Impact of selection for residual feed intake on production traits and behavior of mule ducks.

A divergent selection experiment of Muscovy sires based on the residual feed intake (RFI) of their male mule progeny was initiated in 2009. Using electronic feeders, the aim of this study was to establish whether 3 generations of selection for RFI had an impact on feeding behavior traits and general behavior, and to examine its effect on liver and meat quality. Eighty mule ducks, issued from 8 Muscovy drakes per line with extreme RFI, were tested in a pen equipped with 4 electronic feeders. Feeding behaviors were recorded from 3 to 7 wk after hatching under ad libitum feeding conditions. Then animals were prepared for overfeeding with a 3-week period of restricted feeding, and overfed during 12 d before slaughter. The RFI was significantly lower in the low RFI line than in the high RFI line (-5.4 g/d, P = 0.0005) and daily feed intake was reduced both over the entire test period (-5 g/d, P = 0.049) and on a weekly basis (P = 0.006). Weekly and total feed conversion ratios were also significantly lower (-0.08, P = 0.03 and -0.06, P = 0.01, respectively). Low RFI ducks had more frequent meals, spent as much time eating as high RFI ducks, and their feeding rate was lower when analyzed at the wk level only. Additionally no significant correlation between feed efficiency and feeding behavior traits was evidenced, indicating only limited relationships between RFI and feeding patterns. Some differences in behavioral responses to stressors (open field test combined with a test measuring the response to human presence) suggested that a lower RFI is associated with less fearfulness. Selection for RFI had no effect on liver weight and quality and a slightly deleterious impact on meat quality (decreased drip loss and L*). Finally, low RFI animals had higher body weights after restricted feeding from wk 10 to wk 12 and after overfeeding than high RFI ducks. This suggests that selection for reduced RFI until 7 wk of age increases the feed efficiency up to slaughter.

Detailed analysis of the individual feeding behavior of male and female mule ducks.

The feeding behavior of 19 mule ducks (males and females) bred in a group was studied during their growth phase (between 3 and 8 wk of age) using the recording system for waterfowl feeding behavior developed in our lab. The basic feeding behavior data obtained allowed us to confirm on the one hand the reliability of our tool and, on the other hand, to compute food intake traits per day (ADFI, number of visits, and time spent feeding per day), per visit (feed intake per visit, visit duration, and visit feeding rate), and per meal (meal size, meal duration, and meal feeding rate). Daily feed intake increased with age (130 to 248 g/d) while the time spent feeding decreased from 14 to 5.5 min/d. Because the duration of visits remained stable (average 45 s), this reflected a decrease in the number of visits per day. At the same time the feed intake per visit and the feeding rate per visit increased sharply with age. The same trend was observed at the meal level for both the feed intake and the feeding rate. Feed intake did not differ between males and females, but the time spent feeding was significantly greater for females than for males (10.8 and 8.9 min per day and 53 and 37 s per visit for females and males, respectively), leading to significantly greater feeding rate for males (30 g/min) than for females (24 g/min). Grouping visits in meal events minimized the differences between genders as the meals tended to comprise fewer visits for females. Under the hypothesis of a genetic link between feeding behavior during growth and force-feeding ability of ducks, genetic selection of these behavioral traits could be included in breeding programs to improve the force-feeding capacity of mule ducks.

Feeding behaviour of artificially reared Romane lambs.

A consequence of increasing litter size in sheep is that a portion of the lambs have to be reared artificially. Detailed information about the pattern of milk consumption of artificially reared lambs would help improve their management. The purpose of this study is to describe the individual and group feeding behaviour of 94 Romane artificially reared lambs from 5 to 28 days of age using an electronic automatic lamb feeder. Animals were located in four pens of 8 to 15 lambs of similar age with one teat per pen. They were fed ad libitum. In our experimental situation (group rearing, continuous lightning) on average a lamb made 1.4±0.7 visits to the teat per meal and 9.5±3 meals per day. Mean meal duration was 247±158 s and the mean daily time spent feeding was 38±25 min. The mean quantity of milk intake was 176±132 ml per meal and 1.68±0.8 l per day. With age, the number of daily meals and their duration decreased while the quantity of milk consumed per meal and per day increased. Females tended to make more visits to the teat per meal and perform more meals per day but their milk consumption per meal was lower. The feed conversion ratio was 1.36±0.2. Synchrony in feeding (group meal) was estimated as the percentage of lambs that wanted to access the teat within the same short period (relative group meal size). On average 65% of lambs in the pen wanted to access the teat within the same period, but for 35% of group meals the relative group meal size was >90%. There was no consistency in the order in which lambs accessed the teat during a group meal. Our evaluation suggested that electronic automatic lamb feeders are tools that can provide, on a large scale, data describing the feeding behaviour of artificially reared lambs. It is then possible to study factors influencing these traits in order to improve the outcome of artificially reared lambs.

[A look into the past: improves in obstetrical and neonatal outcome in maternity since the 19th century]. / Un regard dans le passé : évolution du devenir materno-fœtal en maternité depuis le xixe siècle.

OBJECTIVE: Evaluate changes in obstetrical and neonatal outcome of women who delivered in maternity hospital since the 19(th) century. MATERIALS AND METHODS: Data from a historic cohort of 1022 women who delivered between 1871 and 1874 in the hôtel Dieu hospital of Marseille were compared to those from 1159 women who delivered from 2005 to 2006 in the level 3 maternity of Nord hospital of Marseille (contemporary cohort). Deliveries that had occured before 22 weeks and/or with a foetal birth weight of less than 500 g were excluded. RESULTS: A total of 2131 pregnancies were included: 1011 and 1120 in historic and contemporary cohort, respectively. Despite comparable mean term of delivery, mean birth weight of neonates from historic cohort were significantly lower: 2971 g (550-4900 g) vs 3250 g (500-5375 g), respectively (p<0.001). Stillbirths were reported in 72 (7.1%) cases in historic cohort compared to nine (0.8%) in contemporary cohort (p<0.001). Neonatal mortality was 3.7% in historic cohort and 1.9% in contemporary cohort (p=0.012). A total of 99 (9.8%) maternal deaths were reported in historic cohort, while none in contemporary cohort (p<0.001). A wide majority of maternal deaths were caused by maternal infection (72.9%); 5.2% were caused by postpartum haemorrhage. CONCLUSION: Our results illustrate the tremendous impact on maternal and neonatal outcome of advances in obstetrical management. The significant increase in the median foetal birth weight is likely to be related to wide changes in environmental conditions and behaviour.