Widespread expression of inducible NOS and citrulline in lupus nephritis tissues
E. Avalos-Diaz 1 , C Rodríguez-Padilla 3 and R Herrera-Esparza
Heifers
Unfasted live weight was recorded on D- l O, 0- 1 , 02, 0 1 9, 036, 042, 064, D88, 0 1 09, 0 1 34, 0 1 59, 0 1 94, 0225, 0239, and 0267. Further unfasted live weights were recorded within 24 h of parturition, on 032 1 , D34 1 , 037 1 , 0396 and D438. Pregnancy to rebreeding was detected using rectal palpation on D438. Every parturition was classified as assisted or non-assisted. In cases where fetal malpresentation had contributed to the dystocia, this was noted.
Calves
All calves were weighed within 24 hours of birth, and sex of calf was recorded. Additionally, body length, height at withers, depth of shoulders (from the withers to the breast bone), circumference of head, width of shoulders, thoracic girth, width of hips, and length and girth of left and right forelimb cannon bones were recorded on live calves (Nugent et al. 1 99 1 ). Crown-rump length and the distance between the top of the left scapula and the top of the greater tubercle of the left humerus were also recorded. Calves were standing upright while these measurements were made. Body dimensions were not made on one calf with contracted tendons on its front limbs that was unable to stand upright.
Fasted live weight was recorded on 032 1 , D34 1 and 037 1 (mean age 40, 60 and 90 days). Unfasted live weight was recorded on 0396 and 0438 (mean age 1 1 5 and 1 57 days). Milk intake of the calves was assessed on 032 1 , 034 1 and 037 1 using the weigh-nurse-weigh technique (Barton 1 970).
Statistical methods
Data were analysed using the Statistical Analysis System (SAS version 9. 1 , SAS Institute Inc., Cary, NC, USA, 2003). Live weights from 0- 1 0 until 0267 were analysed using a linear model in the M IXED procedure with treatment, sex of calf, day of gestation and treatment-by-day of gestation interaction fitted as fixed effects. The random effects of farm of origin, service sire and the random effect of heifer to allow for repeated measures were considered. Similarly, average daily liveweight gain was
analysed using linear models in the MIXED procedure with treatment fitted as a fixed effect. Farm of origin was fitted as a random effect. Live weights from calving to weaning were analysed using a l inear model in the MIXED procedure with treatment, assistance at calving (binomial trait), day of experiment and the interaction of day of experiment with treatment as fixed effects, and farm of origin of heifer and heifer as random effects to allow for repeated measures. Pregnancy rate on D438 was analysed as a binomial trait using a logistic regression model with the GENMOD procedure. Treatment and assistance at first parturition were considered as fixed effects. Incidence of assistance at parturition was analysed as a binomial trait using a logistic regression model with the GENMOD procedure and treatment considered as a fixed effect.
Birth weight of the calf was analysed using a linear model in the M IXED procedure, with treatment and sex of calf as fixed effects and sire as a random effect. Gestation length and the interaction of sex of calf with gestation length were considered but excluded from the model as their effects were not significant. Models were run with and without post-partum live weight of the heifer as a covariable. Linear models within the MIXED procedure were used for body dimensions, with birth weight of the calf as a covariable and treatment and sex of calf as fixed effects. Sire was fitted as a random effect.
Milk intake of calves was analysed using a linear model for repeated measures within the M IXED procedure. Fixed effects were sex of calf, treatment, day of age, treatment by day interaction, assistance at birth and assistance by day of age interaction. Sire and calf were fitted as random effects. Date of birth of calf was fitted as a covariable but did not explain a significant amount of variation and was removed from the model . Simil arly, l ive weights o f calves from birth t o weaning were considered as repeated measures using a similar model as for milk intake, although date of birth of calf was significant in this model. Grazing herd was considered as a random effect for milk intake and live weight of calves.
The contribution of birthweight-adjusted body dimensions to the probability of assistance at parturition was explored using the LOGISTIC procedure, with non significant effects removed from the model. Body dimensions were adjusted for birth weight using linear models in the GLM procedure, and the residual body dimensions were fitted in the logistic regression model. S ire of calf was considered as a contributor
Liveweight gain and birth weight - Experiment 3
to the probability of assistance at parturition, but was excluded from the model because it had no significant effect.
Results
Heifers
Nutritional treatments were applied in the first trimester of pregnancy so that a significant difference in the rate of liveweight gain amongst the groups was achieved (Table 7. 1 ). Rates of liveweight gain differed from targeted rates in some periods, particularly D42 to D88, however, the differences between the treatments were consistent with the target differences. Heifers in treatment 1 were heavier than heifers in the other treatments by D42 and this difference remained until D267. There were no differences in liveweight of the heifers among treatments from day of parturition until D438.
Sixteen heifers were assisted at parturition and fetal malpresentation was a contributing factor in four of these cases. There were no differences among treatments in the proportion of heifers assisted (data not shown), but numbers were too low for detecting differences for this binomial trait. Heifers that were assisted were lighter (P<0.05) throughout their calf-rearing period than heifers that were not assisted (364 ± 1 1 kg versus 399 ± 9 kg post-partum and 387 ± 1 1 kg versus 425 ± 9 kg at weaning), but there was no difference in the growth rate of these heifers from parturition to weaning ( 1 70 ± 20 g/day compared with 1 59 ± 40 g/day for non-assisted and assisted heifers, respectively). Pregnancy rates to rebreeding were not different among the treatments, or between assisted and non-assisted heifers (data not shown), however, the experiment had limited power to detect differences as pregnancy status was also a binomial trait.
Calves
Birth weight of calves was not affected by the liveweight gain treatments of the heifers (32.3 ± 0.9 kg, 32.9 ± 0.9 kg and 32.5 ± 0.9 kg for treatments 1 , 2 and 3, respectively). Similarly, there were no differences among treatments in birth weight with adjustment for post-partum liveweight of the heifer (data not shown). Generally, body dimensions of calves were not affected by treatment (Table 7.2). All body dimensions were related to birth weight.