A study was conducted comparing ovary and oviduct development following photostimulation in two lines of turkey breeder stocks (female line and male line). Birds were euthanatized for assessment of reproductive organ morphology at 3-d intervals following photostimulation (203 d of age) to 245 d and on the day following their first oviposition. The age at first oviposition was similar for both lines. Male line birds were 3 to 4 kg heavier than female line birds throughout the study, but had lower abdominal fat pad weights when expressed as a percentage of BW. Female line birds had significantly more total carcass lipid as a percentage of BW than male line birds (24.76 vs 22.79%, respectively). Male line birds had significantly more large ovarian follicles with a greater proportion in a triple or greater hierarchical arrangement at first egg. To determine the incidence of unreconciled ovulations (presumed to be internally ovulated follicles and defined as ovulations occurring prior to first oviposition), postovulatory follicles on the ovary were reconciled with observed ovipositions and the developing eggs that were in the oviduct at the time of study. On average, male line hens had 3.0 unreconciled postovulatory follicles at first egg, whereas the female line hens had 1.6. The incidence of birds with physical remnants of internal ovulation was correlated (r = 0.44) to the number of unreconciled ovulations. The developing oviduct of the female line birds reached its mature weight (84.8 g) 3 d earlier than the ovary did. The developing ovary and oviduct of the male line hens reached their mature weights on the same day. The development of the male line oviduct is seemingly accelerated relative to that of the ovary, resulting in lost ovulations early in lay.

The effect of level of removal of current season's shoots of heather (0. 40 and 80% ofthe dry matter ofthe shoots) in the summer and autumn on the intake and diet selection by grazing Scottish Blackface wether sheep was examined in an experiment conducted over two years in which all combinations of level and season of grazing were provided. The treatment plots were grazed for 5 weeks at any one time and measurements made of intake and diet selection in weeks 2 and 5.In both the summer and autumn grazing periods level of removal in week 2 had little efTect on the quality of the diet selected. In week 5, digestibility of organic matter was higher for the 40% than the 80% level of removal in the summer (0-543 vs 0-508) and particularly in the autumn (0-503 vs 0-449). Digestibility of the diet selected was higher in week 2 than in week 5 in both the summer (0-555 vs 0-525) and in the autumn (0-511 vs 0-476). Mechanisms of die* selection are discussed.In the summer grazing period only small differences existed in intake of organic matter between levels of removal but in the autumn intakes were higher at the 40% than the 80% level of removal. In a clipping experiment in which 0, 40 or 80% of the length of current season's shoots was removed in

The influence of feed restriction during rearing was investigated in male-line Large White breeder hens with regard to effects on ovarian morphology, egg production, laying patterns, and egg characteristics. Two hundred poults were reared from 4 to 28 wk of age under four treatments as follows: full-fed controls (FF), low-protein diet (12% CP from 12 to 28 wk; LP), and reduced BW (10 to 20% lower BW than FF; R10 and R20). At photostimulation (28 wk), all birds consumed a commercial breeder diet ad libitum for the remainder of the study (48 wk of age). Settable egg production (eggs per hen) to 48 wk for all hens, and those in lay was: FF, 39.4 (48.6); LP 42.7 (51.7); R10, 41.4 (52.8); R20, 40.7 (55.4). Inferior egg production per bird in R10 and R20 hens reflected a reduced persistency of lay. At first egg, hens of all treatments had a mean of 4.9 postovulatory follicles (POF) not accounted for by an egg. Number of unreconciled POF correlated with abdominal fat pad weight (P < or = .01). Ovary weight correlated with BW (P < .0001) and fat pad weight (P < .0004). Proportion of yolk and shell in the egg and egg specific gravity were improved with feed restriction. Sequence length was longest in R20 treatment hens and pause length shortest in R10 and R20 hens. Incidence of multiple-follicle sets was reduced in the R10 and R20 treatments. Feed restriction during rearing can potentially improve laying characteristics by altering ovarian morphology without limiting shell quality or yolk size. Quantitative feed restriction was most effective at improving egg quality, reducing average pause length, and reducing ovarian multiple-follicle sets. If problems with persistency of lay are addressed, the R10 and R20 treatments are the recommended rearing restriction treatments for male-line turkey breeder hen candidates.

No abstract

The influence of feed allowance during rearing was investigated in male-line Large White breeder hens. A flock of 200 poults was reared from 4 to 28 wk of age under four treatments as follows: full-fed controls (FF), low-protein diet (12% CP from 12 to 28 wk; LP), and reduced BW (10 or 20% lower BW than FF; R10 and R20). At photostimulation (28 wk), all birds consumed a commercial breeder diet ad libitum for the remainder of the study (48 wk of age). Body weight differed among treatments during most of rearing. The LP birds were similar in BW to the R10 birds at 28 wk of age. By 40 wk of age, growth curves of all treatments became similar, with the R20 group having lower BW. Feed restriction reduced frame size during rearing. Flock uniformity in the R10 and R20 treatment hens was reduced during rearing, but improved early in the breeder period. Feed restriction reduced breast muscle and abdominal fat pad weight early in lay, except for the LP group. Liver lipid content increased throughout the breeder period. Changes in liver weight followed the pattern of BW changes. Total carcass protein content changes in time reflected breast muscle mass changes. In R20 hens, carcass lipid content was reduced and protein content increased. Sexual maturity was delayed in the R20 hens. Body weight at first egg was negatively correlated with settable egg production (r = -.37, P < or = .0015). The R20 treatment is recommended for male-line turkey breeder hen candidates during rearing.