Profitability and meat quality of fast-, medium- and slow-growing meat-type chicken genotypes as affected by growth and length of rearing.

The study aimed to evaluate the profitability, meat quality, and carcass parameters of fast-, medium-, and slow-growing meat-type chicken genotypes of Bangladesh. Nine hundred DOCs were randomly allocated to 6 treatments: T1 = commercial broilers, T2 = CPF-3 (central poultry farm-3), T3 = cockerel, T4 = sonali, T5 = NDD (non-descriptive desi), and T6 = hilly, having 5 replications of 30 chicks each. Birds were reared under complete confinement until their respective market ages (commercial broilers = 35 d; CPF-3 = 45 d; cockerel = 56 d, and hilly = 77 d; sonali = 63 d and NDD = 77 d) and fed commercial broiler diets. Net returns, meat quality, growth, and carcass yield were measured. NDD and hilly showed significantly the highest profitability and superior meat quality. Commercial broilers exhibited the highest final body weight (2355.59 g/b) followed by hilly (1241 g/b) and NDD (1006 g/b), while CPF-3 (860.21 g/b), cockerel (915.49 g/b), and sonali (788.43 g/b) had lower final body weights at their respective market ages. Commercial broilers had the highest carcass weight and dressing yields, followed by hilly and cockerel, and lower in sonali, CPF-3, and NDD. The study concluded that rearing slow- or medium-growing NDD and hilly is superior to fast-growing commercial broilers or CPF-3 regarding profitability, and meat quality. The results of current findings help small-scale farmers in choosing a suitable meat-type chicken that yields better profitability and also for the consumers who wish to pay a fair price for the birds, considering the meat quality specific to each chicken genotype.

Challenges in the profitability of small-scale broiler farming by avoiding injudicious use of drugs and additives.

The aim of the current study was to determine the present scenario of injudicious use of drugs and additives in small-scale broiler operations and whether broilers can be produced successfully and profitably without the injudicious use of drugs and additives. First, a survey was undertaken in relation to farmers' basic information and general management methods in commercial broilers, with special attention given to the usage of medications and additives in drinking water. Second, based on the survey data, an experimental trial was carried out to compare the growth performance and economic profitability of rearing broilers with and without the use of said drugs and additives. A total of 540 broiler DOCs were allotted into three treatments: T1 = self-formulated feed (SFF) with judicious use of drugs and additives; T2 = commercial feed with judicious use of drugs and additives (JUDA) and T3 = commercial feed with injudicious use of drugs and additives (InJUDA), with six replications (30 birds/replication) in each. The results showed that the farmers used a variety of drugs and additives in 35 days of broiler rearing; however, the farmers usually did not consult with veterinary practitioners, instead relying on and being instructed by local dealers and medicine company representatives. Although the medications and additives account for almost 6-8% of total production costs, the experimental trial clearly demonstrated that the broilers kept with either JUDA or InJUDA showed statistically (p < 0.05) similar BW (2181.93 g & 2222.53 g/bird), BWG (2110.0 g & 2129.91 g/bird), and FCR (1.62 & 1.57, respectively), whereas broilers in the SFF group showed significantly lower growth performances (BW = 1799.31 g/bird, BWG = 1746.19 g/bird, and FCR = 1.93, respectively). The net profit per kg bird in the JUDA group was substantially (p < 0.05) greater (BDT- 27.34/-), followed by the SFF group (BDT- 25.56/) and the InJUDA group (BDT- 24.49/-). Taken together, these findings suggest that profitable broiler farming is possible without the injudicious use of drugs and additives.

Changes in the expression of interleukin-1beta and lipopolysaccharide-induced TNF factor in the oviduct of laying hens in response to artificial insemination.

The aim of this study was to determine the physiological significance of interleukin-1beta (IL1B) and lipopolysaccharide-induced TNF factor (LITAF) in the fate of sperm in the oviduct of laying hens after artificial insemination (AI). Laying hens were inseminated with fresh semen, PBS or seminal plasma and tissues from different oviductal segments were collected to observe the general histology, changes in the mRNA expression of IL1B and LITAF and the localization of positive cells expressing immunoreactive IL1B (irIL1B). Semi-quantitative RT-PCR was used to observe the changes in mRNA expression of these molecules in the infundibulum, uterus, utero-vaginal junction (UVJ), and vagina after insemination. Intact sperm in the lumen and between the primary or secondary folds of the vagina were found until 6 h after insemination but were degraded at 12 h. The mRNA expression of IL1B and LITAF was significantly increased in the vagina until 6 h after AI but remained unchanged in the other oviductal segments. In the tissue of the vagina and UVJ, irIL1B was localized in the mucosal stroma. The number of irIL1B-positive cells was increased in the vagina but almost unchanged in UVJ after insemination with semen. Significant changes were not observed in the mRNA expression and irIL1B-positive cells in the vagina after PBS or seminal plasma insemination. The increase of IL1B and LITAF in the vagina may lead to sperm degradation and elimination by cilia of surface epithelium, whereas their lower levels in UVJ may permit sperm to survive in sperm storage tubules.

Expression of transforming growth factor-beta isoforms and their receptors in utero-vaginal junction of hen oviduct in presence or absence of resident sperm with reference to sperm storage.

Our goal was to determine whether transforming growth factor beta (TGFbeta) isoforms were involved in the process of sperm survivability in the sperm-storage tubules (SST) in the utero-vaginal junction (UVJ) of hen oviduct. The birds were artificially inseminated. The mRNA expressions of three types of TGFbeta isoforms (TGFbeta2, TGFbeta3, and TGFbeta4) and three types of receptors (TbetaR1, TbetaR2, and TbetaR3) were examined in the presence or in the absence of resident sperm in SST by semi-quantitative reverse transcriptase-PCR. The mRNA expression of TGFbetas and TbetaRs in sperm was also examined. Immunocytochemistry and western blot were performed for TbetaR2 to confirm its localization in UVJ. The sperm were observed at least 10 days after insemination by histology. The mRNA expressions of TGFbetas and TbetaRs were significantly increased in UVJ in the presence of resident sperm in SST. The mRNA expressions of TGFbetas and TbetaRs were also observed in sperm. Immunohistochemistry revealed that TbetaR2 were located in lymphocytes in UVJ and SST cells. The presence of TbetaR2 in UVJ was also confirmed by western blot. These results suggest that enhanced expressions of TGFbetas and TbetaRs in UVJ may protect sperm in SST, probably by suppressing anti-sperm immunoreactions.

Changes in the expression of estrogen receptor mRNA in the utero-vaginal junction containing sperm storage tubules in laying hens after repeated artificial insemination.

The objective was to determine whether expression of estrogen receptor (ER) mRNA in the utero-vaginal junction (UVJ) of laying hens was altered after repeated artificial insemination (AI). Semi-quantitative RT-PCR was used to determine the expression of mRNA of the two types of receptor, ERalpha and ERbeta. Only ERalpha mRNA was expressed in all segments of the oviducts of both virgin and artificially inseminated birds, whereas ERbeta mRNA was expressed in ovarian follicles but not in the oviduct. The expression of ERalpha mRNA in the UVJ was significantly decreased after repeated AI, whereas that in the uterus was not significantly different between virgin and inseminated birds. Since estrogen may be involved in maintaining the sperm storage function of sperm storage tubules, the decreased expression of ERalpha mRNA in the UVJ after repeated AI may contribute to reduced fertility in these birds.

Changes in the localization of antigen presenting cells and T cells in the utero-vaginal junction after repeated artificial insemination in laying hens.

The goal of our present study was to observe whether the populations of antigen presenting cells (Ia+ cells) and T cell subsets (CD4+ and CD8+ T cells) change in the utero-vaginal junction (UVJ) of Rhode Island Red laying hens that showed dramatic declines in fertility after repeated artificial insemination (AI). Rhode Island Red laying hens were divided into two groups: a virgin group (R-V) and artificial inseminated group (R-AI), which was exposed to weekly AI for a period of 3 mo. Undiluted fresh semen collected from healthy Tosa-Jidori roosters, a native Japanese breed maintained in Kochi Prefecture, was used for AI. The UVJ tissues were processed for frozen sections, and Ia+ cells and CD4+ and CD8+ T cells were identified by immunohistochemistry. The Ia+ cells and CD4+ and CD8+ T cells were observed in the stroma and mucosal epithelium of UVJ in both the R-AI and R-V birds. The frequencies of them in the stroma were significantly higher in R-AI than R-V. The higher frequency of Ia+ cells in the UVJ of R-AI group indicated a greater potential capability for antigen presentation to CD4+ cells. The significant increase in CD8+ and CD4+ T cells in the UVJ of R-AI birds might be the result of a homing process of lymphocytes, which may affect sperm survivability and fertility.