Frequency of removal reasons of sows in Southeastern Mexico.

The aim of this study was to describe the reasons for removal in three pig farms under the tropical conditions of Mexico. Data were obtained from the records from 2003 to 2009, including a total of 7,236 commercial culled sows. Farms 1 and 3 were full-cycle farms with 3,500 and 550 sows. Farm 2 was a two-cycle farm with 450 sows. The specific reasons for removal were grouped into six general categories. The descriptive statistics of the reasons for removal were obtained using cross tabulation tables. Chi-square was used to test between farm differences. Reproductive reasons accounted for the largest proportion of all removals (26.9%) of which anestrous and repeated estrous contributed with 34.2% and 20.8%, respectively. Locomotor problems were responsible for 15.5% of all removals, of which lameness was the main concern (56.3%) followed by "sow downer" syndrome (23.9%). Low production accounted for 12.8% of all removals of which 62.2% were due to small litter sizes and 37.8% due to disgalactia. Diseases were responsible for 13.0% of all removals of which respiratory problems was the most important (73.6%). Age as a cause of removal comprised 24.1% and the category "miscellaneous" 7.7% of all removals. Poor body condition and death reasons represented 2.6% and 1.6%, respectively. Differences between removal reasons were found between farms.

Prevalence of abortion and stillbirth in a beef cattle system in Southeastern Mexico.

Prenatal mortality is an important cause of production losses in the livestock industry. This study estimates the prevalences of abortion and stillbirth in a beef cattle system and determines the significance of some risk factors, in the tropics of Mexico. Data were obtained from a Zebu cattle herd and their crosses with Bos taurus breeds, in Yucatan, Mexico. The logit of the probability of an abortion or stillbirth was modeled using binary logistic regression. The risk factors tested were: year of abortion (or calving), season of abortion (or calving), parity number and dam breed group. The effect of twins on stillbirth was tested using Fisher exact test. Of the 4175 calvings studied 49 were abortions (1.17%). Significant factors in the logistic regression analysis for abortions were season of abortion and parity number. The risk of abortion was lower in the dry seasons compared to the rainy and windy seasons (P = 0.009). The risk of abortion was higher in second parity cows followed by the third and first parity cows, as compared to older cows (P = 0.015). Of the 4126 births, 87 were stillbirths (2.11%). Significant factors in the logistic regression analysis for stillbirth were year of calving (P = 0.0001) and parity number (P < 0.001). The risk of stillbirth in first parity cows was 2.6 times that of old cows. Of the total births, 15 were twins (0.36%) of which 7 were born dead calves. Herd owners must focus on the significant risk factors under their control to reduce the prevalence of prenatal mortality.