Production of Lambs After the Transfer of Fresh and Cryopreserved in vitro Produced Embryos from Prepubertal Lamb Oocytes and Unsorted and Sex-sorted Frozen-thawed Spermatozoa

Cumulus-oocyte complexes from hormone-stimulated 3-4-week-old (n=43) and 6-7-week-old (n=12) prepubertal lambs were matured in vitro and incubated with unsorted, or X- or Y-spermatozoa separated with a high-speed cell sorter (SX MoFlo)frozen-thawed. Presumptive zygotes were then cultured to the blastocyst stage, and transferred to recipients fresh or after cryopreservation (frozen). Oocyte cleavage was higher (p <0.05) with unsorted (515/926, 55.6%) than X- or Y-spermatozoa (261/672, 38.8% and 229/651, 35.2%, respectively) and blastocyst formation (% zygotes) by Day 9 of in vitro culture was lower (p <0.05) for X- (102/261, 39.1%) than unsorted spermatozoa (249/515, 48.3%), but did not differ between Y-spermatozoa (103/229, 45.0%) and unsorted spermatozoa, or between X- and Y-spermatozoa (p >0.05). For fresh embryos, survival to term was 50.0% (3/6) for unsorted, 0.0% (0/6) for X- and 16.7% (1/6) for Y-spermatozoa-derived embryos (p >0.05), and for frozen embryos was 4.0% (2/50) for unsorted, 9.1% (2/22) for X- and 2.9% (1/34) Y-spermatozoa-derived embryos (p >0.05). Of the two lambs born from X-spermatozoa-derived embryos, one was female (50%), and from the two Y-spermatozoa-derived lambs, both were male (100%), demonstrating that lambs can be produced after the transfer of fresh and cryopreserved IVP embryos derived from prepubertal lamb oocytes and frozen-thawed sex-sorted sperm.     

Evaluation of oral, subcutaneous, and nasal administration of Salmonella enteritidis-immune lymphokines on the potentiation of a protective heterophilic inflammatory response to Salmonella enteritidis in day-old chickens.

We have previously reported that the prophylactic administration of factor(s) from T-cell supernatants derived from Salmonella enteritidis-immune chickens (ILK) have a favorable effect in controlling or eliminating salmonellosis in neonatal poultry. Experimentally, we have used the intraperitoneal injection as the standard method of administering ILK to neonatal poultry. However, this method is neither easy, practical, nor economical for the poultry industry. In the present study, we evaluated the effectiveness of oral (p.o.), intranasal (i.n.), and subcutaneous (s.c.) administration of ILK for ease of delivery, induction of protective resistance against Salmonella enteritidis (Se) organ invasion, and the ability to activate peripheral blood heterophils in day-old chickens. In the first experiments, delivery of ILK p.o., i.n., and s.c. significantly (P < 0.01) increased the resistance of day-old chickens to Se organ invasion. The level of protection was equivalent to that induced by the i.p. route. Administration of a comparable protein control (bovine serum albumin, BSA) by the 3 routes induced no protective effect against Se organ invasion. Likewise, a significant increase was found in the number of circulating heterophils within 4 h of administration of the ILK by all routes. In the 2nd experiment, the function of the heterophils from ILK-treated birds was compared with that of the control cells in adherence, chemotaxis, and phagocytosis assays. The heterophils from birds given ILK i.p., s.c., p.o., or i.n. had significantly (P < 0.01) increased functional activities when compared to the activities of the heterophils from the control birds. These studies indicate that the delivery of ILK either orally or parenterally, routes which can be used by the poultry industry, can confer protection to chickens against a localized enteric Se organ invasion by potentiating the systemic heterophilic innate response.     

Changes in various metabolic parameters in blood and milk during experimental Escherichia coli mastitis for primiparous Holstein dairy cows during early lactation

Background:The objective of this study was to characterize the changes in various metabolic parameters in blood and milk during IMI challenge with Escherichia coli(E.coli) for dairy cows during early lactation.Thirty,healthy primiparous Holstein cows were infused(h = 0) with-20-40 cfu of live ? coli into one front mammary quarter at ~4-6wk in lactation.Daily feed intake and milk yield were recorded.At-12,0,3,6,12,18,24,36,48,60,72,96,108,120,132,144,156,168,180 and 192 h relative to challenge rectal temperatures were recorded and quarter foremilk was collected for analysis of shedding of E.coli.Composite milk samples were collected at-180,-132,-84,-36,-12,12,24,36,48,60,72,84,96,132 and 180 h relative to challenge(h = 0) and analyzed for lactate dehydrogenase(LDH),somatic cell count,fat,protein,lactose,citrate,beta-hydroxybutyrate(BHBA),free glucose(fglu),and glucose-6-phosphate(G6P).Blood was collected at-12,0,3,6,12,18,24,36,60,72,84,132 and 180 h relative to challenge and analyzed for plasma non-esterified fatty acids(NEFA),BHBA and glucose concentration.A generalized linear mixed model was used to determine the effect of IMI challenge on metabolic responses of cows during early lactation.Results:By 12 h,E.coli was recovered from challenged quarters and shedding continued through 72 h.Rectal temperature peaked by 12 h post-challenge and returned to pre-challenge values by 36 h post-IMI challenge.Daily feed intake and milk yield decreased(P 0.05) by 1 and 2 d,respectively,after mastitis challenge.Plasma BHBA decreased(12 h;P 0.05) from 0.96 ± 1.1 at 0 h to 0.57 ±0.64 mmol/L by 18 h whereas concentration of plasma NEFA(18 h) and glucose(24 h) were significantly greater,11 and 27%,respectively,after challenge.In milk,fglu,lactose,citrate,fat and protein yield were lower whereas yield of BHBA and G6 P were higher after challenge when compared to pre-challenge values.Conclusions:Changes in metabolites in blood and milk were most likely associated with drops in feed intake and milk yield.However,the early rise in plasma NEFA may also signify enhanced adipose tissue lipolysis.Lower concentrations of plasma BHBA may be attributed to an increase transfer into milk after IMI.Decreases in both milk lactose yield and%after challenge may be partly attributed to reduced conversion of fglu to lactose.Rises in G6 P yield and concentration in milk after challenge(24 h) may signify increased conversion of fglu to G6 P.Results identify changes in various metabolic parameters in blood and milk after IMI challenge with E.coli in dairy cows that may partly explain the partitioning of nutrients and changes in milk components after IMI for cows during early lactation.     

Influence of salinity on the energetics of gill and kidney of Atlantic salmon (Salmo salar)

The effect of seawater acclimation and adaptation to various salinities on the energetics of gill and kidney of Atlantic salmon (Salmo salar) was examined. Smolts and non-smolts previously reared in fresh water were exposed to a rapid increase in salinity to 30 ppt. Plasma osmolarity, [Na⁺], [Cl^–], [K⁺] and [Mg⁺⁺] increased in both groups but were significantly lower in smolts than non-smolts. Gill Na⁺, K⁺-ATPase specific activity, initially higher in smolts, increased in both groups after 18 days in seawater. Kidney Na⁺, K⁺-ATPase specific activity was not affected by salinity in either group. Gill and kidney citrate synthase specific activity was not affected by seawater exposure in smolts but decreased in non-smolts. In a second experiment, Atlantic salmon smolts reared in fresh water were acclimated to 0, 10 or 30 ppt seawater for 3 months at a temperature of 13–14°C. Gill Na⁺, K⁺-ATPase was positively correlated with salinity, displaying 2.5- and 5-fold higher specific activity at 10 and 30 ppt, respectively, than at 0 ppt. Kidney Na⁺, K⁺-ATPase specific activity was not significantly affected by environmental salinity. Citrate synthase and cytochrome c oxidase specific activities in gill were slightly (6–13%) lower at 10 ppt than at 0 and 30 ppt, whereas kidney activities were lowest at 30 ppt. Oxygen consumption of isolated gill filaments was significantly higher when incubated in isosmotic saline and at 30 ppt than at 0 ppt, but was not affected by the prior acclimation salinity. The results indicate that although high salinity induces increased gill Na⁺, K⁺-ATPase activity, it does not induce substantial increases in metabolic capacity of gill or kidney.     

Changes in various metabolic parameters in blood and milk during experimental Escherichia coli mastitis for primiparous Holstein dairy cows during early lactation

Background

The objective of this study was to characterize the changes in various metabolic parameters in blood and milk during IMI challenge with Escherichia coli (E. coli) for dairy cows during early lactation. Thirty, healthy primiparous Holstein cows were infused (h = 0) with ~20-40 cfu of live E. coli into one front mammary quarter at ~4-6 wk in lactation. Daily feed intake and milk yield were recorded. At –12, 0, 3, 6, 12, 18, 24, 36, 48, 60, 72, 96, 108, 120, 132, 144, 156, 168, 180 and 192 h relative to challenge rectal temperatures were recorded and quarter foremilk was collected for analysis of shedding of E. coli. Composite milk samples were collected at -180, -132, -84, -36, -12, 12, 24, 36, 48, 60, 72, 84, 96, 132 and 180 h relative to challenge (h = 0) and analyzed for lactate dehydrogenase (LDH), somatic cell count, fat, protein, lactose, citrate, beta-hydroxybutyrate (BHBA), free glucose (fglu), and glucose-6-phosphate (G6P). Blood was collected at -12, 0, 3, 6, 12, 18, 24, 36, 60, 72, 84, 132 and 180 h relative to challenge and analyzed for plasma non-esterified fatty acids (NEFA), BHBA and glucose concentration. A generalized linear mixed model was used to determine the effect of IMI challenge on metabolic responses of cows during early lactation.

Results

By 12 h, E. coli was recovered from challenged quarters and shedding continued through 72 h. Rectal temperature peaked by 12 h post-challenge and returned to pre-challenge values by 36 h post-IMI challenge. Daily feed intake and milk yield decreased (P <0.05) by 1 and 2 d, respectively, after mastitis challenge. Plasma BHBA decreased (12 h; P <0.05) from 0.96 ± 1.1 at 0 h to 0.57 ± 0.64 mmol/L by 18 h whereas concentration of plasma NEFA (18 h) and glucose (24 h) were significantly greater, 11 and 27%, respectively, after challenge. In milk, fglu, lactose, citrate, fat and protein yield were lower whereas yield of BHBA and G6P were higher after challenge when compared to pre-challenge values.

Conclusions

Changes in metabolites in blood and milk were most likely associated with drops in feed intake and milk yield. However, the early rise in plasma NEFA may also signify enhanced adipose tissue lipolysis. Lower concentrations of plasma BHBA may be attributed to an increase transfer into milk after IMI. Decreases in both milk lactose yield and % after challenge may be partly attributed to reduced conversion of fglu to lactose. Rises in G6P yield and concentration in milk after challenge (24 h) may signify increased conversion of fglu to G6P. Results identify changes in various metabolic parameters in blood and milk after IMI challenge with E. coli in dairy cows that may partly explain the partitioning of nutrients and changes in milk components after IMI for cows during early lactation.     

Device Applications of Side-Chain Ferroelectric Liquid Crystalline Polymer Films

Side-chain ferroelectric liquid crystalline polymers are currently used in a number of applications, including displays and electrical sensors. Comparisons with existing technologies and materials indicate that relative to ceramics, such polymers have lower figures of merit but offer greater durability in sensor applications.     

Acute post-parturient haemoglobinuria in dairy cows and phosphorus status

During the conduct of an experiment designed to examine the nutritional management of dairy cows in late pregnancy, four cows out of 72 suffered from acute haemoglobinuria two to four weeks after calving. Thirty-six thin and 36 fat cows were individually fed one of three diets based on a total mixed ration with different energy or protein concentrations during the last 3 to 4 weeks before expected calving date. After calving, cows grazed pasture and were offered 6 kg dry matter of pelleted concentrates daily. The P concentrations of the feeds offered suggested that the cows' diets were marginally deficient in P relative to requirements. Plasma P concentrations were significantly (P < 0.05) lower in fat cows than in thin cows during the first 6 weeks of lactation (0.87 versus 1.12 mmol/L), but precalving diet had no effect (P > 0.05). Concentrations of plasma inorganic P of the four fat cows that developed acute haemoglobinuria were less than 0.3 mmol/L. However, plasma P concentrations in another 12 cows, none of which displayed overt symptoms, declined to similar levels. It appeared that inadequate dietary P may have predisposed cows to acute haemoglobinuria, but the precipitating cause was not readily obvious.     

Impact of Distillery Effluent on Soil Carbon and Nitrogen Dynamics in a Vertisol of Central India

Distilleries produce a huge quantity of effluents, popularly known as spent wash (SW), which when bio-methanated produce post-methanation effluents (PME). A field experiment on soybean–wheat system was conducted for five consecutive years in a Vertisol of central India to evaluate the effect of distillery effluent (DE) on soil carbon and nitrogen dynamics. Ten treatment combinations consisting of control, 100% NPK + Farmyard Manure (FYM), and graded level of SW and PME were applied. Total carbon content of soil increased significantly with applications of FYM and DE. SW was found superior in enhancing carbon content of soil in comparison to PME. Farmyard Manure contributed more carbon toward the recalcitrant pool, whereas DE contributed more carbon toward the active and slow pool. Nitrogen (N) availability was significantly improved with the application of DE. Balanced application of DE may act as amendment for increasing C and N stocks in Vertisol.     

Factors associated with the risk of antibiotic residues and intramammary pathogen presence in milk from heifers administered prepartum intramammary antibiotic therapy

Heifers (n=136) from 5 herds were treated with a commercially available beta-lactam intramammary (IMM) antibiotic preparation containing cephapirin sodium at 10-21 d prior to anticipated parturition to evaluate the risk of antibiotic residues occurring in milk postpartum and to determine factors associated with antibiotic residues and IMM pathogen presence in milk postpartum. Mammary secretions collected from quarters before antibiotic administration and during weeks 1, 2 and 3 postpartum were analyzed for mastitis pathogens. Composite milk was collected at milkings 3, 6 and 10 postpartum and analyzed for beta-lactam residues using a microbial inhibition antibiotic residue screening test. Antibiotic residues were confirmed with beta-lactamase treatment and re-tested for residues. Residues were detected in 28.0, 8.82 and 3.68% of milk samples obtained at the third, sixth, and tenth milking postpartum, respectively. Increases in interval between prepartum antibiotic therapy and parturition and an increase in the postpartum interval to sampling were associated with a decrease in risk of antibiotic residues. The presence of antibiotic residues in milk at the third milking was associated with a reduced risk for IMM pathogen prevalence in the first 21 d postpartum. Lower somatic cell counts, an increase in mean milk yield over 200 days in milk and a reduction in IMM pathogen prevalence were associated with the presence of an antibiotic in milk postpartum. Screening milk for antibiotic residues in milk postpartum following prepartum antibiotic therapy in heifers is recommended to reduce the risk for antibiotic residue contamination of milk.