Estimation of body weight using body measurements in female water buffaloes reared in southeastern Mexico

Buffalo farming is an important livestock activity in Mexico. However, the low technological level of the farms makes it difficult to monitor the growth rates of the animals. The objectives of this study were to analyse the body measurements of 107 adult female Murrah buffaloes, to estimate the interrelationships between those measurements and body weight, and to develop equations to predict body weight (BW) using body measurements including withers at height (WH), rump height (RH), body height (BH), heart girth (HG), abdominal girth (AG), pelvic girth (PG), body length (BL), girth circumference (GC), diagonal body length (DBL), pelvic circumference (PC), and abdomen circumference (AC). The study was conducted on two commercial farms in southern Mexico. Pearson correlation and stepwise regression techniques were used for the data analysis. To find out the best regression models, we used model quality criteria such as coefficient of determination (R²), adjusted R² (Adj.R²), root mean square error (RMSE), Mallow's Cp, Akaike's information criteria (AIC), Bayesian information criteria (BIC), and coefficient of variation (CV). Correlation results indicated that BW had a positive high correlation (P < 0.01) of all the measured traits. Model 4 (-780.56 + 311.76GC + 383.51DBL + 51.82PC + 47.65AC-106.78BL) was the best regression model with a higher R² (0.87), Adj. R² (0.86) smaller Cp (4.24), AIC (749.19), BIC (752.16), and RMSE (36.91). The current study suggests that GC, DBL, PC, AC, and BL might be used in combination to estimate BW of adult female Murrah buffaloes.

Models to predict live weight from heart girth in crossbred beef heifers

The objective of this study was to develop and evaluate linear, quadratic, and exponential mathematical models to predict live weight (LW) from heart girth (HG) in crossbred heifers raised in tropical humid conditions in Mexico. Live weight (363.32 ± 150.88 kg) and HG (166.83 ± 24.88 cm) were measured in 400 heifers aged between 3 and 24 months. Linear and non-linear regression was used to construct the prediction models. The goodness of fit of the models was evaluated using the Akaike information criterion (AIC), the Bayesian information criterion (BIC), coefficient of determination (R²), mean squared error (MSE), and root MSE (RMSE). In addition, the developed models were evaluated through internal and external cross-validation (k-folds) using independent data. The ability of the fitted models to predict the observed values was evaluated based on the root mean square error of prediction (RMSEP), R², and mean absolute error (MAE). The correlation coefficient between LW and HG was r = 0.98 (P < 0.001). The quadratic model showed the lowest values of MAE (736.57), RMSEP (27.13), AIC (3783.95), and BIC (3799.91). Additionally, this model exhibited better goodness-of-fit values regarding external and internal validation criteria (higher R² and lower RMSEP and MAE), thus having better predictive performance. The RMSE represented about 8% of the observed LW. Heart girth is highly correlated (r = 0.98) with LW. The quadratic model showed a high predictive capacity for crossbred heifers kept in tropical conditions.

First report and risk of infection of Fasciola hepatica (Linnaeus, 1761) in water buffaloes (Bubalus bubalis - Linnaeus, 1758) in Mexico

The aim of this study was to determine the prevalence and risk of Fasciola hepatica infection in water buffaloes (Bubalus bubalis) during peripartum in southeastern Mexico. An observational study was designed, in which 94 pregnant buffalo cows near calving and naturally exposed to F. hepatica were included. Farm visits were made on days 60, 30, 15 prepartum, at calving, and on days 15 and 30 postpartum. Feces were obtained from all animals to confirm the presence of F. hepatica eggs. A group of 49 animals was randomly treated twice at day 60 prepartum and at calving with nitroxynil and the other group (n = 45) was kept untreated. Buffaloes would be treated once presenting a positive coproparasitological diagnosis up to 30 days postpartum. F. hepatica was detected in 5.3% of the buffaloes (5/94) with a prevalence between 1.7 and 12%. It was observed that treated buffaloes had a lower risk (4.08%) of being positive than untreated buffaloes (6.67%) (P > 0.05). It was also found that untreated animals had 1.6 times more risk of being positive than treated buffaloes. This paper presents the first report of F. hepatica in water buffaloes in Mexico, demonstrating that the two preventive treatments reduced F. hepatica egg shedding during parturition. These findings highlight the need for monitoring for F. hepatica even in unreported/silent potential disease areas.

Ovulatory response and embryo quality in Katahdin ewes supplemented with palm oil

The aims of this study were to evaluate the superovulatory response (SR), embryo quality and embryonic development in Katahdin ewes that received a dietary supplement of palm oil (PO). Ten ewes were assigned to receive 35 g palm oil (n = 10, PO3) and 10 to receive 70 g palm oil (n = 10, PO6) for 25 days. On day 0, the ewes were synchronized with 0.3 mg progesterone-releasing devices (CIDR-G®). From days 6 to 9, the donors were superovulated with 200 mg follicle-stimulating hormone (FSH) (Folltropin-V®) at decreasing doses every 12 hours (40 - 40, 30 - 30, 20 - 20 and 10 - 10 mg/ewe). On day 8, the devices were removed and donors were mated twice with fertile rams at 12-h intervals. Seven days after mating, the embryos were recovered and evaluated for their stage of development and quality grade (1 = excellent, 2 = good, 3 = bad and 4 = degenerated). In addition, on days 0, 7 and 15, blood samples were taken to determine cholesterol, triglycerides, insulin and insulin-Iike growth factor-1 (IGF-1) concentrations in serum blood. Using chi-square and t-tests, the superovulatory response (SR), ovulation rate (OR), total embryonic structures (TES), transferable embryos (TE), degenerated embryos (DEs) and developmental stage and quality were evaluated. No significant differences were observed between treatments for SR, OR, TES and TE variables or for cholesterol, triglycerides, insulin and IGF-1 concentrations. There were differences in the numbers of DE, as well as a trend for more homogeneous developmental stage in the embryos of ewes supplemented with PO6, as well as a higher number of quality 1 embryos and lower numbers of quality 3 and 4 embryos. Palm oil supplementation could be a recommendable practice to improve the quality of embryos and homogenous developmental stage (morula and blastocyst).Keywords: Fatty acids, ovarian activity, sheep