15. Sodium chloride helps to maintain an ideal pH balance for ruminal fermentation and to regulate osmotic pressure at the cellular level, which effects the passage of nutrients across cell membranes. Where cattle receive optimal levels of salt in their diet, increased consumption will not improve performance. However, deficient intake can lower weight gain, reduce milk production, and hinder fertility. See,
T. W. Perry, ed.,
Beef Cattle Feeding and Nutrition
(
San Diego
:
Academic Press
,
1995
),
42
–
43
;
Troy Smith,
“Salt: An Essential Element,”
Angus Journal
29
(
Feb.
2008
):
177
–
79
. For the low levels of salt in tropical grasses, such as guinea, compared to ideal percentages, see,
R. J. W. Gartner and
G. M. Murphy,
“Evidence of Low Sodium Status in Beef Cattle Grazing Coloniao Guinea Grass Pasture,”
Proceedings of the Australian Society of Animal Production
10
(
1974
):
95
–
98
;
James G. Morris,
“Assessment of Sodium Requirements of Grazing Beef Cattle: A Review,”
Journal of Animal Science
50
(
Jan.
1980
):
145
–
52
. For the provision of salt in Colombia, see,
Luis Marulanda,
“Industria animal: alimentación del ganado,”
El Agricultor Caucano
5
(
Feb.
1939
):
212
–
21
. For sources on vaccination, tick eradication, and improved management, see,
Manuel Gómez,
“Informe del Departamento Nacional de Ganadería al Señor Ministro de la Economía Nacional,”
Boletín deGanadería
1
(
July
1939
):
18
;
Oakley,
“Cattle Raising,”
36
;
Luis Sanclamente,
“Departamento de Bolívar circular sobre vacunación,”
Ganadería de Bolívar
4
(
Jan.–Mar.
1936
):
902
–
904
; FAO,
Livestock
,
23
;
Mario E. D'Orsonville,
“La garrapata, enfermedades, perdidas que ocasiona y su erradicación,”
Suplemento al Boletin de Agricultura
4
(
Jan.
1931
):
1
–
31
;
Anon., Untitled, First radio broadcast for ranchers,
Boletín de Agricultura
5
(
May
1932
); MAC,
Memoria del Ministerio de Agricultura y Comercio 1935
;
Luis Sanclamente et al.,
“Informe que rinde la comisión de profilaxia a la Quinta Asamblea de Ganaderos en sus sesiones ordinaries correspondientes al año de 1936,”
Ganadería de Bolívar
4
(
Jan.–Mar.
1936
):
889
–
91
;
Congreso de la República,
“Ley 224 de 1938,”
Ganadería de Bolívar
6
(
Sept.
1939
):
22
–
29
;
Washington Bernal,
“Una cruzada en defensa del ternero,”
La Vida Rural
4
(
Jan.
1943
):
9
–
10
;
Cortes G. Randell,
La Industria Ganadera en Colombia
(
Washington, DC
:
np
,
1953
).