Effects of age, body weight, semen collection frequency and holding duration on semen traits of broiler breeder reared under different housing systems

Semen traits play the vital role in determining the fertility of a broiler breeder flock; however, it can be influenced by several factors. This experiment was carried out to assess some of these factors affecting the semen. A total of 89 male birds and 960 hens of 20-week-old broiler breeder (2215 g ± 7.5%) were divided into two main groups; one was kept in cages (AIC) and another group was kept on deep litter floor (AIF), while both these groups were subjected to AI. The male birds of aforementioned groups (44 males and 480 females) were further divided into 4 sub-groups (11 males and 120 females) to execute different semen collection frequencies i.e., 2, 3, 4, and 5th days' interval. The impact of time duration between semen collection and insemination on sperm kinematics was monitored. The quantitative and qualitative analysis of semen including sperm concentration and sperm kinematics of the collected semen was conducted through a computer-assisted sperm analyzer (CASA) and ONGO machine (working on the CASA principle). Resultantly, the data revealed that the studied parameters of semen were deteriorated with the progression of age of male birds, while the group of males with standard body weight produced the best semen quantitatively and qualitatively followed by overweight particularly during the post peak phase (46-65 = 20 weeks). Although the 3rd day, semen collection frequency was found better for quality, the higher quantity of semen was achieved when males were being collected at the intervals of 4th and 5th day respectively regardless of housing systems. Significant decline in sperm kinematics was recorded with the progression of semen holding duration at the temperature of poultry farm. Furthermore, the highest contamination of E. coli, Salmonella, and Mycoplasma gallisepticum was recorded in the reproductive tract of hens and semen of the AIF group as compared to AIC. Thus, conclusion can be settled that the semen properties are significantly affected by age, body weight, and semen collection intervals in both housing systems, while sperm kinematics is being disrupted with the progression of holding duration. Although housing systems could affect the semen insignificantly, yet lesser contamination was recorded in semen and in the reproductive tract of hens of AIC.

Interventions in mating strategies of broiler breeder during peak and post peak phase influence hatching traits

The study evaluated the effect of housing system, insemination frequency, and sperm concentration on hatching traits of commercial broiler breeder. Experiment was set up as 2 × 4 × 4 factorial arrangement under completely randomized design. A total of 960 broiler breeder females (Ross-308) were divided evenly (480) into two groups for Artificial Insemination in cages (AIC) and on deep litter floor (AIF) with 41 and 48 males were allocated for aforesaid flocks, respectively. Females birds of both flocks (AIC and AIF) were further divided into 4 treatment groups to apply 4 various insemination frequencies at 4, 6, 8, and 10th days. These treated groups were further divided into 4 subgroups to apply each of insemination frequencies with 4 different sperm concentrations per insemination dose 100, 125, 150, and 175 × 106 sperms during peak phase of production which were replaced with 200, 225, 250, and 275 × 106 sperms in post peak phase. According to the results, significantly higher egg production, fertility, hatchability and number of chicks were documented when AI was conducted in cages as compared to deep litter floor. Although, the best reproductive performance was observed on 4 and 6th day insemination frequencies on all subjected sperm concentrations during peak; however, these parameters were found better on only 4th day during post peak. Sperms concentrations of 150, 175 × 106 during peak and 250 and 275 × 106 during post peak brought forth the best reproductive performance on all insemination frequencies. Although, embryonic mortality was significantly higher, when AI was conducted in floored flocks particularly when repeated after 4th day; however, various sperm concentrations found inert. In conclusion, AI found advantageous in caged flock as compared to floored. The consortium of different insemination frequencies and sperms concentrations are required for sustainable reproductive traits with progression of breeder age.

Asymmetry patterns are associated with body size and somatic robustness among adult !Kung San and Kavango people

Asymmetry of bilateral anatomical structures is widely found in nature. Fluctuating asymmetry, i.e. mostly tiny random deviations from perfect symmetry in bilateral structures, is mainly interpreted within the framework of developmental instability. This interpretation is mainly due to the fact, that higher fluctuating asymmetry is often found in association with various pathological conditions but also from increased stress during somatic development. Directional asymmetry, in contrast, describes a distinct pattern of bilateral variation in a group of individuals, characterized by the tendency to find the larger side mainly at the same side for all individuals. This kind of asymmetry is mostly caused by behavioral lateralization. Somatic stress during development affect not only asymmetry patterns, it is has also an adverse effect on somatic growth. Therefore, the present study tested the hypothesis, that increased asymmetry is associated with decreased body height as well as postcranial length and robustness dimensions. The association patterns between fluctuating as well as directional asymmetry and parameters of somatic growth and robustness are analyzed among 236 !Kung San and 248 Kavango people of Namibia between the ages of 18 and 65 years. Fluctuating asymmetry was determined by ear length and ear breadth. Directional asymmetry was determined by hand length and hand breadth dimensions. Fluctuating as well as directional asymmetry correlated significantly negatively with body height and length dimensions, the correlations however, were weak. The results are interpreted as a corroboration of the theory that developmental stress may increase fluctuating asymmetry but on the other hand may decrease body size.

Influence of physiological stress on the presence of hypoplasia and fluctuating asymmetry in a medieval population from the village of Sypniewo

This study aims to estimate the levels of physiological stress in the medieval rural population of Sypniewo by evaluating patterns of fluctuating asymmetry (FA) and enamel hypoplasia (EH), and provide information on the influence of physiological stress during the prenatal and perinatal period on early childhood development. Stress is defined as any external or internal condition that challenges homeostasis of an organism. FA is associated with physiological stress occurring mainly during prenatal development and early childhood. The level of FA is thought to reflect the intensity of the stressor(s). EH is caused by physiological stress such as nutritional instability during the first years of life. The studied material consisted of 126 skulls from the village of Sypniewo (Poland). Cranial radiographs were taken in postero-anterior (P-A) and basal views. The images were scanned and calibrated. Measurements of the cranium were used to estimate FA. The presence of EH was assessed using standard anthropological methods The highest levels of FA were observed in the region of the cranial base. EH was observed in 29% of individuals from the rural skeletal series. There was no statistically significant correlation between FA and EH occurrence or between sex and the studied stress indicators.

Comparison of semen variables, sperm DNA damage and sperm membrane proteins in two male layer breeder lines

Semen variables are affected by the breed and strain of chicken. The present study was undertaken to compare the semen quality in two lines of adult chickens with particular reference to sperm chromatin condensation, sperm DNA damage and sperm membrane proteins. Semen from a PD3 and White Leghorn control line was collected at 46 and 47 weeks and 55 weeks of age. The semen was evaluated for gross variables and sperm chromatin condensation by aniline blue staining. Sperm DNA damage was assessed by using the comet assay at 47 weeks of age and sperm membrane proteins were assessed at 55 weeks of age. The duration of fertility was studied by inseminating 100 million sperm once into the hens of the same line as well as another line. The eggs were collected after insemination for 15days and incubated. The eggs were candled on 18th day of incubation for observing embryonic development. The White Leghorn control line had a greater sperm concentration and lesser percentage of morphologically abnormal sperm at the different ages where assessments occurred. There was no difference in sperm chromatin condensation, DNA damage and membrane proteins between the lines. Only low molecular weight protein bands of less than 95kDa were observed in samples of both lines. The line from which semen was used had no effect on the duration over which fertility was sustained after insemination either when used in the same line or another line. Thus, from the results of the present study it may be concluded that there was a difference in gross semen variables between the lines that were studied, however, the sperm chromatin condensation, DNA damage, membrane proteins and duration over which fertility was sustained after insemination did not differ between the lines.

Asymmetries in chickens from lines selected and relaxed for high or low antibody titers to sheep red blood cells

Wattle length, width, and area were measured to classify bilateral asymmetries in four lines of chickens. The lines were the S26 generation of White Leghorns selected for high (HAS) or low (LAS) response to sheep red blood cells and sublines in which selection had been relaxed for three generations (high antibody relaxed [HAR] and low antibody relaxed [LAR]). Antibody titers (AB) were greater for HAS than for HAR with both greater than for LAS and LAR which while different for males did not differ for females. The low antibody lines were heavier and reached sexual maturity at younger age than the high antibody lines. In general, wattle length, width, and area were greater in the low than high antibody lines. In 24 comparisons for bilaterality 18 exhibited fluctuating asymmetry and 6 exhibited directional asymmetry with 5 of the 6 being for wattle length. There was not a clear pattern for changes in degree of asymmetry when selection was relaxed for 3 generations. For females, the relative asymmetry (RA) of wattle area was larger (p≤0.05) for HAR than for LAR and not different from the selected lines and relaxed lines. There were no differences among lines for RA of wattle length and width of females and wattle length, width, and area of males.

Effect of age on semen quality in naked neck and dwarf chicken under tropical climatic conditions

The present study was undertaken to elucidate the effect of age on semen quality of naked neck and dwarf chicken lines under tropical climatic conditions. Semen collected by abdominal massage at 4-week intervals from 24 to 48 weeks of age was evaluated for different semen quality parameters. Except sperm concentration and appearance, all other parameters were significantly (P < 0.05) affected by the age of the birds. The semen volume, motility, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide dye reduction test and percentage of live sperm were significantly (P < 0.05) lower at 24 weeks of age compared with 40 weeks of age. At 24 weeks of age the dead sperm percentage was significantly (P < 0.05) high and with advancing age it decreased. There was a significant difference (P < 0.05) between the gene lines for volume, appearance, motility, sperm concentration, and percentage of live and dead sperm. Except for sperm concentration, significant (P < 0.05) interaction between gene lines and age was observed in other parameters. In conclusion, semen quality was different between naked neck and dwarf line males and age affected semen quality of the gene lines studied in different manners.