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The high-water (85%) and low protein (5%) content of cactus cladodes (Opuntia spp.) reduce the amount of dry-matter consumed by ruminants. The objective of this study was to use protein enrichment technology to increase Opuntia protein content and to feed Dorper lambs, comparing the Opuntia protein enrichment and the basal diet in the liveweight gain. The experiment was carried out for 60 days, using a biodigester (100 kg of cactus) -Title No. 2641-IMPI. The process was based on the daily aerobic semisolid fermentation of Opuntia by applying yeast of the Sacharomyces cereviceae (1%) type, urea (1%) and ammonium sulfate (0.1%) during 20 h (1 h of movement and 1.5 h of rest) recycling the yeast for a week. Unfermented Opuntia cladodes were used as the control. The enriched Opuntia was provided in the final stage in two treatments in a completely randomized design with three replications: 1) Basal diet (control), and 2) Basal diet + fermented fresh Opuntia. The liveweight of each animal was recorded weekly. Analysis of variance and comparison of means were performed (Tukey HSD p=0.05 and orthogonal contrasts p<0.05). The results of the fermentation showed that fermented Opuntia significantly (p<0.01) decrease carbohydrates content (48.9 to 26.4%); increased crude protein content (5.64 to 33.17%) and energy (2.26 to 2.67 Meal kg-1) compared with unfermented Opuntia. However, on the seventh day of fermentation, these values decreased significantly, because of the temperature decrease. At the end of the experiment, the live-weight increased significantly 11.62 ± 0.99 kg animal-1 month-1 in groups of four lambs fed with enriched Opuntia, while the liveweight of animals fed with the basal diet only increased 8.42 ± 1.69 kg animal-1 month-1, showing a difference in the liveweight gain of 800 g lamb'1 week'1 fed with fermented Opuntia cladodes. [ABSTRACT FROM AUTHOR]

Social hierarchies among animal species are established on the dominance-aggressiveness level of the animal aligned with the subordination of their mates. This study aimed to evaluate the association among social rank hierarchy, scrotal circumference (SC), semen quality (SQ), and sexual drive (SD). Adult Dorper rams (n=24) with similar live weight (LW), body condition score (BCS), and age (AG) were subjected to a behavioral test to define the success index (SI) based on male-to-male interactions, determining three social ranks: low hierarchy rams (LHR; SI = 0-0.33; n=9), medium hierarchy rams (MHR; SI=0.34-0.66; n=10) and high hierarchy rams (HHR; SI= 0.67-1; n=5). Afterward, the SC, SQ, and SD were evaluated. The GLM procedure of SAS (SAS Institute, Cary, NC) was used to analyze LW, AG, BCS, SC and SQ variables such as ejaculate volume, and sperm concentration. Microscopic characteristics of sperm cells were subjected to an ANOVA using the MIXED procedure of SAS. The GENMOD procedure was used to assess the effect of social rank (three levels) on the SD variables. Differences were considered as significant at P < 0.05. SC was greatest (P< 0.05) for HHR rams (40.0±3.5) and least for rams with medium social rank (MHR; 29.3±1.20). SQ was greatest (P< 0.05) for HHR rams (3,848±187) and least for LHR (2,660±463). The rejection percentage to mount an estrous ewe or SD was 77.7 for LHR and 20% for HHR and MHR rams (P < 0.05). To conclude, the HHR rams presented the highest successful copulation, the greatest scrotal circumference, and the greatest sperm cell concentration compared with rams with lesser social rank scores. [ABSTRACT FROM AUTHOR]

Usually, social order is defined by the animal size, live weight, or age. This study aimed to evaluate the association among horn presence (HP), and horn size (HS) on social rank hierarchy. Adult Dorper rams (n=24) with similar live weight (LW), body condition score (BCS), and age (AG) were subjected to a behavioral test to define the success index (SI, ranked form 0 to 1) based on male-to-male interactions, determining three social ranks: low hierarchy rams (LHR; SI = 0-0.33; n=9), medium hierarchy rams (MHR; SI=0.34-0.66; n=10) and high hierarchy rams (HHR; SI= 0.67-1; n=5). Afterward, skull, horn (HP and HS), and body morphometrics were measured. The GLM procedure of SAS (SAS Institute, Cary, NC) was used to analyze LW, AG, BCS, HS and HP with three social ranks and five to ten replicates per group. Rams within social rank were the experimental units. Differences were considered as significant at P < 0.05. Regarding HP, 80% of the HHR rams had horns, while 77.7% of the LHR rams were hornless, with intermediate values for MHR (50%), but no differences were found regarding HS between low, medium and high hierarchy rams (85.1±2.6, 84.3±3.3, and 90.7±4.7, respectively). In conclusion, while presence of horns have an important role for establishing social hierarchy, it is a complex trait influenced by factors other than horn presence or size so, we recommend more research in relation to other factors that could influence the position of rams in the hierarchy rank levels of the herds. [ABSTRACT FROM AUTHOR]

Goat production concentrated in developing countries (tropics, dry areas), contributes largely to the livelihoods of low and medium income farmers. Farming systems in these areas have evolved to cope with the formidable constraints imposed by harsh natural and economic conditions by adapting integrated crop/livestock production strategies. In Asia, Africa and Latin America, due to its almost exclusive extensive nature, goat production relies mainly on grazing on communal lands that hardly provide the minimum nutrient requirements due to overstocking and degradation. While some of these production systems are becoming semi-intensive, appropriate breeding strategies should be designed to promote conservation and improvement of their unique attributes, such as adaptability, water use efficiency and suitability under harsh climatic conditions. In Europe, dairy goat production is more common around the Mediterranean basin, where it is important from an economic, environmental and sociological perspective to the Mediterranean countries: Spain, France, Italy and Greece. Europe owns only 5.1 % of the world's dairy goat herds, but produces 15.6 % of the world's goat milk; this is the only continent where goat milk has such an economic importance and organization. In developing countries the dairy goat sector requires a systemic approach, whereby nutrition, animal health, breeding, know-how, inputs and technologies must be assembled. This would allow the optimization of natural and local resources and would promote the transition from a risk reduction strategy towards an increased productivity strategy. Such an increase would privilege production efficiency based on clean, green and ethical practices for responsible innovation. [ABSTRACT FROM AUTHOR]

This study was conducted to determine whether flushing or the stimulus of estrogenized goats is necessary to achieve a high reproductive response in anestrous goats on rangeland. Does were feed-supplemented on rangeland (flushed, n = 20). Other group was exposed to estrogenized does during the mating period (stimulated, n = 20). A third group was both supplemented and stimulated (stimulated-flushed, n = 20) and other group grazed on rangeland only (control, n = 18). More goats in the stimulated and stimulated-flushed groups showed estrus during the first 5 days of joining (45% and 60%, respectively) than the control and flushed groups (11% and 5%, respectively; P < 0.05). Flushing did not improve prolificacy and reduced ( P < 0.05) kidding rates (40% and 35% for the flushed and stimulated-flushed groups, respectively) compared to 67% and 55% for the control and stimulated groups, respectively. This experiment demonstrates potential shortcomings of use of flushing in range goats with inadequate nutrition during gestation. [ABSTRACT FROM AUTHOR]

Limited data is available on reproductive seasonality in French Alpine goat bucks raised under intensive conditions in northern Mexico, at subtropical latitude (26° N). A study was done of eleven young French Alpine bucks subject to natural, regional photoperiod variations (13:41 h/light at summer solstice; 10:19 h/light at winter solstice). Animals were fed alfalfa hay (17% CP) ad libitum and a commercial supplement (14% CP) at 200 g animal-1 day-1 during the experimental period (December to September). Sperm motility increased (P<0.05) from 1.5 units from January to May to 2.5 units from July to September. Sperm viability also increased, from 25 % in January to May to 40 % in July to September. Ejaculate volume was 0.1 ± 0.03 ml ejaculate-1 from January to July, lower (P<0.05) than the 0.5 ± 0.04 ml ejaculate-1 recorded in August, September and December. Latency to ejaculate in an artificial vagina decreased (P<0.05) from 102 ± 7 sec in December to July, to 52 ± 1 sec in August and September. The studied French Alpine bucks exhibited seasonality in semen quality characteristics, body and testicular variables and sexual response, with generally lower variable values and less sexual activity from January to July followed by increased values and activity. [ABSTRACT FROM AUTHOR]

The high temperatures recorded during the summer season in hot regions compromise the reproductive capacity of domestic animals. In rams, heat stress (HS) causes in the body a series of physiological, metabolic, endocrine and molecular adjustments in order to maintain normothermia and survive; however, several of these changes are negatively associated with their fertility, mainly endocrine ones. HS in rams causes a decrease in blood testosterone concentrations through different mechanisms, and this is negatively reflected on the process of spermatogenesis and sexual behavior. Consequently, heat-stressed rams exhibit low seminal quality and libido; at the sperm level, structural and DNA damage has been observed. Given this situation, the use of HS mitigation strategies during the summer in sheep farms in hot regions is recommended, such as the use of shades in pens, administration of antioxidants or modifications in the diet. Therefore, the objective of this document is to review the current knowledge regarding the effect of HS on the thermoregulation and reproductive capacity of rams, as well as the application of strategies for its mitigation. [ABSTRACT FROM AUTHOR]

Nutritional requirements of sheep during late gestation increase as a consequence of high fetal growth, mammary tissue development and colostrum synthesis. While prepartum energy supplementation is a nutritional strategy to improve lamb postnatal performance in thermoneutral environments, this has not been studied under heat stress. This study aimed to evaluate effects of maternal energy supplementation during the last third of pregnancy on post-weaning feedlot performance and thermoregulation capacity of heat-stressed male lambs born from multiple births. Twenty Dorper x Pelibuey entire male lambs with initial body weight of 18.2 ± 0.4 kg, aged 2.7 mo (weaned) and born in multiple pregnancies were used in a 32 d feeding study. Treatments were based in the prenatal origin of the lambs: 1) ewes fed 100 ( n  = 10, Control) and 2) 125% ( n  = 10, Supplemented) of metabolizable energy requirements from day 100 of gestation to lambing. Lambs were housed outdoor in individual pens under summer environment conditions in an arid region (temperature = 36 ± 4.4 °C and temperature-humidity index = 81 ± 3.9 units). Overall feedlot performance was not affected by pre-partum maternal feeding, although lower (P = 0.04) growth rate and feed efficiency occurred during the last 8 d of the study in lambs born from supplemented ewes. Rectal temperature, respiratory rate and hair coat temperature during daytime were unaffected by prepartum supplementation. Serum concentrations of glucose, cholesterol, urea, total protein and thyroid hormones were similar between lambs born from control and supplemented ewes. It is concluded that, in hair sheep breeds, prepartum energy supplementation did not alter overall post-weaning productive performance and thermoregulation capacity of heat-stressed male lambs that were born in multiple pregnancies. [ABSTRACT FROM AUTHOR]

This study characterizes the goat response to the buck stimulus during the transition from anestrus to complete sexual function in mixed-breed goat herds maintained on an arid rangeland (25°N). In a first experiment, seasonal incidence of behavioural estrus was recorded by exposure of does to bucks (buck to doe ratio 1:18-1:24; n= 60- 96) in February, April, May and June. Signs of estrus were observed in 89, 1, 100 and 88% of goats exposed to bucks during these months, respectively, within a mean ± SD of 5.6 ± 3.8, 8.0 ± 0.0, 9.4 ± 4.9 and 4.7 ± 3.7 days from the initiation of teasing to first standing estrus. In a second experiment, two groups of goats were joined to bucks in January, one group (n= 44) undergoing cold stress (constant drizzling and 8°C mean daily temperature), the other without rain and mild temperatures (13.6°C; n= 44). A lower proportion of goats under cold stress, manifested by higher (p<0.01) plasma cortisol levels, showed estrus compared with goats under mild weather (27 vs. 80%; p<0.01). From a production standpoint, a high estrus response is expected in winter and early June in mixed-breed grazing goats in agro- pastoral production systems at 25°N, although wet cold weather in winter hampers the responsiveness of does to the buck stimulus. [ABSTRACT FROM AUTHOR]