This study aims to use advanced machine learning techniques supported by Principal Component Analysis (PCA) to estimate body weight (BW) in buffalos raised in southeastern Mexico and compare their performance. The first stage of the current study consists of body measurements and the process of determining the most informative variables using PCA, a dimension reduction method. This process reduces the data size by eliminating the complex structure of the model and provides a faster and more effective learning process. As a second stage, two separate prediction models were developed with Gradient Boosting and Random Forest algorithms, using the principal components obtained from the data set reduced by PCA. The performances of both models were compared using R², RMSE and MAE metrics, and showed that the Gradient Boosting model achieved a better prediction performance with a higher R² value and lower error rates than the Random Forest model. In conclusion, PCA-supported modeling applications can provide more reliable results, and the Gradient Boosting algorithm is superior to Random Forest in this context. The current study demonstrates the potential use of machine learning approaches in estimating body weight in water buffalos, and will support sustainable animal husbandry by contributing to decision making processes in the field of animal science.

Creole breeds are an invaluable genetic reservoir due to their adaptation to the environments where they are exploited. In particular, Creole goats in Latin America and the Caribbean play a preponderant role in the development and economic growth of rural communities. They represent a strategic option for these communities to migrate from poverty to prosperity, taking advantage of the adaptability and rusticity of these goats, given that they survive, reproduce, and produce acceptable levels of meat and milk in adverse conditions and environments. For this reason, they are a key species for generating foods of high biological and nutritional value, in the face of changing environmental and climatic conditions. Therefore, public policies should consider local or Creole goats as a priority species in productive support programmes, as well as in research programmes seeking to improve productivity in a sustainable manner in all environments where they are raised.

The study was carried out to evaluate the effect of energy and protein supplementation on parasitological and hematological response during peripartum and lactation of productive and non-productive Pelibuey ewes in a tropical environment. Forty-eight Pelibuey ewes aged 3–5 years and with a body weight of 31 ± 5 kg were used. Four groups of 12 ewes, including non-pregnant and productive ewes, were formed. A factorial treatment design was formulated, where two levels of energy (low, 9.6 MJ/kg, n = 24; and high, 10.1 MJ/kg, n = 24) and two levels of protein (high, 15% crude protein in diet, n = 24; and low, 8% crude protein in diet, n = 24) were studied. Fecal and blood samples were collected to determine the fecal egg count (FEC) of gastrointestinal nematodes (GIN), packed cell volume (PCV) and peripheral eosinophil (EOS) count. These variables were rearranged with respect to the lambing date in a retrospective study. The high dietary protein level had a significant effect on reducing the FEC and increasing the PCV of ewes during lactation, in comparison with animals fed with the low protein level. Differences in the study variables were attributed to physiological stage. Lactating ewes showed the highest FEC values (2709 ± 359 EPG), the lowest PCV values (21.9 ± 0.7%) and the lowest EOS (0.59 ± 0.6 Cells × 10³ µL). It is concluded that high levels of dietary protein improve the hematological response and reduce the FEC in Pelibuey ewes under grazing conditions. The non-pregnant ewes maintained some resilience and resistance to GIN infection compared to productive ewes.

This study was designed to develop predictive equations estimating carcass tissue composition in growing Blackbelly male lambs using as predictor variables for tissue composition of wholesale cuts of low economic value (i.e., neck and shoulder). For that, 40 lambs with 29.9 ± 3.18 kg of body weight were slaughtered and then the left half carcasses were weighed and divided in wholesale cuts, which were dissected to record weights of fat, muscle, and bone from leg, loin, neck, rib, and shoulder. Total weights of muscle (CM), bone (CB) and fat (CF) in carcass were recorded by adding the weights of each tissue from cuts. The CM, CF and CB positively correlated (p < 0.05; 0.36 ≤ r ≤ 0.86), from moderate to high, with most of the shoulder tissue components, but it was less evident (p ≤ 0.05; 0.32≤ r ≤0.63) with the neck tissue composition. In fact, CM did not correlate with neck fat and bone weights. Final models explained (p < 0.01) 94, 92 and 88% of the variation observed for CM, CF and CB, respectively. Overall, results showed that prediction of carcass composition from shoulder (shoulder) tissue composition is a viable option over the more accurate method of analyzing the whole carcass.

This study evaluated the effect of three feeding levels on the pathogenesis and establishment of H. contortus upon the first infection of parasite-naïve Pelibuey hair sheep lambs. Forty-two 6-month-old hair sheep lambs (24 ± 4 kg) raised parasite free from birth were used. The lambs were assigned to 3 groups (n = 14), and each was fed a diet designed for different daily weight gain (DWG): 75 g/d (Diet 1), 125 g/d (Diet 2) and 200 g/d (Diet 3). After four weeks of diet adaptation, 10 lambs/group were infected with 450 L₃H. contortus/kg BW (infected), and 4 lambs/group were kept parasite-free (NInf). DWG, hematocrit (Ht), hemoglobin (Hb), peripheral eosinophils (EOS), IgG concentration against H. contortus, and eggs per gram (EPG) of feces were measured in each lamb from day 14 before infection until day 29 postinfection (PI). On day 29 PI, the lambs were slaughtered to determine the total number of adult parasites (TAW), the length of the female worms, and the number of eggs in utero (EIU). Each group reached the expected DWG (P = 0.001), and there was no effect of infection or the diet × infection interaction. Ht was lower in infected lambs than in NInf lambs, and this difference was significant for animals on Diets 1 and 2 (P = 0.044). From day 14 PI onward, Hb was lower in the infected lambs than in the NInf lambs (P = 0.001). Furthermore, compared with NInf lambs, the infected lambs had higher EOS from day 7 PI and higher IgG from day 14 PI. Neither EOS nor IgG were affected by diet. Lambs on Diet 3 had lower EPG during patency than those fed Diets 1 or 2 (days 25 and 28 PI; P = 0.002). Furthermore, lambs fed Diet 3 had lower TAW (Diet 1 vs 3 P = 0.037; Diet 2 vs 3 P = 0.049) and EIU (P = 0.004) than lambs fed Diet 1 or 2. Lambs were resilient to infection regardless of diet. Although EOS and IgG were higher in all infected animals than in Ninf animals, EPG, TAW and EIU decreased only in lambs fed Diet 3. Thus, a diet targeting a DWG of 200 g/d can significantly limit the establishment of H. contortus in Pelibuey lambs infected for the first time.