The effect of different management systems on milk yield and milk quality in Awassi sheep

The survival analysis of some environmental factors associated with lamb mortality in Awassi sheep

Most of the economic losses in the Turkish sheep industry are due to lamb deaths between birth and weaning period. Survival analysis is an essential step in the understanding of the lamb's survival function and the hazards that have an impact on mortality. The lamb records were accessed from 2013 to 2019, with the information of 11,523 lambs from birth to weaning at 90 days of age. The Kaplan-Meier method was used for the estimation of the survival function of the lambs. The Cox proportional hazards survival analysis was performed to evaluate the factors influencing Awassi lamb mortality in the central Anatolian region of Türkiye. A multivariable Cox regression was fitted to the data after checking the assumptions of the regression. Year of birth, lambing season, lamb sex, method of birth, and birth weight groups were used as explanatory variables. The overall survival of the lambs to weaning was 75.7%, and the Kaplan-Meier estimate of the average survival time to weaning was 62.25 days. Cox proportional hazards modeling showed that the hazard rate of death before weaning was higher in male lambs (1.205 and 95% CI, 1.119-1.300) compared to female lambs. It was also noted that the hazard rate of death (HR = 0.956 and 95% CI, 0.937-0.974) had significant years. The single-born lambs had a lower risk of death among the lambs. The summer and autumn seasons had a very highly advanced effect on the survival rate of the lambs. The hazard rate for the categorical birth weight group was 0.703 (95% CI, 0.667-0.741). This indicates that the risk of pre-weaning mortality decreased with increasing birth weight > 3.5 kg. The results of this study showed that lamb survival can be increased by paying more attention to winter born lambs, male sex, twin births, and lambs about birth weight (< 3.5 kg).

Effects of Feeding Management System on Milk Production and Milk Quality from Sheep of the Turcana Breed

Milk and dairy products are among the foods preferred by consumers, as they are rich in nutrients, have high biological values, are easily accessible, and present a low risk to health. This study aimed to comparatively analyze the milk from sheep of the Turcana breed that were subjected to different feeding systems. The milk from the sheep was analyzed quantitatively and qualitatively; in this sense, the following were determined: daily milk production (DMY), physical parameters (pH, freezing point), chemical composition (lactose (L), fats (F), total proteins (TP), non-fat solids (Snf)), the content of heavy metals and trace elements (Zn, Cd, Cu, Fe, Mn, Pb), and microbiological parameters (the number of somatic cells (SCC), the total number of aerobic mesophilic germs that develop at 30 °C (NTG), the number of coliform bacteria (CT), the number of Staphylococcus aureus). Administration of the fodder complex produced, on the farm determined a slight quantitative increase in milk production, as well as in fat, protein and lactose content. The content of trace elements Zn, Fe, and Mn registered increases in milk samples from sheep that were administered the fodder complex. The content of heavy metals did not indicate any source of pollution in the grazing area. Furthermore, the microbiological parameters were within the allowed limits, indicating a good general state of health at the emergency level and the absence of microbiological contamination of the milk samples.

Feeding and Nutritional Factors That Affect Somatic Cell Counts in Milk of Sheep and Goats

The purpose of this quantitative review is to highlight the effects of feeding strategies using some mineral, vitamin, marine oil, and vegetable essential oil supplements and some agri-food by-products to reduce SCCs in the milk of sheep and goats. According to the results, only specific dietary factors at specific doses could reduce SCCs in the milk of dairy sheep and goats. The combination of Se and vitamin E in the diet was more effective in sheep than in goats, while the inclusion of polyphenols, which are also present in food matrices such as agro-industrial by-products, led to better results. Some essential oils can be conveniently used to modulate SCCs, although they can precipitate an off-flavoring problem. This work shows that SCCs are complex and cannot be determined using a single experimental factor, as intramammary inflammation, which is the main source of SC in milk, can manifest in a subclinical form without clinical signs. However, attention to mineral and vitamin supplementation, even in the most difficult cases, such as those of grazing animals, and the use of anti-inflammatory substances directly or through by-products, can improve the nutritional condition of animals and reduce their SCCs, offering undeniable benefits for the milk-processing sector as well.