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Simple Summary: This study investigated the milk production and quality of two breeds of Mediterranean donkeys, Masri and North African. Donkey milk is known for its potential health benefits, making it valuable for people with allergies and for infant nutrition. The research aimed to compare the amount of milk produced by each breed and analyze the nutritional content, such as proteins, fats, and essential nutrients. Results showed that North African donkeys produced more milk than Masri donkeys. Additionally, North African donkey milk contained more protein and certain beneficial nutrients, while Masri milk had a higher fat content. The study also examined the levels of important amino acids and fatty acids, which are essential for health. North African milk had similar saturated fats, while Masri milk had more unsaturated fats, which are considered more beneficial for cardiovascular health. These findings suggest that although both breeds can produce milk suitable for human consumption, North African donkeys may be more suitable for producing milk with a higher nutritional value. This research could enhance the use of donkey milk as a healthy food option, contributing to the enhancement of rural economies by promoting sustainable farming practices. The aim of the study was to model lactation curves and assess the physicochemical properties, amino acid, and fatty acid profiles of milk from two Mediterranean donkey populations, Masri (n = 14) and North African (n = 14), using the Wood model. Over a lactation period of 205 ± 12.5 days, North African donkeys produced more milk (188.66 ± 7.19 kg) than Masri donkeys (163.42 ± 7.21 kg, p < 0.05). Peak milk yields occurred on day 57 for North African donkeys (1.212 kg/day) and day 59 for Masri donkeys (0.991 kg/day), with similar persistency indices of 7.19 and 7.21, respectively. North African donkey milk had significantly higher protein (1.45 ± 0.03 g/100 g) and β-lactoglobulin (4.75 ± 0.06 mg/mL) contents, while Masri donkey milk contained more fat (1.16 ± 0.05 g/100 g). Amino acid analysis revealed higher glutamate (0.27 ± 0.12 g/100 g) in North African donkey milk, while Masri donkey milk had more aspartate (0.16 ± 0.04 g/100 g). North African donkey milk had higher palmitic acid (20.1 ± 0.07 g/100 g), while Masri donkey milk had more oleic acid (21.4 ± 0.42 g/100 g). Lactation curve fitting yielded R2 values of 93.8% for Masri donkeys and 95.7% for North African donkeys. These findings suggest that both populations are well-suited for milk production, particularly for human consumption or food applications. North African donkeys exhibited superior yields and nutrient profiles suitable for functional food applications. [ABSTRACT FROM AUTHOR]

Simple Summary: Age at puberty is a main factor affecting reproductive efficiency and, thus, livestock production. Besides species and breed, nutrition during growth plays a crucial role in the attainment of puberty. Controversial results are reported about the critical period during which heifers are more sensitive to the effects of nutrition on pubertal acceleration. Numerous papers are available about such topics, but they are characterized by very different experimental conditions (such as genetics, feeds, planes of nutrition, season and pasture quality, time windows, and parameters considered), making difficult the comparison among inconstant results by various trials. Several indicators during growth have been proposed as predictors of age at puberty, such as body weight gains, body fat reserves, and linear body measurements. Blood concentrations of hormones strictly linked to growth and reproduction have also been considered: higher Insulin-like Growth Factor-1 levels are reported to be related to earlier puberty, while leptin is not. More uniform experimental conditions should be encouraged for future research. Puberty onset and age at first calving have a critical impact on livestock production for good reproductive efficiency of the herd and to reduce the duration of the non-productive stage of the growing heifer. Besides genetic factors, sexual maturation is also affected by environmental factors, such as nutrition, which can account for up to 20% of the observed variability. The rate of body weight gain during growth is considered the main variable influencing the age at puberty, dependent on planes of nutrition in growing animals during the prepubertal-to-pregnancy stage. This paper reviews current knowledge concerning nutrition management and attainment of puberty in heifers, considering the relevance of some indicators such as body measurements and hormones strictly linked to the growth and puberty process. Puberty onset is dependent on the acquisition of adequate subcutaneous adipose tissue mass, as it is the main source of the hormone leptin. Until a certain level, body condition score and age at puberty are negatively correlated, but beyond that, for fatter animals, such correlation is gradually lost. Age at puberty in heifers was reported to be negatively related to IGF-1. Future research should be planned considering the need to standardize the experimental animals and conditions. [ABSTRACT FROM AUTHOR]