caa a22 4500 388060727 CHVBK 20180307125120.0 cr unu---uuuuu 161130e199804 xx s 000 0 eng 10.1017/S1357729800009619 doi S1357729800009619 pii (NATIONALLICENCE)cambridge-10.1017/S1357729800009619 Modification of body composition by altering the dietary lysine to energy ratio during rearing and the effect on reproductive performance of gilts [Elektronische Daten] Fifty-four lean genotype crossbred gilts were allocated at 118 days of age among three diets with different protein concentrations to give lysine: energy (g/MJ digestible energy) ratios: high (0·9), medium (0·6) and low (0·3) given twice daily at 2·9 × maintenance energy. At 160 days of age, gilts were treated with exogenous gonadotropin (PG600™) and animals were examined daily for signs of oestrus. Animals were slaughtered after the second oestrus, if they had shown behavioural oestrus, or at the age of 212 days. Reproductive tracts were recovered for counting of corpora lutea and albicantia. L gilts were lighter than M or H gilts at puberty induction (80, 95, 97 (s.e. 0·73) kg for L, M, H respectively, P < 0·001), with greater backfat thickness (10·8,10·0, 9·2 (s.e. 0·21) mm P2,P < 0·001), lesser longissimus muscle depth (57·4, 65·9, 64·3 (s.e. 0·77) mm, P < 0·001) and poorer food conversion ratio during rearing (3·87, 2·48, 2·42 (s.e. 0·098) kg food per kg gain, P < 0·001). There was no statistically significant difference in the total number of animals that responded to the puberty induction, although L had a greater latency to oestrus than H. Ovulation rate at this induced oestrus was significantly lower in L gilts than in M or H gilts (12·5, 17·3, 21·5 (s.e. 1·32), P < 0·02). A lower proportion ofL, compared with M or H gilts showed spontaneous ovulation in a subsequent cycle (0·15, 0·75, 0·77, %2 = 12·72, P < 0·005). It proved possible, by means of low protein (lysine) diets, to increase body fat reserves in breeding gilts but protein restriction in the rearing phase negatively affected aspects of reproductive performance. Copyright © British Society of Animal Science 1998 gilts nationallicence lysine nationallicence ovulation nationallicence puberty nationallicence reproduction nationallicence Cia M. C. Scottish Agricultural College, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA Edwards S. A. Scottish Agricultural College, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA Glasgow V. L. Scottish Agricultural College, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA Shanks M. Scottish Agricultural College, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA Fraser H. Scottish Agricultural College, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA Animal Science Cambridge University Press 66/2(1998-04), 457-463 1357-7298 66:2<457 1998 66 ASC https://doi.org/10.1017/S1357729800009619 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S1357729800009619 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cia M. C. Scottish Agricultural College, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA NATIONALLICENCE 700 1- Edwards S. A. Scottish Agricultural College, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA NATIONALLICENCE 700 1- Glasgow V. L. Scottish Agricultural College, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA NATIONALLICENCE 700 1- Shanks M. Scottish Agricultural College, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA NATIONALLICENCE 700 1- Fraser H. Scottish Agricultural College, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA NATIONALLICENCE 773 0- Animal Science Cambridge University Press 66/2(1998-04), 457-463 1357-7298 66:2<457 1998 66 ASC CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge