Biomedical subjects

C D McDaniel

Publications and source records attributed to C D McDaniel.

At least 19 recordsLinked to original sources

PubMed2006

The immediate impact of semen diluent and rate of dilution on the sperm quality index, ATP utilization, gas exchange, and ionic balance of broiler breeder sperm.

The sperm quality index (SQI) is a tool used to predict overall rooster semen quality, fertility, and hatchability. However, semen must be diluted before SQI analysis, and research has shown that the SQI is most predictive of fertility at lower semen dilutions. Therefore, the present study was undertaken to determine why the SQI is not as predictive of fertility at higher semen dilutions and whether semen diluent type alters the SQI, adenosine triphosphate (ATP) utilization, gas exchange, and ionic balance of broiler breeder sperm. Semen was diluted with saline, seminal plasma, or minimum essential medium (MEM) from 2- to 200-fold. The following parameters were measured for each diluent type at each dilution: SQI, ATP, Na+, Ca2+, K+, Cl-, CO2, and O2. To examine the rate of sperm motility, the SQI was expressed as SQI/million sperm per mL (SQI/sperm). There was an interaction between diluent type and dilution for the SQI, SQI/sperm, CO2 generated, O2 used, as well as Na+, Ca2+, and K+ internalization. For sperm diluted with saline, the SQI declined more rapidly with increasing dilution. However, SQI/sperm increased rapidly when semen was diluted with MEM or SP. Sperm diluted in SP used ATP with increasing dilution whereas sperm diluted with saline and MEM generated ATP. Neat semen contained no free O2; however, each diluent type contained abundant O2 resulting in more O2 available as semen was diluted. Sperm diluted in SP produced more CO2 and used more O2 than semen diluted in saline or MEM. For SQI/sperm, ATP and CO2 generated, as well as Na+ and Ca2+ internalization, differences between diluent types occurred when semen was diluted 50-fold and greater. In conclusion, it appears that sperm motility, ATP utilization, gas exchange, and ionic balance are altered by diluent type and rate of dilution. These alterations in semen quality are exacerbated at semen dilutions of 50-fold and greater yielding an SQI that is not indicative of sperm motility or fertility.

Adenosine Triphosphate↗

PubMed2006

Similarities and differences between the sperm quality index and sperm mobility index of broiler breeder semen.

The sperm quality index (SQI) and sperm mobility index (SMI) both predict sperm motility. Previous research was conducted comparing the SMI with the SQI; however, semen was diluted improperly for the SQI (40-fold). For an accurate comparison, semen must be diluted 10-fold for the SQI. Therefore, the overall objective of this study, utilizing 4 experiments, was to examine the relationship of the SQI with the SMI when: 1) active, heat-inactivated, and boiled sperm were incubated and analyzed over 60 min, 2) motile and immotile sperm were combined, 3) dead sperm (boiled or frozen) and live sperm were combined, and 4) sperm were rendered immotile by adding Zn. In experiment 1, the SQI was stable throughout incubation for active sperm and zero for heat-inactivated and boiled sperm. The SMI from active sperm steadily increased over incubation. However, the SMI from heat-inactivated sperm increased drastically resulting in values higher than active sperm after 35 min of incubation. The SMI from active sperm was higher than boiled sperm throughout incubation. For experiment 2, a cubic increase in the SQI occurred as active sperm increased from 0 to 100%. However, there was no difference in SMI readings until samples contained 80% active sperm. In experiment 3, for both boiled and frozen sperm, as the percentage of viable sperm increased, there was a logarithmic increase in the SQI. The SMI values were similar for 0 and 100% viable sperm when using boiled sperm, and all SMI readings were similar to 0% viable for frozen sperm. For experiment 4, both the SQI and SMI values from semen incubated with Zn were lower than that of saline. The SQI from sperm incubated in saline was higher than that of Zn throughout incubation, yet there were no differences in SMI values after 90 min of incubation. In conclusion, both the SQI and SMI of sperm decrease in response to Zn. However, it appears that immotile and dead sperm are capable of increasing SMI values but not SQI values.

Animals↗

PubMed2006

Apparent attachment of Campylobacter and Salmonella to broiler breeder rooster spermatozoa.

It has been demonstrated that horizontal and vertical transmission of Salmonella and Campylobacter can occur in broiler breeder flocks. The mechanism of this transmission is still unclear. Previously negative broiler breeder flocks have been reported to become positive with Salmonella, Campylobacter, or both after the introduction of "spike" roosters at 45 wk of age. To determine whether the rooster semen is a possible source of transmission to hens for colonization, we evaluated the association of both Salmonella and Campylobacter spp. to segments (head, midpiece, and tail) of individual spermatozoa after artificial inoculation. Salmonella typhimurium, Salmonella heidelberg, and Salmonella montevideo, or Campylobacter jejuni (in 0.85% saline) was added to a freshly collected (by abdominal massage) aliquot of pooled semen from roosters housed in individual cages. The semen and bacteria solutions were incubated 1 h at room temperature. Samples were fixed using Karnosvsky and Zamboni fixatives for 24 h prior to centrifuging and rinsing in 0.1 M cacodylate x HCl buffer. Individual aliquot samples were then subjected to both scanning (JSM-5800) and transmission (JEM-1210) electron microscopy. The scanning electron microscopy showed that Salmonella was associated with all 3 segments (head, midpiece, and tail) of the spermatozoa and apparently equally distributed. Campylobacter was mainly associated with the midpiece and tail segments; few isolates were located on the head segment. The transmission electron microscopy showed apparent attachment of Salmonella and Campylobacter to the spermatozoa.

Animals↗

PubMed2005

Breeder hen dietary L-carnitine affects progeny carcase traits.

(1) Ross 308 broiler breeder hens were given diets containing 0 or 25 mg L-carnitine/kg from 21 weeks of age. (2) Hens were inseminated with semen from Ross broiler breeder males and subsequent growth performance and carcase traits, of progeny obtained from hatches at 30, 35 and 37 weeks of age, were evaluated. (3) Progeny were hatched in a common facility and separated by gender. Experimental treatments employed for the 30-, 35- and 37-week hatches, respectively, were: hen diet and progeny gender (16 replications with two subplots); hen diet, progeny diet (0 and 50 mg L-carnitine/kg of diet) and progeny gender (16 replications with 4 subplots); and hen diet and progeny diet (high and low density; 16 replications with two subplots). (4) Females had lower growth rate and less breast meat, but greater proportions of carcase fat and breast meat than males. Growth performance measurements of progeny were not affected by hen L-carnitine, but hen L-carnitine decreased abdominal fat in progeny. Increasing diet density in the chick diets increased growth and carcase weights. Hen and progeny dietary L-carnitine interacted to increase male mortality. However, dietary hen L-carnitine decreased carcase fat and increased breast meat in progeny fed on high nutrient density diets. (5) In conclusion, L-carnitine in the diet of hens affected carcase traits of their progeny.

Animal Feed↗

PubMed2005

Broiler breeder semen quality as affected by trace minerals in vitro.

Research has shown that trace elements, such as Se, Mn, and Zn, can alter reproductive functions. The aim of the current study was to evaluate the sperm quality index (SQI) and sperm viability as affected by various levels and sources of Se, Mn, and Zn when added in vitro to broiler breeder semen. In vitro treatments consisted of the following sources and levels of minerals: Control, no minerals added to sperm; seleno L-methionine, 4 levels ranging from 8.78 to 7,896 microg/L; sodium selenite, 4 levels ranging from 8.78 to 7,896 microg/L; MnSO4, 8 levels ranging from 6,500 to 65,000 mg/L; Zn 180 (Zinpro Corporation), 4 levels ranging from 0.65 to 650 mg/L; and ZnSO4, 4 levels ranging from 0.65 to 650 mg/L. The addition of 7,896 microg of sodium selenite/L to semen was detrimental to sperm motility. Also, MnSO4 adversely affected SQI and sperm viability at concentrations of 6,500 mg/L and greater. Sperm viability was decreased when 650 mg/L of Zn 180 was added to semen. Sperm motility was depressed by exposure to Zn 180 at 650 mg/L and ZnSO4 at 65 and 650 mg/L. Our results suggest that these trace minerals must act at the reproductive tissue level during spermatogenesis to improve semen quality. Direct in vitro application of these elements to semen appears to be detrimental to spermatozoa.

Animals↗

PubMed2003

Semen dilution prior to analysis influences the ability of the sperm quality analyzer to predict fertility whether inseminating with a constant number of sperm or a constant volume of semen.

Previous research has shown that the sperm quality index (SQI) is positively correlated with semen characteristics as well as fertility when broiler breeder semen is diluted 10-fold prior to analysis. However, research has not been conducted to establish if semen dilution rate affects the ability of the SQI to predict fertility when inseminating a constant number of sperm or a constant volume of semen. As a result, 3 experiments were undertaken. The objective of the first study was to determine if diluent, minimum essential media, or 0.85% saline affects the SQI. The second objective was to identify potential semen dilution rates for the SQI by obtaining the range in live sperm concentrations to which the SQI is most sensitive. The purpose of experiment 3 was to determine which semen dilution rate, 10-, 25-, 50-, 75-fold, or a constant concentration of 180 x 10(6) sperm/mL, yields an SQI that is most predictive of fertility. Once a week for 3 wk, 20 hens were individually inseminated with either 20 microL of 4-fold diluted semen or a constant 45 x 10(6) sperm from each of 29 broiler breeder males. To determine which semen dilution rate yielded an SQI that was most predictive of fertility, Pearson's correlation coefficients were obtained between the SQI at each dilution rate and fertility. There was no difference in the SQI due to diluent. Sperm quality index values declined logarithmically as live sperm concentration decreased. The SQI was most sensitive to live sperm concentrations from 11 to 232 x 10(6) sperm/mL. The SQI for semen diluted 10-fold was the best predictor of fertility when inseminating with a constant volume of 4-fold diluted semen (r = 0.71). When hens were inseminated with a constant 45 x 10(6) sperm/hen, the SQI for semen diluted 10- and 25-fold as well as to a constant concentration of 180 x 10(6) sperm/ mL was equally effective at predicting fertility (r = 0.59, 0.52, and 0.61, respectively). Apparently, the SQI is predictive of fertility when semen samples are diluted 10-fold prior to analysis regardless of insemination method used. Dilution beyond 10-fold appears to alter semen quality, rendering the SQI less accurate.

Animals↗

PubMed2002

Utilisation of a sperm quality analyser to evaluate sperm quantity and quality of turkey breeders.

1. A relatively new instrument known as a Sperm Quality Analyzer (SQA) offers a rapid assessment of sperm quality and quantity by providing a sperm quality index (SQI). The SQA measures a combination of the intensity of sperm activity and motile concentration by determining the number and amplitude of sperm movements per second in a capillary tube as detected through light beam interference. 2. Because the SQA has not been tested for its potential use in turkeys, the objective was to determine if the SQA could accurately respond to changes in turkey sperm concentration, viability, and motility in semen collected from turkey breeders. 3. The effect of varying concentrations of sperm on SQI values was evaluated by diluting replicate pools of semen from 4 different aged turkey breeder flocks with saline. Results from all 4 flocks showed that semen dilutions greater than 20-fold resulted in a linear decline in SQI values. 4. Additional in vitro analysis evaluated the effects of turkey sperm viability on the SQI under conditions of constant sperm concentration. Incubated, live sperm was mixed in various proportions with thawed, dead sperm to determine changes in viability. Increased proportions of dead sperm caused a decline in the SQI. 5. To assess sperm motility, turkey semen was incubated under either aerobic (motile) or anaerobic (immotile) conditions. Varied amounts of immotile and motile sperm samples were mixed. A linear increase in the SQI was observed as per cent motile sperm increased. 6. These results indicate that the SQA can respond to differences in turkey sperm concentration, viability, and motility using in vitro analyses.

Animals↗

PubMed2002

The effects of heat stress and sperm quality classification on broiler breeder male fertility and semen ion concentrations.

1. The present study was undertaken to determine the effects of heat exposure on fertility, semen quality, and semen ion concentrations of broiler breeders classified on sperm quality index (SQI) before heat stress. 2. Cobb males (108) were individually caged in 6 temperature-controlled rooms. Each room contained an equal number of males from each of the 4 SQI population quartiles as follows: best (B), good (G), fair (F), and poor (P). Three rooms were heated to 35 degrees C, and the other three rooms were maintained at a constant 23 degrees C as controls. For each SQI group in each room, 15 Leghorn hens were artificially inseminated (5 x 10(7) sperm/hen) once a week for 8 weeks for fertility observations. 3. Body weight, sperm concentration, SQI, and fertility of P males were lower than in the other three SQI groups. Body temperature of the top three SQI groups was increased by heat exposure, but body temperature was not altered by heat stress in the P group. Fertility, sperm viability, and SQI of the top three SQI groups, but not the P group, was decreased by heat stress. Seminal plasma K+ of P males was lower than that of B males. However, seminal plasma Ca2+ concentration of P males was higher than that of B males. 4. In conclusion, high ambient temperatures had more impact on semen quality and fertility of males in the top 75% of the SQI population than in males in the bottom 25% of the population. In addition, calcium ions (Ca2+) appear to play a major role in heat stress infertility.

Animals↗

PubMed2002

Use of a sperm quality analyser on semen of turkey breeders to monitor storage time effects and age-related changes during a reproductive cycle.

1. A relatively new instrument known as a Sperm Quality Analyzer (SQA) offers a rapid assessment of sperm quality and quantity by providing a sperm quality index (SQI). The SQA measures the intensity of sperm activity and motile concentration by determining the number and amplitude of sperm movements per second in a capillary tube as detected through light beam interference. 2. The objectives of the current study were to determine if the SQA could accurately reflect changes in semen quality that occur with prolonged storage of semen and to determine the variation and change in SQI values among individual breeding male turkeys during their semen production cycle. 3. The effect of storage time on SQI values was evaluated by diluting semen with extender and placing the semen on an oscillating shaker at 4 degrees C for 8 h. The SQI values and sperm viability, expressed as % dead sperm, were recorded hourly. The SQI readings declined linearly with increased storage time while % dead sperm increased linearly with increased semen storage. 4. Semen from 220 individual males was analysed monthly for 9 months. Semen diluted 50-fold with saline had lower SQI values during pre- and post-peak phases of production (months 1, 7, 8, and 9 as compared with months 2 to 6 of semen production). The highest SQI values occurred during months 2 to 6. The largest variation in SQI values occurred during months 1 (CV = 26%) and 9 (CV = 31%) with a CV that averaged 16% for the remaining months. 5. Correlation analysis of SQI values for each bird averaged over 9 months with individual male SQIs for each month showed monthly correlation coefficients that ranged from 0.22 to 0.63. 6. These results indicate that the SQA accurately assessed the decline in sperm quality that occurs with prolonged storage of turkey semen and reflected age-related changes in semen quality and quantity that occurred during a semen production cycle of turkey breeders. In addition, the semen quality rank of some turkey breeders in a population changed with age.

Aging↗

PubMed2002

Elevated body temperature directly contributes to heat stress infertility of broiler breeder males.

Alterations in the male reproductive tract, sperm, or both may be responsible for heat stress infertility of broiler breeder males. The present study was conducted to determine the direct effects of hyperthermia during heat stress on sperm viability, the spermquality index (SQI), and seminal plasma ion concentrations by incubation of semen in vitro at and above normal body temperature. Thirty-seven Cobb males were divided into the upper (best group = B) and lower (poor group = P) 50% of the population according to their SQI. Semen characteristics and seminal plasma ion concentrations (Ca++, Na+, K+, and Cl-) for B and P males were evaluated at two temperature treatments (41.5 and 42.5 C) and four incubation times (0, 30, 60, and 90 min). The results revealed that sperm viability and the SQI were decreased by increasing incubation temperature and duration of exposure. Seminal plasma ion concentrations were not affected by semen incubation temperature; however, plasma Ca++ concentration in the P-SQI group was higher than that of the B-SQI group. Seminal plasma K+ concentration increased in both SQI groups over time. In conclusion, it is apparent that changes in semen characteristics due to elevated body temperature alone contribute to heat stress infertility of broiler breeders.

Animals↗

PubMed2002

Role of seminal plasma in heat stress infertility of broiler breeder males.

The present research was undertaken to determine the role of seminal plasma in heat stress (HS) infertility. Males were exposed to HS at 32 C or maintained at 21 C as controls. Centrifugation and reconstitution of semen samples created four final treatments: control sperm + control plasma (CsCp), control sperm + HS plasma (CsHp), HS sperm + HS plasma (HsHp), and HS sperm + control plasma (HsCp). Semen samples with HS males' seminal plasma had lower sperm quality index values than those containing plasma from control males. Seminal plasma from HS males diminished fertility of control sperm, and control seminal plasma did not improve fertility of HS sperm. Therefore, regardless of seminal plasma source, HS sperm had a lower fertilization rate than control sperm. Also, seminal plasma from semen samples with HS sperm (HsHp and HsCp) contained lower Ca, Na+ and Cl- concentrations than seminal plasma from semen samples with control sperm (CSCp and CsHp). When HS seminal plasma was mixed with control sperm, plasma ion concentrations increased, indicating an efflux of ions from the control sperm to the HS seminal plasma. On the other hand, when control seminal plasma was mixed with HS sperm, plasma ion concentrations decreased, indicating an influx of ions from the control seminal plasma to the HS sperm. Therefore, control sperm appear to have higher intracellular ion concentrations than the sperm from HS males. In conclusion, high temperatures might decrease male fertility by decreasing seminal plasma and intracellular ion concentrations.

Animals↗

PubMed2002

Fertility of broiler breeders following categorization by the OptiBreed sperm quality index when hens are inseminated with a constant number of sperm.

If semen quality was known prior to insemination, sperm doses could possibly be decreased, maximizing the number of hens inseminated. The sperm quality index (SQI), an indicator of overall semen quality, is determined by the number of deflections in a light path due to sperm movement inside a capillary tube. The objectives of this study were 1) to determine the age at which the SQI becomes a static predictor of semen quality and 2) to determine if fertility of males with a higher SQI responds more favorably to insemination dose reduction than that of males with a lower SQI. Weekly from 23 to 32 wk of age, 144 Cobb males were tested for SQI. At 32 wk of age, males were placed into four groups that represented the SQI population quartiles as follows: poor, fair, good, and best. A fifth SQI group, uncategorized, was created to determine fertility of the original population by mixing equal amounts of semen from each of the four groups. Semen was collected weekly from 33 to 40 wk of age from 18 males in each of the four groups, pooled by group, and used to inseminate 30 hens per group with 50 or 100 million sperm. Eggs were collected daily, incubated, and broken out to determine fertility. Correlation coefficients between weekly SQI results and overall averages for individual males indicated that the SQI stabilized after the birds were 28 wk of age. The main effect for SQI selection revealed that the best SQI group had the highest fertility (88%), which did not differ from the good (83%) or fair group (82%) but was greater than the uncategorized group (80%). Fertilities of the top three groups and the uncategorized group were higher than the poor group (63%) (P < 0.0001, SEM 2.18). In addition, there was an interaction between SQI classification and insemination dose. Fertilities of the top three SQI groups were similar at the 50 and 100 million sperm doses. However, the poor and uncategorized SQI groups had lower fertility at the 50 million dose as compared to the 100 million dose. By categorizing males into SQI groups after 28 wk of age, insemination dose can be reduced, maximizing a male's fertilizing potential.

Animals↗

PubMed2000

Use of a sperm analyzer for evaluating broiler breeder males. 2. Selection of young broiler breeder roosters for the sperm quality index increases fertile egg production.

Previous research has shown that the sperm quality index (SQI) of rooster semen is indicative of overall semen quality. The objectives of the present experiments were to determine the correlation of the SQI with semen characteristics and fertility and to determine if selection of young males for the SQI would improve fertility. In Experiment 1 semen was collected from 35 Peterson males and was analyzed individually for sperm concentration and viability. To determine fertility, 100 microL of diluted semen was inseminated into 10 hens for each rooster. Positive correlations of the SQI with total and live sperm concentrations as well as fertility were found. A negative correlation of the SQI with the percentage of dead sperm was observed. In Experiment 2, four semen samples were collected at 2- to 3-d intervals from each of 142, 27-wk-old Peterson roosters to determine their SQI. Males were then allocated to six treatment groups based on their average SQI readings as follows: 0 to 150, 151 to 200, 201 to 250, 251 to 300, 301 to 350, and >350. For each SQI group, semen was collected weekly for 8 wk, pooled, and used at a rate of 50 microL/hen to inseminate 40 hens. The percentage of fertilized eggs increased linearly across the SQI groups, from a minimum of 65% for the 0 to 150 SQI group to a maximum of 98% for the >350 SQI group. The SQI groups of 301 to 350 and >350 produced the slowest decline in fertility over days postinsemination. Therefore, selection of males for the SQI at an early age appears to improve flock fertility.

Animals↗

PubMed1998

Use of a sperm analyzer for evaluating broiler breeder males. 1. Effects of altering sperm quality and quantity on the sperm motility index.

A new instrument for assessing mammalian semen attributes, the Sperm Quality Analyzer, was evaluated as a potential tool for determining rooster sperm quality. The Sperm Quality Analyzer measures the "activity" of sperm in a semen sample as the sperm motility index (SMI). The SMI is defined as the number and amplitude of deflections in a light path per second as a result of sperm movement within a capillary tube. In the present study, effects of sperm concentration, viability, and motility on the SMI were evaluated. Peterson broiler breeder males (n = 40) were used as semen donors. In the initial experiment, semen was diluted from 2- to 25-fold and SMI readings were obtained. The SMI was very low in neat semen samples but increased when semen was diluted up to threefold. However, at dilutions greater than fivefold, the SMI decreased. Apparently, sperm concentration in undiluted semen is so great that sperm are unable to move freely within the capillary tube. Maximum SMI values were obtained at sperm concentrations of approximately 1 billion sperm per milliliter. When thawed, dead sperm were mixed with incubated, live sperm, the SMI decreased with decreasing sperm viability even though sperm concentration was constant. Obviously, fewer sperm move across the light beam as sperm mortality increases. When motile, aerobically incubated sperm were mixed at different rates with immotile, anaerobically incubated sperm samples, the SMI increased with increasing concentrations of motile sperm, whereas total sperm concentration was static. In addition, the SMI was strongly correlated with motility scores obtained by microscopic analysis. The Sperm Quality Analyzer provides an estimate of the overall quality of sperm from broiler breeder males by reflecting sperm concentration, viability, and motility in a single value, the SMI.

Animals↗

PubMed1997

Effects of added lard fed to broiler chickens during the starter phase. 1. Body and selected organ weights, feed conversion, hematology, and serum glucose.

The effects of added lard in starter diets on BW, selected organ weights, feed conversion, hematological indices, and serum glucose were determined weekly in broiler chickens between 14 and 42 d of age. Nonisocaloric starter diets were formulated to contain either 0, 3, or 7% added lard, where the megacaloric percentages of all major nutrients were held constant. Broiler chickens received either 0, 3, or 7% added lard in starter diets through 10 d of age (S1), followed by either 3 or 7% added dietary lard through 21 d of age (S2). All possible combinations of the three S1 diets and two S2 diets yielded six total dietary treatments. A common grower diet was provided after 21 d. Body weight was not affected by diet and feed conversion did not increase between 21 and 42 d when birds were fed 3 or 7% added lard in the S1 diet. The effects of the S1 and S2 diets on relative liver weight were inconsistent over time and were not influenced by sex. Hematocrits were increased across time in birds fed 3% S1 diets and plasma protein concentrations were increased at 14 d in birds fed 7% S1 diets. It was concluded that the response of broiler chickens between 14 and 42 d to different levels of dietary lard was influenced by age of feeding during the starter period.

Animals↗

PubMed1997

Effects of added lard fed to broiler chickens during the starter phase. 2. Serum lipids.

The effects of lard added to starter diets on various serum lipids were determined in broiler chickens between 14 and 42 d of age. Nonisocaloric starter diets were formulated to contain either 0, 3, or 7% added lard, where the megacaloric percentages of all major nutrients were held constant. Birds received either 0, 3, or 7% added lard in starter diets through 10 d of age (S1), followed by either 3 or 7% added dietary lard through 21 d of age (S2). All possible combinations of the three S1 diets and two S2 diets yielded six total dietary treatments. A common grower diet was provided after 21 d. Concentrations of various serum lipids were determined weekly from 14 to 42 d of age. The effects of both the S1 and S2 diets on total cholesterol, low density lipoprotein cholesterol (LDLC), and high density lipoprotein cholesterol (HDLC) were inconsistent and were influenced by sex between 14 and 42 d of age. However, serum triglycerides and very low density lipoprotein cholesterol concentrations showed progressive increases over the 14 to 42 d period in birds that received dietary lard at either level in the S1 diet. These same serum constituents also increased to the greatest extents over the same period when birds were provided 3% added lard in the S2 diet. It was concluded that the response of broiler chickens between 14 and 42 d to different levels of dietary lard were influenced by age of feeding during the starter period. Furthermore, the specific effects of the diets on serum cholesterol, LDLC, and HDLC concentrations between 14 and 42 d varied with the sex and age of the bird.

Aging↗

PubMed1997

Naloxone attenuates serum corticosterone and augments serum glucose concentrations in broilers stimulated with adrenocorticotropin.

The effects of exogenous naloxone and adrenocorticotropin (ACTH) on circulating concentrations of corticosterone and glucose in broilers were determined. Birds were injected i.m. at 0 and 2 h with either saline or naloxone, then i.v. at 2.5 h with either saline or ACTH. Control birds received saline at each injection. Blood samples were taken before the experiment started (0 min) and 30, 60, and 90 min after the last injection. Intramuscular injections of naloxone significantly reduced subsequent ACTH-stimulated increases in serum corticosterone; however, when followed by saline, naloxone elevated corticosterone by 90 min after the final injection of saline. Glucose levels were significantly elevated at 60 min in birds receiving ACTH i.v., but remained elevated through 90 min in birds pretreated with naloxone. Naloxone pretreatment attenuated serum corticosterone but augmented serum glucose concentrations in ACTH-stimulated broilers.

Adrenocorticotropic Hormone↗

PubMed1997

Development of a novel fluorescence technique for quantifying the total number of spermatozoa stored in the uterovaginal junction of hens.

A technique was developed to determine the total number of spermatozoa stored in the uterovaginal junction of hens. After insemination of spermatozoa treated with the nuclear fluorescent dye bisbenzimide, oviductal tissue was collected from hens and homogenized. Samples of homogenate were dried, and the number of spermatozoa mm-2 was determined with the use of a fluorescence microscope. When spermatozoa were added to excised uterovaginal junction tissue before homogenization, results indicated a 1:1 linear relationship between actual numbers of spermatozoa added to the tissue and calculated numbers of spermatozoa added to the tissue. This new technique was used to show that insemination of hens with 25, 50 or 100 x 10(6) spermatozoa resulted in a linear increase in the number of spermatozoa stored in the uterovaginal junction. Insemination of hens with 328 x 10(6) spermatozoa produced no increase in uterovaginal junction storage of spermatozoa over insemination with 100 x 10(6) spermatozoa. At the maximum sperm storage tubule filling dose of 100 x 10(6) spermatozoa, only 0.22% of the spermatozoa inseminated were found in the uterovaginal junction 24 h after insemination. Treatment of spermatozoa with bisbenzimide had no detrimental effects on fertility or penetration rates when compared with untreated (control) spermatozoa. However, when spermatozoa were treated with bisbenzimide, hatchability of fertile eggs was reduced. In conclusion, this new fluorescence technique appears to be valuable in determining the total number of spermatozoa stored in the uterovaginal junction of hens.

Animals↗