Bacterial Cell Counts in Goat Milk and Their Correlations with Somatic Cell Counts, Percent Fat, and Protein

Abstract

Representative milk samples at morning and afternoon milking were collected periodically for 5 mo from 32 does in a Prairie View A&M University milking herd to test the concentrations of total bacterial, coliform, and staphylococcus counts and to determine the correlations among the bacterial cell counts, somatic cell counts, percent fat, and percent protein. Bacterial cell counts were assayed by microbiogical methods using different nutrient media for the three cell types. Somatic cell counts were determined by an automated fluorescent microscopic somatic cell counter. Percent fat and protein were analyzed by an automated dual beam infrared absorption analyzer. Mean counts for total bacterial, coliform, staphylococcus, and somatic cell were 2.54 X 10(4), .966 X 10(3), 3.32 X 10(3), and 9.08 X 10(5) cells/ml, respectively. The Nubian goats had higher counts in all three bacterial cell types than the Alpines, and the difference in staphylococcus counts between breeds was significant (P less than .05). However, Alpine milk contained slightly higher somatic cell counts than the Nubians. None of the correlation coefficients (r) between somatic cell and bacterial cell counts was significant for the pooled data from the two breeds, but r between staphylococcus and somatic cell counts for Alpine breed was significant (P less than .05). The r between somatic cell counts and percent fat or protein were significant (P less than .01) for combined or separated breed data. Bacterial cell counts could not explain high somatic cell counts in the goat milk with the present testing standards of cow milk.

Análise das metodologias diretas e indiretas para a contagem de células somáticas no leite de cabras hígidas

“…Alguns autores (Contreras et al 1996, Silva 1997, Park & Humphrey 1986, Andrade et al 2001, Fernandes 2002 encontraram valores médios maiores que os obtidos neste estudo. Sabe-se que o número de células somáticas presentes no leite é influenciado por diversos fatores não-infecciosos, tais como número de lactações, raça, ambiente de criação e tipo de ordenha empregado, fatos que poderiam justificar as diferenças nas contagens encontradas em relação aos trabalhos acima citados.…”

“…Sabe-se que o valor da contagem de células somáticas aumenta com o avançar da lactação, fato já relatado por diversos autores (Droke et al 1993, Gonzalo 1995, Gomes 2003. Alguns autores (Park & Humphrey 1986, Droke et al 1993, Gonzalo 1995 verificaram maiores níveis celulares nas primeiras semanas pós-parto, os quais diminuíram durante o período de máxima produção de leite, voltando a aumentar até o final da lactação, resultados também observados neste trabalho.…”

“…Essas partículas são anucleadas em sua maioria (Paape & Capuco 1996), são preenchidas por glóbulos de gordura (Perrin & Baudry 1993), e correspondem a 35% dos elementos celulares observados no leite de cabras (Sierra et al 1998). Tais partícu-las estão ausentes no leite de vaca (Park & Humphrey 1986, Perrin & Baudry 1993, Gonzalo 1995, o que aumenta aparentemente a concentração de leucócitos no leite de fêmeas caprinas, quando são utilizados os méto-dos tradicionais de contagens celulares para o leite de vacas (Dulin et al 1983, Hinckley 1983, Droke et al 1993, Silva et al 1996. Este fato salienta a importância da padronização e adoção de técnicas de contagens celulares específicas para caprinos.…”

Postmortem recovery of proliferative fibroblasts up to three days in livestock ear skin stored at 35°C

“…These results show that sheep tissues remain alive for longer time followed by bovine and goat. Perhaps it may be due to less amount of fat in goat tissues as compared to bovine and sheep (Park & Humphrey, 1986). …”

Variation in Milk Yield, Contents and Incomes According to Somatic Cell Count in a Large Dairy Goat Population

“…In other studies, however, higher fat concentration was found in infected glands than in uninfected ones [20] or related to high levels of SCC [6]. Positive [18,20,21]; negative [22,23] or no relationship [9] was also described between protein content and SCC or intramammary infection. The variation of milk contents could be also associated with a dilution or concentration effect in variable milk volumes similarly to SCC, as suggested, for example, Fuertes et al [21].…”