A regional evaluation of injections of high levels of vitamin A on reproductive performance of sows1,2

Abstract

A regional study involving 443 litters from 182 sows was conducted at 5 cooperating experiment stations to determine the effects of an i.m. injection of vitamin A at weaning and breeding on subsequent litter size of sows. Sows were assigned to 1 of 3 treatments given at weaning and again at breeding: 1) a placebo i.m. injection (2 mL of corn oil), 2) i.m. injection with 250,000 IU of vitamin A (1 mL of vitamin A palmitate in oil), and 3) i.m. injection with 500,000 IU of vitamin A (2 mL of vitamin A palmitate in oil). Corn-soybean meal diets in gestation were formulated to contain 13% CP and 0.60% total Lys. Lactation diets were formulated to contain 17% CP and 0.90% Lys. A common vitamin-mineral premix that supplied 11,000 IU of vitamin A/kg of diet (as-fed) was used by all stations. As expected, station effects were noted for many response measures. Analysis of the data also revealed both treatment x station and treatment x parity interactions for litter size responses. The treatment x parity interactions were stronger than the treatment x station effects, and when the litter size response was separated into early parity sows (parity 1 and 2) and late-parity sows (parity 3 to 6), the treatment x station interactions were no longer present in either subgroup. For sows of parity 1 and 2, litter sizes were increased linearly (P <or= 0.003) for treatment 1 to 3, respectively, for the total (10.15, 12.14, and 13.18), live born (9.70, 11.14, and 12.16), and weaned (8.92, 10.12, and 10.60) piglets. For sows of parity 3 to 6, litter sizes were not affected for treatment 1 to 3, respectively, for the total (11.82, 11.71, and 11.46), live born (10.82, 10.64, and 10.23), and weaned (8.65, 9.01, 8.79) piglets. Piglet BW were affected (P < 0.001) by station and were associated with station differences (P < 0.05) in lactation length. Piglet BW decreased due to vitamin A treatment in parity 1 and 2 sows (linear, P <or= 0.026) and was likely due to the differences observed in litter size. The results of this regional project demonstrated that injection of high doses of vitamin A in young sows at weaning and breeding improves the subsequent number of pigs born and weaned per litter, indicating that vitamin A requirements for maximal performance may vary with age.

Reduced vitamin supplementation with fat-soluble vitamins A, D, and E added at National Research Council requirements may not be adequate for optimal sow and progeny performance

“…The vitamin A requirement for optimal reproductive performance is age dependent and likely greater in younger sows. 12 Gilts that received adequate dietary vitamin A through nine months of age completed two reproductive cycles without vitamin A supplementation without developing deficiency symptoms, suggesting adequate vitamin A stores in the liver. 13,14 Moreover, mature sows without vitamin A supplementation required 4 parities before deficiency symptoms became evident.…”

A cooperative study assessing reproductive performance in sows fed diets supplemented with organic or inorganic sources of trace minerals

“…Although none of the three participating universities possessed the animals and resources necessary to conduct the current experiment alone, combined data from over 120 farrowing events per treatment were adequate to detect significant differences for several response measures. Members of the multistate research committee of which the authors are members, have successfully used this strategy before ( Lindemann et al, 2004 , 2008 ; Carter et al, 2018 ). Animal and facility characteristics, and performance measures for the research sites employed in this study appear in Tables 1 and 3 .…”

Modulation of Gut Microbiota and Oxidative Status by β-Carotene in Late Pregnant Sows

“…It has been reported that injection or dietary supplementation of β-carotene during early gestation can enhance embryo survival, litter size and litter weight of piglets (9,20,21), but less information on its impact in late pregnancy has been obtained. However, in this study, dietary supplementation of β-carotene at late stage of pregnancy showed limited effect on the number of live birth and litter weight at parturition.…”