Rozeboom D W, Pettigrew J E, Moser R L, Cornelius S G, el Kandelgy S M
Department of Animal Science, University of Minnesota, St. Paul 55108, USA.
J Anim Sci. 1996 Jan;74(1):138-50. doi: 10.2527/1996.741138x.
Regression analysis was used to evaluate the effects of gilt age and body composition at first breeding on sow performance over three parities. Eighty-seven Yorkshire x Landrace F1 gilts were used. Variation in age and body composition at first breeding was obtained by breeding gilts at puberty, second, or third estrus and by providing those gilts bred after puberty one of four nutritional regimens from puberty until breeding: 1) 2.7 kg/d of a 14.3% CP, 3.5 Mcal ME/kg diet (H), 2) maintenance ME and CP/d (M), 3) half-maintenance ME and CP/d (1/2M), and 4) M or 1/2M until anestrus, then 2.27 kg/d of a 14.0% CP corn-soybean meal diet until first breeding. Body composition at first breeding was determined using live weight, backfat thickness, and deuterium oxide space as variables in prediction equations. All females were treated similarly after first breeding. Age and body composition at first breeding were not related (P > .10) to litter size at birth or weaning in parities 1, 2, 3, or overall. Increasing age at first breeding was related to small increases in pig birth weights (P < .001) in parity 1 and average pig weaning weight (P < .001) in parities 1, 2, and overall. Body composition of gilts at first breeding was not related (P > .10) to pig birth weights and was inconsistently related to pig weaning weights in parities 2 and 3 (P < .001). Females heavier at first breeding remained heavier (P < .01) throughout the experiment. Age and body composition at first breeding were not different (P > .10) for gilts completing three parities (n = 53) compared with gilts failing to complete three parities (n = 34). Results show no large effects of gilt age or body composition at first breeding on sow productivity and longevity over three parities.
采用回归分析来评估初配时后备母猪年龄和体组成对其三个胎次繁殖性能的影响。使用了87头约克夏×长白F1后备母猪。通过在初情期、第二次发情期或第三次发情期配种后备母猪，并为初情期后配种的后备母猪提供从初情期到配种期的四种营养方案之一，获得初配时年龄和体组成的差异：1）14.3%粗蛋白、3.5兆卡代谢能/千克日粮，2.7千克/天（H）；2）维持代谢能和粗蛋白/天（M）；3）维持代谢能和粗蛋白的一半/天（1/2M）；4）M或1/2M直至发情间期，然后2.27千克/天的14.0%粗蛋白玉米-豆粕日粮直至初配。使用体重、背膘厚度和氧化氘空间作为预测方程中的变量来确定初配时的体组成。初配后所有母猪的处理方式相同。初配时的年龄和体组成与第1、2、3胎次或总体的出生窝仔数或断奶窝仔数无关（P＞0.10）。初配年龄增加与第1胎次仔猪出生体重小幅增加有关（P＜0.001），与第1、2胎次及总体的仔猪平均断奶体重增加有关（P＜0.001）。初配时后备母猪的体组成与仔猪出生体重无关（P＞0.10），与第2、3胎次的仔猪断奶体重关系不一致（P＜0.001）。初配时体重较重的母猪在整个实验过程中体重仍较重（P＜0.01）。与未完成三个胎次的后备母猪（n = 34）相比，完成三个胎次的后备母猪（n = 53）初配时的年龄和体组成没有差异（P＞0.10）。结果表明，初配时后备母猪的年龄或体组成对其三个胎次妊娠的繁殖性能和寿命没有很大影响。
