Effect of sequential feeding using whole cereal grains during finishing period in male mule ducks (Carina moschata × Anas platyrinchos)

The feeding of waterfowl for fatty liver production is largely based on the use of completely pelleted feed. To reduce both the economic and environmental costs caused by transport and processing of feed and to respond to consumer demands for natural feeding systems, the use of whole grains has increased recently. The aim of this trial was to study the influence of 1) sequential feeding based on cereal grain and 2) cereal type (corn or triticale) during the finishing period on performance traits in male mule ducks. Present results suggest that a sequential feeding system modifies feeding behavior, growth, and body traits, and reduces feed intake during the finishing period (−6 and −10% for corn and triticale, respectively), but has no effect on performance during the overfeeding period. This system offers interesting prospects for a more sustainable rearing method, and the use of locally grown grains could reduce both the economic and environmental impacts of duck feeding.     

Comparative study on 15-ketodihydro-PGF(2α) plasma concentrations in newborn horses, donkeys and calves

The aim of this study was to compare the plasma profiles of 15-ketodihydro-PGF(2α) (PGM) in healthy neonates of three different species from birth until the third week of life. Twenty-four horse foals, 12 donkey foals, and 9 calves were studied. Blood samples were collected at 10, 20 and 30 min after birth, at 3, 24 and 72 h after birth, and at 7, 10, 17 and 21 days of life. All mothers experienced normal gestation lengths and normal, spontaneous deliveries. All newborns were judged mature and viable. Hormone concentrations were higher (p < 0.05) in horse foals 20 and 30 min after birth compared to later samples, and at 10 min in donkey foals compared to later samples (p < 0.05). In calves, higher (p < 0.05) concentrations of PGM were observed 10, 20, 30 min and 3 hours from parturition compared to later samples. These findings may be related to increased fetal placental unit production during parturition, while the relatively high PGF(2α) levels in the days after parturition may be connected with their role in completing organ maturation. Despite the existing differences between these species, the statistical analysis did not discover significant differences in PGM profiles during the first 3 weeks of life in donkey, horse and cattle newborns. The low levels observed 10 days after birth are possibly due to a fast completion of maturational development in these species.     

Changes in the plasma concentrations of prolactin,luteinising hormone,progesterone and d‐(β)‐hydroxybutyrate in turkey hens (meleagris gallopavo), during treatment of broodiness under commercial conditions

1. An experiment was done under commercial conditions to investigate the physiological effects of isolating broody turkey hens, for 72 h, in sand and wire floored pens on the third, 10th and 16th weeks of production.

2. Hens identified as broody and removed from the flock had higher plasma prolactin concentrations than the laying hens at each of the three experimental stages.

3. Confinement in sand and wire floored pens, induced a decline in plasma prolactin concentrations. This decline probably impeded immediate development of broody behaviour. Alternately, levels of prolactin higher than those of laying hens were again measured 7 and 14 days after treatment during third week but not after the 10 th and 16th week of production.

4. Confinement did not induce consistent changes in luteinising hormone (LH) and progesterone concentrations from one period to an other.

5. An increase in the plasma concentration of D‐(/?)‐hydroxybutyrate was observed in the hens which had an egg present in the oviduct on day 2, 3 and/or 4 of the treatment. Subsequently, a decrease in ovulation rate was observed in the hens with higher concentrations of D‐(β)‐hydroxybutyrate while under treatment, during the 10th week of production.

6. These data confirm that the effectiveness of the traditional methods for broodiness prevention under commercial conditions is related to the induction of a decrease of prolactin.     

Effects of sex‐linked imperfect albinism in the chicken (s al‐c) on plasma luteinising hormone concentrations and early egg production

1. When measured before and after the onset of darkness, plasma LH concentrations in 40‐day‐old sex‐linked albino pullets (s^al‐c ) were slightly lower than those of nonalbinos (s ⁺ ).

2. This finding prompted an experiment in which plasma LH concentrations were measured between 12 and 33 weeks of age when daylength was increased at 15 or 21 weeks. Egg production of the early and late maturing albino hens was measured.

3. Plasma LH concentrations overall and at 17 weeks were lower for albinos than for nonalbinos. In the early maturing group egg production of albinos was higher than that of nonalbinos.

4. Results suggest that increased egg production of albinos is not the direct result of differences in plasma LH concentrations but may be a consequence of differences in the control of LH secretion.     

Changes in plasma gonadotrophins, 17β-oestradiol,progesterone, prolactin,thyroxine and triiodothyronine concentrations in female Japanese quail (Coturnix coturnix japonica) of a heavy body weight line during photo-induced ovarian growth and regression

1. Simultaneous changes of the width of the cloacal opening and plasma luteinising hormone (LH), follicle stimulating hormone (FSH), 17β-oestradiol, progesterone, prolactin, thyroxine (T₄) and triiodothyronine (T₃) during photo-induced ovarian growth and regression were measured in commercially bred Japanese quail from a heavy body weight line.

2. Somatically mature female Japanese quail were transferred from short days (light:dark 8L:16D) at 10°C to long days (16L:8D) at 20°C, and sexually mature female Japanese quail were transferred from long to short days. All variables were measured at transfer and every five days thereafter (except for a measurement at 12 instead of 10?d) for 35?d.

3. Transfer from short to long days caused significant increases in LH, FSH, 17β-oestradiol, ovary weights and oviduct weights after five days, and in the cloacal opening after 12?d. T₃ decreased after five days, whereas no significant changes were observed in T₄ concentrations. Progesterone and prolactin both decreased after 25 long days.

4. The transfer of quail from long to short days caused significant decreases in LH, FSH, 17β-oestradiol, progesterone, prolactin, ovary and oviduct weights after 12?d and an increase in T₃. There was no significant change in T₄ concentrations. The cloacal opening decreased after 25 short days.

5. These results are the first to show simultaneous changes in gonadotrophins, sex steroids, thyroid hormones and prolactin during photo-induced gonadal growth and regression in female Japanese quail.     

Effect of aglepristone (RU534) administration during follicular phase on progesterone,estradiol-17β and LH serum concentrations in bitches

Aglepristone was administered in bitches during the follicular phase to evaluate its effects on progesterone, estradiol-17β and LH serum concentrations. Ten German Shepherds were divided into two groups (treated n = 5; control n = 5). Treated bitches received 10 mg/kg BW of aglepristone subcutaneously during the early follicular phase, 24 hr after and then 7 days later. The control group was injected, at the same time periods, with saline solution (0.3 ml/kg BW). For the steroid evaluations, blood was collected daily from the onset of proestrus until the first day of cytological dioestrus. For LH base-line serum determination, blood was also collected every 20 min for 2 hr at the onset of proestrus. For LH surge identification, blood was collected daily (every 6 hr) starting from the day of the first administration of aglepristone or saline solution until the first day of dioestrus. All animals ovulated but the treated group presented longer ovulation-dioestrus intervals than the control group (5.2 ± 2.2 days p < .05). Serum concentrations of the evaluated hormones were similar between experimental animals except for serum LH. Indeed, no LH peaks were detected in the treated group while LH surges were clearly observed in the control group (9 ± 1 days after the beginning of proestrus. In particular, the area under the curve for LH was significantly lower in treated than control animals (12 ± 4 ng/ml x Day; p = .01). In conclusion, administrations of aglepristone during the follicular phase of the bitch does not affect the steroid hormone patterns but does prevent the occurrence of a LH surge. This work raises significant questions and opens perspectives concerning the mechanisms of ovulation in bitches.