Feeding fennel (Foeniculum vulgare) seed as a potential appetite stimulant for Holstein dairy calves: Effects on growth performance and health.

This experiment was conducted to determine the effect of increasing dietary doses of fennel seed powder (FSP) on growth performance and health status in calves. Holstein calves (n = 48; 3 d of age; 36.3 ± 1.06 kg BW; mean ± SE) were allocated randomly to diets containing 0 (FSP0), 1.5 (FSP1.5), or 3 g/d (FSP3) FSP in milk (morning feeding; during the first month) and then in the starter feed (top-dressed; from d 31 until weaning on d 71). The calves remained in the trial until d 81. Weight gain and final BW were greater in FSP-supplemented calves compared with control calves. Heart girth and hip width gained more in FSP-supplemented calves compared with control calves. Body weight gain and frame growth were not affected by calf sex. The calves receiving FSP had a lower chance of having elevated rectal temperature (≥39.4°C) and a lower probability of suffering from diarrhea or pneumonia. The chance of having diarrhea, but not pneumonia, was greater in female calves. The chance of medication occurrence for diarrhea and pneumonia was not affected by FSP and calf sex. The FSP3 calves had shorter days with elevated rectal temperature (≥39.4°C) compared with the FSP1.5 (1.2 d; SEM = 0.10) and FSP0 (2.9 d; SEM = 0.10) calves. Days with diarrhea but not its frequency and medication days was shorter (4 d; SEM = 0.10) in the FSP-supplemented calves. Control calves experienced more days with pneumonia compared with calves fed FSP1.5 (3.1 d; SEM = 0.08) and FSP3 (5.4 d; SEM = 0.08). Calves fed FSP3 experienced shorter days (2.3 d; SEM = 0.08) with pneumonia compared with calves fed FSP1.5. Feeding FSP tended to decrease (1.6 d; SEM = 0.10) medication days for pneumonia compared with control group. The duration (2.2 d; SEM = 0.10) and medication days (1.3 d; SEM = 0.15) for diarrhea were higher in female calves compared with the male calves. Compared with the control calves, feeding 3 g/d of FSP may be more beneficial in improving the weight gain and skeletal growth (heart girth and hip width) and in reducing the susceptibility to and duration of diarrhea and pneumonia in dairy calves.

Reproductive performance, expression of TRAP6 and TGF-ß4 genes in utero-vaginal junction mucosa, and indicators of liver function in female Chukar partridge (Alectoris chukar) breeders fed with fish oil and calcitriol during the egg-laying period.

Reproductive attributes, expression of TRAP6 and TGF-ß mRNA in the mucosa of the utero-vaginal junction (UVJ) of oviduct, and liver function were evaluated in Chukar partridge (Alectoris chukar) breeders subjected to long-term oral administration of fish oil (FO) and/or calcitriol (CT). A total of forty-eight 1.5-year-old laying Chukar partridges and 16 age-matched males (female:male ratio of 3:1) were randomly allocated to four groups (4 replicates of 3 female birds and one male bird each). Breeder females in groups 1, 2, and 3 were orally administered daily with 0.2 mL (0.24 g)/500 g body weight FO, 0.2 mL solution containing 10 µg CT, or their combination (FO + CT) for 42 successive days, respectively. Pure crystalline calcitriol was dissolved in ethanol (30%) prior to administration. The control group (CON), received a similar volume of a 30% solution of ethanol only. Eggs were collected and incubated to evaluate the reproductive performance. Blood samples were taken on days 0, 21, and 42 of the trial for the quantification of serum alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). On day 43, one bird per replicate was killed by cervical dislocation to assess the expression of TRAP6 and TGF-ß genes in the UVJ mucosa. Administration of CT or FO + CT increased the egg production rate, fertility rate, and hatchability rate of the set eggs. Fertility duration and sperm penetration rate were higher in partridges receiving FO and (or) CT, but chick quality, and embryonic mortality were not affected by the treatment effect. Administration of CT or FO + CT decreased the serum ALT and AST levels. Administration of FO or CT was associated with a lower expression of TGF-ß mRNA in the UVJ mucosa. Oral administration of FO resulted in a reduction in the expression of TRAP6 in the UVJ mucosa. However, the birds fed with CT or FO + CT recorded a higher mRNA expression for TRAP6. Although the reproductive performance and TRAP6 expression were higher following the feeding of FO or FO + CT, expression of TGF-ß was decreased, suggesting plausibly that TGF-ß may not have a determinant effect on the reproductive attributes in female Chukar partridges. Further studies are required to understand the mechanisms underlying the effects of TRAP6 and TGF-ß on other reproductive criteria in partridges.

Extended transition milk feeding for 3 weeks improves growth performance and reduces the susceptibility to diarrhea in newborn female Holstein calves.

Dairy calves may benefit from extending the duration of feeding transition milk (TM; the subsequent two to six milkings after parturition) to enhance performance and health during early life. The objective of this study was to assess the effect of replacing pasteurized waste milk (non-saleable milk containing antibiotic and/or drug residues) with pasteurized TM for 3 weeks on the growth performance and health of dairy calves. A total of 84 healthy newborn female Holstein calves were blocked by birth order and assigned randomly to 4 treatment groups with partial replacement of pasteurized waste milk by TM (second milkings after parturition) at 0 (0 l/day TM + 6 l/day milk), 0.5 (0.5 l/day TM + 5.5 l/day milk), 1 (1 l/day TM + 5 l/day milk), or 2 l (2 l/day TM + 4 l/day milk) for a 21-day period. From day 22 onward, all calves were fed individually with 6 l/day pasteurized waste milk. Calves were weaned on day 60 and monitored until day 90 of the study. Liquid feed DM intake (DMI) was increased with increasing levels of TM (P = 0.001). Starter feed DMI and total DMI (liquid feed DMI + starter feed DMI) were not affected by the treatment effect. Calves were fed 2 l/day TM gained more BW compared with those in the control group during the postweaning and overall periods. The average daily gain tended (P = 0.06) to be higher in calves fed 2 l/day TM compared with calves fed 0 (+ 65 g/day), 0.5 (+ 53 g/day), or 1 (+ 76 g/day) l/day TM during the preweaning period. Daily weight gain was also higher in calves fed 2 l/day TM compared with calves in the control group during the postweaning (+ 137 g/day; P = 0.04) and overall (+89 g/day; P < 0.01) periods, respectively. Calves fed 2 l/day TM had a higher feed efficiency compared with calves in the control group during all studied periods. The calves fed TM2 had a lower chance of having diarrhea compared with other treatment groups. Duration but not the frequency of diarrhea was lower in calves fed TM2 vs TM0 (2.5 vs 4.2days; P = 0.03). In general, partial replacement of waste milk with TM (2 l/day) may be recommended to feed dairy calves at an early stage of life to support a higher growth rate and health benefits.

The localization and expression of gonadotropin inhibitory hormone in the hypothalamus of turkey hens during the prepubertal, pubertal and postpubertal phases.

Gonadotropin inhibitory hormone (GnIH), initially discovered in birds as a hypothalamic neuropeptide, inhibits the synthesis and release of gonadotropins by affecting GnRH neurons and gonadotropes. Therefore, it may be a key neuropeptide in reproduction in birds. The aim of the present study was to investigate the prepubertal, pubertal, and postpubertal localization of GnIH and changes in hypothalamic GnIH expression in British United Turkey hens. In prepubertal, pubertal, and postpubertal periods, the brains of turkey hens (n = 15) were removed after fixation. Sections (30 µm) were prepared from the entire hypothalamus and stained immunohistochemically against GnIH antibody. Gonadotropin inhibitory hormone-immunoreactive neurons were observed in the paraventricular nucleus. These neurons were significantly more abundant in the prepubertal turkeys than pubertal and postpubertal turkeys (P < 0.05). The results suggested that GnIH neurons have an important role in regulating the pubertal events in British United Turkey hens.

Effects in broiler hens of genetic lines differing in fertility, biotin supplementation, and age on relative abundance of oviductal transforming growth factor-ß and carbonic anhydrase mRNA transcripts.

There was evaluation of effects of biotin administration on oviductal abundance of transforming growth factor-ß (TGF-ß) and carbonic anhydrase (CA) mRNA transcript in younger and older broiler hens of relatively lesser and greater fertility lines. Additionally, effects of biotin supplementation on attenuation of age-related subfertility were evaluated. Hens from the relatively greater (Line D, n = 60) and lesser (Line B, n = 60) fertility rate line were randomly assigned to three treatment groups. Biotin was not or was administered in drinking water from 30 to 33 (younger age) and 53 to 56 (older age) wk of age to have access to no biotin (T0), or 0.3 (T1), or 0.45 (T2) mg/L of biotin. There was assessment the relative oviductal abundances of TGF-ß and CA mRNA transcript abundances. Supplemental biotin and age had no effect on the relative abundance of oviductal TGF-ß mRNA transcript in hens of Line D. There, however, was a ten-fold greater abundance of TGF-ß in hens of the T0 group of Line B compared with Line D. Relative abundance of TGF-ß mRNA transcript was greater in younger hens of Line B; however, biotin supplementation of older hens of the T2 group of Line B resulted in a similar TGF-ß abundance to that of younger hens. Inconstant with the TGF-ß abundance, CA abundance in hens of Line B was not affected by supplemental biotin or bird age. Overall, differences in TGF-ß or CA abundances did not affect fertility of broiler hens.

Extended colostrum feeding for 2 weeks improves growth performance and reduces the susceptibility to diarrhea and pneumonia in neonatal Holstein dairy calves.

The objective of this study was to determine the effect of partial replacement of whole milk with colostrum on the growth performance and health status of Holstein dairy calves. Neonatal heifer calves (n = 144; 2 d of age; 39.3 ± 0.82 kg of body weight, BW; mean ± SE) were assigned randomly to 3 groups with partial replacement of pasteurized whole milk with pasteurized colostrum at 0 (C0; 0 kg/d of colostrum + 5 kg/d of whole milk), 350 g (C350; 0.350 kg/d of colostrum + 4.650 kg/d of whole milk), or 700 g (C700; 0.700 kg/d of colostrum + 4.300 kg/d of whole milk) for 14 d; there were no refusals of liquid feed. From d 15 onward, the calves were fed with 5 kg/d of pasteurized whole milk, weaned on d 61, and monitored until d 81 of life. Throughout the study, the calves had free access to fresh clean water and calf starter. Partial replacement of whole milk with colostrum increased liquid feed dry matter intake (DMI) but decreased milk DMI; however, intakes of starter DMI, total DMI, metabolizable energy, crude protein, and ether extract were not affected by treatments. Overall, the C700 calves recorded greater weaning weight, final BW, heart girth change, feed efficiency, and average daily gain (ADG). The calves fed milk had a higher chance of having rectal temperature ≥39.4°C and general appearance score ≥2 compared with those receiving colostrum in their milk. Diarrhea was more prevalent in C0 versus C700 calves. The occurrence of pneumonia tended to be higher in milk-fed calves compared with C350 and C700 animals. Colostrum feeding resulted in fewer days with a rectal temperature ≥39.4°C, general appearance ≥2, diarrhea, and pneumonia. We computed Cliff's delta (effect sizes) of the extended colostrum feeding (C350 vs. C0, C700 vs. C0, and C700 vs. C350) on starter and milk DMI, ADG, BW, and feed efficiency. In C350 calves, the effect sizes (Cliff's delta) for milk DMI, ADG, BW, and feed efficiency were positive and small, but negative in C700 calves. Compared with C350 treatment, C700 treatment resulted in greater final BW with moderate effect size. Positive and moderate effects of feeding colostrum (C700 vs. C0) were observed on postweaning ADG and final BW. The findings showed that the inclusion of 700 g of colostrum in 5 kg of milk may be beneficial to the growth and health of dairy calves.

Changes in broiler breeder hen's immunity by zinc oxide and phytase.

BACKGROUND: The immune response of aged broiler breeder hens is influenced by many factors including obesity and aged lymphatic organs, but may improve by increasing the bioavailability of various nutrients such as zinc (Zn). Dietary supplementation of phytase can improve Zn availability in senescent broiler breeder hens. AIMS: The aim of this study was to investigate the effect of supplementary zinc oxide (ZnO) and phytase in a maize-soybean meal-based diet on immune responses of broiler breeder hens. METHODS: In a 2 × 4 factorial arrangement, a total of 128 hens were randomly assigned into eight groups. The birds received two levels of phytase (0 or 300 U/kg diet) and four levels of ZnO (30, 60, 90, and 120 mg/kg diet) for 13 successive wk (59-72 wk of age). RESULTS: Results showed that phytase supplementation significantly increased immunoglobulin M (IgM), cutaneous basophil hypersensitivity (CBH) responses, total number of leukocytes, percentage of lymphocytes, and heterophil to lymphocyte ratios. The percentage of basophils and monocytes, however, decreased with phytase supplementation. Supplementation of ZnO increased anti-sheep red blood cells (SRBC) antibody titer, IgM, CBH responses, the total number of leukocytes, and the percentage of lymphocytes. Dietary supplementation of ZnO decreased the percentage of heterophil, and heterophil to lymphocyte ratio. A significant interaction effect of phytase and ZnO was found on the total number of leukocytes and percentage of lymphocytes. CONCLUSION: Dietary supplementation of ZnO (90 mg/kg diet) and phytase had some positive effects on improving immune responses in broiler breeder hens.

Introducing a combined Leishman-Giemsa stain as a new staining technique for avian blood smears.

BACKGROUND: The use of conventional stains including Giemsa, Wright and Leishman have become an essential tool for differential diagnosis of cells in peripheral blood. AIMS: The aim of the study was to develop a new combination of Leishman-Giemsa (L&G) stain for avian blood smears and to compare its efficacy with conventional staining methods. METHODS: Three sets of peripheral blood smears, one smear for L&G stain and two other smears for Leishman and Giemsa stains, created from 50 broiler chickens blood samples. All the three sets of slides were blind screened by two expert clinical pathologists and scored based on the staining characteristics (4 parameters) such as nuclear features of red blood cell (RBC) and white blood cell (WBC), cytoplasmic features and cytoplasmic granularity of WBC. The average grading score assigned by two experts for each staining method were compared. RESULTS: The average grading score of two conventional Leishman and Giemsa staining methods were significantly lower (P<0.001) than new L&G staining method in avian nuclear features of the RBC and WBC. The L&G stain gave a better clarity of nuclear features of avian RBC and WBC. The new L&G staining technique created significant differences (P<0.001) in cytoplasmic features of avian WBC compared to the other two methods. CONCLUSIONS: For the first time, the results of the present study showed that the avian blood cells are more desirable stained with a new combination of L&G stain. In addition, it gives a better nuclear and cytoplasmic differential staining than the conventional Giemsa and Leishman stains when used alone.

The long-term oral administration of thyroxine: effects on blood hematological and biochemical features in broiler breeder hens.

Published data on the beneficial effect of short-term administration of thyroxine (T4) in broiler breeder hens to reduce the ascites incidence in their progeny chicks raises the question as to what extent might the long-term maternal administration of T4 affect the blood hematological and biochemical attributes in breeder hens. A total of 70 broiler breeder hens (47-wk-old) were randomly allotted to control or thyroxine treated (T4) groups. Pure T4 (0.3 mg/bird per day) was orally administered to T4 birds for 14 successive weeks, whereas the control group received the drinking water only. Blood samples were obtained from the brachial vein prior to the initiation of the trial as well as weeks 50, 53, 55, 57, 59, and 61 of age. Body weight was decreased but egg production was not affected by T4 treatment. Plasma concentration of T4, but not triiodothyronine (T3), was increased in T4-treated hens (P < 0.05). The total number of leukocytes and erythrocytes were also higher in T4 birds. A significant effect of time was observed for erythrocyte number and plasma cholesterol concentration (P < 0.05). The long-term administration of T4 did not affect the concentrations of serum calcium and plasma total protein, albumin, globulin, cholesterol, triglyceride, high density lipoprotein, low density lipoprotein, very low density lipoprotein, alanine amino transferase, and aspartate amino transferase (P > 0.05). However, serum concentrations of phosphorus, glucose, and alkaline phosphatase were higher in T4 hens as compared to their control counterparts. In spite of differences in circulatory concentrations of a number of traits between the experimental groups, the recorded values were within their reference ranges. Therefore, the administration of T4 for an extended period of time had no apparent adverse effect on the clinical profile in subjected hens, which may practically support the implementation of this preventative treatment as an approach to decrease the ascites incidence; however, a lower incidence rate in the progeny chicks produced from hens receiving T4 for long-term periods of time remains to be elucidated.

Sperm characteristics of Chukar partridge (Alectoris chukar) breeders as affected by the addition of calcitriol to the semen extender.

This study was carried out to determine the effect of supplementing the semen extender with calcitriol on in vitro sperm characteristics in Chukar partridges. A total of 60 male Chukar partridges were habituated for semen collection by abdominal massage. Pooled ejaculates from several males were extended (1 to 5 v/v ratio) in the Sexton's diluent containing 0, 24, 48, 96, or 192 µg calcitriol/mL. These concentrations represented 0-, 2-, 4-, 8-, and 16-fold levels of the mean seminal calcitriol concentration, respectively. A total of 12 subsamples from each treatment group were kept at 4 to 5°C or 19 to 24°C for 4, 24, or 48 h. The percentages of motile sperm, live sperm, abnormal sperm, incidence of hypoosmotic swelling (HOS), and thiobarbituric acid reactive species (TBARS) concentrations were determined. The data were analyzed by the xtmixed procedure of STATA software. The percentages of motile sperm, live sperm, abnormal sperm, and seminal TBARS were affected by calcitriol (P < 0.05). There was no effect of treatments on HOS (P > 0.05). There was an interaction effect between calcitriol, storage time, and storage temperature on sperm motility, sperm viability, and seminal TBARS. Supplementation of the diluent with 96 µg calcitriol/mL resulted in the highest sperm motility at 4°C. Also, the same treatment group recorded the highest sperm viability and lowest seminal TBARS at 19 to 24°C. Supplementing the diluent with calcitriol had beneficial effects on spermatozoa; however, the fertility rate of spermatozoa extended in calcitriol-supplemented diluent needs to be determined before the procedure can be recommended for use in artificial insemination programs.

Effects of dietary curcumin supplementation on seminal quality indices and fertility rate in broiler breeder roosters.

1. Decreased semen quality is an underlying contributor to age-related subfertility in broiler breeder roosters. This study investigated the effects of dietary curcumin (derived from turmeric) supplementation as an antioxidant source on semen quality and fertility in broiler breeder roosters. 2. Twenty-eight Ross 308 roosters were randomly allotted to four groups with seven birds in each and were fed a standard diet supplemented with different levels of curcumin at 0 (C0), 10 (C10), 20 (C20) and 30 (C30) mg/bird per day from 48 through to 61 weeks of age. Body weight and semen quality traits were evaluated on a weekly basis and seminal concentrations of malondialdehyde (MDA) as a measure of antioxidation status were quantified at one-week intervals during the first 11 weeks of the trial (48-59 weeks of age). Semen samples from last 2 weeks (60 and 61 weeks of age) were used to artificially inseminate to assess the sperm-egg penetration (SP) in perivitelline membrane and fertility rates. 3. Except for body weight and ejaculate volume, other characteristics, including semen concentration, total sperm production, progressive motility and plasma membrane integrity were linearly improved by the increasing levels of curcumin supplementation (P < 0.01). However, dietary curcumin levels were linearly and quadratically associated with decreased seminal concentration of MDA (P < 0.01 and P < 0.03), percentage of abnormal sperm (P < 0.01 and P < 0.07) and increased plasma membrane functionality (P < 0.01 and P < 0.04), respectively. The SP holes in perivitelline membrane were increased in a linear and quadratic manner in response to increasing levels of curcumin (P < 0.01). Moreover, fertility rate was linearly improved (P < 0.01) as the dosage of curcumin increased, and resulted in 8, 12 and 14% improvements in the birds fed C10, C20 and C30, compared to C0, respectively. 4. In conclusion, the results showed that increasing levels of dietary supplementation of curcumin was associated with beneficial effects on semen quality indices and fertility rate in aged broiler breeder roosters.

TGF-ß4 and HSP70 responses in breeder hens treated with thyroxine.

A hypothesis was tested that long-term administration of thyroxine (T4) in broiler breeder hens would affect fertility, sperm penetration rate, and the duration of fertility. Relative abundance of oviductal TGF-ß4 and HSP70 mRNA was determined to ascertain whether T4 treatment affected these genes, and modulated the sustained storage of spermatozoa within the uterovaginal sperm storage tubules of hens. A total of 70, 47-week-old Cobb 500 breeder hens was randomly allotted to two treatment groups (T4 treatment (ET) and control). The T4 was orally administered to the ET group (0.3 mg T4/bird/day) for 100 consecutive days; whereas the control group was not administered T4 during the experimental period. Breeder hens were artificially inseminated to evaluate specific reproductive variables. On the last day of the treatment period two hens /replicate were randomly killed to estimate oviductal gene expression. The T4 treatment resulted in an increase in plasma concentration of T4; however, the T3 concentration was not affected. The long term administration of T4 had no effect on fertility; however, it resulted in a decreased sperm penetration rate and decreased the duration of fertility compared with the control group. The relative abundance of TGF-ß4 and HSP70 mRNA in the SST was not influenced by T4 supplementation. The correlation coefficients between fertility and sperm penetration rate with relative abundance of TGF-ß4 and HSP70 were not significant. Overall, among the diverse reproductive variable assessed in the current study, the sperm penetration rate and the duration of fertility were most responsive to long-term treatment with T4.

Histomorphometrical changes of oviduct during the long-term exposure of breeder hens to extra thyroxine.

In this research a 100 day long treatment period was considered to unmask the probable adverse effects of long-term induced hyperthyroidism on histomorphometrical attributes of the oviduct in broiler breeder hens. A total of seventy 47-week-old Cobb 500 breeder hens were randomly allotted to two treatment groups (5 replicates of 7 hens each). Thyroxine (T4) was orally administered to the hyperthyroid group (0.3 mg/bird/d) for 100 consecutive days; whereas the control group received drinking water only throughout the trial. At 64 weeks of age, 2 birds per replicate were killed by cervical dislocation and their oviducts were removed. For histomorphometrical observations, segments were taken from five different regions. After tissue preparation and staining with haematoxylin and eosin, histological layers were evaluated using light microscopy. The assessment of histomorphometrical characteristics of oviduct showed the height of mucosal folds in the magnum, thickness of mucosal folds of the magnum and uterus, thickness of tunica muscularis in the magnum and vagina, epithelial thickness of the isthmus and vagina, and uterine tubular glands percentage were decreased in the hyperthyroid birds compared with the control counterparts. The results showed long-term induced hyperthyroidism was associated with a decrease in a number of histomorphometrical traits in different regions of the oviduct. Some studies should be done to clarify to what extent the long-term maternal hyperthyroidism might affect the egg production, fertility rate, duration of fertility, and sperm penetration rate to make a final decision on exploitation of this preventative treatment to diminish the ascites incidence in progeny chicks.

Is immunosuppression, induced by neonatal thymectomy, compatible with poor reproductive performance in adult male rats?

With increasing knowledge that the immune system has a major impact on reproductive health, the potential for cells arising in organs such as the thymus to alleviate oxidative stress has been revealed. This study addresses the impact of neonatal thymectomy on male reproductive function in pubertal and adult animals. Neonatal Sprague Dawley rats were allotted to four treatments consisting of fully thymectomized, partially thymectomized, intact, and sham-operated rats. Half of the rats in each treatment were sacrificed at 40 and the other half at 80 days of age. Testicular volume, ventral prostate and spleen weight, several sperm attributes (concentration, motility, livability, membrane integrity, sperm penetration into mucus, total antioxidant capacity, mitochondrial dehydrogenase activity), plasma superoxide dismutase, glutathione, and testosterone level as well as fertility decreased in thymectomized rats. Adrenal gland weight, sperm malondialdehyde level, indices of oxidative stress, sperm abnormality, testicular and sperm lipid peroxidation, protein carbonylation, and sperm reactive oxygen species generation increased in thymectomized rats. In thymectomized rats, the testes contained high levels of malondialdehyde but low levels of glutathione and ferric-reducing antioxidant power. Epididymal sperm reactive oxygen species, blood lipid peroxidation, and oxidative stress indices in blood and spermatozoa were highest in fully thymectomized, intermediate in partially thymectomized, and lowest in both pubertal and mature control rats. Blood levels of superoxide dismutase, lipid peroxidation indices, and testosterone, and mitochondrial adenosine triphosphate and dehydrogenase activities in epididymal spermatozoa were lowest in fully thymectomized, intermediate in partially thymectomized, and highest in both pubertal and mature control rats. The data indicated that increased oxidative stress and mitochondrial dysfunction might play a role in the mechanism of immunosuppression-induced testicular and sperm abnormalities.

Eggshell temperature manipulations during incubation and in ovo injection of thyroxine are associated with a decreased incidence of cold-induced ascites in broiler chickens.

A hypothesis was tested that eggshell temperature manipulations during incubation and in ovo injection of thyroxine (T4) would help their progeny chicks to better survive the ascites-inducing condition during the growing period. In experiment 1, a total of 4,800 hatching eggs was randomly arranged in a 2 × 4 factorial design (8 replicates of 75 eggs per treatment), in which the eggs were incubated at a constant eggshell temperature (EST) of 37.8°C throughout the incubation period (CON) or were exposed to 15°C for one h on d 11, 13, 15, and 17 of incubation (EST manipulations; ESTM), and 4 treatment groups of 3 control groups (no injection; INJN, needle pricked; INJP, and sterilized distilled water injection; INJW) and one T4 treatment group (injected with sterilized distilled water containing 65 ng of T4; INJT4). In experiment 2, 240 one-day-old male broiler chicks from 2 temperature conditions and injection (INJN and INJT4) treatment groups were reared for 42 d in a completely randomized design with a 2 × 2 factorial arrangement. To induce ascites, all chicks were exposed to a 15°C room temperature from 14 d onwards. Results from experiment 1 showed that second-grade chicks and yolk sac weight were decreased, and body weight at hatch was increased in the ESTM and INJT4 groups. Also, final body weight was increased in the ESTM group. Ascites mortality rate was decreased in the ESTM and INJT4 groups. In the ESTM and INJT4 groups, the red blood cell (RBC) and the packed cell volume (PCV) count were decreased. In conclusion, the results showed that the ESTM and INJT4 treatments during incubation were associated with improved chick quality, productive performance of broilers, and a decreased incidence of cold-induced ascites in broiler chickens.

Periodical low eggshell temperatures during incubation and post hatch dietary arginine supplementation: Effects on performance and cold tolerance acquisition in broilers.

An experiment was conducted to evaluate the effects of a periodically low eggshell temperature exposure during incubation and dietary supplementation of arginine on performance, ascites incidence, and cold tolerance acquisition in broilers. A total of 2,400 hatching eggs were randomly assigned to 2 treatment groups (16 replicates of 75 eggs per treatment). The eggs were incubated at a constant eggshell temperature (EST) of 37.8ºC throughout the incubation period (CON) or were periodically exposed to 15°C for one hour on days 11, 13, 15, and 17 of incubation and the EST was measured (periodical low EST; PLE). After hatching, 240 one-day-old male broiler chicks from both treatment groups were reared for 42 d with or without dietary arginine supplementation in a completely randomized design with a 2 × 2 factorial arrangement. In order to induce ascites, all chicks were exposed to a 15°C room temperature from 14 d onwards. Results showed that second grade chicks and yolk sac weight were decreased, and final body weight was increased in the PLE group. Ascites mortality rate was decreased only in the PLE group and dietary arginine supplementation had no apparent effect. In the PLE group, the packed cell volume (PCV) percentage and red blood cell (RBC) count were decreased. In conclusion, the results showed that the PLE treatment during incubation was associated with improved hatchability, chick quality, and productive performance of broilers and decreased ascites incidence during post hatch cold exposure. Dietary arginine supplementation had no beneficial effects in cold exposed broilers.

Effect of feeding guanidinoacetic acid and L-arginine on the fertility rate and sperm penetration in the perivitelline layer of aged broiler breeder hens.

Two experiments were conducted to evaluate the effects of feeding guanidinoacetic acid (GAA) and L-arginine (ARG) on fertility and sperm penetration (SP) rate of broiler breeder hens. In the first experiment, a total of 200 broiler breeder hens (Ross 308) aged 53 weeks were randomly allotted to four dietary treatments (0, 0.6, 1.2 and 1.8 g GAA/kg diet) with five replicates of 10 birds each. In the second experiment, 320 broiler breeder hens (Ross 308) were used from 53 to 62 weeks of age in a 2 × 4 factorial arrangement (0 or 1.2 g GAA/kg diet along with 0, 3, 6 or 9 g ARG/kg diet). The hens received a diet containing 2800 kcal ME/kg and 14% CP. Sixteen sexually mature Ross 308 breeder roosters (34 weeks old) were used to artificially inseminate the hens. Fertility of the hens was determined in 61 and 62 weeks of age. The sperm penetration holes in the inner perivitelline layer (IPL) overlying the germinal disc were enumerated on days 3 and 7 following each insemination. Adding GAA to the breeder diet increased the number of SPs in the IPL and fertility in both experiments (p < 0.01). The interactive effect of ARG and GAA on the SP and fertility was significant. Supplementary ARG increased the SP rate in the IPL (p < 0.01). In conclusion, dietary supplementation of GAA and ARG might be potentially used to improve the fertility of broiler breeder hens at the later phase of the egg production period.

Oral administration of supplementary biotin differentially influences the fertility rate and oviductal expression of avidin and avidin-related protein-2 in low- and high-fertility broiler line hens.

Probable involvement of avidin and avidin-related protein-2 (AVR2) in sperm viability in the sperm storage tubules of turkeys has been suggested. The high affinity of biotin to avidin and its analogs is also well documented. The present study aimed to determine the effect of oral biotin on reproductive performance and oviductal mRNA expression of avidin and AVR2 in 2 broiler hen lines with different fertility rates. Low-fertility (line B) and high-fertility (line D) hens (n=144) were randomly allotted to receive 0 (T0), 0.30 (T1), or 0.45 (T2) mg/L biotin in drinking water from 30 through 33 wk of age. The reproductive performance of the hens was evaluated using artificial insemination. At the end of the treatment period, 24 hens per line were killed to assay the expression of avidin and AVR2 in the uterovaginal junction. Supplementary biotin increased egg production from 73.5% for T0 to 87.8% for T2. Hens administered with biotin in line B, but not in line D, showed an increase (8.4%) in fertility rate. Hatchability, chick quality, and overall embryonic mortality were not different among the experimental groups. Real-time PCR data showed that both avidin (P=0.0013) and AVR2 (P<0.0001) expressions were influenced by a biotin×line interaction effect, where low-fertility line B hens receiving the high biotin level recorded respectively a 3.9 and 15.3% increase in avidin and AVR2 mRNA expression, although biotin did not affect these traits in line D hens. Control hens in line D had a dramatically higher AVR2 expression record (7.4-fold) compared with the control hens in line B. The correlation coefficients of fertility rate and avidin expression were 0.73 and 0.66 in lines B and D, respectively. However, the correlation of fertility and AVR2 (r=0.65) was significant for line D hens only. Overall, fertility rate and oviductal expression of avidin and AVR2 were dichotomously affected by oral biotin in low- and high-fertility line hens, where only low-fertility birds showed improvements in these attributes.

Effect of thymol and carvacrol on nutrient digestibility in rams fed high or low concentrate diets.

Published data on the effects of essential oils (EO) on in vivo nutrient digestibility in sheep are contradictory. In 2 experiments, the effect of thymol and carvacrol on nutrient digestibility was studied in sheep fed with high (70%) or low (52%) concentrate diets, using incomplete Latin Square designs. The essential oils were mixed with the concentrate portion of the diet at the rate of 0.0, 0.3, or 0.6 g per kg dry matter (DM) diet. Supplementation of thymol had no significant effect on digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and acid detergent fiber (ADF). The main effect of thymol on neutral detergent fiber (NDF) and ether extract (EE) digestibility and on nitrogen balance (NB) was significant (P<0.05), but within each level of dietary concentrate no significant differences were observed for these measurements. Overall, ruminal ammonia concentration was higher (P<0.05) in both HCD and LCD lambs receiving 0.3 mg thymol per kg diet. Supplementation of carvacrol had no significant effect on nutrient digestibility. The main effect of carvacrol on ruminal ammonia levels and NB was significant, but within each level of dietary concentrate no significant differences were observed in ammonia levels and NB. Inclusion of 0.3 g/kg diet DM of carvacrol or thyme was more effective than 0.6 g/kg diet DM in terms of NB but neither dose affected nutrient digestibility. Future research should determine the long-term effects of essential oils on digestibility and performance in sheep, before recommendation can be made for their use under practical husbandry conditions.

The endometrial expression of prostaglandin cascade components in lactating dairy cows fed different polyunsaturated fatty acids.

Feeding n-6 polyunsaturated fatty acids (PUFA) increases the endometrial percentages of linoleic and arachidonic acids (AA), enhances the synthesis of prostaglandin F2α (PGF2α), and improves uterine health. In contrary, the n-3 PUFA, eicosapentaenoic acid, and docosahexaenoic acid may play pivotal roles by suppressing the synthesis of uterine PGF2α, a component being centrally involved in the control of the bovine estrous cycle and in early embryo survival. The objectives of the present study were to determine the effect of feeding a diet enriched in either α-linolenic acid (n-3) or linolenic acid (n-6) on the uterine expression of genes related to prostaglandin cascade and uterine release of PGF2α (measured as 13, 14-dihydro-15-keto PGF2α [PGFM]). From calving to 60 days in milk, cows (n = 24) were fed isonitrogenous, isocaloric, and isolipidic diets that differed in the ratio of n-3/n-6 PUFA. Treatments including palm oil ([PLM]; saturated FA, n = 8), soybean whole roast ([SOY]; n-6, n = 8), and linseed extruded ([LIN]; n-3, n = 8). At 30 days in milk, the ovulatory cycles of cows were synchronized using 2 injections of PGF2α with a 14-day interval. On day 15 postovulation, cows were injected with oxytocin and blood samples were collected to monitor the uterine release of PGF2α (measured as PGFM) and uterine endometrial biopsies were prepared to evaluate the expression of genes related to prostaglandin cascade (prostaglandin F synthase [PGFS], prostaglandin E synthase [PGES], prostaglandin endoperoxide synthase-2 [PGHS-2]), phospholipase A2 (PLA2), peroxisome proliferator-activated receptors [PPAR]). Results showed that uterine endometrial PPAR-δ genes were higher in cows fed LIN (3.17-fold) compared with cows fed PLM or SOY (P < 0.05). The messenger RNA (mRNA) level of PGES in the LIN group was threefold as high as those found in SOY and PLM diets (P < 0.05). The mean relative gene expression of PLA2 and PGFS was increased in animals fed the SOY diet (2.4- and 1.7-fold, respectively) compared with LIN and PLM diets (P < 0.05). The expression of mRNA for the PGHS-2, PPAR-α, and PPAR-γ was not influenced by the diet effect. Dietary inclusion of soy FAs was associated with an increase in the PGFM concentration, possibly through an increase in the expression of genes involved in prostaglandin cascade. The uterine concentration of PGFM, however, was decreased in cows fed diets containing n-3 FAs.