Does preincubational in ovo injection of buffers or antioxidants improve the quality and hatchability in long-term stored eggs?

peer reviewedA hypothesis was tested that providing buffer solutions or antioxidants during egg storage may help embryos in combating the harmful effect of longer holding periods. Hatching eggs were obtained from a breeder flock (35 wk) and stored for 13 d before setting. In experiment 1, the eggs were injected (d 4) with bicarbonate buffer solution (BBS) or PBS. For experiment 2, l-carnitine (LC), vitamin E (VE), and vitamin C (VC) were injected (d 7) at 3 different doses. The egg internal quality characteristics were evaluated at 2-d intervals after injection and the remaining eggs were incubated for 21 d under standard conditions. At 21 d, hatchability was recorded and unhatched eggs were broken open to assess the fertility and stage of embryonic mortality. No differences were noted in albumen pH due to using buffer solutions or antioxidants except for a decreased pH at 2 d postinjection of the high dose of VC (75 mg). In ovo injection of BBS increased the albumen index and Haugh unit at d 6 postinjection; however, the response to PBS was not different from that in the control group. In ovo injection of antioxidants did not influence the albumen index, Haugh unit, and yolk index; however, the yolk percentage was partly affected. Irrespective of the dosage, hatchability was greatly decreased following in ovo injection of buffers or antioxidants (as low as 4.3 vs. 87.5% in control), with the highest mortality percentage recorded at early embryonic stages (d 0 to 6). Data suggested that, despite improvement in certain egg internal qualities, preincubational in ovo injection of BBS, PBS, LC, VE, or VC was associated with a profoundly decreased hatchability for which the underlying mechanism(s) remain(s) to be clarified

Effects of Long-term Induced Hyperthyroidism on Egg Quality Traits in Cobb 500 Broiler Breeder Hens

Published data on 4-week-long administration of exogenous thyroxine in broiler breeder hens to decline the cold-induced ascites in their progeny suggest that the long-term maternal hyperthyroidism would affect egg quality characteristics traits in Cobb 500 broiler breeder hens. Seventy 47-w-old broiler breeder Cobb 500 hens (5 replicates and 7 hens each) were assigned in separate cages and allotted to two treatments, control and hyperthyroid. Thyroxine was orally administered to the hyperthyroid group (0.3 mg hen/day) for a period of 100 days consecutively. Simultaneously, distilled water was orally administered to the control group. The blood sampling was done every two weeks to analyze T3, T4, and estrogen assays, using commercially kits and the egg quality attributes were evaluated for weeks 0, 3, 6, 9, and 12. Thyroxine treatment resulted in an increase in plasma concentration of T4; however, the T3 level and estrogen were not affected. The results of this study showed that the long-term administration of thyroxine had adverse effect on the most of egg quality traits in broiler breeder hens; although the results may be distinct for treatments that using other birds, doses and duration of treatments, among the different egg quality traits of broiler breeder hens evaluated in this research. Therefore, further studies should be done to make a final conclusion to use of long-term maternal hyperthyroidism treatment to reduce the ascites incidence

Effects of Peppermint (Mentha piperita L.) Alcoholic Extract on Carbon Tetrachloride-induced Hepatotoxicity in Broiler Chickens Under Heat Stress Condition

In order to investigate the effects of peppermint (Mentha piperita L.) alcoholic extract on liver injury caused by the oxidant carbon tetrachloride (CCl4), an experiment was performed as a completely randomized design in a factorial arrangement (2 × 2) with 4 replications of 10 broilers each. Factors included two levels of peppermint leaf alcoholic extract (0 and 2 mL/Kg body weight) and CCl4 (0 and 1 mL/Kg body weight). Results showed significant (P) interactions for body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) on d 42 of the experiment. The alcoholic extract of peppermint leaf did not improve growth performance, whereas CCl4 worsened BWG and FCR (P). The interaction between peppermint extract and CCl4 indicated an ameliorative effect of peppermint extract on BWG and FCR (P). The interaction effects between peppermint extract and CCl4 significantly differed for blood serum concentrations of total protein, albumin, albumin:globulin ratio, glucose, triglyceride, total cholesterol, HDLC, LDLC, LDLC:HDLC ratio, and VLDLC as well as the amount of blood liver enzymes (P). Peppermint extract significantly increased blood serum concentrations of total protein, albumin, triglyceride and HDLC, whilst CCl4 decreased those concentrations (P). Blood serum concentrations of total cholesterol, LDLC, LDLC:HDLC ratio, VLDLC and glucose were decreased by peppermint extract, whereas those concentrations were increased by CCl4 (P). A significantly higher level of liver enzymes was found in blood serum of birds treated by CCl4 than those by peppermint extract (P). A moderate effect on blood serum liver enzymes was observed by the interaction between 2 mL of peppermint extract and 1 mL of CCl4 (P). Generally, this study indicated that in vivo administration of peppermint alcoholic extract ameliorated the adverse effects of CCl4 on growth performance and liver function, therefore it might be useful for the prevention of oxidative stress-induced hepatotoxicity in broilers

Using an incomplete gamma function to quantify the effect of dystocia on the lactation performance of Holstein dairy cows in Iran.

peer reviewedThe aim of the present study was to estimate the effect of dystocia on lactation performance, using an incomplete gamma function. Data from March 2000 to April 2009 comprising 100,628 lactations of 65,421 cows in 204 dairy herds collected by the Animal Breeding Center of Iran were used. Of 100,628 births, 91.8% required no assistance, whereas 8.2% required assistance of some sort. Factors associated with the presence of dystocia were calving season, calving year, herd, calf sex, parity, and age of dam. Peak yield for primiparous cows with dystocia at calving occurred on d 87.2 [standard error (SE) 0.47], and for primiparous cows with easy calving, the peak of lactation was on d 83.3 (0.25). Peak yield was lowered by 0.39 (SE 0.07), 2.20 (SE 0.15), 2.22 (SE 0.21), and 2.54 (SE 0.32) kg for cows with incidence of dystocia compared with normal cows in parity 1 to 4, respectively. Dystocia was associated with decreased 305-d lactation performance in all parities, mostly in early lactation. Although more difficult births occurred in heifer calvings, loss in lactation performance was greater in second or later lactations following a difficult birth

Oral exposure of broiler breeder hens to extra thyroxine modulates early adaptive immune responses in progeny chicks.

peer reviewedBased on the findings of a recent study suggesting a decreased cold-induced ascites incidence in broiler progeny from hyperthyroid (HYPER) breeder hens, and a controversy on the effects of hyperthyroidism on immunocompetence, the present study was conducted to determine the probable adverse effect of induced maternal hyperthyroidism on immune function in progeny chicks. Breeder hens (n = 88) were randomly allotted to the control or HYPER groups and received common or thyroxine (T4)-added (1 mg/L) water, respectively. The hens were artificially inseminated, and hatching eggs (n = 924) were incubated. Thereafter, the male hatchlings (n = 288) were reared for 42 d, and several cellular and humoral immune responses were evaluated at standard or low ambient temperature. Prevaccination antibody titers to Newcastle disease, infectious bronchitis, and infectious bursal disease virus were higher in HYPER chicks during 1 wk of age, although not different in their dams. For primary response to SRBC administered at 7 d of age, HYPER chicks recorded higher total, IgM (d 14), and IgG (d 21) anti-SRBC antibody titers. Higher cutaneous basophilic hypersensitivity response in HYPER chicks (d 10) was not observed at 35 d of age. Carbon clearance assay showed no difference, but in vitro lymphoproliferative response to concanavalin A was higher in 19-d-old HYPER chicks, independent of temperature treatment. An increase in lymphocyte percentage coincided with a decreased heterophil percentage and heterophil to lymphocyte ratio (d 14) in the HYPER group. The weight of lymphoid organs in progeny was not influenced by the oral exposure of dams to extra T4. Independent of T4 treatment, cold exposure was generally associated with decreased immune functions at early stages. The data suggested that oral exposure of broiler breeder hens to 1 mg/L of T4 not only had no adverse effect on immune function, but also modulated early adaptive immune responses in progeny chicks for which the causal mechanisms remain to be unraveled

Maternal hyperthyroidism is associated with a decreased incidence of cold-induced ascites in broiler chickens

peer reviewedA hypothesis was tested that providing the breeder hens with exogenous thyroxine (T(4)) would help their offspring to better survive the ascites-inducing condition during the growing period. In total, 132 broiler breeder hens were randomly assigned to one of 3 treatments: control (CON), hypothyroid [HYPO; 6-N-propyl-2-thiouracil (PTU)-treated], and hyperthyroid (HYPER; T(4)-treated). The hens were artificially inseminated, and the hatching eggs (n = 1,320) were incubated. No eggs in the HYPO group hatched. The 1-d-old male chicks (n = 288) from other groups were reared for 42 d under standard or low ambient temperature to induce ascites. Blood samples were drawn from the hens, embryos, and broilers for determination of T(4) and triiodothyronine (T(3)). The hematocrit was also determined in broilers. The PTU-treated hens had an increased BW along with lower plasma T(3) and T(4) concentrations. Plasma T(4) was higher in the HYPER hens compared with CON hens, but T(3) concentration was not different between these groups. The fertility rate was not affected by either hypo- or hyperthyroidism. The embryos in the HYPO group had lower plasma T(3) and T(4) concentrations at d 18 of embryonic development and internal pipping. Higher plasma T(4) was recorded in the HYPER birds at internal pipping, although plasma T(3) concentration was not affected at this stage. Maternal hyperthyroidism decreased the overall incidence of ascites in the cold-exposed chickens (10.0 vs. 33.4% for HYPER and CON groups, respectively). Although the effect of maternal PTU or T(4) treatment on plasma thyroid hormones and on the right ventricle-to-total ventricular weight ratio in the broilers was not significant, the cold-exposed healthy CON chicks showed higher hematocrit values, compared with the HYPER birds. It was concluded that maternal hyperthyroidism could decrease the incidence of cold-induced ascites in broiler chickens; however, probable causal mechanisms remain to be elucidated