≤ 0.001), followed by immunoglobulin (P ≤ 0.01) and beta lactoglobulins (P ≤ 0.05). Casein and alpha lactalbumin contents were not altered significantly.The total fat content of colostrum was not influenced by dietary horse beans, but the percentages of C 18:1 increased (P ≤ 0.001) and C 18:2 decreased (P ≤ 0.001) with increasing amounts of horse beans in the diet.The effect of horse beans on the composition of sow milk was insignificant, although there was a tendency to higher dry matter and protein content in milk from sows fed diets without horse beans.Horse beans at both levels had a negative effect on milk yield (linear trend: P ≤ 0.05).     

Effects of postweaning dietary energy source on reproductive traits in primiparous sows

An experiment was conducted to study the effects of major dietary energy source fed from weaning to ovulation or from ovulation to d 35 of pregnancy on reproductive traits in primiparous sows. Dietary energy sources were used to manipulate the plasma insulin concentration. One hundred thirteen sows were used in a split-plot design. From weaning to ovulation sows were fed at two times maintenance either a diet with tallow (Fat) or maize starch plus dextrose (Starch) as the major energy source. From ovulation onward, sows within each dietary group were alternately reassigned to either the Fat or the Starch diet and were fed at 1.25 times maintenance. Estrus detection was performed three times a day from d 3 to 9 after weaning and sows were inseminated each day of standing estrus. On d 35 of pregnancy, the sows were slaughtered and their reproductive tracts were removed. Plasma insulin concentration was higher in sows fed the Starch-rich diet than in sows fed the Fat-rich diet on d 4 after weaning (1.30 vs 0.97 ng/mL, P = 0.08) and on d 32 of pregnancy (1.20 vs 0.51 ng/mL, P < 0.001). Plasma glucose and IGF-I concentration on d 4 after weaning and d 32 of pregnancy did not differ between sows on the two dietary energy sources. The percentage of sows exhibiting estrus within 9 d after weaning was 52 and 67% for the Fat and Starch diet before ovulation, respectively (P = 0.11), whereas the weaning-to-estrus interval was 134 vs 123 h, respectively (P = 0.12). Survival analysis showed that sows fed the Fat-rich diet had a 1.6 times higher risk to remain anestrous until d 9 after weaning than sows fed the Starch-rich diet (P = 0.04). No effect of dietary energy source, either before or after ovulation, on uterine, placental, or embryonal development on d 35 of pregnancy was found. It can be concluded that the dietary energy source provided after weaning can affect the risk of sows to remain anestrous but does not affect uterine, placental, or embryonic traits.     

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 induced parturition in goats on immunoglobulin G and chitotriosidase activity in colostrum and plasma and on plasma concentrations of prolactin

The effect of induction of parturition with a PGF(2)α analog on plasma concentration of prolactin (PRL) and its effects on colostrum concentration of IgG and chitotriosidase (ChT) activity were studied in 16 pregnant Majorera goats. Treated goats, those in which parturition was induced, had greater concentrations of PRL than control goats 24 h before parturition (P < 0.05) and 48 h after parturition (P < 0.05). Control goats had greater concentrations of PRL than treated goats 96 h after parturition (P < 0.05). Plasma concentration of IgG did not differ between groups during the experimental period, but colostrum concentrations of IgG were greater in control goats than in treated goats at parturition (P < 0.05). Plasma ChT activity decreased during the period 72 h before parturition to 24 h after parturition in control and treated goats. Time evolution after partum affected the colostrum ChT activity, being greater at parturition than after parturition in both groups (P < 0.05). In summary, concentration of IgG in colostrum is slightly diminished if parturition is induced. Induction of parturition causes an early increase in PRL, which is most likely responsible for preterm suppression of IgG transport into mammary secretions.     

Prostaglandin F2 alpha and prolactin in experimental hypogalactia in sows

Peripheral plasma concentrations of 13,14-dihydro-15-keto-prostaglandin F2alpha(PGFM), progesterone, prolactin and oestrone were determined in 20 sows for two days before and three weeks after parturition. Groups of four sows each received one of the following five treatments post partum: 30 ml sterile 0.9 per cent saline solution intrauterinely; ovariectomy and 30 ml saline solution intrauterinely; 10 ml Lugol's iodine plus 20 ml saline solution intrauterinely; ovariectomy and 10 ml Lugol's iodine plus 20 ml saline solution intrauterinely, or progesterone (0.5 mg [kg bodyweight]-1 intramuscularly). Saline solution and iodine were administered every 48 hours, starting immediately after parturition, for one week. Ovariectomy was performed within eight hours of delivery. Progesterone was given every third day for 12 days. Piglet weight gains were used as a reflection of milk yield. In all sows, oestrone values were elevated before parturition, but fell by the end of delivery and were very low during lactation. PGFM concentrations rose during the last two days of pregnancy to reach maximal values at the time of delivery. Plasma progesterone levels declined concomitantly with the rise in PGFM values before parturition. Basal values of progesterone were achieved within 24 hours after delivery in control sows receiving saline treatment. Progesterone values fell immediately after ovariectomy in sows receiving saline or iodine treatment but were slightly elevated for one week in sows that received only intrauterine iodine treatment, suggesting that complete regression of corpora lutea is prevented by suppression of post parturient uterine prostaglandin production. Sows injected with progesterone maintained plasma values of about 5 to 15 nmol litre-1.(ABSTRACT TRUNCATED AT 250 WORDS)