Evaluation of Udder Cisterns and Effects on Milk Yield of Dairy Ewes

Abstract

Nine Manchega (0.94 L/d) and 10 Lacaune (2.07 L/d) ewes at the same stage of lactation (90 d in milk) were used to study the interbreed differences in milk yield, mammary morphological traits, and machine-milking ability. Udder traits were measured after 6 h of udder filling before the start of the experiment. Cisternal area (by ultrasonography), cisternal milk (by teat cannula drainage), and alveolar milk (by machine milking after an intravenous oxytocin injection) were randomly measured 8 h after milking for 2 wk consecutively either with an intravenous injection of an oxytocin receptor blocking agent (atosiban, AT) or without (control, C) to avoid the occurrence of milk letdown before milking. Lacaune ewes had greater udder depth (22.5 +/- 0.9 vs. 19.6 +/- 0.9 cm) and cistern height (27.1 +/- 3.8 vs. 15.6 +/- 3.5 mm), whereas Manchega ewes had longer (42.7 +/- 1.5 vs. 32.7 +/- 1.5 mm) and wider teats (17.4 +/- 0.5 vs. 13.9 +/- 0.5 mm). Values per half udder for Manchega and Lacaune ewes differed in cisternal area (12.8 +/- 0.7 and 23.7 +/- 0.6 cm(2)) and cisternal milk (120 +/- 0.6 and 269 +/- 0.5 mL), but not in alveolar milk (95 +/- 0.5 and 102 +/- 0.4 mL), respectively. Cisternal area and cisternal milk were positively correlated (r = 0.79). Ratios between cisternal and alveolar milk were 56:44 and 73:27 for Manchega and Lacaune ewes, respectively. Cisternal milk volumes obtained with the AT or C treatment were similar in Manchega (111 +/- 10 vs. 122 +/- 8 mL) but differed in Lacaune ewes (239 +/- 8 vs. 299 +/- 8 mL), respectively. Consequently, alveolar milk with AT vs. C was similar in Manchega (104 +/- 8 vs. 86 +/- 7 mL) but different in Lacaune ewes (115 +/- 7 vs. 89 +/- 7 mL). Results of this experiment confirm the need for the use of an oxytocin-blocking agent for accurate evaluation of milk contained in the udder of dairy ewes. Moreover, despite the differences in daily milk yield, alveolar milk did not vary between breeds, emphasizing the role of the cisternal more than the alveolar compartment for maximizing daily milk secretion in dairy sheep.

Evolution of udder morphology, alveolar and cisternal milk compartment during lactation and their relationship with milk yield in Najdi sheep

“…No significant differences were observed between milk protein, lactose and total solid percentages of cisternal and alveolar milk during suckling and milking periods. These results agree in part with those findings in dairy ewes (Rovai et al, 2008), dairy goats (Salama et al, 2004), dairy cows and lactating dromedary camels (Ayadi et al, 2013).…”

“…The discrepancies in results between the latter study and our findings are probably due to their longer milking period, milking with machine and breed differences. The teat width and angle observed in the current study for Najdi ewes were smaller in values than those values reported for Manchega, Lacaune, Merino Rambouillet and Chios dairy breed ewes Ochoa-Cordero et al, 2006;Rovai et al, 2008;Gelasakis et al, 2012). Teat angle in Najdi ewes was greater than the average value observed in French Rouge de l'Ouest ewes (26.5°, Malher & Vrayla-Anesti, 1994).…”

“…The udder depth, width and circumference measurements in this study were greater than the values reported for Sicilo-Sarde dairy ewes (Ayadi et al, 2011), but similar to those reported for Manchega, Lacaune and Merino Rambouillet dairy ewes Ochoa-Cordero et al, 2006;Rovai et al, 2008). Correlations between udder traits and daily milk yield were positively significant (p < 0.05) during suckling and milking periods, which is in agreement with previous reports by Labussiere (1988), Arranz et al (1989), Fernández et al (1995, Rovai et al (2008) and Ayadi et al (2011).…”

The Course of Machine Milking in Small Ruminants

“…Conversely, ewes with a higher machine stripping rate had higher log SCC. The level of milk production in high-yielding dairy sheep depends mainly on the capacity of their udder cisterns and greater storage of milk between milkings (Rovai et al, 2008). In that study ewes of two breeds, Manchega and Lacaune, produced approximately the same amount of alveolar milk; however, Lacaune ewes had greater volumes and larger areas of the cisterns, and greater milk yield when compared with Manchega ewes.…”

Recent developments in cattle, pig, sheep and horse breeding - a review

“…Attention is also paid to breeding for morphological characteristics of the udders in dairy sheep Rovai et al 2009;Sadeghi et al 2014).…”