Effect of subclinical mastitis on the yield and cheese-making properties of ewe's milk

[EN] This review covers an update of scientific knowledge about productive and technological consequences of subclinical mastitis in sheep milk. The literature reports individual milk yield losses of 2.6-43.1 %, being modulated by several factors as infection severity, production level, causal agents, and unilateral or bilateral IMI (1 or 2 infected glands, respectively). A compensatory increase of milk production from the uninfected gland when only one half was infected has been quantified in 6.6 %, compared with healthy halves of control sheep. This compensatory adaptation highlights the risk of underestimating subclinical mastitis in sheep. The mammary gland response is quick and milk yield losses in absolute terms remained constant within the following weeks, both when infection appear during lactation and when it is present from lambing. With respect to the changes on main components in milk due to subclinical mastitis it has been clearly established a decrease in the concentration of lactose and an increase of that of whey proteins. The role played by lactose as an osmotic regulator results in a more accentuated decrease of its concentration in milk. This is why lactose is considered at present as a reliable potential indicator of subclinical mastitis. Whey proteins increase as a result of the increase of the blood-milk barrier permeability and the increased proteolysis of caseins. However, the content in milk of fat and casein are modified depending on the magnitude of milk yield reduction, being affected by a concentration or dilution effect. In any case, the ratio casein to protein (parameter independent of the milk volume) decreases as a result of infection. The impairment of physical and chemical characteristics due to decreased udder health status is the responsible of the negative effect of increased SCC on the coagulation properties of milk, the curd yield and the quality of cheese. Low ratio of casein to protein in high bulk tank SCC milk enhances the extension of the rennet coagulation time (RCT) and curd firming time (k20) because there are more serum proteins and the stability of casein micelles are reduced as a result of hydrolysis. Those changes in turn led to poor syneresis, lower cheese yield, increased moisture content and lower fat and protein content in cheese. Finally, there is a favourable relationship between lactose and milk technological properties because the decrease of this component in case of mastitis is associated with an increase of milk pH. Thus, the three parameters, SCC, pH, and lactose affect, contemporarily and independently, milk quality and coagulation properties, and this is why have been highlighted as potential indicators traits for improving cheese-making ability of sheep milk.This review is based on knowledge gained during work financially supported by means of a research fellowship from the regional government of Valencia ("Generalitat Valenciana").Martí-De Olives, A.; Peris Ribera, CJ.; Molina Pons, MP. (2020). Effect of subclinical mastitis on the yield and cheese-making properties of ewe's milk. Small Ruminant Research. 184:1-7. https://doi.org/10.1016/j.smallrumres.2019.106044S17184Albenzio, M., Marino, R., Caroprese, M., Santillo, A., Annicchiarico, G., & Sevi, A. (2004). Quality of milk and of Canestrato Pugliese cheese from ewes exposed to different ventilation regimens. Journal of Dairy Research, 71(4), 434-443. doi:10.1017/s0022029904000330Albenzio, M., Caroprese, M., Santillo, A., Marino, R., Muscio, A., & Sevi, A. (2005). Proteolytic patterns and plasmin activity in ewes’ milk as affected by somatic cell count and stage of lactation. Journal of Dairy Research, 72(1), 86-92. doi:10.1017/s0022029904000676Albenzio, M., Santillo, A., Caroprese, M., d’ Angelo, F., Marino, R., & Sevi, A. (2009). Role of endogenous enzymes in proteolysis of sheep milk. Journal of Dairy Science, 92(1), 79-86. doi:10.3168/jds.2008-1439Albenzio, M., & Santillo, A. (2011). Biochemical characteristics of ewe and goat milk: Effect on the quality of dairy products. Small Ruminant Research, 101(1-3), 33-40. doi:10.1016/j.smallrumres.2011.09.023Albenzio, M., Figliola, L., Caroprese, M., Marino, R., Sevi, A., & Santillo, A. (2019). Somatic cell count in sheep milk. Small Ruminant Research, 176, 24-30. doi:10.1016/j.smallrumres.2019.05.013Auldist, M. J., Coats, S., Sutherland, B. J., Mayes, J. J., McDowell, G. H., & Rogers, G. L. (1996). Effects of somatic cell count and stage of lactation on raw milk composition and the yield and quality of Cheddar cheese. Journal of Dairy Research, 63(2), 269-280. doi:10.1017/s0022029900031769Balcones, E., Olano, A., & Calvo, M. M. (1996). Factors Affecting the Rennet Clotting Properties of Ewe’s Milk. Journal of Agricultural and Food Chemistry, 44(8), 1993-1996. doi:10.1021/jf960138uBastian, E. D., & Brown, R. J. (1996). Plasmin in milk and dairy products: an update. International Dairy Journal, 6(5), 435-457. doi:10.1016/0958-6946(95)00021-6Bianchi, L., Bolla, A., Budelli, E., Caroli, A., Casoli, C., Pauselli, M., & Duranti, E. (2004). Effect of Udder Health Status and Lactation Phase on the Characteristics of Sardinian Ewe Milk. Journal of Dairy Science, 87(8), 2401-2408. doi:10.3168/jds.s0022-0302(04)73362-7Burriel, A. R. (1997). Dynamics of intramammary infection in the sheep caused by coagulase-negative staphylococci and its influence on udder tissue and milk composition. Veterinary Record, 140(16), 419-423. doi:10.1136/vr.140.16.419Burriel, A. R., & Wagstaff, A. (1998). The influence of ewe intramammary infection caused by coagulase-negative staphylococci on the milk constituents total protein, albumin, potassium and sodium. Animal Science, 67(3), 499-502. doi:10.1017/s1357729800032926Caballero-Villalobos, J., Garzón, A. I., Martínez Marín, A. L., Arias, R., Ciocia, F., & McSweeney, P. L. H. (2018). Plasmin activity in Manchega ewe milk: The effect of lactation, parity and health of the udder, and its influence on milk composition and rennet coagulation. Small Ruminant Research, 158, 57-61. doi:10.1016/j.smallrumres.2017.10.005Considine, T., Healy, Á., Kelly, A. L., & McSweeney, P. L. H. (2004). Hydrolysis of bovine caseins by cathepsin B, a cysteine proteinase indigenous to milk. International Dairy Journal, 14(2), 117-124. doi:10.1016/s0958-6946(03)00171-7Dhondt, G., Burvenich, C., & Peeters, G. (1977). Mammary blood flow during experimental Escherichia coli endotoxin induced mastitis in goats and cows. Journal of Dairy Research, 44(3), 433-440. doi:10.1017/s0022029900020392European Union 1994 Council Directive 94/71/EEC of 13 December 1994 amending Directive 92/46/EEC laying down the health rules for the production and placing on the market of raw milk, heat-treated milk and milk-based products. Official Journal of European Community L368 33–37.Fthenakis, G. C., & T.Jones, J. E. (1990). The effect of inoculation of coagulase-negative Staphylococci into the ovine mammary gland. Journal of Comparative Pathology, 102(2), 211-219. doi:10.1016/s0021-9975(08)80126-0Giadinis, N. D., Arsenos, G., Tsakos, P., Psychas, V., Dovas, C. I., Papadopoulos, E., … Fthenakis, G. C. (2012). «Milk-drop syndrome of ewes»: Investigation of the causes in dairy sheep in Greece. Small Ruminant Research, 106(1), 33-35. doi:10.1016/j.smallrumres.2012.04.018González-RodríGuez, M. C., Gonzalo, C., San Primitivo, F., & Cármenes, P. (1995). Relationship Between Somatic Cell Count and lntramammary Infection of the Half Udder in Dairy Ewes. Journal of Dairy Science, 78(12), 2753-2759. doi:10.3168/jds.s0022-0302(95)76906-5Gonzalo, C., Carriedo, J. A., Baro, J. A., & San Primitivo, F. (1994). Factors Influencing Variation of Test Day Milk Yield, Somatic Cell Count, Fat, and Protein in Dairy Sheep. Journal of Dairy Science, 77(6), 1537-1542. doi:10.3168/jds.s0022-0302(94)77094-6Gonzalo, C., Ariznabarreta, A., Carriedo, J. A., & San Primitivo, F. (2002). Mammary Pathogens and Their Relationship to Somatic Cell Count and Milk Yield Losses in Dairy Ewes. Journal of Dairy Science, 85(6), 1460-1467. doi:10.3168/jds.s0022-0302(02)74214-8Gonzalo, C., Tardáguila, J. A., De La Fuente, L. F., & San Primitivo, F. (2004). Effects of selective and complete dry therapy on prevalence of intramammary infection and on milk yield in the subsequent lactation in dairy ewes. Journal of Dairy Research, 71(1), 33-38. doi:10.1017/s0022029903006526Grufferty, M. B., & Fox, P. F. (1988). Milk alkaline proteinase. Journal of Dairy Research, 55(4), 609-630. doi:10.1017/s0022029900033409Hernández-Ramos, P. A., Vivar-Quintana, A. M., & Revilla, I. (2019). Estimation of somatic cell count levels of hard cheeses using physicochemical composition and artificial neural networks. Journal of Dairy Science, 102(2), 1014-1024. doi:10.3168/jds.2018-14787Klei, L., Yun, J., Sapru, A., Lynch, J., Barbano, D., Sears, P., & Galton, D. (1998). Effects of Milk Somatic Cell Count on Cottage Cheese Yield and Quality. Journal of Dairy Science, 81(5), 1205-1213. doi:10.3168/jds.s0022-0302(98)75680-2Le Roux, Y., Colin, O., & Laurent, F. (1995). Proteolysis in Samples of Quarter Milk with Varying Somatic Cell Counts. 1. Comparison of Some Indicators of Endogenous Proteolysis in Milk. Journal of Dairy Science, 78(6), 1289-1297. doi:10.3168/jds.s0022-0302(95)76749-2Leitner, G., Chaffer, M., Caraso, Y., Ezra, E., Kababea, D., Winkler, M., … Saran, A. (2003). Udder infection and milk somatic cell count, NAGase activity and milk composition—fat, protein and lactose—in Israeli-Assaf and Awassi sheep. Small Ruminant Research, 49(2), 157-164. doi:10.1016/s0921-4488(03)00079-8Leitner, G., Chaffer, M., Shamay, A., Shapiro, F., Merin, U., Ezra, E., … Silanikove, N. (2004). Changes in Milk Composition as Affected by Subclinical Mastitis in Sheep. Journal of Dairy Science, 87(1), 46-52. doi:10.3168/jds.s0022-0302(04)73140-9Leitner, G., Silanikove, N., & Merin, U. (2008). Estimate of milk and curd yield loss of sheep and goats with intrammamary infection and its relation to somatic cell count. Small Ruminant Research, 74(1-3), 221-225. doi:10.1016/j.smallrumres.2007.02.009Leitner, G., Merin, U., & Silanikove, N. (2011). Effects of glandular bacterial infection and stage of lactation on milk clotting parameters: Comparison among cows, goats and sheep. International Dairy Journal, 21(4), 279-285. doi:10.1016/j.idairyj.2010.11.013Leitner, G., Lavon, Y., Matzrafi, Z., Benun, O., Bezman, D., & Merin, U. (2016). Somatic cell counts, chemical composition and coagulation properties of goat and sheep bulk tank milk. International Dairy Journal, 58, 9-13. doi:10.1016/j.idairyj.2015.11.004Martí-De Olives, A., Le Roux, Y., Rubert-Alemán, J., Peris, C., & Molina, M. P. (2011). Short communication: Effect of subclinical mastitis on proteolysis in ovine milk. Journal of Dairy Science, 94(11), 5369-5374. doi:10.3168/jds.2011-4269Martí De Olives, A., Díaz, J. R., Molina, M. P., & Peris, C. (2013). Quantification of milk yield and composition changes as affected by subclinical mastitis during the current lactation in sheep. Journal of Dairy Science, 96(12), 7698-7708. doi:10.3168/jds.2013-6998Martí-De Olives, A., Navarro-Ríos, M. J., Rubert-Alemán, J., Fernández, N., & Molina, M. P. (2015). Composition, proteolysis indices and coagulating properties of ewe milk as affected by bulk tank somatic cell count. Journal of Dairy Research, 82(3), 344-349. doi:10.1017/s0022029915000394Merin, U., Fleminger, G., Komanovsky, J., Silanikove, N., Bernstein, S., & Leitner, G. (2008). Subclinical udder infection withStreptococcus dysgalactiaeimpairs milk coagulation properties: The emerging role of proteose peptones. Dairy Science and Technology, 88(4-5), 407-419. doi:10.1051/dst:2008022Park, Y. W. (2007). Rheological characteristics of goat and sheep milk. Small Ruminant Research, 68(1-2), 73-87. doi:10.1016/j.smallrumres.2006.09.015Paschino, P., Vacca, G. M., Dettori, M. L., & Pazzola, M. (2019). An approach for the estimation of somatic cells’ effect in Sarda sheep milk based on the analysis of milk traits and coagulation properties. Small Ruminant Research, 171, 77-81. doi:10.1016/j.smallrumres.2018.10.010Pazzola, M., Cipolat-Gotet, C., Bittante, G., Cecchinato, A., Dettori, M. L., & Vacca, G. M. (2018). Phenotypic and genetic relationships between indicators of the mammary gland health status and milk composition, coagulation, and curd firming in dairy sheep. Journal of Dairy Science, 101(4), 3164-3175. doi:10.3168/jds.2017-13975PELLEGRINI, O., REMEUF, F., RIVEMALE, M., & BARILLET, F. (1997). Renneting properties of milk from individual ewes: influence of genetic and non-genetic variables, and relationship with physicochemical characteristics. Journal of Dairy Research, 64(3), 355-366. doi:10.1017/s0022029997002203Pinto, G., Caira, S., Nicolai, M. A., Mauriello, R., Cuollo, M., Pirisi, A., … Addeo, F. (2013). Proteolysis and partial dephosphorylation of casein are affected by high somatic cell counts in sheep milk. Food Research International, 53(1), 510-521. doi:10.1016/j.foodres.2013.05.016Politis, I., Lachance, E., Block, E., & Turner, J. D. (1989). Plasmin and Plasminogen in Bovine Milk: A Relationship with Involution? Journal of Dairy Science, 72(4), 900-906. doi:10.3168/jds.s0022-0302(89)79183-9Precetti, A. S., Oria, M. P., & Nielsen, S. S. (1997). Presence in Bovine Milk of Two Protease Inhibitors of the Plasmin System. Journal of Dairy Science, 80(8), 1490-1496. doi:10.3168/jds.s0022-0302(97)76077-6Raynal-Ljutovac, K., Pirisi, A., de Crémoux, R., & Gonzalo, C. (2007). Somatic cells of goat and sheep milk: Analytical, sanitary, productive and technological aspects. Small Ruminant Research, 68(1-2), 126-144. doi:10.1016/j.smallrumres.2006.09.012Revilla, I., Rodríguez-Nogales, J. M., & Vivar-Quintana, A. M. (2009). Effect of somatic cell counts on ewes’ milk protein profile and cheese-making properties in different sheep breeds reared in Spain. Journal of Dairy Research, 76(2), 210-215. doi:10.1017/s0022029909004002Maristela, R., Natalia, R., Gerardo, C., Jordi, S., & Gabriel, L. (2015). Effect of subclinical intrammamay infection on milk quality in dairy sheep: I. Fresh-soft cheese produced from milk of uninfected and infected glands and from their blends. Small Ruminant Research, 125, 127-136. doi:10.1016/j.smallrumres.2015.02.019Saratsis, P., Alexopoulos, C., Tzora, A., & Fthenakis, G. . (1999). The effect of experimentally induced subclinical mastitis on the milk yield of dairy ewes. Small Ruminant Research, 32(3), 205-209. doi:10.1016/s0921-4488(98)00189-8SCHULTZ, L. H. (1977). Somatic Cells in Milk-Physiological Aspects and Relationship to Amount and Composition of Milk. Journal of Food Protection, 40(2), 125-131. doi:10.4315/0362-028x-40.2.125Silanikove, N., Merin, U., & Leitner, G. (2006). Physiological role of indigenous milk enzymes: An overview of an evolving picture. International Dairy Journal, 16(6), 533-545. doi:10.1016/j.idairyj.2005.08.015Silanikove, N., Merin, U., & Leitner, G. (2014). On effects of subclinical mastitis and stage of lactation on milk quality in goats. Small Ruminant Research, 122(1-3), 76-82. doi:10.1016/j.smallrumres.2014.07.018Vacca, G. M., Cipolat-Gotet, C., Paschino, P., Casu, S., Usai, M. G., Bittante, G., & Pazzola, M. (2019). Variation of milk technological properties in sheep milk: Relationships among composition, coagulation and cheese-making traits. International Dairy Journal, 97, 5-14. doi:10.1016/j.idairyj.2019.05.002Verdi, R. J., & Barbano, D. M. (1991). Effect of Coagulants, Somatic Cell Enzymes, and Extracellular Bacterial Enzymes on Plasminogen Activation. Journal of Dairy Science, 74(3), 772-782. doi:10.3168/jds.s0022-0302(91)78224-6Vivar-Quintana, A. M., Beneitez De La Mano, E., & Revilla, I. (2006). Relationship between somatic cell counts and the properties of yoghurt made from ewes’ milk. International Dairy Journal, 16(3), 262-267. doi:10.1016/j.idairyj.2005.03.00

Milkability and milking efficiency improvement in Murciano-Granadina breed goats

[EN] The aim of this study was to verify the effect of cluster, udder characteristics and milking parameters on milkability and milking efficiency of Murciano-Granadina breed goats, in order to improve them. The cluster used is well adapted to the goats, except that the teat-floor distance is too short for the teat-cup used and the cluster rests on the platform instead of hanging from the udder, something apparently attributed to a poor udder conformation rather than an excessively-long teat-cup. Udder parameters studied are classified as medium or medium-high by the Murciano-Granadina breed association, and do not seem to represent a problem for good milkability except for the teat sphincter strength, which reduced milk flows (P<0.001) and increased milking times (P<0.001). Maintaining 60% as pulsator ratio, a combination 42 kPa:120 ppm (vacuum level:pulsator rate) milking parameters reduced total milking time by 22 s per goat compared to 40 kPa:90 ppm, commonly used in this flock, but increased teat thickness measured before and after milking. Studies of longer duration are needed to ensure that the new Milking parameters do not affect the udder health status. (C) 2015 Elsevier B.V. All rights reserved.Fernández Martínez, N.; Martínez, A.; Martí Vicent, JV.; Rodríguez Garcia, M.; Peris Ribera, CJ. (2015). Milkability and milking efficiency improvement in Murciano-Granadina breed goats. Small Ruminant Research. 126:68-72. doi:10.1016/j.smallrumres.2015.03.001S687212

Kid growth comparison between Murciano-Granadina and crossed Murciano-GranadinaxBoer in a mixed rearing system

[EN] Usually, goat dairy farms have a major problem with the kids they produce for sale, due to their low average daily gain, high feed conversion ratio and poor body conformation, which leads to poor profitability. This paper proposes a solution by crossing the dams not used for replacement with males of a meat breed in a mixed rearing system. The results show that crossbred kids (Murciano-GranadinaxBoer) reached the minimum slaughter weight a week earlier than Murciano-Granadina purebred kids, and that there is a decrease of energy content in milk and in the consumption by the kids as their age increases, which shows the importance of having a concentrated feed that complements their needs to express all the genetic potential for growth observed in the references, especially in the crossing of these two breeds. In addition to this, farms that follow this strategy will also be able to improve their profitability through a higher quantity of milk sold. In dairy goats, the low average daily gain and the high conversion ratio for milk and concentrate of the kids mean that their sale price does not offset the costs generated. The hypothesis proposes that a crossbreeding of the Murciano-Granadina breed (MG) with the Boer breed (MGxBoer) will improve the profitability of the kids sold. Thus, the effect of two different groups of kids (purebred MG and crossbred MGxBoer) on birth weight (BW), mortality, average daily gain (ADG), the time for minimum slaughter weight (7 kg) and its variation factors were studied. MGxBoer kids had a 27% greater BW than purebred MG kids (2885 +/- 84 g and 2275 +/- 74 g, respectively), similar ADG (156 +/- 6 g and 142 +/- 6 g, respectively) and mortality (18% and 20%, respectively), and reached minimum slaughter weight a week sooner. ADG was less and less as the lactation period progressed due to a lower milk consumption and milk energy value, which highlights the importance of providing a concentrate that will compensate for this reduced energy content. In conclusion, the results show that MGxBoer crossbred kids reached the minimum slaughter weight a week earlier than purebred MG kids, and highlighted the improvement of farm profitability through the increase of milk sold and the need to provide a concentrate feed to enhance the growth of the kids.This research was funded by the project RTA2013-00107 (INIA) with ERDF funds.Fernández Martínez, N.; Palomares Carrasco, JL.; Pérez Baena, I.; Rodríguez Garcia, M.; Peris Ribera, CJ. (2021). Kid growth comparison between Murciano-Granadina and crossed Murciano-GranadinaxBoer in a mixed rearing system. Animals. 11(4):1-9. https://doi.org/10.3390/ani11041051S1911

Effect of the rearing system on financial returns from Murciano-Granadina breed goats

[EN] In dairy goats, the kid rearing system can have critical importance in financial returns. Commonly used criteria for the choice of rearing system are not always clear due to the high number of factors involved. The aim of this study was to quantify all those factors to facilitate decision making. So, the effect of two different kid rearing systems, mixed (MRS) and artificial (ARS), on milk yield, milk composition and somatic cell count (SCC), milk yield loss at weaning for MRS, kid growth and costs of the different traits on the financial returns in Murciano-Granadina breed goats was studied. Twenty-four goats per group were used. In the MRS, goats reared only one kid, which had free access to goat milk 24 h a day and were weaned at week 6 of lactation, whereas kids in the ARS were separated from their mothers at kidding, colostrum and artificially reared. In both systems, dams were machine-milked once a day throughout lactation and the records took place weekly. Potential milk yield was estimated according to the oxytocin method up to week 12 of lactation, and was similar for both rearing systems, although a 12.3 per cent drop in potential milk yield at weaning was observed for MRS. During the first 6 weeks of lactation, marketable milk was lower for dams in MRS compared to those in ARS (72.1 versus 113.0 l), but similar for the rest of the experiment (101.5 versus 99.4 l, respectively). Marketable milk composition and SCC throughout the 12 weeks of lactation were unaffected by the rearing system. Artificial rearing system entailed an increment in production cost of 22.2 € per kid compared to the rearing by MRS. A similar economic return per goat and kid was obtained from ARS and MRS in this experiment, although, due to one herd¿s prolificacy of 1.8, the actual results would be 16.2 € per goat in favour of MRS. The real interest of this experiment may be the possibility of extrapolation to different flocks with diverse levels of milk production, prolificacy and prices and costs for incomes and outputs, to estimate the production system that increases returns. In conclusion, the results showed an increase in the cost of € 22.2 per kid bred in the artificial rearing system, compared to the mixed rearing system, and a final return of 16.2 € per goat in favour of the mixed system.This work was funded by the project RTA2013-00107 (INIA) with FEDER funds.Fernández Martínez, N.; Palomares Carrasco, JL.; Pérez Baena, I.; Rodríguez Garcia, M.; Peris Ribera, CJ. (2019). Effect of the rearing system on financial returns from Murciano-Granadina breed goats. Animal. 13(8):1730-1735. https://doi.org/10.1017/S1751731118003336S17301735138Silanikove, N., Leitner, G., Merin, U., & Prosser, C. G. (2010). Recent advances in exploiting goat’s milk: Quality, safety and production aspects. Small Ruminant Research, 89(2-3), 110-124. doi:10.1016/j.smallrumres.2009.12.033Doney, J. M., Peart, J. N., Smith, W. F., & Louda, F. (1979). A consideration of the techniques for estimation of milk yield by suckled sheep and a comparison of estimates obtained by two methods in relation to the effect of breed, level of production and stage of lactation. The Journal of Agricultural Science, 92(1), 123-132. doi:10.1017/s0021859600060573Delgado-Pertíñez, M., Guzmán-Guerrero, J. L., Mena, Y., Castel, J. M., González-Redondo, P., & Caravaca, F. P. (2009). Influence of kid rearing systems on milk yield, kid growth and cost of Florida dairy goats. Small Ruminant Research, 81(2-3), 105-111. doi:10.1016/j.smallrumres.2008.12.007Ali, A. K. A., & Shook, G. E. (1980). An Optimum Transformation for Somatic Cell Concentration in Milk. Journal of Dairy Science, 63(3), 487-490. doi:10.3168/jds.s0022-0302(80)82959-6Peaker, M., & Wilde, C. J. (1996). Feedback control of milk secretion from milk. Journal of Mammary Gland Biology and Neoplasia, 1(3), 307-315. doi:10.1007/bf02018083Baumrucker, C. R., & Blum, J. R. (1993). Secretion of insulin-like growth factors in milk and their effect on the neonate. Livestock Production Science, 35(1-2), 49-72. doi:10.1016/0301-6226(93)90181-gLabussière, J. (1988). Review of physiological and anatomical factors influencing the milking ability of ewes and the organization of milking. Livestock Production Science, 18(3-4), 253-274. doi:10.1016/0301-6226(88)90035-8Sanz B 2005. Tipo de alimentación, modo de encalostrar y estacionalidad de la paridera como factores condicionantes del crecimiento de los cabritos lechales de la raza Murciano-Granadina (Type of feeding, colostrum administration method and seasonality of births as conditioning factors of kid growth in Murciano-Granadina breed). In Proceedings of the XXXth Jornadas Científicas de la Sociedad Española de Ovinotecnia y Caprinotecnia, 28 September to 1 October, Granada, Spain, pp. 236–238.LABUSSIÈRE, J., COMBAUD, J.-F., PETREQUIN, P., & CHESNE, P. (1974). INFLUENCE DE LA FRÉQUENCE DES TRAITES ET DES TÉTÉES SUR LA PRODUCTION LAITIÈRE DES BREBIS PRÉALPES DU SUD. Annales de Zootechnie, 23(4), 445-457. doi:10.1051/animres:19740403Delgado-Pertíñez, M., Guzmán-Guerrero, J. L., Caravaca, F. P., Castel, J. M., Ruiz, F. A., González-Redondo, P., & Alcalde, M. J. (2009). Effect of artificial vs. natural rearing on milk yield, kid growth and cost in Payoya autochthonous dairy goats. Small Ruminant Research, 84(1-3), 108-115. doi:10.1016/j.smallrumres.2009.06.014Eik LO , Eknœs M , Havrevoll Ø , Garmo T , Raats J and Ädnøy T 1999. Partial suckling during the grazing period as a management tool for improving the annual production patterns of goat’s milk in Norway. In Proceedings of the VIth International Symposium on Milking of Small Ruminants, 26 September to 1 October 1999, Athens, Greece, pp. 263–266.Fernández, N., Balasch, S., Pérez, I., Rodríguez, M., & Peris, C. (2013). Milk yield estimation during suckling using the double oxytocin injection-milking and the double weighing–suckling methods in dairy goats. Small Ruminant Research, 112(1-3), 181-185. doi:10.1016/j.smallrumres.2012.12.023Gargouri A , Caja G , Such X , Ferrett A , Casals R and Peris S 1993. Evaluation of a mixed system of milking and suckling in Manchega dairy ewes. In Proceedings of the Vth International Symposium on the Milking of Small Ruminants, 14–20 May 1993, Budapest, Hungary, pp. 484–499.Keskin, M. (2002). Effect of Rearing Systems on Kid Performance, Lactation Traits and Profitability of Shami (Damascus) Goats. Journal of Applied Animal Research, 22(2), 267-271. doi:10.1080/09712119.2002.9706409McCance, I. (1959). The determination of milk yield in the Merino ewe. Australian Journal of Agricultural Research, 10(6), 839. doi:10.1071/ar9590839McKusick, B. C., Thomas, D. L., & Berger, Y. M. (2001). Effect of Weaning System on Commercial Milk Production and Lamb Growth of East Friesian Dairy Sheep. Journal of Dairy Science, 84(7), 1660-1668. doi:10.3168/jds.s0022-0302(01)74601-2McKusick, B. C., Thomas, D. L., Romero, J. E., & Marnet, P. G. (2002). Effect of Weaning System on Milk Composition and Distribution of Milk Fat within the Udder of East Friesian Dairy Ewes. Journal of Dairy Science, 85(10), 2521-2528. doi:10.3168/jds.s0022-0302(02)74335-xPeris, S., Caja, G., Such, X., Casals, R., Ferret, A., & Torre, C. (1997). Influence of Kid Rearing Systems on Milk Composition and Yield of Murciano-Granadina Dairy Goats. Journal of Dairy Science, 80(12), 3249-3255. doi:10.3168/jds.s0022-0302(97)76299-4Requena, R., Balasch, S., Peris, C., Rodríguez, M., & Fernández, N. (2010). Dose response of lactating dairy ewes during suckling and milking to bovine somatotropin1. Journal of Animal Science, 88(9), 3136-3144. doi:10.2527/jas.2009-2690Requena R , Molina P , Fernández N , Rodríguez M , Peris C and Torres A 1999. Changes in milk and cheese composition throughout lactation in Manchega sheep. In Proceedings of the VIth International Symposium on Milking of Small Ruminants, 26 September to 1 October 1999, Athens, Greece, pp. 501–506.Sanz Sampelayo, M. R., Hernandez-Clua, O. D., Naranjo, J. A., Gil, F., & Boza, J. (1990). Utilization of goat milk vs. milk replacer for granadina goat kids. Small Ruminant Research, 3(1), 37-46. doi:10.1016/0921-4488(90)90029-6Silanikove, N., Merin, U., & Leitner, G. (2006). Physiological role of indigenous milk enzymes: An overview of an evolving picture. International Dairy Journal, 16(6), 533-545. doi:10.1016/j.idairyj.2005.08.015Marnet, P.-G., & Negrão, J. A. (2000). The effect of a mixed-management system on the release of oxytocin, prolactin, and cortisol in ewes during suckling and machine milking. Reproduction Nutrition Development, 40(3), 271-281. doi:10.1051/rnd:200013

Effect of stress on somatic cell count and milk yield and composition in goats

[EN] There is little information about the effect of the stress on Somatic Cell Count (SCC) and milk yield and composition in goats. A total of 40 goats in their 4th month of lactation were assigned to two groups: stress (STR) and untreated (CON). Goats of STR were exposed to acute stress (visual and auditory stimulus from a barking dog for 20 min on day 0). After the stress, average values of plasma cortisol were higher in STR than CON (P = 3 goats (P = 3 goats (P = 3 produced 11% less milk compared with day 0 and, regarding milk composition, only lactose showed a significant drop. Stressed parity 1 + 2 goats showed no changes in SCC and milk yield and composition. We conclude that, in goats, stress is a non-infectious factor that can interfere in the use of SCC as an indirect method of intramammary infection (IMI) detection or, in bulk tank milk, as a commercial milk quality parameter.Mehdid, MEA.; Marti-De Olives, A.; Fernández Martínez, N.; Rodríguez Garcia, M.; Peris Ribera, CJ. (2019). Effect of stress on somatic cell count and milk yield and composition in goats. Research in Veterinary Science. 125:61-70. https://doi.org/10.1016/j.rvsc.2019.05.015S617012

Terminal Crossbreeding of Murciano-Granadina Goats with Boer Bucks: Characteristics of the Carcass and the Meat

[EN] In Murciano-Granadina-breed dairy goat farms, meat production from purebred kids is not very profitable due to its high costs, so it is proposed to cross unused dairy females to produce a replacement for the herd with a breed specialised for meat production, i.e., the Boer breed. Our previous results verified that this crossbreeding strategy improved the productive characteristics of the kids (growth and costs), so the aim of this work was to ascertain its consequences on the carcass and meat characteristics of suckling kids (9 kg weight at slaughter) of both sexes. Ninety-four kids were used. It was found that crossbred kids reached slaughter weight at a younger age, and although their carcass yield did not improve, they did show higher muscle/bone and meat/bone ratios and better meat texture (less firmness). In turn, males slightly improved the proportion of expensive cuts, but their carcasses contained a lower proportion of intermuscular fat and lower muscle/bone and meat/bone ratios than females. There were no sensory differences in any case. It is concluded that this crossbreeding also improves the carcass and meat characteristics, constituting a valid alternative to improve the economic results of Murciano-Granadina breed herds. After verifying productive improvements from the crossbreeding (MB) of Boer males with females of the Murciano-Granadina (MG) breed, the aim of this work was to determine its consequences on the carcass and meat characteristics of suckling kids (9 kg of weight at slaughter) of both sexes. A total of 94 kids (25 purebred MG males, 19 purebred MG females, 25 crossed MB males and 25 crossed MB females) were used. It was found that MB kids reached slaughter weight at a younger age (44 +/- 1 vs. 63 +/- 1 days, p < 0.001). For carcass yield, the interaction genotype x sex was observed, where MB females presented a higher value (51.71 +/- 0.34%) than the rest of the animals (MB males 50.53 +/- 0.34, p < 0.05; MG males 50.60 +/- 0.34, p < 0.05; MG females 49.62 +/- 0.39, p < 0.001). MB kids had greater leg compactness, (36.28 +/- 0.27 vs. 34.71 +/- 0.29 g/cm, p < 0.001), slightly improved expensive carcass cuts (75.93 +/- 0.31 vs. 74.77 +/- 0.34%, p = 0.014) and higher muscle/bone (2.93 +/- 0.03 vs. 2.76 +/- 0.03, p < 0.001) and meat/bone ratios (3.56 +/- 0.04 vs. 3.36 +/- 0.04, p < 0.001) than MG kids. They also showed a somewhat more intense red colour (8.57 +/- 0.25 vs. 7.74 +/- 0.27, p = 0.027), higher colour saturation (9.06 +/- 0.24 vs. 8.20 +/- 0.26, p = 0.016) and less meat firmness (1.95 +/- 0.08 vs. 2.23 +/- 0.081 kg/cm(2), p = 0.021). On the other hand, males had a slightly improved proportion of expensive cuts (75.98 +/- 0.31 vs. 74.73 +/- 0.34, p = 0.008), but their carcass contained a higher proportion of bone (22.16 +/- 0.21 vs. 21.17 +/- 0.17%; p < 0.001), a lower proportion of intermuscular fat (9.54 +/- 0.24 vs. 10.93 +/- 0.24, p < 0.001), a higher muscle/fat ratio (5.01 +/- 0.10 vs. 4.41 +/- 0.10, p < 0.001) and lower muscle/bone (2.80 +/- 0.03 vs. 2.89 +/- 0.03%, p = 0.016) and meat/bone ratios (3.36 +/- 0.04 vs. 3.56 +/- 0.04%, p < 0.001) than females. There were no sensory differences in any case. It is concluded that this crossbreeding strategy also improves the carcass and meat characteristics, making it a valid alternative to improve the productive results of MG dairy goat herds.This research was funded by the project RTA2013-00107 (INIA) with FEDER funds.Pérez Baena, I.; Peris Ribera, CJ.; Fernández Martínez, N.; Franch-Dasí, J.; Sagbay, C.; Teran-Piña, JC.; Rodríguez Garcia, M. (2022). Terminal Crossbreeding of Murciano-Granadina Goats with Boer Bucks: Characteristics of the Carcass and the Meat. Animals. 12(19):1-17. https://doi.org/10.3390/ani12192548117121

Uso de LinkedIn como herramienta docente en el Máster de Producción Animal

[EN] LinkedIn professional social network was used as a common platform for exposure, discussion and analysis of information. Its use can facilitate collaborative learning of students, stimulate their motivation and enhance their professional career project. The study was conducted in three subjects of the Master in Animal Production at the Universitat Politècnica de València during 2014-2015 academic year. The specific objectives were: i) to create a virtual learning community, ii) to facilitate student’s active participation, iii) to enhance teacher-student and student-student interactions, iv) to promote critical thinking, and v) to encourage the use of this professional network that favors student’s professional career plan. Four actions based on the development and maintenance of a LinkedIn group and the ellaboration of a heading of critical thinking were established. The achievement of the objectives was assessed by the instrinsic network’s activity, as well as by quantitative and qualitative evaluations and a survey of self perception. All students created and used their profile regularly. Discussion topics were proposed, assessing student’s participation during the study. The difficulty of evaluating the development of critical thinking was demonstrated.[ES] Se utilizó la red social profesional LinkedIn como una plataforma común de exposición, discusión y análisis de contenidos. Su uso puede facilitar el aprendizaje colaborativo de los alumnos, estimular su motivación y potenciar su proyecto de carrera profesional. La experiencia se llevó a cabo en tres asignaturas obligatorias del Máster en Producción Animal de la Universitat Politècnica de València durante el curso 2014-2015. Los objetivos específicos fueron: i) crear una comunidad de aprendizaje virtual, ii) facilitar la participación activa de los alumnos, iii) fomentar la interacción profesor-alumno y alumno-alumno, iv) potenciar el pensamiento crítico y v) potenciar el uso de una red profesional que favorezca el proyecto de carrera profesional de los alumnos. Para ello se establecieron 4 acciones basadas en la creación y mantenimiento de un grupo LinkedIn y el desarrollo de una rúbrica de evaluación del pensamiento crítico. La consecución de los objetivos se evaluó mediante la propia actividad de la red, así como evaluaciones cuantitativas y cualitativas y una encuesta de autopercepción. Todos los alumnos crearon y utilizaron su perfil de forma regular. Se propusieron temas de debate, valorando la participación del alumno durante la experiencia. Igualmente, quedó evidenciada la dificultad de evaluar el desarrollo del pensamiento crítico.Cambra López, M.; Estellés Barber, F.; Pascual Amorós, JJ.; Calvet Sanz, S.; Peris Ribera, CJ. (2015). Uso de LinkedIn como herramienta docente en el Máster de Producción Animal. En In-Red 2015 - CONGRESO NACIONAL DE INNOVACIÓN EDUCATIVA Y DE DOCENCIA EN RED. Editorial Universitat Politècnica de València. https://doi.org/10.4995/INRED2015.2015.158

Elección de los parámetros de ordeño en caprino

[ES] La elección correcta de los equipos y los parámetros mecánicos de la máquina de ordeño es de gran importancia, ya que es en este punto donde diariamente cada animal tiene que devolver, en forma de leche, todos los cuidados y las atenciones que se le han brindadoPérez Baena, I.; Martinez Galiano, A.; Martí Vicent, JV.; Palomares Carrasco, JL.; Rodríguez Garcia, M.; Peris Ribera, CJ.; Fernández Martínez, N. (2014). Elección de los parámetros de ordeño en caprino. Albéitar. (181):4-5. http://hdl.handle.net/10251/74663S4518

Study of ultrasound scanning as method to estimate changes in teat thickness due to machine milking in Manchega ewes

[EN] To assess the ultrasound technique as a method for estimating the effect of machine milking on teat thickness in Manchega ewes, this work was carried out with a twofold objective: (1) to study the most suitable ultrasound exploration frequency and the effect of the operator in applying the technique and (2) to validate the approach, comparing it with measurements taken by another method (cutimeter). Three studies were designed for this purpose. In the first of them (E1), two experiments were carried out; the first tested frequencies at 5, 7.5 and 10 MHz and the second (E2) checked frequencies at 3.5 and 5 MHz. In the second study, 2 different operators (OP) independently performed ultrasound scans on the same animals (experiment 3, E3): they chose the best ultrasound exploration image recorded on video (experiment 4, E4) and took measurements in ultrasound images of ewes (experiment 5, E5). Finally, in the third study (experiment 6, E6) we designed an experiment in which ultrasound examinations and measurements by cutimeter were performed in the same animals. The variables measured in the ultrasound scans were teat wall thickness (TWT), teat wall area (TWA) and teat end wall area (TEWA), while the cutimeter was used to gauge teat wall thickness (11). At 10 MHz frequency it was not possible to obtain quality images of teats in ewes, so its subsequent use was ruled out. The teat canal was visible in 45%, 55% and 30% of the pre-milking images at frequencies of 5, 7.5 and 3.5 MHz, with values increasing after milking (63.4%, 77.5% and 36.3%). No significant differences were found in any of the variables (TWT, TWA and TEWA) between the measurements taken before and after milking at the 5 and 7.5 MHz frequencies. Similarly, TWT, TWA and TEWA were significantly greater (p < 0.001) at the 3.5 MHz frequency than at 5 MHz. It was concluded that frequencies of 5 and 7.5 MHz were the most suitable for estimating the teat wall changes caused by mechanical milking. Operator experience had no effect on the ultrasound explorations performed in the field, although it did significantly influence the choice and measurement of the images. Mechanical milking caused an increase in TWT of 0.11 cm measured by ultrasound scanning and a reduction in TT of -0.06 cm measured by cutimeter, which would indicate that ultrasound scanning is a more effective method to determine the degree of oedema and congestion caused by machine milking in ewes. In addition, we found a high correlation between TWT, TWA and TEWA with TT before and after milking. The use of ultrasound techniques may be a useful tool to evaluate the changes that occur in teat tissue due to machine milking in Manchega breed sheep, although it would be necessary to carry out further studies to enable the development of software to choose and measure the frames automatically to help reduce the operator effect on the choice and measurement of ultrasound variables. (C) 2014 Elsevier B.V. All rights reserved.The study was supported by Project AGL2006-06909 (Ministerio de Educacion y Ciencia and FEDER).Alejandro, M.; Rodríguez Garcia, M.; Peris Ribera, CJ.; Díaz, JR. (2014). Study of ultrasound scanning as method to estimate changes in teat thickness due to machine milking in Manchega ewes. Small Ruminant Research. 119(1-3):138-145. https://doi.org/10.1016/j.smallrumres.2014.02.007S1381451191-

Effect of estrus synchronization on daily somatic cell count variation in goats according to lactation number and udder health status

[EN] Two repeated experiments were carried out in 2 different years to study the effect of estrus on somatic cell count (SCC) in dairy goats. In the first year, 36 Murciano-Granadina goats were used [12 primiparous and 24 multiparous; 22 healthy and 14 with an intra-mammary infection (IMI)] and, after a 6-d pre-experimental period, were divided into 2 groups according to lactation number, udder health status, SCC, and milk production. One group was kept as a control, whereas the other received an estrus synchronization hormonal treatment lasting 11 d. At 24, 48, and 72 h after cessation of the hormone treatment, goats were placed in contact with a buck to confirm that they were in estrus. For 32 consecutive days (6 pre-experimental, 11 in hormone treatment, and 15 post-treatment) the SCC per gland and udder were monitored in all animals. In the second year, we repeated the same experimental design using a total of 38 Murciano-Granadina breed goats (12 primiparous and 26 multiparous; 26 healthy and 12 with IMI). Throughout this experiment, milk yield and composition were also recorded daily for each goat. Upon termination of the hormonal treatment, the SCC in udder milk increased significantly in the treatment group compared with the control group over 3 consecutive days. This increase was observed for year (1 and 2), parity (primiparous and multiparous), and udder health status (healthy and IMI). The log(10) SCC (cells/mL) increased from 5.5 +/- 0.09 before estrus to 6.04 +/- 0.09 during treatment; therefore, the geometric mean of the SCC increased 3.5 times during treatment. The maximum values obtained in healthy glands of primiparous goats (geometric mean = 0.37 million cells/mL) were lower than in healthy glands (1.1 million cells/mL) or infected glands (1.7 million cells/mL) of multiparous goats. The increase in SCC observed during estrus (200% increase in geometric means) could not be explained by the changes in milk production, which only fell by 13%. During estrus, the percentage of protein and dry matter in the milk also increased significantly. We concluded that it is necessary to consider the presence of estrus to correctly interpret milk SCC, as an indirect method for detecting IMI or as a commercial milk quality parameter.Mehdid, A.; Díaz, J.; Martí, A.; Vidal, G.; Peris Ribera, CJ. (2013). Effect of estrus synchronization on daily somatic cell count variation in goats according to lactation number and udder health status. Journal of Dairy Science. 96(7):4368-4374. doi:10.3168/jds.2012-6393S4368437496