We tested whether the milk yield capacity of mixed-breed goats on a Chihuahuan desert rangeland in northern Mexico during the dry season affects milk composition, body weight gain, and weaning weight of their progeny. Milk yield and composition, and progeny postnatal growth performance, were recorded weekly. One week after kidding, mixed-breed goats (a mixture of Criollo × dairy breeds; n = 40) were allotted into medium (MP) or low (LP) milk yielding groups (20 goats per group). Mean 105-d total milk yield for MP and LP goats was 45.2 ± 12.5 and 20.7 ± 5.2 L, respectively. Milk lactose (4.3 vs. 4.2%) and solids-non-fat (SNF; 8.2 vs. 8.0) differed (p < 0.05) between MP and LP goats; milk protein content tended to differ (p = 0.08) between MP and LP goats with no difference for milk fat content (p > 0.05). Maternal body weight was positively associated with milk yield, milk lactose, and SNF content (p < 0.05 to p < 0.001). Goats giving birth to males produce more milk than goats giving birth to females, but milk fat percentage was higher in goats bearing females (p < 0.001). Milk yield and composition throughout lactation did not influence body weight gain (47.8 vs. 48.7 g/day for kids from MP and LP goats) and weaning weight (6.7 vs. 6.7 kg from MP and LP goats) of the offspring (p > 0.05). Birth weight and weaning weight of the progeny were positively related to maternal body weight (p ≤ 0.05). The postnatal growth of the kids was reduced, extending the time to reach market weight. Nevertheless, non-supplemented mixed-breed goats reared on semi-arid rangeland of northern Mexico have the potential for moderate milk production. Therefore, due to the limited nutrients ingested by grazing goats during the dry season, a nutritional supplement is necessary to keep up milk production and adequate growth of kids.

Tillandsia recurvata is an epiphyte that grows on the canopy of many trees in tropical and subtropical areas of America. The objective of this study was to evaluate the effect of partial or complete substitution of sorghum stubble with T. recurvata on liveweight change, metabolic profile, and complete blood count of goats fed increasing levels (0, 30, and 60%, dry matter basis) of T. recurvata. Thirty non-pregnant three-year-old, non-lactating, healthy mixed-breed goats, ten animals per treatment (T0, T30, and T60), were adapted to diets and facilities for 14 days (d-14). Blood samples were collected at d-15, 28, and 56. At the last phase of the trial (from days 67 on), control goats tended to gain more (p = 0.09) weight than their counterparts consuming T. recurvata. Plasma protein, glucose, triglycerides, calcium, and phosphorus concentrations did not differ among dietary treatments (p > 0.05). Dietary treatment influenced red blood cells (higher for T60; p < 0.01), white blood cells (higher for T30; p < 0.05), mean corpuscular volume (higher for T0; p < 0.001), and mean corpuscular hemoglobin concentration (higher for T0; p < 0.01), although not the rest of the blood variables (p > 0.05). The hematocrit percentage tended to be higher (p = 0.06) in T30 than T0 and T60. It was concluded that replacing sorghum stubble with T. recurvata did not modify the metabolic status and maintained live weight of goats. Nevertheless, the use of T. recurvata as feed for goats would improve the nutrition of these animals in the dry season compared to the current diet obtained from an arid rangeland, reducing production costs, and would alleviate the damage caused by this aggressive epiphyte to host trees.

The present study aimed to evaluate the effect of copra meal (the waste coconut of the oil industry) on in vitro ruminal kinetic and greenhouse gases production and on in vivo lamb performance. Twenty-eight male Rambouillet sheep (initial body weight 24.5 ± 3.9 kg) were randomly assigned to one of the four treatments: 0, 50, 100, and 150 g of copra meal/kg in their diet (dry matter basis). Final weight, weight gain, and feed intake were not affected (p > 0.05) by the copra meal addition. The gas production volume (V) decreased, and the gas production rate increased, in a linear trend (p < 0.05) as copra meal was added to the diet. In contrast, methane and CO2 production showed an opposite quadratic trend (p < 0.05), with the highest and lowest values reported at 100 g/kg DM of copra meal, respectively. The addition of copra meal in the lambs’ diet decreases the volume of gas production and is a strategy to decrease methane and carbon dioxide production in feeding without affecting animal performance.

No abstract

In Mexico, the concepts of rangeland site and condition are not well known. For this reason, most of the rangelands of private ranches on the high plateau of San Luis Potosí and Zacatecas are undergoing a process of severe generalized deterioration. The purpose of this study was to survey and characterize multi-branched rangeland sites of three beef cattle ranches on the San Luis Potosí-Zacatecas High Plateau, as well as to assess their condition using a quantitative ecological method complemented by updated technological tools. The hypothesis proposed was that the site and condition of rangeland evaluated with the quantitative ecological method (used for grasslands and soil), complemented by updated technology, are also identifiable in multi-branched rangelands of this type of production units on the San Luis Potosí-Zacatecas High Plateau. Based on a Landsat satellite image, an unsupervised classification process was performed for the three ranches, which was then confirmed by field observations. A total of 11 sites were surveyed, three on each ranch (microphyll desert scrub, predominantly Bouteloua gracilis; microphyll desert scrub, with predominance of Sporobolus airoides; and an ecotone between microphyll desert scrub and rosetophile desert scrub) and two exclusive locations (crassicaule scrub and rosetophile desert scrub with predominance of Muhlenbergia villiflora). Rangeland condition was evaluated by measuring density and volume (volumetric biomass) of the main plant species, categorized by forage value, and the actual state of the soil surface was assessed in terms of bare soil and vegetation, litter, feces and rock cover. The data were ordered and classified with the DECORANA and TWINSPAN modules from the PC-ORD program. Site and condition evaluation under this approach was satisfactory for surveying the state of the rangelands of the three private cattle ranches studied on the San Luis Potosí-Zacatecas High Plateau.