Gluconeogenic feed additives

Propylene glycol (PGL)

[13]

Despite evidence of improved metabolic status, PGL failed to increase LH pulse frequency, and failed to increase the proportion of first postpartum follicle waves resulting in ovulation

[14]

Reduced interval from calving to first ovulation was observed and pulsatile release of LH at 2 and 5 weeks was greater in cows fed PGL

[15]

Cows fed PGL commenced ovarian cyclicity earlier than controls

[16]

Improved conception rate (33 to 57%) and day of first ovulation from 44.5 Day to 32.3 Day

PGL + Ca-propionate

[17]

Treatment did not change the proportion of puerperal diseases and reproductive performance

Glycerol

[18]

No effect on DMI, glucose ↑, NEFA and BHB ↓

[19]

Conception rate and insulin cc. ↑

Propionate salts

[20]

Improves reproductive efficiency

Fat supplementation

Ca-long chain fatty acid (LCFA)

[21]

Pregnancy rate per AI increased from 35.5% to 51.1%

Fish oil

[22]

Reduced PGFM

Ca-LCFA of palm oil

[23]

From cows fed 800 g fat/day a higher percentage of oocytes developed into blastocysts

Soybean oil refining by-products (SORB)

[24]

Loss of body condition was less and first ovulation was experienced earlier in cows fed SORB

Saturated fatty acid (FA),

Ca-salts of t-octadecanoic FA,

Ca-salts of safflower oil FA

[25]

Mean concentrations of glucose, IGF-1 and P4 were higher in cows fed a safflower oil enriched diet

Ca salts of palm oil, Ca salts of safflower oil (SO) and fish oil (FO)

[26]

Overall pregnancy rate per AI was higher in cows fed an SO diet and pregnancy loss was reduced in FO-fed cows