Nutrition plays a critical role in developmental programs. These effects can be during gametogenesis, gestation, or early life. Omega-3 polyunsaturated fatty acids (PUFA) are essential for normal physiological functioning and for the health of humans and all domestic species. Recent studies have demonstrated the importance of n-3 PUFA in ruminant diets during gestation and its effects on pre-and postnatal offspring growth and health indices. In addition, different types of fatty acids have different metabolic functions, which affects the developmental program differently depending on when they are supplemented. This review provides a broad perspective of the effect of fatty acid supplementation on the developmental program in ruminants, highlighting the areas of a developmental program that are better known and the areas that more research may be needed.

Rotational grazing has been mentioned as a potential tool to reduce losses caused by high tick loads. This study aimed: (1) to evaluate the effect of three grazing modalities (rotational grazing with 30- and 45-day pasture rest and continuous grazing) on Rhipicephalus microplus infestation in cattle, (2) to determine population dynamics of R. microplus in cattle under the three grazing modalities mentioned in the humid tropics. The experiment was carried out from April 2021 to March 2022 and consisted of 3 treatments of grazing with pastures of African Stargrass of 2 ha each. T1 was continuous grazing (CG00), and T2 and T3 were rotational grazing with 30 (RG30) and 45 d of recovery (RG45), respectively. Thirty calves of 8–12 months of age were distributed to each treatment (n = 10). Every 14 days, ticks larger than 4.5 mm were counted on the animals. Concomitantly, temperature (°C), relative humidity (RH), and rainfall (RNFL) were recorded. Animals in the RG45 group had the lowest count of R. microplus compared to the RG30 and CG00 groups; these results suggest that RG45 days of rest could be a potential tool to control R. microplus in cattle. Yet, we also observed the highest population of ticks on the animals under rotational grazing with a 30-day pasture rest. A low tick infestation characterized rotational grazing at 45 days of rest throughout the experiment. The association between the degree of tick infestation by R. microplus and the climatic variables was nil (p > 0.05).

Grazing management through pasture rotation has been mentioned as a viable alternative for the control of Rhipicephalus microplus; however, there is limited information on rotational grazing at field level. The objectives of this research were (1) to evaluate the effect of rotational grazing with 30 and 45 days of pasture rest and continuous grazing (without rest) on R. microplus tick loads in Brahman heifers and its most common crosses with Holstein; (2) to know the parasite dynamics of R. microplus under the three grazing systems in the humid tropics of Mexico; and (3) to determine the effect of the treatments on the characteristics of the pastures (availability of forage biomass, plant height, and soil cover). The experiment was carried out for 1 year from April 2022 to March 2023, with three grazing treatments: Treatments 1 and 2 considered rotational grazing with 30 (RT30) and 45 days of rest (RT45), respectively, and Treatment 3 as continuous grazing (CT00). Thirty calves from 8 to 12 months of initial age were distributed in each treatment (n = 10). Every 14 days, the number of engorged and semiengorged female ticks in cattle was determined. Concomitantly, the region’s temperature, relative humidity, and rainfall were recorded, as well as the agronomic characteristics of the pasture. Rotational grazing animals with 30 days of rest had the highest number of ticks, while grazing animals with 45 days of rest had the least. Tick load dynamics among groups did not correlate with climatic variables (p > 0.05). The height and grass cover presented significant changes due to grazing (p < 0.05), which could influence the tick cycle by the exposure of the soil, modifying the microclimatic conditions and consequently harming the survival and development of R. microplus in the evaluated systems. The negative effect of rotational grazing on the nonparasitic phase of R. microplus deserves further studies.

The use of omega fatty acids during pregnancy and lactation could be a beneficial strategy to improve health and production in ruminants. In this study, the effect of the dietary addition of c9, t11 and t10, c12 isomers of conjugated linoleic acid (CLA) in pure soybean oil (T1) was compared with pure soybean oil (T2) and soybean oil discarded after frying fish (Centropomus undecimalis, Pagrus pagrus, and Caranx crysos; T3) on the fatty acid profile in ewe milk and the tissues of their lambs. Forty-five multiparous ewes (East Friesian × Katahdin), 32 to 35 months old, 70 days pregnant, were randomly assigned to one of the three experimental diets. The fatty acid profile, total solids, fat, protein, and lactose in milk were determined 14 days postpartum. Fifteen lambs from each treatment were sacrificed at 70 days of age, and the fatty acid profiles in perirenal fat, muscle, and brain were determined. In milk, fat and total solids content were lower with T1. On the other hand, linoleic acid content, the sum of omega-6 and DHA were higher in T1 compared to other groups (p < 0.05). In the brain, stearic acid and linoleic acid concentration increased with T1; eicosapentaenoic acid decreased and omega-3s increased with T3, while DHA was lower in T2 (p < 0.05). The addition of CLA isomers or discarded soybean oil in ewe diet from pregnancy to lactation is advantageous for the ewe since less energy in the form of milk fat is lost. In addition, increasing the concentration of omega fatty acids in ewe diet to improve omega fatty acids in lamb’s brain could be a feed strategy to increase their productivity and health.

El Búfalo de agua Bubalus bubalis: una alternativa para aprovechamiento