The comparison of the lactation and milk yield and composition of selected breeds of sheep and goats

Abstract

The objective of this study was to characterize the milk yield (MY) and milk composition of relevant sheep and goat breeds raised around the world to be used with nutrition models for diet formulation and nutrient balancing. A 2-step approach was used. First, a database developed by the Food and Agriculture Organization was used to identify relevant breeds (i.e., frequently raised) by comparing the occurrence of transboundary breed names across countries. We selected transboundary breeds that occurred more than 3 times and other relevant breeds obtained from the specialized literature that had milk production information (e.g., MY, days in milk, and milk fat, protein, and lactose). The majority of sheep breeds were classified as nondairy (76%) because they lacked milk production information. Karakul and Merino accounted for up to 2.4% of sheep breeds raised around the world, whereas the other individual breeds accounted for less than 1%. In contrast, nondairy breeds of goats accounted for 46.3% and of the remaining 53.7%, Saanen, Boer, Anglo-Nubian, Toggenburg, and Alpine accounted for 6.5, 5, 4.4, 4, and 3%, respectively, of the transboundary breeds. Second, a database compiled from published studies for the selected sheep (n = 65) and goats (n = 78) breeds were analyzed using a random coefficients model (studies and treatments within studies as random effects). For sheep breeds, the average and SD were 1.1 ± 0.3 kg/d for MY, 6.9 ± 1% for milk fat, 5.4 ± 0.4% for milk protein, 5 ± 0.3% for milk lactose, 17.7 ± 1.4% for milk total solids, and 1,073 ± 91 kcal/kg of milk energy. Lacaune had the greatest MY compared to Comisana and Tsigai (1.65 versus 0.83 and 0.62 kg/d; respectively, P < 0.05), but milk components were not different among breeds. For goats breeds, the average and SD across breeds were 1.7 ± 0.6 kg/d for MY, 4.2 ± 0.9% for milk fat, 3.3 ± 0.4% for milk protein, 4.4 ± 0.4% for milk lactose, 12.7 ± 1.1% for milk total solids, and 750 ± 75 kcal/kg of milk energy. Alpine had similar MY to Saanen (2.66 versus 2.55 kg/d, respectively; P > 0.05), but greater (P < 0.05) than other breeds. The Boer breed had the greatest milk fat, protein, lactose, and total solids than several other breeds, leading to the greatest milk energy content (907 kcal/kg). Because there are many factors that can alter MY and milk composition, averages provided in this study serve as guidelines, and nutritionists must obtain observed values when using nutrition models.

Udder Measurements and Their Relationship with Milk Yield in Pelibuey Ewes

“…Our analysis was highly accurate (Cb > 0.852 and RMSEP > 29%) in predicting milk yield according to the selected udder measurements, but the precision (r 2 < 0.632) was systematically low, resulting in under prediction (CD < 1.897) across equations. The variation in milk yield may be largely explained by environmental effects [6] or genotype [6,15,37]. Although the previous studies indicated that ewes rearing twin lambs had higher daily milk yields [6,38], because of low prolificacy in the present study (1.13), the effect of litter size could not be determined due to insufficient statistical power.…”

“…Among these indirect methods, udder measurements and the weight gain of lambs has been evaluated in addition to more sophisticated and expensive techniques, such as the dilution of isotopes [5,6,[12][13][14]. The need to correctly assess milk yield is important, but there is a chronic lack of information [15,16] and a lack of dissemination of available and accurate methods [10].…”

Influence of storage temperature on the population of microorganisms in raw sheep milk and its physical-chemical profile

“…In this study, the values of ash (0.92%), lactose (4.43%), cryoscopy index (0.575°H) and titratable acidity (0.23 g of lactic acid/100 mL) ( Table 1) were similar of the means values described in others studies about sheep milk. (Merlin Junior et al, 2015;Rafiq et al, 2016;Balthazar et al, 2017;Ferro et al, 2017;Panayotov et al, 2018;Sobrino et al, 2018). In addition, the values of fat (6.28%), protein (5.30%) and TDM (16.52%) were lower ( Table 1).…”

“…* analysis in triplicate /sample ** Source: (2015-2020) MerlinJunior et al, (2015);Rafiq et al, (2016);Balthazar et al, (2017);Ferro et al, (2017);Panayotov et al, (2018);Sobrino et al, (2018).…”

Developing a continuous adjustment factor for dry matter intake of gestating and lactating ewes

“…The NRC (2001) of dairy cattle uses fat content of 4 % as a standard value of milk fat. Dairy ewes compared to the meat and wool sheep show distinct milk production, lactation peak, and milk composition (protein and fat) (Dove and Kelman, 2015;Ferro et al, 2017;Gonzalo et al, 1994;Massouras et al, 2018;Nudda et al, 2002;Park, 2007). In contrast to dairy cattle, an exact value has not been stipulated for dairy sheep to use as a standard value for sheep milk, but predictive equations for DMI take into account milk composition to assess the energy content of the milk.…”